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1 min read

Rulon 641: Performance from Food Processing to Medical Equipment Manufacturing

By Dave Biering on July 16, 2019

Rulon 641: Performance from Food Processing to Medical Equipment Manufacturing

The food and medical manufacturing industries share many commonalities; most notably, they operate in environments with strict regulations for quality, safety and sanitation.  Processing equipment must be of the highest quality and offer contamination resistance.  Rulon® 641 is the only FDA-cleared material for use in food processing that also has USP Class VI approval for medical applications.

Two demanding manufacturing environments, one common material ― Rulon 641.  See our Rulon Comparison Chart to explore the advantages.

Temperature tolerance for food processing

A major food processor approached us seeking a replacement for their virgin-PTFE seals located on the miniature cryogenic valves of the fast-freeze systems. The equipment is used to flash-freeze fruits and other foodstuffs. The PTFE seals were failing from exposure to the cryogenic temperatures and required frequent and expensive change out. Rulon 641 offered our partner a material with superior temperature stability and a longer lifespan for significant savings. Rulon 641 is non-abrasive for use against the systems’ stainless mating hardware, and has maintained good sealability under difficult conditions. 

Superior sterilization for medical manufacturing

We’ve also partnered with the manufacturers of surgical laser devices to replace failing PTFE valves seats with Rulon 641.  Rulon excels in the rotary and oscillating movements required of this application and has a very low coefficient of friction and a superior wear factor.   The material can be lapped using standard procedures to produce extremely good surface finishes in precision valve seats.  And the material’s white, stain-resistant color indicates a sanitary compound for medical environments.  Rulon 641 has USP Class VI approval, and easily tolerates all standard CIP procedures required of both the food and medical industries.

Is Rulon 641 the right material for your application?  Contact our Engineering Experts for a consultation. Or read our free Rulon White Paper to learn about the advantages of Rulon’s processing controls.

Rulon - Quality Assurance Begins With Precision Processing

Topics: Food Rulon Medical
1 min read

(VIDEO) Hyper-Hydrophobic Membranes Repel Liquid like Nobody’s Business

By Frank Hild on May 21, 2019

Hyper-Hydrophobic Membranes Repel Liquid like Nobody’s Business

Our Ultraflon M18+ is a hyper-hydrophobic PTFE membrane that can be used to separate gas from liquid. There are several of these membranes on the market, but our unique membrane stands alone.

The hydrophobic quality of this membrane allows for air to pass through, but not water (or aqueous solutions). The membrane is clean with no residue or other agents to provide pure filtration. Under pressure it is possible to get liquids with very low surface tension to pass through, which makes Ultraflon M18+ ideal for controlled phase separation as well.

Click here to read how Ultraflon M18+ was recently chosen for a High-Performance Liquid Chromatography application.

Take a look at our short (4 minute) video, embeded below, to see me demonstrate just how hydrophobic this particular membrane is compared to several competitive products.

The other membranes shown in the video are:

  • Porex MD15
  • Versapor LCB-3000
  • Advantech PF100

If you think Ultraflon M18+ may be ideal for your gas-separation filtering application, reach out to our Enhanced Materials Division engineers to explore the possibilities.

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Topics: Enhanced Materials membranes
2 min read

National Robotics Week is Here – Explore the Plastic Bearings Factor

By Dave Biering on April 9, 2019

National Robotics Week is Here – Learn How Plastic Bearings Fit In

This year National Robotics Week falls on April 6-14 and there are a wide range of activities and events intended to inspire students in STEM-related fields and to educate audiences of all ages about the cultural and economic impact of robotics – today and into the future.

One thing you may not be aware of is the importance of plastic bearings to the success of many innovative robotic applications. From precision surgical robot arms to pipeline oil-leak sniffing subseas, plastic bearings are a key component driving innovation in this field.

Plastic Bearings Replace Rolling Elements and the Benefits are Clear

Plastic bearings are greaseless, durable and nearly maintenance-free. Compared to metal bearings they can be easily custom fabricated to precise specifications at a significantly lower cost than metal bearings. It’s no wonder that the robotics industry has been so eager to embrace this technology.

Plastic Bearings in Robotics – Some Specific Examples

There are many uses for plastic bearings in robotic applications; here are just a few interesting examples:

  • Swimming Pool Cleaning Robots – Swimming pools are harsh environments and pool chemicals, algae, and UV exposure can quickly weaken metal bearings. Rulon W2 flanged bearings in the wheels of robotic pool vacuums offer clear benefits over metal. The tribological properties of Rulon W2 actually improve when wet and they do not absorb water at all, which keeps them dimensionally stable.
  • Picking and Packing Robots on Food Assembly Lines – TriStar’s FCJ composite bearings excel in the pivot points of robotic arms. They are increasingly used to replace bronze bearings, which corrode and seize in the sub-zero and high-moisture environments encountered in food processing. FCJ bearings offer the same strength-to-weight ratio as powdered steel, but in a lighter, flexible design that can help boost production.
  • Surgical Spherical Robots – Surgical spherical robots require bearing materials that are rigid enough to exert a good level of force, yet also remain flexible enough to deliver precise control. In addition, any components specified must be FDA compatible to meet clean room standards. Rulon 641 meets these requirements. They are self-lubricating to eliminate the risk of oil contamination and give surgical arms excellent rotary and oscillating movements for incredibly precise cutting and placement.
  • Military Remote Tracked Vehicles – Remote tracked vehicles play a key role in protecting soldiers by allowing them to investigate and detonate IEDs from a safe distance. Our CJ Bearings proved to be more reliable than bronze bushings in early tracked vehicle designs. More recently, our Ultracomp bearings have been specified for sophisticated lifting arms and rotating grips due to their tight tolerances and ability to function at the lowest possible friction levels.

These are just a few of the many robotics applications for plastic bearings. Why not grab a copy of our free Robotics White Paper for a deep dive on the subject with many additional examples?

For more on National Robotics Week check out the official website or explore the ongoing conversation using the #RoboWeek hashtag on Twitter. If you have a robotics application you’d like us to take a look at, don’t hesitate to reach out to our engineering team!

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Topics: Robotics
1 min read

Defined: Hydrophilic, Hydrophobic, Oleophilic, Oleophobic & Hygroscopic

By Frank Hild on February 27, 2019

Hydrophilic, Hydrophobic, Oleophilic, Oleophobic & Hygroscopic

When discussing enhanced materials we often use terms like “hydrophilic/hydrophobic” and “oleophilic/oleophobic.” Just what do these terms mean exactly? Let’s take a quick look.

  • Hydrophilic − Refers to substances that absorb water. A hydrophilic substance will bond, on a molecular level with water.
  • Hydrophobic − Refers to materials that will repel water.
  • Oleophilic − Refers to a substance that absorb oils or nonpolar liquids.
  • Oleophobic − Refers to a substance that repels oils or nonpolar liquids.
  • Hygroscopic − Refers to the ability of a material to absorb humidity from the air. A hygroscopic substance will actively attract and absorb water, without bonding. (A hygroscope is an instrument that indicates changes in humidity.)

Water is itself hydrophilic (it mixes with more water easily) and oils or fats are generally hydrophobic and will separate from water, forming an oily layer.

Note: The suffix "philic" means loving or attracted to. The suffix "phobic" means fear or fearful.

There’s a lot more to learn, but this is certainly a useful place to start. If we can help you sort these terms out or provide information on how to modify materials to enhance (or suppress) any these characteristics, please do not hesitate to reach out to our experts.

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Topics: Surface Modification Enhanced Materials
2 min read

Wettability Defined and Correlation to Bonding

By Frank Hild on August 28, 2018

Wettability Defined and Correlation to Bonding

There is usually a good correlation between bonding and wetting. Wettability can be defined as “the ability of a solid surface to reduce the surface tension of a liquid in contact with it such that it spreads over the surface and wets it.”

So, it seems intuitive that good wetting would automatically result in strong bonds. However, this is not always the case. Two different cases where this correlation can break down are:

  • Case #1 - Where the surface is wettable but the structure beneath (the "bulk property" of the material) is too weak to have good bond strength.
  • Case #2 - Where the surface is not wettable by water but there is still excellent bonding.

In this post, we will explore two examples of the first case: the bonding of PTFE (Teflon®) and the bonding of a waxy or oily surface.

Example #1 – Poor Bonding due to Inherent PTFE Surface Weakness

Polytetrafluoroethylene (PTFE) can be plasma treated to promote good wetting by water or adhesives; however, when the surface is bonded, the measured bond-strength is about half to three-quarters of that obtained by using a commercially acquired sodium etchant. The reason is that the surface structure of PTFE is very weak due to almost no cross-linking within the material composition. The top layer of the polymer will shear off with the adhesive, even if the surface is treated with plasma to give good and uniform wetting.

To get good bond-strengths between PTFE and an adhesive, it is necessary to use a surface treatment that cross-links to a significant depth within the polymer (usually 1 micron or more), such as the aforementioned sodium etching method. Plasma treatments generally only affect the top 0.01 microns of the material, so the resulting surface treatment is just not thick enough to give a strong bond even though it is wettable and bondable by the adhesive.

Example #2 – Poor Bonding Due to Oily/Waxy Contamination Layer

As a second example of a weak surface layer; it is easy to plasma-treat a waxy or oily surface and make it completely wettable and bondable by adhesives. However, these bonds will show almost no strength because the adhesive is not bonded to the substrate - only the surface contamination layer. This is the ultimate example of a weak boundary layer. It is also the primary fault of using a "wetting test" as the sole quality control test for plasma treatments. The apparent surface of the part may be completely wettable but still give very poor bonding because that surface is really a layer of cross-linked contaminate.

The Bottom Line

These are examples of scenarios where plasma treatment is not the best approach for improving bondability; there are many other situations where it is appropriate. The key is to partner with engineers with the expertise to use the best method for your specific situation. Let us know what you are dealing with, and we’ll let you know how best to proceed!

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Topics: Plasma Treatment featured
2 min read

Q&A – Do You Have Any Tips for Annealing Cast Acrylic?

By Dave Biering on August 15, 2018

Do You Have Any Tips for Annealing Cast Acrylic?

We recently had a customer ask us for some tips on annealing cast acrylic. There are definitely some potential pitfalls when working with acrylic in both sheet and finished part form, but following the guidelines outlined below should yield excellent results.

First… What is Annealing?

Annealing is the process of relieving stresses in molded or formed plastics by heating to a predetermined temperature, maintaining this temperature for a set period, and slowly cooling the parts. Sometimes, formed parts are placed in jigs to prevent distortion as internal stresses are relieved during annealing.

Tips for Annealing Acrylic Sheet

To anneal cast acrylic sheet, heat it to 180°F (80°C), just below the deflection temperature, and cool slowly. Heat one hour per millimeter of thickness – for thin sheet, at least two hours total.

Cooling times are generally shorter than heating times – see the chart below. For sheet thickness above 8mm, cooling time in hours should equal thickness in millimeters divided by four. Cool slowly to avoid thermal stresses; the thicker the part, the slower the cooling rate.

Wait until oven temperature falls below 140°F (60°C) before removing items. Removing a part too soon can offset annealing’s positive effects.

Tips for Annealing Parts Made from Acrylic Sheet

While annealing acrylic sheet parts, support them to avoid stress. For example, a part’s raised center section will need independent support – it can’t be supported from the ends. Lack of support may inhibit relaxation or cause warpage. Be sure parts are clean and dry before annealing. Remove paper masking to avoid baking it onto the material. Remove any spray masking, protective tape, or similar material. Plastic masking may remain in place.

For post machined acrylic parts - Heat to 180°F over a 2 hour period, hold for 30 minutes per each ¼” of thickness, cool at 50°F per hour until room temperature. This must be done in a nitrogen oven.

If the only fabrication you have done is surface machining and you do not need to anneal cemented joints, heating time can be reduced. This reflects the fact that machining forms stresses only at and slightly below the surface – the entire sheet thickness needn’t be annealed. Heat at least two hours; cool the same amount of time. If holes have been drilled entirely through the sheet, position the part so heated air flows through the holes.

What are your Material Fabrication, Machining, and Processing Challenges?

This post focused on a specific process for one material, but any product you work with is going to bring it's own challenges – and have a corresponding “cheat sheet’ that experienced engineers pull out to make it all go smoothly. Our engineering team has decades of combined experience and can provide this information. In fact, we’ve just launched an entirely new Enhanced Materials Division (EMD) to help people with just this sort of thing! We have a full suite of services and products to help you find the best, most cost-effective way forward.

Custom Plastic Fabrication: Get the Guide!

Topics: Q&A
1 min read

What are ‘Fluoropolymers’ and What are their Common Attributes

By Dave Biering on June 12, 2018

The first fluoropolymer was polytetrafluoroethylene, better known by its abbreviation, PTFE

First, a definition: fluoropolymers are a family of plastic resins which are based on fluorine/carbon bonding. The family of products is varied through a manipulation of that bond by adding or subtracting fluorine through other bonds such as chlorine, ethylenes and other chemical agents.

The first fluoropolymer was polytetrafluoroethylene, better known by its abbreviation, PTFE, and by its brand name “Teflon.” It was discovered accidentally by a scientist at DuPont in 1938.

Fluoropolymers are strong, lightweight, and durable. They can also resist heat, water, salt and chemicals and do very well in demanding environments.

PTFE (which is the only fluoropolymer which does not melt) is processed through press and sinter techniques while the other common fluoropolymers (FEP, PVDF, PCTFE, PFA and a few others) are melt-processible. This means they can be compression and injection molded as well.

Fluoropolymers come in several forms:

  • Granulate
  • Melt-processable
  • Films
  • Paste
  • Dispersions

As with anything, there are both positives and negatives to fluoropolymers:

Positive attributes:

  • Chemically inert (with few exceptions)
  • Broad temperature ranges
  • Low friction
  • Excellent dielectric properties
  • Good thermal insulation
  • Good wear properties (with certain additives)

And on the negative side:

  • Cost (they can be expensive)
  • Processability – grades establish which method is used
  • Cold flow with some grades
  • High expansion rates

Typical applications for fluoropolymers are in electrical and electronics, pipe and chemical processing.

Fluoropolymers are an extremely diverse family of plastics and this blog post really just scratches the surface. For a deeper dive into the topic, watch our video (below).

If you think a fluoropolymer is the right fit for your application, we can help you choose the right one.

Bearing Selection: Get the Ultimate Plastic Bearing Design

Topics: Fluoropolymers
2 min read

Slide Bearings for Pipelines and Bridges

By Dave Biering on May 29, 2018

Slide Bearings for Pipelines and Bridges

Slide plate bearings provide support and a low coefficient of friction while allowing an object to move (or slide) freely along a supporting surface. They consist of an upper and lower component and can be used in both guided and free-moving applications.

Applications for Slide Bearings

Slide bearings are engineered to fit anywhere there is the potential or threat of movement, such as bridges, building footplates, tank farms and petrochemical applications. For example, an oil pipeline — at roughly 800 miles long — could be subjected to a mile of liquid flow movement (hysteresis) within the structure. Such an application requires a bearing designed to resist corrosion, temperature extremes and rugged terrain.

TriStar is your Best Source for Slide Bearings

Here are several materials that we often recommend for slide bearings.

  • Ultracomp, one of our tier one products, is an ideal material for slide bearings. A composite wound bearing, Ultracomp is engineered especially for low speed, high load applications and has a very high corrosion resistance. One interesting application is for the slide bearings used to deploy a retractable swimming pool in an ultra-luxury yacht (cost: $100 million). Ultracomp also excels in railroad and agricultural applications.
  • Rulon materials are ideal for slide bearings and various variants can be chosen based on the specifics of your application. For example, FDA compliant Rulon 1337 has been specified for use in the slide bearings used inside food processing vacuum chambers. Rulon 1337 is ideal for this application due to it’s high load capacity and durability. It’s low abrasion characteristics make it safe to use against softer mating surfaces and high chemical resistance means it can withstand the chemical washdown procedures required for food industry applications.
  • Fluorogold slide bearings easily tolerate thermal expansion and liquid flow movement and hold up well in cold temperatures. They also absorb vibration and impact, making them a preferred bearing material for use in earthquake zones. They also offer outstanding chemical and electrical properties and have proven resistant to radiation, where neither the bearing strength nor the epoxy bond were impacted by doses as high as 10^6 rads.

…And There’s More!

There are many additional materials available for slide bearings and our engineering team has years of experience matching the material to the application. Why not share the details of your application and let us provide our recommendations?

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Topics: slide bearings
2 min read

Ultracomp Grades Decoded

By Dave Biering on May 15, 2018

Ultracomp Grades Decoded

Ultracomp is a family of laminate wound bearing materials with migratory lubricants added to the resin system. All Ultracomp bearing materials are high load, low speed materials designed to operate in extreme conditions without additional lubrication.

Most competitors use a wet-wind system, but Ultracomp uses a prepregnated fabric system. Prepreg is a cleaner and more efficient manufacturing system, as wet-wind processing results in a loss of properties; in other words, the wet-wind process reduces the performance of the resulting bearing.

Ultracomp is constructed of synthetic resins and reinforcing fibers and each variant uses one of three migratory lubricants:

1. Graphite

2. PTFE

3. MOS2

Here’s a breakdown of the core Ultracomp products

UC200

  • Description: Designed for high load, high impact, slow speed, and vibratory applications. UC200 has excellent abrasion resistance, does not require lubrication, and has extremely low moisture absorption.
  • Resin and Lubricant: Bearing Grade Polyester / Graphite Composite
  • Applications: Oscillating and sliding applications.

 

UC300

  • Description: Similar in construction to UC200, with PTFE lubricant added to the resin matrix to reduce its coefficient of friction.
  • Resin and Lubricant: Bearing Grade Polyester / PTFE Composite
  • Applications: Rotary or linear applications

 

UC400

  • Description: Similar in construction to UC200 with moly lubricant
  • Resin and Lubricant: Bearing Grade Polyester / MOS2 Composite
  • Applications: Slow rotary, salt water, and dry oscillation applications

 

UC500

  • Description: Unique interwoven laminate using PTFE, polyester fibers, and graphite lubricant.
  • Resin and Lubricant: Bearing Grade Blended Fiber / Graphite Composite
  • Applications: full rotary applications where self-lubricated low friction and long wear is required.

Other Varieties

There are a number of other varieties of Ultracomp, designed to be used in specialized situations. An example of this is UC200FR which has similar performance characteristics to UC200 but utilizes a special resin fabric which makes it fire resistant.  Another variation is UC300AR, which is similar to UC300 but is manufactured with a resin with a higher temperature rating which allows it to operate at a peak temp of 340°F (versus 325°F for regular UC300).

Learn More About Ultracomp

We encourage you to read our Ultracomp case studies, search through our past blog posts, and watch our online videos to learn more about this versatile product line. If you have any questions about Ultracomp just let us know and we’ll put our bearing experts on the case.

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Topics: Ultracomp
2 min read

Thermal Expansion a Key Consideration in Plane Bearing Design

By Dave Biering on April 17, 2018

Blog_20180417Thermal Expansion a Key Consideration in Plane Bearing Design

We are all aware that plastics expand and contract at different rates. When designing plastic plane bearings, one of the most critical considerations is to understand the thermal reactions of the material; designing not just for the normal operating temperatures of your environment, but to consider the minimum and maximum operating temperatures as well. Otherwise, you may lose the press fit (in cold temperatures) or expand to the point of shaft seizure (with hot temperatures).

Here’s a Basic Definition for Thermal Expansion

“Thermal expansion is the tendency of matter to change in shape, area, and volume in response to changes in temperature.”

Expanding (pun intended) on that, the Wikipedia page for thermal expansion offers some solid information, like how expansion is a result of the change in kinetic energy of molecules. Also included is a table a comparison of various materials.

Calculating the Coefficient of Linear Thermal Expansion (CLTE)

The Coefficient of Linear Thermal Expansion is a critical metric when working with dissimilar materials in applications where large temperature changes are anticipated.

This measurement is the ratio of the change in a linear dimension to the original dimensions of the material for a unit change of temperature. This is generally expressed as in/in/°F.

When it Comes to Thermal Expansion - Some Materials are Definitely Better Than Others

Our CJ material has a similar thermal expansion rate to steel, so we can run much tighter press fits and ID tolerances because the materials will stay stable from cryogenic to 350° F.

Some exotic materials like Torlon and polyimides also have good thermal expansion rates. On the other hand, UHMW would not be a good choice in an application with extreme heat as it has up to 13x the thermal expansion of steel!

Here is a breakdown of linear expansion in some of the key materials from our tier one product line along with some other common materials.

 Coefficent-of-Linear-Expansion---Material-Comparison

We can Help

This is a lot to unpack! We can answer any questions you might have about thermal expansion. Let us review your materials and design criteria.

Bearing Selection: Get the Ultimate Plastic Bearing Design

Topics: bearing temperature
2 min read

UHMW 101: From Molecular Weight to Machining

By Dave Biering on March 20, 2018

UHMW 101: From Molecular Weight to Machining

UHMW remains a hot topic here on Tech Talk, and on our Ask the Experts portal, too. Why is this true? For one, the material offers great value over other plastics, and has good abrasion-resistance properties, plus it is processed via a unique control (no molding, only machining). This trifecta of properties values make for a distinctive material, read on for more top FAQs:

UHMW is short for ultra-high molecular weight polyethylene; or a semi-crystalline polymer. As a point of reference, high-temperature polymers are classified based on their molecular structure. Semi-crystalline polymers are solid until heated to certain temperatures, where they will quickly turn to liquid. Amorphous polymers do not exhibit any crystalline properties and resist liquid melting. UHMW is a considered a high-density polyethylene with a median molecular weight (falling within a range of 3.1 to 5.0 million).

1) UHMW has a low melt point, but a high COF

Like all polyethylenes, UHMW has a low melting point (270°) and a high COF (120 x10” In/In/°F). It gives one of the lowest wear rates (even better than steel, nylon or fluoroplastics) to resist most forms of abrasive media. These qualities give the material good impact resistance.

2) Molecular weight = better abrasion resistance

Molecular weight has a direct impact on a material’s ability to resist abrasion. For instance, a molecular weight grade of 4 million has an abrasion resistance of 100 when measured using a sand slurry test. Yet when you increase to the molecular weight to 6 million, the abrasion rate goes to 75, or an improvement of 25%. Compare this with steel, which has a resistance of 160 and it becomes clear why the material is a good choice for abrasive wear environments.

3) No molding, machining only

Though known as a tough material, UHMW cannot be molded; machining is the best processing method. In fact, waving and warping are common to large sheets of virgin UHMW, so molding is nearly impossible without compromising the integrity of the material. And unless you use the right tools and techniques (revealed in this technical guide), your machine cutting tools are known to actually become melting tools instead! Coolants are critical to maintaining the right heat levels.

4) Beware of expansion to avoid deformation

When machining UHMW, special attention must be paid to how quickly the material expands (up to 20x the rate of steel expansion). Anytime you machine UHMW, or any material with instability, it’s critical to consider the final operating conditions of the part and machine accordingly. Materials that are fabricated in a warm climate will expand and contract and otherwise behave differently when installed and operated in cold-weather environments, and vice versa.

5) Inert to most chemicals

Most liquid solutions are compatible with UHMW, including various forms of alcohol, ketones, and acids. But one should beware of chemicals with high-oxidation, like bleach, and hydro carbons like gasoline.

UHMW is available in many variations, including glass or moly-enhanced or cross-linked. Submit your specs to our team, and we can walk you through the pros and cons of each.

Custom Plastic Fabrication: Get the Guide!

Topics: UHMW
2 min read

Q&A Can Composites Replace Bronze Plain Bearings?

By Dave Biering on March 6, 2018

Can Composites Replace Bronze Plain Bearings?

If you’re a regular reader of Tech Talk, it will be no surprise that we’re big fans of composite plastics as a replacement for bronze bearings.

Composites offer a simple, one-piece construction and they eliminate many of the downsides of metal bearings – which we will outline below. When designing for your next application, here’s why you might want to consider a composite design instead.

No matter the operating conditions or bearing load, chances are there’s a composite replacement for traditional bronze bearings. Plastic composite bearings eliminate the regular maintenance required of bronze, yet still provide good strength and versatile movement to support construction, automotive and other heavy-duty applications.

Composites bearings are advancing manufacturing designs:

Have high-load and high-shock conditions?
Unlike rigid metals or bronze bearings, composites have inherent elastic qualities, so they can accommodate tremendous compression and shock and vibration— without deformation.
Operating in dangerous temperatures?
Unlike metals, composite bearings excel in temperatures ranging from cryogenic right on up to +600°F, depending on whether constant or intermittent operating service is required.
Working in FDA or other high-sanitation environments?
Plastic composite bearings meet a range of food and medical certifications and most are RoHS compliant, unlike metal ball bearings. Read more on bearings and certification.
Need a thick-wall or reinforced design?
Custom design options are virtually endless with composite materials, and off-the shelf options are a quick delivery away. Like metals, plastics can be fabricated to thick or thin wall construction, or reinforced with a hybrid design featuring two layers of materials to protect expensive machinery from a bearing failure. Composites are also good choices for press fit and freeze fit to ensure good mounting between parts.
What about dimensional stability and corrosion?
Metals and bronze plain bearings are susceptible to rust and corrosion after extended exposure to liquids and chemicals. Not so with composite bearings, which easily endure most solutions with little pitting or swelling.
Friction a concern in your application?
You can’t go wrong with composites, which offer coefficients as low as 0.05 in dry applications and 0.09 in lubricated environments.

What is the key takeaway? Composites are an excellent choice to replace bronze bearings by offering quality-without-compromise in heavy-duty applications. TriStar has been offering them to manufacturers for over thirty years to 70+ industries. Get the Industrial Bearings Technical Paper to learn more.

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Topics: Bronze Bearings
2 min read

The Dust Stops Here: Which Bearing Types Overcome Dusty Environments?

By Dave Biering on January 30, 2018

Which Bearing Types Overcome Dusty Environments?

Dust and debris are a challenge to all bearings. but impact some bearing types more than others. Food processing lines, paper mills, construction sites and other environments produce airborne contaminants than can clog and impede bearing rotation. And lubrication levels play a key role in bearing success or bearing failure, too. Let’s clear the dust to review bearing attributes for overcoming a dusty environment.

Why is dust a problem in bearing performance?

It boils down to length of service. A contaminated bearing will simply fail sooner, which can impact production rates, as manufacturers are forced to stop their equipment for maintenance and replacement. Dust can be in the form of sand (from paper processing), food debris (generated from peanut processing), metal particulate (kicked-up from machining) are just a few examples. No matter the cause, as dust accumulates, it becomes abrasive, which lowers the effectiveness of seals and bearings alike.

Dusty environments are a big challenge for rolling element bearings, as particulate pits the rollers. racers and bearing surface. Dust thickens into layers as it accumulates (forming a lapping compound), which interferes with the clearance between the bearing and shaft. And without good clearance, bearings will stop running and equipment will seize.

How can you stop dust accumulation?

We have a few solutions. A good filtration system is essential to capture larger contaminants. Good compatibility between bearing and seal should be considered. Regular cleaning of your metal bearings and housings will also make a difference; it’s critical to remove excess grease by following a regular maintenance schedule. Because the more grease build-up, the thicker the lapping compound.

Beyond these preventative measures, you can also eliminate the problem of lubrication buildup entirely by considering a non-metal, composite bearing design. Although all bearing types require a level of lubrication to block contaminants from entering the bearing surface, self-lubricating bearings operate in a way that does not produce excess grease. They can reduce overall bearing maintenance costs, and promote a cleaner manufacturing environment. An extended service lifetime is another benefit; you can learn more about avoiding bearing failure here.

Connect with an Expert with any questions about the right bearing type for your environment!

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Topics: Bearing Selection
2 min read

Why Choose a Career in Plastics Manufacturing?

By Dave Biering on January 23, 2018

Why Choose a Career in Plastics Manufacturing?

Are you a problem solver? I read this interesting article in Design World, which describes manufacturing as one of the best career choices for problem solvers. Given my plastics manufacturing and engineering background, this topic sparked my interest. Here’s why I chose this career, and some of the steps needed to grow the industry...

Generations ago, manufacturing was considered a repetitive job requiring limited skills and offering limited opportunity. This perception could not be further from the truth today. Modern manufacturing plants now incorporate robotic automation, 3-D printing, AI and other leading technologies. The field requires highly-skilled workers; employees that are becoming harder to find as baby boomers retire. In fact, as we dive into 2018 and beyond, Deloitte cites that nearly two million manufacturing jobs are expected to go unfulfilled in the next decade – that’s a significant number!

What can we do to develop the next generation of plastic manufacturers?

  • Start earlyCompanies that invest in developing the next generation of engineers and designers will reap the benefits. Events like National Robotics Week, which emphasize STEM education and competitions are sparking a love of building and engineering in millennial students.
  • Changing perceptionPlastics manufacturing – and manufacturing in general– is not your father’s manufacturing. Today, 3D design, CAD, AI, robotics are all common on the manufacturing floor. Manufacturing is no longer a staid environment.
  • Opportunity knocksManufacturing may be a non-traditional career, but there’s no doubting there’s opportunity for future growth and a stable career. In fact, 6 out of 10 open positions are a result of a talent shortage, as seen in the graphic below.
  • Consider the benefitsManufacturing is one of the best industries for employee-sponsored healthcare benefits, cites the Kaiser Foundation. And 80% of manufactures are willing to pay above-market rates for their employees, as noted.

These are just a few steps that I believe will keep us headed in the right direction. And having just returned from a tour of our partners in China, it’s evident that a shortage of workers is not exclusive to the US. Manufacturers there are experiencing a similar challenge.

If you are interested in an exciting career in plastics manufacturing, we just might have the job for you here at TriStar Plastics!  What are your thoughts on the future of plastics manufacturing? Share below!

us-pip-skills-gap-infographic.jpg(Source: Deloitte)

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Topics: Plastic Manufacturing
2 min read

6 Reasons to Choose Filament Wound Composite Bearings

By Dave Biering on January 16, 2018

CJ - Filament Wound Composite Bearings

Looking for a tough, durable and versatile bearing for an industrial application? A filament wound composite bearing might be just the ticket based on several key qualities. Let’s review the top reasons:

What is a filament?

A filament is defined as a conducting thread or wire that has a high melting point. Filaments are usually associated with an electric or vacuum tube, which is then heated to produce an electric current inside a bulb.

In the world of composite bearings, multiple filament threads are wound in a helix configuration to improve the strength of a bearing wall. In the case of our CJ (composite journal) bearing, the liners are made of PTFE/Nomex/Polyester which are woven into a sock and then intertwined with glass filaments to produce a reinforced product. This multilayer design gives the bearing reinforcement for good reliability, and longer service uptime without the need for maintenance. The bearings are wound on precision mandrels with preset ID dimensions.

What are the benefits of a filament wound bearing?

Filament wound bearings are among the strongest in their class and offer superior versatility:

  1. Element of elasticityFilament wound bearings present a good level of elasticity that falls between rigid metals and soft plastics. This modulus gives the bearing the ability to support heavy loads, but enough flexibility to tolerate shaft misalignment without stressing the bearings ends.
  2. Shock absorptionA composite filament wall acts like a spring to absorb shock and vibration in high-stress environments. Even our thin wall CJ’s have the ability to compress and recover during shock and impact conditions without failure.
  3. Resistance to corrosionThe special winding technique and multilayer construction gives filament bearings good resistance to chemical, galvanic (electrochemical contact) and fretting corrosion. These are all primary causes of bearing failure. Explore more causes of bearing failure.
  4. Versatile motionsFilament wound CJ’s and FCJ’s are best applied in oscillating motions at variable frequencies but can also be utilized in lubrication free rotary and lineal motions.
  5. Good service lifetimeA filament wound composite is best used against a hard shaft and 8-16 rms finish to resist abrasion and fretting and improve overall service. In fact, one test showed that improving the surface of 50-55 Rc hardness and an 8 rms finish could extend the wear life of a bearing from 500,000 cycles to over 1 million cycles. All without lubrication.
  6. Self-lubricating qualitiesComposite bearings run dry and grease-free to help you save on all costs associated with manual grease application.

You’ll find filament wound composites work exceptionally well as a bronze replacement in applications including transportation, construction, mining and more. For best results, we also recommend that you look for bearings that are designed and manufactured in the US. Ask us for details.

Bearing Selection: Get the Ultimate Plastic Bearing Design

Topics: filament wound composite bearings
2 min read

8 Simple Rules for Bonding Plastics

By Dave Biering on January 9, 2018

Blog_20180109.jpg

Today’s post is designed as a quick list of must-follow rules to help you achieve best results from bonding plastics. Whether your industry application is medical or consumer, aerospace, construction or another field, the bonding rules are the same.

Securely bonding plastics begins with choosing the right materials, preparing the surface finish, and following a few simple rules:

  1. Be sure that the substrate and the plastic are properly prepared via mechanical, primer or thermal properties.
  2. Once you’ve cleaned the substrate, clean again! Even a small amount of oil or contamination left on the surface can impede thorough bonding results. 
  3. For best results, we advise that you avoid petroleum-based cleaners, and instead consider IPA or acetone formulas.
  4. Always handle parts with gloves, as skin oils can lead to line failures.
  5. Check adhesive for compatibility with the plastic. Some adhesives will cause amorphous (see through) plastics to haze and crack.
  6. We recommend that you avoid fast-cure adhesives which are more likely to crack during the 24-hour cure period. Even those products which are specially designed to cure faster can lead to crystallization and cracking.
  7. When working with materials like nylon, acetal, and polyester, consider using a primer before applying the adhesive to enhance bond strength.
  8. Bonding PTFE? The top rule with this material is to prepare all PTFEs and PTFE blends (like Rulon) with one side etched before bonding can begin. Read more about proper storage of etched Rulon.

With these rules in place, you can expect positive results and lifetime treatment. Or if you’d prefer to outsource your bonding process, we’ve got an all-new adhesive system in place that can bond virtually any plastic to any substrate. This system even eliminates the risk of over compressing the adhesive. Just ask us for details! 

Or watch our video (below) for additional tips!

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Topics: Bonding Plastics
2 min read

Why Choose Plasma Surface Treatment of Plastics to Enhance Adhesion?

By Dave Biering on January 2, 2018

Why Choose Plasma Surface Treatment of Plastics to Enhance Adhesion?

Good adhesion of manufactured parts. Whether you want to adhere one part to another, or secure paint to a component, good adhesion can be difficult to achieve in the regular manufacturing process. Plasma surface treatment can help you enhance adhesion at a good value, and with excellent results - but the process remains a mystery to many designers. Let’s take a look behind the curtain to learn why plasma cleaning is often recommended: 

Adhesion. It sounds like a simple concept, but can be quite complex to achieve. To start, your parts must be ultra clean before you can even attempt to adhere parts, and virtually any contamination can reduce the bond strength between surfaces. Even parts that have been “cleaned” can still have a monolayer of contamination (or 0.1 microgram/cm2) remaining after rinsing with a liquid solvent. Once these cleaners evaporate, up to 0.2 drops/cm2 of liquid containing 10ppm of non-volatile organic material can be left behind, which will also interfere with bonding. Plasma treatment can completely remove all trace amounts of organic contamination to promote better adhesion. 

This is where low-pressure plasma (or vacuum plasma) is your friend. Plasma surface treatment eliminates even the thinnest layer of contamination to promote the best bonding results. Unlike atmospheric treatments, plasma treatments are placed in a vacuum chamber where complete, 3-D treatment of the entire component can be achieved. No area is left untreated with plasma (unless they are intentionally masked).

To demonstrate this power of plasma, I wanted to share this research article I recently read, which cites the high-adhesion properties of PTFE after plasma treatment. It notes the impact of “Heat and power on the adhesion of PTFE was very clear… the adhesion was so strong that the (material) tore apart instead of separating from the PTFE.” The article goes on to note that the bond strength lasted even a year after treatment.

Imagine the implications of your part or paint adhesion lasting for a year – or even for the lifetime of your product, which is often achieved.

Beyond cleaning, plasma surface treatments offer other advantages to enhance bonding:

Parts will remain thermally stable
The pressure inside the plasma chamber is maintained well below the 500mT, deformation point to eliminate the risk of thermal deformation to your components.
Surface ablation is minimized
Plasma surface treatment will not alter the transmittance clarity of treated parts. Your bond will remain true and not have an impact on secondary painting processes.
Repeatable with each manufacturing batch
All phases of the plasma process are computer controlled so your process can be repeated every time.

Does enhanced adhesion sound like a good match for your manufacturing process? You may want to start by reading our Surface Modification technical paper. Our plasma surface expertise spans hundreds of industries and applications.

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Topics: Plasma Treatment
2 min read

Rulon Shapes, Forms or Fabrication – Which is Right for You?

By Dave Biering on December 19, 2017

Rulon is available in shapes and forms like rod, tube, sheet, and tape.

Have you heard about the newest Rulon formula, Rulon 1834?  It’s an exciting addition to the Rulon fluoropolymers product line. You may already know that each Rulon formula can be custom blended with fillers and pigments, but did you know that Rulon is available in shapes and forms like rod, tube, tape, or even custom fabrication to your specs? Let’s review some options: 

All Rulons offer similar temperature ratings, chemical resistance, friction and wear values. But when it comes to choosing a shape, much will depend on the intended function of your part, your delivery timeline, and your budget:

Rulon tape

Need to prevent metal-to-metal contact? Consider Rulon tape, which is also known as bearing tape. It can be cut to any length, and is available wound flat or spiral shaped. Tape prevents metal-to-metal contact between piston rods/cylinders and mating hardware in hydraulic and pneumatic applications. It guides the bearing between the metallic components during stroke and static movements, or can act as a barrier for insulated wire.

Rulon rings

Solid and split piston rings can be designed with any number of joint, length and diameter configurations, and with unique performance attributes.

Basic shapes or standard forms

In a rush for off-the-shelf parts? Rulon is available in standard sleeve, flange, thrust, mounted and spherical shapes for use as standard plane bearings. Sizes are also compatible with bronze standards for precise hardware fitting. Explore the Rulon comparison chart.

Molded rods, sheet or tube

Want to machine your own parts? Rulon can be easily machined, but there are some considerations. Get the Essential Machining Guide technical paper for specific instructions. With the right tools and training, your shop can finish Rulon via sawing, grinding, tapping threading, reaming, turning, screw machining and etching. With some expert advice we can even help you reduce scrap loss to save on material costs.

Have a tight delivery and need to outsource your fabrication? We can help you here, too. Custom options are virtually unlimited, just fill out an engineering worksheet with your specs, and we’ll set you up a quote. With outsourcing, you’ll never have to buy and maintain your own equipment, and we can help you make your production delivery goals.

Let’s start a project together!

Rulon - Quality Assurance Begins With Precision Processing

Topics: Rulon
2 min read

What is Bearing Service Life? And Which Qualities Impact it?

By Dave Biering on November 7, 2017

What is Bearing Service Life? And Which Qualities Impact it?

We often talk about the importance of bearing service life in this forum, but what exactly is a good standard of measure to this question? The truth is, bearing longevity depends on factors beyond operating conditions. Here’s the rest of the story:

As defined by Machine Design, bearing service life is, “The life of a bearing under actual operating conditions before it fails or needs to be replaced.”

Simple enough.

But which factors contribute to how long you can expect your bearing to last in your “typical” environment? We consider these main factors:

1) Lubrication is critical

Without good lubrication levels (whether manually-greased rolling element bearings, or self-lubricated composites), bearing friction will build. Which means heat will build, and so, too, the possibility of bearing overheating and failure. Environmental factors like dust and contamination can also have a negative impact on lubrication (causing a lapping compound to form around the hardware), which will result in a shorter bearing service life. Good lubrication is very important.

2) Bearing load is a key contributor

Knowing the full load potential of an application is key to determining bearing lifetime. This is especially true with cantilevered and uneven loads (as in construction equipment lifting applications). Best practice is to “overdesign” a bearing by overestimating the highest load it may encounter in order to leave some room for additional weight.

3) Operating temperatures (not too hot!)

Matching the right material formula to the anticipated temperature, as we recently explored, Bearing Temperatures and Plastic Composites) Temperatures impact press fits and the thermal expansion, which, in turn, impact the tolerance between the shaft and the ID of the bearing. These all contribute to the total service lifetime of the bearing.

4) Speeds are important, too

Bearings that are improperly matched to the SPM (or speed for minute) of the rotary application will wear more quickly and have a detrimental impact on service life. Good bearing alignment is also important.

While the above are the primary contributors to how long you can expect a bearing to last, it’s important to also consider additional factors like material storage. Some materials, like etched-PTFE Rulon, require a UV-blocking bag or else the etching will degrade in standard warehouse conditions. For best results and longer service, bearing materials must be stored and handled properly. Read more about bearing wear.

Ultimately, the better a bearing is matched to your application environment, the longer it will last. We can help guide you to the right material!

Bearing Selection: Get the Ultimate Plastic Bearing Design

Topics: Bearing Service Life
2 min read

Waterproof Bearings: Why Replace Stainless with Plastic?

By Dave Biering on October 31, 2017

Rulon W2 waterproof bearings excel in water meters without leaking or absorption

“You want to replace tough bronze bearings with plastic?” This was the comment one of our OEMs heard when attempting to retrofit their metal waterproof bearings with a plastic material on a water meter assembly. We were up to the challenge of answering this critical question, with this reply:

Customer questions posed to our Ask the Experts portal are always answered, as this engineer discovered when he described his situation:

The background

This manufacturer produces fresh-water industrial meters, and needed to replace a porous Oilite bronze bearing that was slowly leaching oil into the water. The oil not only contaminated the water supply but the bronze contained lead. The engineer also noted that the meter’s bronze hardware was incompatible with the stainless shaft which could lead to a cathodic reaction. The incompatibility caused the meter to give unreliable data readings on the water flowing through the pipes.

The recommendation

Our recommendation was to replace the bronze bearings with Rulon W2. While most filled-PTFEs are reserved for dry applications, Rulon W2 fluoropolymer contains an additive to enable waterproof service with minimal (to no) moisture absorption.

The result

After some initial hesitation about the durability of Rulon W2 vs. traditional bronze water meter bearings, our client agreed to testing. Results were overwhelmingly positive, as W2 eliminated oil leakage, and the material’s self-lubricating properties also eliminated abrasive wear on the stainless hardware. Rulon W2 provides one of the best wear and friction rates, plus good thermal dissipation for a longer service life – without replacement for years at a time. Explore more Rulon technical case studies.

Rulon W2 waterproof bearings excel by:

  • Eliminating stick/slip
  • Reducing abrasion in mating hardware
  • Providing dimensional stability in fresh and chemical environments
  • Ending moisture absorption
  • Ensuring compatibility with drinking water (DWGV certified in Europe)

While our client had excellent results with their Rulon W2 waterproof bearings, we also cautioned them about the prevalence of counterfeit bearing materials posing as genuine Rulon. Unfortunately, counterfeiting remains a challenge in industrial bearings, according to the World Bearing Association.

As the exclusive North American distributor of Rulon, only TriStar can guarantee the authenticity and proper processing controls are used in manufacturing. Read more in our paper, Rulon: How to Recognize Genuine and Avoid Counterfeit.

Rulon Bearings - How to Recognize Genuine and Avoid Counterfeit

Topics: waterproof bearings
3 min read

Let’s Compare: Metal Bearings vs. Plastic Bearings in Robotics

By Dave Biering on October 17, 2017

Let’s Compare: Metal Bearings vs. Plastic Bearings in Robotics

Have you downloaded your copy of the Robotics and Manufacturing White Paper? It’s a free resource to help you evaluate plastic and metal bearings to help increase your production levels. Let’s review the pros and the cons of each:

To succeed in a manufacturing application, robots need to assume human-like abilities like walking, bending and lifting. After all, bearings are to robots what joints are to humans; they help the moving parts rotate and roll.

Historically, rolling element bearings have been the go-to material for robotic designers, and they have worked well. These metal bearings are designed of pure materials and contain many moving parts (the outer ring, ball, two-piece steel ribbon retainer, shield and inner ring, plus the rolling racers). Metals provide good strength and durability, and good range of motion to accommodate a robot’s rotary, oscillating and linear movements.

But metal bearings also have limitations. They present several challenges to a robotic design, including

  • Lubrication - Oil-impregnated metals lose their oil through heat and normal use over time. Other metal plain bearings require regular lubrication which is often overlooked by the operator. Also the use of lubrication can lead to wear from contamination caught up in the lube.
  • Sanitation - Metal bearings need lubricating oil to operate, yet this oil can leak and contaminate any equipment used in high-sanitation environments like medical and clean-rooms.
  • ValueInitially, metal rolling element bearings appear inexpensive. But given the sheer number of moving parts, these bearings are susceptible to failure from corrosion, and brinelling. And with failure comes frequent replacement, which becomes costly when compared to bearings that deliver a longer lifespan. 
  • Wall design - Metal bearings require a thick shell to accommodate moving racers, but the thick walls can hinder the tight tolerances required of robotic pivot points.

    Weight - Metal bearings are up to 5x heavier than other materials, which adds significant weight to a robotic design. For best dexterity, robots need lightweight materials.

Often, lighter plastic bearings and polymers can yield best results. Plastic plane bearings are a hybrid of different polymers deliver enhanced versatility. They present a simple, design and can help designers achieve:

  • No lubrication - Since plastic composites self-lubricate, there’s almost no need for an additional lubricating film layer, which can save you the cost of maintenance, and unplanned maintenance downtime.
  • Certified agency approval - Different composite formulas offer FDA, USD, and 3A sanitation compatibility to ensure the robotic components are compatible to high-sanitation environments. Explore sanitation and agency approval.
  • Long-term value - Composites can last 5% longer than metal bearings, to give you a longer bearing lifespan on their manufacturing equipment for long-term value.
  • Flexible thin design - Unlike metal bearings, plastic composites are thin and flexible to fit a tight design envelope.
  • Lightweight components - With no rollers and a one-piece construction, plastics give robots good flexibility and strength-to-weight ratio.

Metal and Plastic Bearings for Robotics

Plastic bearings also resist environmental corrosion, and offer good impact, vibration, and temperature tolerance ― unlike metal bearings. They’re available in stock shapes or can be custom fabricated. 

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Topics: metal bearings
2 min read

Machining UHMW: Why Is Holding Tolerances So Difficult? (GUIDE)

By Dave Biering on October 10, 2017

Machining UHMW: Why Is Holding Tolerances So Difficult?

Ever tried to machine UHMW? It’s no easy task given the material’s instability. In fact, UHMW has 12x the expansion rate of steel. Controlling heat with the right coolant and tools is critical. Let’s review some techniques:

Ultra High Molecular Weight (UHMW) polyethylene is a semi-crystalline polymer that offers good abrasion and impact resistance plus a low coefficient of friction. It’s flexible enough to excel in both wet and dry environments with good wear and service life. These are the pluses.

But one of the negatives that we often hear about is that the material is incredibly hard to machine; particularly for those shops who are new to plastics. Yet machining is a must, since the material is impossible to mold. Like all polyethylenes, UHMW has a low melting point (270°) and a high COF (120 x10” IN/IN/ÜF), which all contribute to the challenge.

Limit heat!

For best results, it’s critical to reduce heat buildup, since the very act of machining generates friction, and thus, heat. An accumulation of heat presents dimensional challenges where your cutting tool can instead become a “melting tool.” To avoid this challenge, consider these techniques:

Drilling:

  • Drills with twist angles of 12°-18° and with large flute areas will help remove chips and heat from the drilling hole
  • Grinding relief onto the drill will also reduce friction. Angles will vary by material, but 20°-50° is a good starting point
  • Remove the drill from the hole (pecking) frequently to remove chips and give the material a chance to cool slightly

Milling and Cutting: 

  • Climb milling is recommended over conventional milling
  • To reduce chatter marks from vibration and moving, use vacuum systems or fixture clamps. Double-sided adhesive tape is another option to keep parts stable. 
  • Sharp tools are critical, and avoid tools that have been used to drill metal, as they are dull and will impact tolerances and surface finishes

Sawing:

  • Rip and combination blades with a 0° tooth rake and 3°-10° tooth set are best to reduce frictional heat
  • Hollow ground circular saw blades without set will yield smooth cuts up to 3/4" thickness
  • Tungsten carbide blades wear well and provide optimal surface finishes

Speeds and feeds:

  • Feed speeds can range from 10-40 FPM
  • Cutting speeds of 600-1,000 FPM are required
  • Use high-speed steel bits with a higher RPM to clear chips

Coolants:

  • For a premium surface finish, avoid water- and petroleum-based fluids to reduce stress fractures and moisture absorption
  • Vacuum air blowing is preferred for a tight tolerance. Vacuum keeps cutting tools cool, plus helps reduce dust from chip evacuation.

Without the right heat levels, you risk an uneven surface finish and an accumulation of plastic debris (burrs). For more UHMW machining techniques, get the Guide to Machining and Custom Fabrication!

Custom Plastic Fabrication: Get the Guide!

Topics: UHMW
2 min read

Composite Plain Bearings: 5 Benefits of a Lightweight Material

By Dave Biering on August 1, 2017

Composite Plain Bearings: 5 Benefits of a Lightweight Material

If you’re a regular reader of this space, you may recall our debate about plain bearing vs. a plane bearing. While the spelling might be hotly debated, today I want to focus on the benefits that lightweight composite plain bearings can bring to your design. 

A quick Google search will tell you that plain bearings are available in materials ranging from bronze and acetals, to ceramic, carbon alloy and, of course, composites. While each material can be installed at the point where two surfaces meet, why should you choose composite bearings over the other materials? 

One key advantage of composite plain bearings is their weight – or lack thereof. Plastic is up to 5x lighter than steel. The balls and racers required of metal rolling element bearings can add significantly to the total weight of a finished component. Not so with plastic plain bearings.

Choose lightweight plastic composites for the following benefits:

  1. Total weight of the finished component is criticalAerospace bearing applications are a prime example. With potentially thousands of bearings in a typical airplane, a lightweight bearing will lower the total weight of the aircraft to give better liftoff and dexterity in the air. Less weight requires less thrust (and fuel) to get off the ground.
  2. Power costs are a prime considerationHave a line of rolling conveyors in your manufacturing facility? Than you know firsthand the expense of running the conveyor belts 24/7/365. Lightweight bearings require less power to run and give better efficiency. A simple switch from metal to plastic conveyor bearings will reduce power consumption and deliver big savings on electric bills. 
  3. Space savings is a key design specificationLet’s take the robotics industry as an example. Spherical robotic arms pack great dexterity in a small space. Designers need a material that will wear well, but not weigh much. Plastic composites have a thinner wall design than rolling element bearings to accommodate the tightest spaces. They can even be custom fabricated to your exact specifications for the right fit.
  4. You need good strength-to-weight ratioThough they are lighter, plastic composite plain bearings never compromise on strength. They can withstand tough environments like agriculture and construction, but still maintain a small design envelope.
  5. Rigidity is important, tooLightweight plastic composites maintain their shape and stiffness despite high heat, UV exposure and other environmental elements that can cause metal bearings to fail. Learn more about avoiding bearing failure.

All of these qualities are key to the success of plastic composite plain bearings, and the material is even self-lubricating to reduce your bearing maintenance costs.

What’s not to love about composite plain bearings?  We invite you to learn more!

Topics: composite plain bearings
2 min read

Food Bearings for Peanut Processing: Solving a Lubrication Challenge

By Dave Biering on July 25, 2017

Food Bearings for Peanut Processing: Solving a Lubrication Challenge

Thanks for your feedback to our recent post about food bearings and the Food Safety Modernization Act. It’s a topic that has some serious implications for manufacturers, and we’ll continue to follow new developments. Today we turn to solving the challenges involved in peanut processing, which is a particularly tough environment for lubricated bearings.

Peanuts, almonds, pistachios; no matter the nut application, the cracking and husking process generates volumes of dust. This poses a real challenge with lubricated metal bearings, as the lubricating grease acts as a magnet and attracts fine peanut dust. Over time, the dust can thicken into layers, and will interfere with the clearance between the bearing and the shaft. Without proper clearance, bearings stop rolling and processing equipment can seize up.

We recently worked with a major peanut manufacturer to retrofit several pieces of their processing equipment to avoid this challenge; and the answer was self-lubricating bearings. Self-lubricating bearings excel in environments with high dust, as there is no excess grease build-up (or lapping compound). Self-lubricating plastic food bearings run cleaner than metals, and will not attract environmental dust.

Solutions included Ertalyte TX and Ceram P on the impact plates of the nut cracking station. Ertalyte is known for its excellent wear and abrasion resistance, plus high mechanical strength. The material gives superior lubricity, without the need for additional greasing. It also excels has good release properties for use in food applications with sticky ingredients like pasta.

Ceram P and Rulon were also used on areas like nut processing trays and equipment brake pads. View the Rulon Comparison Chart to learn about food-grade formulas. By combining a variety of food bearing types, we were able to meet the needs of this high-velocity and high-impact processing application.

This application is a good example of the need to look at each piece of processing equipment individually. Often, the best solution is a combination of food bearings shapes with distinct properties to achieve the best fit. We recommend that you partner with a food bearing manufacturer with both in-stock and custom bearing options for speedy delivery.

Want to learn more? Let’s talk about your food bearing needs!

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Topics: food bearings
2 min read

How it Works: Coordinate Measuring Machine for Plastic Fabrication [Video]

By Dave Biering on July 11, 2017

 How it Works: Coordinate Measuring Machine for Plastic Fabrication

We’ve got an exciting new addition to our plastic fabrication shop – a new coordinate measuring machine! Today I want to share some of the benefits of this new equipment, and explore how it can help you realize your product design dream.

Our new Coordinate Measuring Machine is now a key feature of our testing and inspection lab. It measures the geometrical characteristics of a component, and shows the collected data in a mathematical form using X, Y, and Z axes. The measurements are obtained via a probe that is attached to the third moving axis of the machine. The CMM allows for incredible accuracy and precision to within a micrometer.

What is the importance of a CMM in plastic fabrication?

Essentially, our goal of acquiring this machine is to enhance our quality commitment. We look to the CMM to test if engineered parts are up to the rigorous specifications of an application design. And beyond accuracy and product integrity, the machine also helps to ensure that a manufacturing process is repeatable. This CMM model is designed for large assemblies and will help us to increase throughput.

The CMM machine is just one piece of our custom plastic fabrication machine shop, which boasts: 

CNC Swiss Screw Machines

  • High-speed turning
  • Bar capacity up to 1.25”
  • Continuous bar feeding
  • 6-axis control system
  • Secondary milling and drilling

CNC Milling

  • Up to 36” x 81” travel
  • Rapid tool change
  • Close tolerance
  • Prototype/production
  • CAD/CAM

CNC Turning

  • Live mill head attachments
  • Bar capacity up to 2.75”
  • Secondary milling & drilling
  • Chucking capacity up to 21”

Consider TriStar’s plastic fabrication; we can guarantee your parts will meet design specs and that they are fully inspected and certified. 

We can also help you save on component costs by suggesting alternate materials, or providing machining tips to help you manage your own fabrication. Get your copy of the Plastic Fabrication White Paper for exclusive machining tips! Let us help!

Custom Plastic Fabrication: Get the Guide!

Topics: Plastic Fabrication
2 min read

How Will the Food Safety Modernization Act Impact Your Bearing Selection?

By Dave Biering on June 27, 2017

How Will the Food Safety Modernization Act (FSMA) Impact Your Bearing Selection?

Are you ready for the Food Safety Modernization Act (FSMA)? The clock is ticking — and most manufacturers need to be in full compliance with the regulations by the end of 2017. Bearing selection can play a key role in helping you achieve compliance of your food processing and packaging equipment. We’ve got some insights to make the selection process easier.

The FDA’s Food Safety Modernization Act was signed into law back in 2011, and represents the most-sweeping overhaul of food safety legislation in over 70 years. The goal of FSMA, of course, is to increase consumer safety by preventing food contamination through better processing and preparation of food products. Although implementation dates have been staggered over several years, 2017 represents the year most US food manufacturers must be fully compliant.

But the reality is that not all manufacturers are ready.

Recent interviews with food processing OEMs cite that only 50% are prepared to meet the FSMA’s timeline. And of those interviewed, most claim that they are having the most difficulty with getting the right cleaning systems in place. They need clean-running equipment to expedite GMP and FSMA.

Granted, equipment bearings are just one small part of an overall manufacturing compliance plan, but these small devices can pay big dividends.

With the right bearing selection on their processing equipment, food manufacturers can:

Realize easier industry certification

Some bearings are pre-certified with industry third-parties such as FDA, USDA, and 3A standards. With these bearings on food conveyors and pick and place equipment, food processors are a step ahead in meeting the requirements of FSMA. Pre-certifed bearings can shorten the installation approval timeline.

Reduce cross-contamination

Bearings with high-release properties stay cleaner, longer since they eliminate food residues from accumulating. For example, poultry processing includes a series of drills and hooks to move the meat along the production line. When meat residue clings to the drill housing, bacteria and other contaminants can cross from one bird to the next. Bearings with good release properties (such as Tivar and Ertalyte) do not hold on to this residue, to reduce the chance of cross contamination.

Eliminate impurities from lubricating films

Bearings need lubrication to run, yet excessive lubricating grease promotes a lapping compound to form around the bearing. The compound then acts as a magnet for dust and other impurities. By using grease-free equipment bearings, manufacturers can eliminate this common form of food contamination.

Promote good sterilization

Good cleaning and sterilization of processing equipment is a key way to prevent food contamination per the FDMA. But not all bearings can tolerate the common chemicals used to clean food processing equipment like phosphoric, nitric, and hydrochloric acids. These can all weaken and cause failure in metal bearings, but have no impact on composites and polymers. When selecting your equipment bearings, look for those that are compatible with required sterilization chemicals.

Beyond improving FSMA compliance, your bearing selection can also impact your overall productivity. Because bearings that require little maintenance and have good environmental tolerance also tend to last longer. And longer-lasting bearings can save on your replacement costs. It’s a win-win.

Want more information on FSMA? Check out this FAQ sheet from the FDA, or get a custom consult on bearing selection!

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Topics: Bearing Selection
2 min read

Understanding Low Friction Bearings: What are They and Why are They Important?

By Dave Biering on June 13, 2017

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I had a great conversation this week with a manufacturer about low-friction bearings. Low-friction bearings can reduce surface degradation and friction levels by 30% or more when compared to standard bearings. But have you ever wondered how a low-friction bearing is classified or why they’re important? I wanted to share some of the points we reviewed:

We often talk about the benefits of low-friction plastic bearings, yet how is low-friction really classified? Coefficient of friction (COF) is one of the key tribological properties of a bearing. It’s the measure of resistance between the sliding of one hardware surface against another.

You can test the COF of a bearing through a thrust washer test (or ASTM D 3702); which is the most common method. Test results can help you compare the relative “slickness” of bearing materials. Tests are generally run as unlubricated materials against steel or other materials. The lower the sliding resistance of the material, the more “slick” you can expect the material to be. 

Friction values are classified into two categories:

  • Static COF refers to the resistance of the initial movement when a bearing starts up from a resting position.
  • Dynamic COF is the resistance once the bearing (or mating surface) is already in motion at a given speed. 

One quality that is unique to many polymer bearings is that the static coefficient of friction is lower than the dynamic. Another unusual quality, especially with materials that utilize PTFE as the primary resin is that the higher the load the lower the friction. Both of these qualities fly in the face of conventional wisdom!

Why is it important to know the COF of a bearing?

A bearing’s friction level will help to determine how well and how long a bearing will wear so that you can gauge the expected service lifetime. For best results and extended wear, low-friction bearings should include a self-lubricating design feature. With lubrication, a bearing generates less friction, and less friction means less heat and better overall efficiency for manufacturing. 

Which bearing materials are considered low friction?

Composites and polymers offer excellent low friction properties. Rulon J delivers one of the lowest COF, TriSteel bearings can be reinforced with PTFE and other liners which virtually eliminate friction wear. The exact type of low friction bearing will vary by your service requirements. 

Let’s talk to find the right fit for your application!

Bearing Selection: Get the Ultimate Plastic Bearing Design

Topics: low-friction bearings
2 min read

Plastic Manufacturing and 3D Printing: An Overview

By Dave Biering on May 16, 2017

Plastic Manufacturing and 3D Printing: An Overview

Have you been following the evolution of 3D/additive printing? It’s changing the traditional model of plastic manufacturing. Once used as a simple way to produce small plastic parts, the technology is projected to become a $7 billion industry by 2020. Given such extraordinary advancement, let’s review the impact.

It’s amazing to witness how quickly 3D/additive processing is evolving plastic manufacturing. While the basic technology began in the 1980s, today’s software and printers have enabled more-sophisticated and less-costly manufacturing design.

3D/additive processing begins with a CAD drawing of an object that is designed via modeling software. The design is then “sliced” into hundreds of layers that are then read and fed into a 3D printer. The objects are then built layer after layer until complete. Printers can range from models for home hobbyists, to sophisticated industrial printers suitable for massive manufacturing.

Although the pace of advancement is still debated, more mass-manufactured products are on the horizon. Aerospace manufacturers are embracing 3D to build lightweight carbon fiber components that will reduce the weight of aircraft and increase efficiency. The US military is adopting the technology to build replacement equipment components right on the battlefield. Medical prosthetics are commonly 3D printed today. And in the future, consumers may even have 3D scanners integrated into their smartphones.

But it’s those manufacturers who embrace the technology that are poised to win. The advantages are real:

  • Cost-effective production - 3D printing can eliminate expensive production lines and prototyping to create even complex assemblies cost-effectively.
  • Less manufacturing waste - Precision design eliminates traditional trial-and-error manufacturing models to reduce expensive scrap. 
  • Faster release to market - Sophisticated software and modeling means there’s less time required for manufacturing ramp-up, or change of tooling devices to fabricate complex components.
  • Greater innovation - Given lower production costs, there’s a greater reward to manufacturers to innovate new products.

From clothing and toys to tiny houses and even human body parts, the potential of 3D printing is unlimited. Astute manufacturers who embrace the technology will reap the benefits. Learn more about plastic manufacturing.

What are your predictions for this form of plastic manufacturing? Share your thoughts below!

Custom Plastic Fabrication: Get the Guide!

Topics: Plastic Manufacturing
2 min read

Q&A - How Do Self-Lubricating Bearings Lubricate?

By Adrian Carrera on April 4, 2017

How Self-Lubricating Bearings Lubricate

Self-lubricating bearings can lower your bearing maintenance costs without sacrificing performance. But have you ever wondered how they lubricate? There are two common systems for lubrication; smearing systems and debris systems which contribute to the surface finish. Here’s a review:

Plastic plane bearings are self-lubricating via two unique processes:

  1. Smearing systems - Smearing occurs when small amounts of lubricating media such as PTFE, silicone, graphite or MOS2 are wiped into the surface micro-finish.
  2. Debris systemsDebris systems process when small particles of the polymer are removed during normal operations and develop plastic “ball bearings.”

Next, let's discuss these two processes in detail.

Smearing systems are typical of PTFE and PTFE-filled polymers. As the shaft makes initial contact with the mating contact surface, softer lubricating material is wiped into the micro-finish of that surface, which builds a thin film of lubricant. The lubricant remains in place and will not migrate, which helps to reduce friction and wear on both the shaft and the bearing.

Some common materials for producing self-lubricating bearings include:

  • Rulon
  • Fluorosint
  • PTFE Blends
  • Delrin AF
  • Ertalyte TX
  • BG PEEK
  • Graphite PI
  • TriSteel PT/PI
  • Ultracomp

The largest family of self-lubricating bearing materials are the filled PTFE materials. And the best known of these is Rulon, a family of blended PTFE materials designed for bearings, seals and structural components.

Debris systems are found in harder thermoplastic or thermoset polymers that deposit particles of the actual resin between the shaft and bearing. These types of materials tend to be less efficient, since the debris remains on the surface area between the dynamic faces rather than embedding. Over time the debris is “cast off” as residue and the wear process tends to be on a slow but continuous basis. Debris materials have inherently low friction, but not as low as smearing systems with migratory lubricants. Debris materials are generally less costly than the smear materials, but also have lower P, V, PV ratings and limited temperature ranges.

Common debris system materials include:

  • Nylon 6/6, 6/12
  • Acetal/Delrin 100/500
  • Cast Nylons
  • UHMW

Want to review any of these self-lubricating bearings materials with our engineering experts?  Fill out a Engineering Worksheet to submit your specs!

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Topics: Self-Lubricating Bearings
2 min read

Q&A - Is Surface Finish Important to Bearing Design?

By Adrian Carrera on March 28, 2017

Q&A Is Surface Finish Important to Bearing Design?

Surface finish is one of the primary considerations in bearing design, since it has a direct impact on the performance of the final product. And achieving the right finish is a careful balance of plastic form vs. plastic function. Consider this:

Is surface finish important? It is, and finish refers to more than just the appearance of the hardware. Ultimately, it relates to how well and how long a bearing will function in your application. When the finish of a shaft is too rough, it will prematurely wear away the plastic bushing. This rate of wear can be compared to having used sandpaper on the component.

If the surface finish is too smooth (such as a mirror finish), the bearing material will not have the right texture to imbed the migratory lubricants. And if the material cannot imbed, the lubricant will not be effective and in fact can raise the coefficient of friction. Increased friction leads to increased wear and now your self lubricating bearing is not living up to it’s potential.

It’s critical to establish the desired finish very early in the bearing design phase to best determine which material to choose, and how to process. The right surface finish and a proper lubrication layer not only reduces friction and wear, but help parts to operate more efficiently and quietly. Explore surface finish in the Bearing Design Technical Paper.

We recently conducted rotary tests using Rulon LR bearings and found that the 8rms mating surface finish had a wear rating of 1, at 16 rms it increased to 1.4, 32 rms 2.2 and at 63 rms 5.3. Roller burnished surfaces performed the best, with ground and polished surface finishes scoring next best. Turned finishes (or mill finishes), tended to have faster wear than the other finishing techniques, even at 16 rms.

As manufacturing becomes more precise, and loads and speeds steadily increase, engineers are paying more attention to the surfaces of bearing design. We’ve got some tips to help you match the right finish to your application in the video below. You’ll also learn how to check a finish using a simple fingernail test.

Bearing Selection: Get the Ultimate Plastic Bearing Design

Topics: Bearing Design
1 min read

Q&A How does temperature impact the properties of PTFE materials?

By Dave Biering on February 28, 2017

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We are often asked about what can be expected when you use a Rulon bearing or any PTFE in high temperatures. Many things can occur, and it varies from material to material based on the use of different fillers. Let’s review:

PTFE is an odd material in that it is a thermoplastic material, but dressed in thermoset clothes. Once molded, the material can’t be remolded like other thermoplastics, so it acts like a thermoset. The other interesting feature of PTFE is that while it has an operating temperature range of -400 to +550°F, it actual starts to transition at around 78°F. This means that the material is “moving” with thermal changes, which is known as cold flow. The big feature of Rulon materials is that the additives used in the hundreds of different Rulon materials help to stabilize the PTFE components to resist cold flow.

So, what happens when these materials are taken to higher temperatures?

It again depends on the nature of the fillers used. As an example, virgin PTFE has a tensile strength of 4075 psi at room temperature, but at 500°F the tensile drops to just over 1000 psi.

As a comparison, a carbon graphite filled material has a tensile at room temperature of 3300 psi but 990 psi at 500°F. Elongation numbers will also be impacted. Virgin PTFE has an elongation of approximately 330% at room temperature but only 210% at 500°F. The carbon graphite is 240% at room temperature and 180% at 500°F.

Why is this information important?

It’s important in the design of seals, bearings and even structural components used at high temperatures. Add to this the thermal conductivity and thermal expansion of these different materials, and it’s clear how important it is to get the right information at the beginning of your design.

For assistance in making heads or tails of the world of PTFE components contact TriStar Engineering.

Bearing Selection: Get the Ultimate Plastic Bearing Design

Topics: PTFE
2 min read

4 Applications Where Polymer Materials Excel in Aircraft Bearings

By Dave Biering on February 14, 2017

Polymer Materials Excel in Aircraft Bearings

Aircraft bearings have strict requirements for quality and performance; they must tolerate massive fluctuations in temperatures, pressurized cabins, tough weather conditions, plus extreme cargo loads. But there are 4 top polymers that are becoming the go-to materials in the aerospace industry. Let’s explore the advantages of Ultracomp, CJ, TriSteel and Rulon in various aircraft bearing applications.

When Boeing delivered it’s 1,500th 747 in 2014, it was a significant milestone for the industry. The 747 model has been in operation since the 1970s and recently reported its largest order in the last nine years from carrier UPS. As a long-time supplier to the aerospace market, our team has followed these developments closely.

More and more, polymer is replacing traditional metals and bronze in the steering, fuselage, wings and other areas of commercial aircraft. Polymer offers significant weight-reduction properties over metals, and requires near-zero maintenance so that aircraft can spend more time in the air instead of the maintenance hangar. Polymer has good vibration and temperature properties to deliver a solid, all-around design material.

Where will you find polymer aircraft bearings? Applications include:

1) Fuselage and pivot points

With excessive compressive strength of 54,000 PSI plus a unique geometry, Ultracomp UC 200 bearings are used in the joining fixtures of fuselage components, landing gears, gear doors, and high-load pivot points used on these unique assemblies.

CJ bearings are another popular choice to replace metal bearings on pivoting lift cylinders.

2) Landing components

To extend service life beyond that of metal, our engineering team designed Rulon LR landing wear bands for the oleo struts (hydraulic shock absorbers) of small aircraft. Rulon easily tolerates high-side load and environmental exposure to excel and provides service life beyond metals.

3) Bonding of engine wire clips

We recently helped a client increase the rubber-to-metal bond of their engine wire clips via surface plasma treatment. Plasma was used to “superclean” the aluminum strips and prepare them for the rubber covering. After this process, we added a special primer coat to further enhance the bond strength. This treatment presented a virtually indestructible rubber-to-metal bond without delamination; one that our client expanded to their jet fuel and hydraulic lines. Submit a Surface Treatment Design Worksheet for a custom quote.

4) Steering gear of aircraft tug

All-weather and vibration-resistant, TriSteel bearings are an ideal replacement to improve the maneuverability of the steering gear of aircraft towing vehicles. They offer a dual-layer design to increase performance properties.

Do you have an aircraft bearing challenge? Fly on over to the Materials Database for detailed technical specs.

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Topics: aircraft bearings
2 min read

Bearing Material Selection - Thermoset or Thermoplastic? [Tech Tip]

By Dave Biering on February 7, 2017

Bearing Material Selection - Thermoset or Thermoplastic

Similar names, yet completely different bearing materials. Which category should you select? In today’s Tech Tip, we examine the “thermo” categories. Here are some key attributes to know before making your plastic bearing material selection:

The key difference between these composites is that thermoset plastics remain in the same state, while thermoplastics can be heated and melted again and again to form new shapes. Ultimately, your application will dictate your choice of bearing material, but understand:

1) Material type

Thermoset: Synthetic materials that are not able to be reheated or remolded.

Thermoplastic: This is the largest group of plastics (polymers) and the group is also known as “thermosoftening” plastics given their ability to melt at high temperatures.

2) Heat Resistance

Thermoset: As it cures, the material increases in its ability to resist heat and succeed in high-heat applications (approaching 400° or more).

Thermoplastic: Readily liquefies upon reaching melting points. The materials also hardens and strengthens after cooling.

3) Chemical Characteristics

Thermoset: This category often incorporates fillers. When heated, the material’s molecules begin to crosslink, which helps to determine final strength and other characteristics. However, some of these materials also have a tend to shatter under certain circumstances.

Thermoplastic: Provides good chemical resistance (will reform without any chemical changes), but keep in mind that material properties will deteriorate if over processed. Thermoplastics offer good impact-resistance as compared to thermoset plastics, and are also easily recycled.

4) Machining

Thermoset: Some of these are brittle and chip easily, making them hard to machine into custom parts. Other thermosets with fillers and fibers are easier to machine and produce very clean finished parts.

Thermoplastic: Are stronger and well-suited to machining techniques – as long as proper heat controls are followed. Get the Machining Slide Deck to review heating and cooling guidelines.

5) Bearing Nomenclature

Thermoset: Common formulas include Phenolic, Epoxy, PTFE, Ultracomp, CJ, Micartas, Melamine and some grades of imides.

Thermoplastic: This group includes both trade and generic names, representing Acetal, ABS, nylon, polyethelene, PET and PBT.

When it comes to bearing material selection, the category of plastic will depend on the end use of the product. Get some expert advice for your application.

Custom Plastic Fabrication: Get the Guide!

Topics: Bearing Selection
1 min read

PTFE and High-Radiation Environments: 5 Important Facts

By Dave Biering on January 31, 2017

PTFE and High-Radiation Environments

We’ve had many questions about the connection between PTFE materials and high-radiation environments. Often, when working in these conditions, engineers turn to fluoropolymers like Tefzel (ETFE) as a preferred material instead of PTFE. But before you make a final material decision, let’s review some key facts about PTFE in this environment.

PTFE has never been recognized for its performance in high radiation environments, as it tends to degrade. But it also can gain some favorable material properties in certain applications. Explore more on the crystallinity of PTFE.

Consider:

1. Threshold

When PTFE is exposed to radiation in air, it’s damage threshold is 2-7 x 104

2. Strength

At these exposure levels, PTFE will lose 50% of its tensile strength. At 7 x 104 it loses nearly all of its elongation, flex and impact properties.

3. Vacuum

When PTFE is exposed to radiation in vacuum, the properties are up to 10x better in terms of tensile, elongation, flex and impact values.

4. Applications

In space applications (which are in vacuum conditions), PTFE can survive service in satellites that may encounter radiation exposures in the Van Allen belt, which is about 10rads per hour. Depending on the other conditions, a PTFE component could survive 5-50 years in earth’s orbit.

5. Alternate materials

  • FEP, another type of fluoropolymer, has a radiation tolerance 10-100 times better than PTFE in air, so it’s an option in many earthbound radiation exposures. However, Tefzel would still be our material of choice.
  • Rulon materials are NASA-approved for satellite service in seals and bearings aboard geosynchronous satellites and deep space probes because the material does not outgas in vacuum and is more tolerant to radiation.

If you have applications where a fluoropolymer seal, bearing, gasket or structural component may be under consideration contact TriStar Engineering to discuss your options. We’ll help you compare materials for the best option.

Bearing Selection: Get the Ultimate Plastic Bearing Design

 

Topics: PTFE
2 min read

How do Surface Treatments Work? Part 1: Corona Treatment

By Dave Biering on December 6, 2016

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It’s a back-to-basics question, but one that we are asked often. Surface treatments are generally separated into two categories: atmospheric and low-pressure (or vacuum). Both use energy to ionize gas and are very effective at altering the surface properties of materials. Both can also help you increase your manufacturing yield. Today we spotlight corona treatment:

Corona surface treatments work by forcing a gas (usually air) between two high-powered electrodes at a high rate of speed. As the air passes through the electrical discharge, it becomes ionized and, in the presence of ambient oxygen, forms chemically functional groups on the surface of a substrate. The functional groups that result from the process increase the surface energy on polymers and other materials.

Corona treatments (or atmospheric treatments) use standard electrical power, but have limited controls, such as the distance the material is held from the electrical discharge, and the speed at which the material passes through the active plasma. Corona is an excellent treatment solution for common plastic films, such as those used in packaging. Review the top 4 questions to ask when sourcing a surface treatment partner.

Advantages of Corona Surface treatment:

Corona treatments can treat large substrates very rapidly, and are effective at making many commodity-grade polymers wettable to facilitate the application of adhesives, paints, inks and tape.

Considerations of Corona Surface treatment:

Treatment lifespan
Treatment lifetime can be relatively short; minutes, hours or days depending on the substrate and the effectiveness of the treatment. However, this is a non-issue in applications where adhesives or paints are applied immediately after the treatment.
Heat distortion
Since the electrical discharge is quite hot, it’s critical to calibrate the speed at which the substrate passes through the plasma region. Also look at the distance between the substrate and the discharge. In cases where the speed is too slow or the distance too short, thermal distortion is likely to occur.
Uniform Coverage
Since only the area of the substrate that is passed through the plasma region is treated, surface areas may not be treated evenly. This is especially true when working with complicated geometries.
Ozone levels
Corona surface treatments generate high levels of ozone, so proper ventilation precautions must be taken.

Share your experience with corona treatment in the comments!

Up Next: Surface treatment Part II: Plasma treatment

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Topics: Surface Modification
1 min read

Chlorine, Corrosion and the PTFE Bearing Connection: A Case Study

By Dave Biering on November 29, 2016

Chlorine, Corrosion and the PTFE Bearing Connection: A Case Study

Our recent post on PTFE and Rulon in water applications generated some solid interest. Today I want to share a case study of how PTFE-based bearings have resisted corrosion in a submerged chlorine tank as a replacement for Torlon ― all despite the fact that PTFE is not generally recommended for chemical exposure.

Corrosion is the second-leading cause of bearing failure, following right behind lubrication. It manifests as flaking and peeling, pitting and rust. Some key sources of corrosion include hard gases and strong chemical forces, or even simple water spray.

Challenge: Torlon bearing corrosion in a chlorine tank

As a general rule, we do not recommend PTFE for any type of chemical environment, since the chemicals can degrade bearing coatings. Our client shared how their Torlon polyamide-imide (PAI) components experienced surface deterioration from a combination of submerged chemical exposure and metal-to-metal contact. This application was for moving parts used in tanks filled with thousands of gallons of chlorine water. As the PAI bearing failed from chemical corrosion, they posed an expensive replacement challenge.

Solution: Rulon W2 performance improves when wet

Our engineering team tested the mechanical properties of the running hardware, and recommended Rulon W2 for its excellent wear life. Rulon is compatible with most water applications, including slurry, DI, fresh and salt water, plus chemical liquids with a full PH range. And unlike Torlon, Rulon does not absorb moisture to give longer wear. The material runs so well in fact, it’s DWGV-certified (European) for drinking water applications.

Our client now reports that Rulon W2 has provided several years of maintenance-free operation at a lower cost than Torlon. Explore the importance of sourcing genuine Rulon products.

Consider Rulon W2 for:

  • Zero moisture absorption
  • Limited regular maintenance
  • Value-driven replacement for PAI
  • Longer service life in wetted environments

Could Rulon W2 work in your submerged application? Connect with the Rulon Experts for a full comparison.

Topics: PTFE
1 min read

Ask the Expert: How Do PTFE and Rulon Bearing Materials Perform in Water? [Test Results]

By Dave Biering on October 25, 2016

Rulon W2

I’ve been getting a lot of questions recently about PTFE-based materials like Rulon for use in water applications. Generally, PTFE is not a good solution for water-lubricated applications. Today I want to share the results of some independent testing we conducted.

PTFE bearing materials, like Rulon, are not usually friends of water-lubricated applications. This is simply because the PTFE does not properly transfer to the mating metal hardware to reach the goal of producing a thin lubricating film. The water is, by itself, a lubricating film, but it isn’t very efficient and does not leave room for lubricant starvation. To confim the connection, we conducted some testing with an outside lab. The goal was to study some traditional, filled PTFE materials along with Rulon W2, which was developed specifically for applications in water lube systems.

The results were definitely telling:

Traditional Filled PTFE Materials vs. Rulon W2

Testing was done using standard ASTM thrust bearing tests at 10,000 PV, 100FPM and 100 psi load.

Further to this testing, one of our customers reported over 4 million rotary cycles on a water micro-turbine shaft bearing using the Rulon W2 and there was no measurable wear at the end of the test. Rulon W2 gives low friction and excellent wear as well as good thermal dissipation, plus it prevents shaft distress. The material actually has enhanced properties when wet.

The bottom line? When it comes to bearing applications in clean water or other clean-water based solutions, Rulon W2 is our go-to material! View the Rulon Comparison Chart to review other unique formulas.

Got a question you’d like to submit to the Bearing Experts?  Submit it here!

Rulon - Quality Assurance Begins With Precision Processing

Topics: PTFE
2 min read

Bearing Engineering: 3 Calculators You Need to Improve Your Design

By Adrian Carrera on October 4, 2016

Bearing PV Calculator - Conversion Calculators - Scientific Calculators

Need assistance with your bearing engineering and dimensions? Want to find all the tools you need for complete bearing calculations in one convenient spot? Check out the Plain Bearing PV Calculator, Conversion Calculators, and Scientific Calculator. Here’s why we feel these tools are critical to the success of your bearing design:

Plain Bearing PV Calculator - Link

You may remember our past discussion about PLAIN bearing vs. PLANE bearing, but no matter which way you spell it, this plain bearing calculator is a critical engineering tool. It can help you visualize the constraints and limitations of your bearing application. You simply plug in the bearing size you need for your equipment, and we help you estimate the pressure, speed and PV value your part may be exposed to.

Choose from these Radial terms:

= Load on bearing (pounds force)
= shaft speed, rotations per minute
= Diameter of shaft (ID of bearing), inches
= Bearing width, inches
= Pressure on bearing, psi
= Velocity of bearing suface, feet per minute
PV = Pressure x velocity

The Plain Bearing PV Calculator also helps you with thrust bearing/washer applications.

Unit Conversion Calculators - Link

Just as the name implies, this set of six handy calculators helps you to convert your engineering units from one set to another via an easy drop-down menu. Choose from the following bearing engineering tools:

  • Metric
  • Temperature
  • Weight
  • Pressure/Force Area
  • Density
  • Thermal Conductivity

Together, these converters can give you a simulated design experience.

Scientific Calculator - Link

This tool will help you double check calculations when sizing a bearing. It also gives you back-up data for checking and verifying bearing or structural material requirements.

As you incorporate these tools into your design, keep in mind that these numbers are just one piece of the puzzle in determining the right polymer of composite fit. Each material has unique design nuances that may impact these numbers. We also recommend that you design with a good safety buffer in place to ensure the best overall bearing performance. Our Bearing Engineering Experts can walk you through, or get your copy of the Plastic Bearing Design white paper for more technical tips!

Bearing Selection: Get the Ultimate Plastic Bearing Design

Topics: bearing engineering
2 min read

Ask the Expert: Dry Plasma Cleaning vs. Wet Cleaning Processes: Which method is best?

By Dave Biering on September 6, 2016

Dry Plasma Cleaning vs. Wet Cleaning Processes: Which method is best?

How can I remove trace contaminants from inorganic substrates?

Which cleaning method will achieve the best bonding results?

These questions were recently posted to our Ask The Experts portal. Proper cleaning of a substrate is a critical first step in many manufacturing processes, particularly for the medical, aerospace, and electronics industries. So which method will render substrates atomic-level clean and ready for bonding? We recommend plasma cleaning for a number of reasons:

Contamination is perhaps the greatest barrier to achieving a smooth bonding of materials. But in order to achieve just the right base surface for a successful bond, most manufacturers use conventional (wet) cleaning methods. This approach can include chemical rinsing, wiping or scrubbing, vapor degreasing, or ultrasonic baths. But here’s the challenge with wet cleaning methods; despite appearing clean upon initial inspections, there’s usually a fine film of gross contamination left behind. These can include organic residuals (machining oils, wax, grease, and polishing compounds), dust and other substances. So your “clean” substrates are anything but, and these materials will impede any attempt at surface bonding.

For best bonding results, we recommend a dry cleaning process; plasma cleaning. Plasma primes any surface for secondary manufacturing processes by removing all traces of contamination. It even removes the materials that wet cleaning methods leave behind. Read about the importance of surface preparation.

Look to plasma cleaning to provide:

  • A truly clean base surface for enhanced bonding
  • Uniform 3-D coverage of the entire substrate (even complex geometries
  • Earth-friendly processing method to eliminate harmful solvents
  • No impact on the dimensional tolerance of components
  • Increased manufacturing yields
  • Fewer in-field failures
  • Lifetime treatment duration compared to wet treatment methods

Plasma cleaning by industry

In the medical industry where sanitation is critical, the plasma process does not adversely affect the biocompatibility of medical products. Instead, it promotes fine cleaning of glasses such as microscope slides, lenses, optical devices and pump components. Electronic devices such as hearing aid components and circuit boards have also been successfully plasma cleaned via potting and encapsulation. In aerospace, plasma has given the wings of aircraft better wind resistance. These are just a few examples of the power of plasma!

While plasma may not be the ideal choice for every application, in most cases there is no better way of achieving the right cleaning level to bond contrasting materials. Why not fill out a Surface Modification Design Worksheet to discuss your specs with our team?

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Topics: Plasma Treatment
2 min read

What is Plasma Treatment? Here’s How it Works

By Dave Biering on June 28, 2016

What is Plasma Treatment? Here’s How it Works.

In honor of this recent commencement season, today we’re sharing a lesson right from our bearing resource center, TriStar University. Here’s a back-to-basics review of how plasma treatment works. Essentially, plasma treatment is a low-pressure gas process that removes all traces of organic contamination to improve the outcomes of secondary applications. 

Here’s how it works:

Have you ever experienced the power of plasma? You only need to look at fluorescent lights or neon signs to see the plasma process in action. Both of these light applications use the visible light that is released by plasma discharge.

Plasma treatment occurs when gas is exposed to an energy source such as electricity or microwave, and becomes a mixture of ions, radicals, free electrons and other types of molecular fragments. The resultant plasma treatment is the means by which all traces of organic contamination are removed. 

How is plasma treatment used?

Plasma treatment is used to treat the surface of virtually any material, including metal, polymer, glass, elastomer, ceramics and others. It increases bonding, which includes the adhesion of one part to another, and the bonding of the thin coatings (or thick layers) of adhesives, overmolding or potting resins to the substrate. 

Plasma can treat materials that are too hydrophobic (non wettable) or too hydrophilic (wettable) for the application they are intended for. The process can be classified into two categories; atmospheric and low-pressure or vacuum, as both use energy to ionize gas. Corona atmospheric treatments are generally used to treat larger substrates, and can easily make commodity-grade polymers wettable to improve coating adhesion. Explore the advantages of corona treatments. Low-pressure plasma treatments incorporate a vacuum chamber instead of direct contact with an open electrical charge. 

Who’s using plasma treatment?

  • Medical and biotech manufacturers incorporate plasma treatment to combat contamination for micro cleaning.
  • Aerospace companies use it to enhance bond strength.
  • Electronic manufacturers incorporate plasma to protect sensitive components in potting.
  • Printing companies use plasma to better adhere water-based inks and screen prints on devices.

Can plasma surface modification improve your manufacturing results? Just fill in a Surface Modification Design Worksheet to discover the potential, or connect with the Experts for advice!

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Topics: Plasma Treatment
2 min read

When Should You Consider a Reinforced Bearing Design?

By Dave Biering on June 7, 2016

When Should You Consider a Reinforced Bearing Design?

Does your application require a bearing with a reinforced design? It depends on just how rigorous the application is. In some cases, a standard bearing will do just fine, but in applications where extreme speeds, loads and conditions are probable, you might consider a reinforced bearing. We’ve got the recommendations to help you decide.

Reinforced bearings have a strong, dual-layer design that renders them nearly infallible in heavy-duty applications. But their greatest advantage is that their secondary layer of material will protect running hardware in the (rare) event of a bearing liner breakthrough. Without this reinforcement, the bearing would corrode (and eventually fail) from direct metal-to-metal contact of the shaft and bore. 

We often recommend choosing a reinforced bearing that is designed of a polymer liner sintered to a metal-backed shell. With this design, your equipment will always be protected and lubricated, since the polymer liner continuously self-lubricates. This also gives you the choice of a variety of liner options along with a stainless, bronze, zinc, or copper backing. Another advantage of this reinforced design is the thickness of the liner can be custom fabricated to accommodate any shaft misalignment or minor ID tolerances. 

Some common reinforced bearing options include:

  • PT (bronze/PTFE) = low friction and high PV 
  • AC (bronze/acetal) = lubrication reservoirs for use in dry or lubricated conditions
  • AT (POM bronze/PTFE) = operation with zero lubrication needed

Ultimately, it’s critical to look at the PV requirements to be sure that your bearing can tolerate the loads and speeds of the application. Depending on the requirements, reinforced bearings can be designed to withstand speeds of 1,000 FPM and loads of 80,000-2 million. All with good wear and low-friction service.

Consider reinforced bearings for extreme requirements: 

  • Aerospace  lift, tilt and pivot points in the aircraft steering, fuselage, wings 
  • Automotive – sliding, oscillating and rotary applications on controls, clutch systems and flywheels 
  • Small construction – hydraulics, control levers and steering of small mowers and movers

Explore how TriSteel reinforced bearings replaced bronze in high-end dental chairs. 

Connect with the bearing experts, and we’ll help you evaluate bearing shell and liner options based on your exact design specifications!

Custom Plastic Fabrication: Get the Guide!

Topics: Reinforced Bearings
2 min read

Bearing Strength: How is it measured?

By Dave Biering on May 31, 2016

Bearing Strength:  How is it measured?

Heavy-duty applications call for superior bearing strength, but how is bearing strength actually measured? In essence, bearing strength is the maximum stress load that the unit can “bear” or hold before the structure fails. But bearing strength can also be measured in terms of tensile, compression, and flexural strength, plus bearing hardness. We’ve got the definition you need to help in your finding the right bearing strength:

How strong is your bearing? Ultimately, it needs to be strong enough to exceed the everyday operating conditions of your environment. After all, bearings are meant to carry the stress and load of your application, but best practice is to measure bearing strength conservatively, so as not to exceed design limits.

Bearing strength is often measured by:

Tensile strength of common materialsTensile Strength

Tensile strength measures the ability of a material to withstand load under tension without failure. Also known as ultimate strength, tensile strength is measured in pounds per square inch (PSI). The higher the tensile strength, the stronger the bearing material, and the better ability it has to resist cracking.

Tensile Elongation

Tensile elongation is the increase in length that occurs when a material is stretched, but before it breaks under tension. It’s indicated as a percentage of the original length of the material. High-tensile strength and high-elongation are key factors in determining the overall toughness of a material.

Compressive Strength

Compressive strength refers to the resistance of a material to breaking under compression. Ultimate compressive strength is closely related to compressive strength.

Flexural Strength

Flexural strength is a material’s ability to resist bending under load (also known as modulus of rupture or bend strength).

Modulus

Modulus covers tensile, compressive and flexural strengths. It is defined as the ratio between the stress or force per unit area. The modulus of a material can predict the reaction of a material, as long as the stress is less than the yield of the material.

Hardness

Plastic hardness measures the ability of a material to resist indentation. See the Rulon bearing Selector Guide.

Beyond bearing strength, what other properties should you consider in your material selection? It’s also critical to review the bearing geometry, mating hardware, clean certification requirements (FDA, 3A), operating conditions, temperature variations and more. Get complete bearing selection help in the Plastic Bearing Design White Paper. Or for a custom consultation, submit a design worksheet.

We’re happy to help guide you to the right material!

Bearing Selection: Get the Ultimate Plastic Bearing Design

Topics: bearing strength
2 min read

Q&A Waterproof bearings: What are the benefits of plastic?

By Dave Biering on May 24, 2016

Waterproof bearings: What are the benefits of plastic?

Have you posted your design question to our Ask the Experts portal? It may be featured in our weekly blog, which is where this post comes from! A designer of offshore marine products wanted to review the benefits of waterproof bearings. And the top answer is that plastic waterproof bearings eliminate corrosion, which is one of the primary causes of metal bearing failure in a water environment. 

Here’s how:

First, let’s review the term “waterproof bearing,” as it is a bit of a misnomer. Bearings that provide the best “waterproof” service are resilient to liquids beyond just water. They should also resist corrosive liquids such as slurry, salt water and chemicals, plus the damaging effects of water spray. In many design circles, bronze and stainless steel are the preferred materials for submerged and marine applications. And these materials provide good service ― until they begin to corrode. 

The simple truth is that metal bearings and water (or other liquids) are only compatible for a certain length of time before bearing corrosion sets it. Eventually, chemicals, sea spray and other contaminants will cause the bearing to flake and peel, before failing altogether. In fact, rolling element bearings that are exposed to water at a rate of even 2% can have a reduced life expectancy of 50%. Liquids cause the films in metal rolling bearings to become contaminated, which leads to corrosion and early failure. 

Unlike pure metal bearings, plastic bearing are a hybrid of engineered polymers and composites that easily resist water and corrosion. Plastics never absorb moisture, which means they will not swell or impact the equipment mating hardware. And because they are self-lubricating, there’s no need to manually grease plastic bearings. Given the cost and labor of manual greasing, self-lubricating plastics can create a significant cost savings. 

Plastic waterproof bearings provide many benefits:

  • Resistance to water, chemicals and slurry
  • Longer life span without corrosion or failure
  • Dimensional stability in heavy-duty environments
  • Excellent service in marine pumps, cranes, davits, winches, motors
  • Industry certification for shipboard use

With a great combination of strength, corrosion-resistance, and grease-free service in linear, oscillating and rotary applications, look to waterproof plastic bearings. Here’s 5 reasons Ultracomp bearings excel in a marine environment. 

Bearing Selection: Get the Ultimate Plastic Bearing Design

Topics: waterproof bearings
2 min read

Plasma Corona Discharge: 4 Advantages for Manufacturers

By Dave Biering on May 17, 2016

Plasma Corona Discharge: 4 Advantages for Manufacturers

The US manufacturing economy continues to waver between marked improvement and ongoing challenge in 2016, according to the National Association of Manufacturers. While progress is being made, there’s still concern around global headwinds. Reading this report, it occurred to me that many manufacturers could realize significant gains by building corona discharge treatments into their production schedules ― and they may not even realize it! Corona alters the surface properties of materials to give them desirable attributes, such as a part that will last longer or boast cleaner finishes.  

Here’s how this surface modification technique works: 

What is corona discharge plasma? It’s a surface modification technique that alters polymers and elastomers in order to control the interactions and responses of a secondary application such as bonding

How does it work? A corona discharge is plasma at standard atmospheric pressure. Plasma is produced by an electric charge that is produced by high voltage when in close contact to metal electrodes. The resultant discharge is the corona discharge. When an electrical discharge occurs, ions and ozone are nearly always generated. It is an ideal method for removing debris and contaminants from circuit boards, for instance. 

How can it help manufacturers? The treatment enhances the properties of components so that they perform better in specific operating conditions. Because without the right properties, surface events can lead to the failure of a device (or the system containing it). Corona discharge is just one of several surface modification techniques. 

Here are 4 key benefits that corona discharge plasma delivers to manufacturers: 

1) Increase manufacturing yields

Corona discharge and other surface modification techniques can remove contaminants from sensitive surfaces to reduce part failure and increase total production yields. This is particularly true in fiber applications. 

2) Better bonding results

By removing all traces of contamination, corona treatment can improve the bond strength of inks or paints, or the bond of one component to another plasma work well with in-line process such as plastic film.

3) Selective surface control

Corona is a two-dimensional treatment process. It offers a robust system that is easy to control. With the right equipment, corona can be done in-house, or the service can be outsourced with a quick turnaround.

4) Longer treatment lifetime

By removing all traces of organic contamination, corona discharge treatments give components longer durability and even corrosion resistance. It’s used widely by the medical, pharma, biotech, aerospace and other industries to treat components.

Corona treatments can rapidly treat large substrates and are effective on many commodity-grade polymers. Submit your design specs to explore if the method is right for your manufacturing environment. 

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Topics: corona treatment
2 min read

Measuring Surface Energy and Surface Tension of Plastics (VIDEO)

By Dave Biering on May 10, 2016

Measuring Surface Energy and Surface Tension of Plastics

Every wonder how to measure plastic materials to determine surface energy and tension properties? The process is easier than you might imagine, and can lead to better manufacturing outcomes through plasma surface treatment. 

As a quick review, surface energy is the sum of all the molecular forces on the surface of a plastic material. It also covers the amount of repulsion or attraction of one material as exerted by another. A goniometer is used to measure surface energy and tension angles. It’s critical that the surface energy and the surface tension are aligned before moving to plasma treatment. If the surface energy of a material is too low, then coatings will not flow and may form defects such as pinholes or fisheyes. If the surface energy it too high, the added liquids (inks and paints) may bleed. 

Why is material surface energy important to know in manufacturing?

Understanding surface energy and tension properties are the precursors to a plasma surface treatment. With plasma, you can extend the performance of secondary manufacturing processes such as ink stamping or bonding. Plasma can help many industries overcome common manufacturing challenges. In medical manufacturing, for instance, plasma treatment of syringes allows us to add calibration marks for more-accurate dispensing of medicines. In aerospace, plasma treatment gives wing edges strong adherence for better wind resistance. 

Here’s a simple formula for liquid testing of surface properties:

Spreading = A - ( B+ C )

Where:

A = surface energy of solid (given below)
B = surface tension of liquid
C = surface energy of solid-liquid interface

If spreading is:

Negative - liquid will bead up
Zero - liquid will spread
Positive - liquid will spread

Want to explore more about the surface energy and surface tension of plastics? Ask the Experts for a recommendation, or check out our brief video below for a demo!

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Topics: surface energy
2 min read

Engineering Plastics Against Steel – Coefficient of Friction

By Jim Hebel on April 28, 2016

Blog_2016QUAD2.jpg

Guest Blogger - Quadrant Plastics

The first step to understanding the Coefficient of Friction (COF) of engineering plastics when compared to that of steel is grasping that the COF is not based on a material’s property alone, but is rather a system’s property. One part/piece/component does not make a system and therefore requires the evaluation of the total solution.

The values for the COF of engineering plastics can be used for comparative purposes in helping the design engineer in selecting the appropriate material option for the intended application. The main parameters that affect the COF in the evaluation and selection of engineering plastics are:

  • pressure
  • relative sliding velocity
  • geometry of the parts in contact
  • temperature
  • nature, roughness and hardness of the steel mating surface
  • total operating time
  • nature of any intermediate medium, e.g. water, lubricants, abrasive particles
  • specific properties of the plastics material

This data has been determined on a specific tribological device under a set of standard laboratory conditions, and should not be used to predict the frictional behavior of the materials under real service conditions which may very well be quite different than those used in our laboratory tests.

Please also note that the values for the COF of Quadrant’s engineering plastics provided in our technical literature should not be compared with other brands of engineering plastics as they were likely tested under a completely different set of test conditions which may result in values that are lower or higher than our published values. You can count on Quadrant’s material data to be accurate for the FINISHED material and not pre-manufacturing resin data.

Quadrant always recommends that the user run a practical test under real service conditions in order to determine the actual COF and performance of an engineering plastic and/or to compare different engineering plastics in an application.  

For detailed information on the COF of Quadrant’s engineering plastics, please get in touch with the bearing experts. Visit TriStar's Video Learning Center to learn more about several of the most popular Quadrant materials.

Topics: Bearing Selection Guest Blogger Quadrant
2 min read

Composite Marine Bearings: No Grease, No Corrosion

By Dave Biering on March 1, 2016

Composite Marine Bearings: No Grease, No Corrosion

We had a great call with a marine designer who wanted to review options for marine bearings. Like many engineers, she was reluctant to replace traditional metal marine bearings with “new” composite materials. But once we reviewed that composites require no grease and will never corrode ― plus some formulas are certified by the American Bureau of Shipping ― we had a new bearing partner. 

Here’s how composite marine bearings beat metal and bronze bushings aboard luxury yachts:

Our new partner builds luxury yachts for a niche market of discriminating clients. Their vessels command a price tag of millions, and are built to exacting standards. Just as their clients demand only the best amenities, this yacht designer demands only the best bearing materials. Composite bearings provide longer service life than bronze bushings, will never corrode and easily resist the effects of corrosive sea and salt water. They are also easier to maintain, since they are self-lubricating and don’t need regular greasing that metal bearings need. 

Composite bearings excel in linear, oscillating and rotary applications with high-loads. They are even installed aboard America’s Cup vessels!

Where will you find composite bearings on luxury yachts?

Transom doors and pivot points
Sliding decks and water-level hatches deploy more evenly with composite bearings, since they remain dimensionally sable in liquid
Bow and stern thrusters
Composite bearings resist salt water corrosion to improve the propulsion and maneuverability 
Gear pumps
Composite bearings as a replacement for rolling element bearings and bronze sheaves in marine gear pumps
Rudder bearings
Ultraflon materials resist vibration for smoother sailing in rough seas
Dockside use
Composite never rust or pit from extended use at the docks. They give longer service in marine cranes, sheaves, davits and winches.

Another key benefit of composite bearings, and one that I feel is often underrated, is that the materials resist damaging UV rays. Given prolonged sun exposure, it’s good to know that the bearings won’t degrade over time.

The bottom line for this luxury yacht builder? Composite bearings give industry certification, grease-free service and no corrosion to luxury yachts.

Sail on over to the marine bearing experts to review composite bearings for your marine application!

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Topics: Marine Bearings
2 min read

Plastic Fabrication: 4 Must-Follow Rules to Success

By Dave Biering on February 23, 2016

Plastic Fabrication: 4 Must-Follow Rules to Success

Have you ever fabricated plastic components? 

For many traditional machine shops, metal is an easy and familiar material to work with, but plastic fabrication presents a whole new set of challenges. Metal is a solid material and predictable to machine, while plastics are a hybrid of different materials, and change shape as they are machined. Simply stated, the basic principles of machining metals do not apply when machining plastics. And any mistake in plastic fabrication can also result in expensive scrap loss. 

How can you master the art of plastic fabrication? We have 4 must-follow rules to success.

Metals are generally easy to machine; they don’t creep or change shape as you fabricate. Plastic materials are prone to substantial creep and can easily melt and chip during machining. Yet with the right tools and techniques, plastic fabrication can be achieved by following these four golden rules: 

1) Choose materials wisely

Plastics are high-performance and an excellent replacement for bronze, stainless steel and cast iron. They excel in high-temperature and extreme working environments. But choosing the right material is critical, since some high-performance formulas are substantially more expensive than metal. For instance, Polybenzimidazole (PBI-Celazole) is 25x the price of cold-rolled steel, and 15x more costly than Type 303 stainless steel.

When choosing plastics, remember that the materials you choose are an investment in performance. Choosing a higher-quality (more expensive) material will yield a higher-quality part. And higher-quality parts can save you from field failures or costly recalls down the line. Find the right bearing material from the materials database. 

2) Limit heat

Heat buildup is the number one cause of failure in plastic fabrication. In fact, the very act of machining generates friction ― or heat. Without the right machine speeds/feeds and coolants, plastic cutting tools can actually become plastic melting tools. Heat also presents dimensional challenges, which makes it more difficult to hold tolerances. Special attention must be paid to limit heat. 

3) Determine the best fabrication technique

Which machining technique is best for you material? Sawing? Milling? Drilling? Threading or tapping? Often, the right technique comes down to the category of plastic you are working with; either thermoset plastic or thermo plastics. Thermoset plastics retain their solid state indefinitely, while thermoplastics can be melted more than once to form new shapes. Thermoplastics are best suited to machining. 

4) Beware of burrs 

Burrs are a common machining hazard and can ruin surface finishes. They usually occur when a machining tool reaches a travel end without additional support. Techniques to avoid burring can take more time, but the time saved in deburring may pay for the longer machining cycle. Avoiding burrs can help you reduce the costs and obtain an optimal finish.

Is in-house plastic fabrication the right choice for your material application? Or would you be better outsourcing this service? Get our copy of our Plastics Machining Guide to help you decide. Or just connect with the Plastic Fabrication Experts to answer your questions! 

Topics: Plastic Fabrication
2 min read

A Comparison of Linear Bearings: Rulon 142 & Turcite B

By Dave Biering on February 9, 2016

A Comparison of Linear Bearings: Rulon 142 & Turcite B

I had a great conversation with a machinist who wanted to compare Rulon 142 and Turcite B; two common materials used for slide and linear bearings. Although both materials are PTFE- blends, they each possess unique characteristics. Here’s a review of some key attributes and applications:

History

Rulon 142 was originally developed to address the market need for a pure product given that (at the time at least), Turcite B contained reprocessed material. 

One of the chief complaints with Turcite was that customers noted that large flakes of bronze separated from the material, which left a void. These particles also caused scores and streaks on the mating hardware. After evaluation, it became clear that the amount and makeup of the metallic oxide pigment was the primary inhibitor. 

To address this concern, Rulon 142 was developed using special screening techniques to improve the uniformity of the bronze distribution. The process was also adjusted to hot form, which gives better stress relief over extruded Turcite. The end result was an improved, cost-effective bearing material. 

Applications

Rulon 142 is an excellent material for high-load, high-speed linear guideway liners for machine tools. It is also a great choice for rebuilding machine tools where efficiencies and tolerances have been lost over time. Today, Rulon is commonly used as a good insurance policy against possible lubrication failures in machine tooling. 

Turcite B is a popular linear bearing that is also used in the machine tool industry, as well as for seals and wear rings. 

Ultimately, Rulon 142 linear bearings are a cost-effective alternative to Turcite B.

Look to Rulon 142 for: 

  • Exceptional vibration resistance
  • Superior mechanical strength
  • Good dimensional stability
  • Elimination of stick/slip
  • Uniform friction
  • High-thermal dissipation
  • Good stability

Ready to learn more about Rulon 142? Check out the video below for common applications and advantages. Or get the Rulon bearings White Paper for additional details.

Topics: Rulon 142
1 min read

How Much Grease Do Bronze Bushings Really Need? See the Picture!

By Dave Biering on January 26, 2016

bucket of grease removed from production line by switching to self-lubricating composite bushings

It’s a fact that bronze bushings require abundant amounts of lubricating grease to keep industrial equipment running. But have you ever wondered just how much grease they need? We did, so we asked a client to show us the sludge that was left behind after a routine cleaning. Since a picture is worth a thousand words, today we want to share this incredible image. Even our experienced designers were amazed at the amount of greasy sludge that was removed!

An entire barrel of grease. Nearly 400 pounds.

That’s the amount of excess lubricant our partner removed from just one machine during routine maintenance of their bronze bushings. In this case, our client had two full-time workers assigned to degreasing their manufacturing and packaging lines. Because bearings that are left with excess grease are prone to seizure which can lead to a halt in production. 

Once our client replaced the high-maintenance bronze with no-maintenance plastic bearings, they realized immediate production gains. They were able to reassign the maintenance crew to other areas of the line, and experienced far fewer work stoppages. Ultimately, our partner estimates they will recover over 2,000 hours a year in lost labor. And their plant will provide a greener footprint. 

Is it any surprise that they decided to say goodbye to bronze bushings forever and switch to greaseless plastic composites? 

Want to learn how you can end bearing lubrication? And save a barrel in maintenance costs? Ask the plastic composite bearing experts ― we can help!

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Topics: bronze bushings
1 min read

Q&A: Causes of Bearing Failure: Metal Brinelling

By Dave Biering on January 19, 2016

How does brinelling cause bearing failure in metal?

How does brinelling cause bearing failure in metal?

Some of our best questions come directly into our Ask the Experts portal, and this one is a prime example. Today, we review brinelling, which is a key cause of bearing failure in metals. Along with lubrication, fatigue, and corrosion, brinelling failure causes costly and premature bearing wear.

Here’s how you can avoid it.

How does brinelling cause bearing failure in metal?

Brinelling is described as indentations or marks in the metal racers of a rolling element bearing. It is named for the Brinell scale of hardness. Brinell marks can indicate a number of issues. They can show that a bearing load was excessive for the material selection, or that the bearing was improperly installed which led to a misalignment. Brinelling can also indicate that the bearing may have been contaminated with debris. Brinelling marks can even present inside bearings in cases where dust or other contaminants are present. 

Brinelling falls into two categories:

True Brinelling – points to a bearing load that exceeded the elastic limit of the bearing material. 

False Brinelling – takes the form of a depression around the race that is caused by vibration or swaying between the rolling elements and the races. This form of brinelling is common in non-rotating applications such as lift and tilt.

In both true and false brinelling, lubrication is not a friend. 

How can I avoid brinelling?

Our recommendation is to consider polymer bearings. With a simple, one-piece design, polymer bearings eliminate racing and metal-on-metal contact. Polymer also incorporates high-elastic values to resist compression and depression, and give better friction tolerance. 

Need to eliminate the cause of your brinelling failure? Submit your application specs to explore the right polymer bearing for your application.

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Topics: Bearing Failure
2 min read

ASTM Standards in Bearing Selection: Why are they Important?

By Dave Biering on December 15, 2015

ASTM Standards in Bearing Selection: Why are they Important?

Have you downloaded your free copy of the Bearing Selection Design White Paper? If so, you’re probably familiar with ASTM Testing Standards for plastic materials. Today we’ll provide a review of why these standards are an important consideration in bearing selection. 

ASTM helps to ensure that only quality, raw materials are used to produce bearings and other industrial goods. The standards are highly-regarded throughout the plastic supply chain. Here are a few FAQs about this industry organization:

  • What is ASTM? - ASTM (formerly American Society for Testing and Materials) is the governing body of the plastics industry and the group responsible for classifying the quality of raw materials. 
  • How are the standards used? - ASTM standards help to specify, test, and assess the physical, mechanical, and chemical properties of plastic products and their polymeric derivatives. 
  • Why are ASTM standards important? - ASTM is in many ways the quality-control “clearing house” of plastic raw materials. When you purchase ASTM-compliant plastics (either as a manufacturer or an end-user), you can be certain that your raw materials will perform as specified. The standards also help determine when products are safe for use. 
  • ASTM Standards and Bearing Selection - In terms of bearing selection, ASTM standards simplify the selection process by creating a level-playing field for material guidelines. In the automotive industry, for instance, ASTM offers assurance to both the auto manufacturer (who can specify exacting requirement for building their parts), and to the consumer (who can be assured they are buying a safe vehicle). ASTM standards for auto bearings may include rigidity and flexural properties, heat deflection, impact and stress resistance, among others. ASTM review can help determine auto performance.

Common ASTM Standard Test Methods for classifying plastic bearings:

D149 Dielectric Strength

D150 Dielectric Constant and Dissipation Factor of Plastics

D256 Izod Impact

D638 Tensile Properties of Plastics

D648 Heat Deflection Temperature

D695 Compressive Properties of Rigid Plastics

D570 Water Absorption of Plastics

D7774 Flexural Fatigue Properties of Plastics 

D790 Flexural Properties of Unreinforced and Reinforced Plastics and Electrical Insulating Materials

D792 Specific Density & Gravity

D953 Bearing Strength of Plastics

D1822 Tensile Impact

D2990 Tensile, Compressive and Flexural Creep and Creep-Rupture of Plastics 

D3418 Melting Point

D3702 Coefficient of Friction

D7107 Creep Measurement of Self-lubricating Bushings*

*ASTM International astm.org

Ready to explore ASTM standards for your next bearing selection? Just Ask an Expert for a recommendation!

Topics: Bearing Selection
2 min read

5 Different Types of Plane Bearings (And Common Uses)

By Dave Biering on December 1, 2015

5 Different Types of Plane Bearings

I’ve just returned from a great week of customer visits, and had some interesting conversations along the way. At one site, I was asked about the different types of plane bearings and their common uses. Plane bearings offer a simple design, yet a complex design envelope. They are a great choice for industrial applications where high-load, long-life and low-maintenance are critical to performance.

Here’s a quick recap of the primary plane bearings and common uses:

Although simple in design, plane bearings (not to be confused with plain bearings), can be customized to deliver enhanced properties. Need uncommon strength or extreme durability? A reinforced liner can be easily added. Want to match the surface finish of other hardware? A close match can be achieved via machining. See the Rulon plane bearing selector guide.

5 Types of Plane Bearings:

  1. Sleeve bearings- Sleeve bearings are the most-common type of plane bearing, and support linear, oscillating or rotating shafts. They function via a sliding action. 
  2. Flange bearings- Flange bearings support a shaft that runs perpendicular to a bearing’s mounting surface. The flange (or rim) of the bearing can also be used as a locating mechanism to hold a sleeve bearing in place. Flange bearings reduce friction between surfaces in rotary and linear movements.
  3. Mounted bearings - To achieve an ideal fit, mounted bearings must be designed exactly to spec. Mounted bearings that fit too loosely can creep or slip on a shaft. Or if the press fit is too tight, free movement can be impeded. To eliminate this concern, plastic plane mounted bearings are available in pillow-block or flange housings, in forms ranging from 2-4 holes. 
  4. Thrust bearings - These plane bearings are designed with a simple washer to prevent metal-to-metal contact in a thrust load application. Plastic thrust bearings are thin, easy to install and self-lubricating to reduce maintenance costs.
  5. Spherical bearings - Spherical bearings rotate from two directions to compensate for any shaft misalignment. They are typically called on to support a rotating shaft that calls for both rotational and angular movement.

Where will you find plane bearings? They have a wide application range covering everything from hygienic FDA/USDA/3A/NSF environments to dirty, wet environments. 

Typical industries include:

  • Automotive 
  • Agriculture 
  • Off-road/Construction
  • Marine
  • Food Processing & packaging

Want to explore design options for plane bearings? Check out Bearing Design: A Guide to Form, Function and Selection, or watch the highlight video (emdedded below) for a quick review.

Topics: Plane Bearings
2 min read

Parylene Coating Facts: A Quick Review

By Dave Biering on October 27, 2015

Parylene Coating Facts: A Quick Review

Why should I choose parylene coating for my devices? 

This question was asked at a recent site visit, and I thought I’d share some quick facts about the various forms of this highly-effective conformal coating. 

Let’s begin by stating that not all devices call for parylene coating; it’s usually reserved for applications that require very sensitive circuit assemblies such as aerospace, electronics and medical devices. The treatment involves applying a vapor-deposited plastic which produces an extremely thin (and pin-free) isolative coating. This barrier protects assemblies from standard chemical contaminants, plus moisture, oxygen and CO2. To ensure the best adhesion of parylene, products should first be micro-cleaned via plasma surface modification. Once clean, the coating can then be applied in thin layers through a dip, spray or flow method.

Parylene is a lifetime treatment application, and includes four unique chemical treatment types.

Parlyene can be applied to any material, and meets strict FDA and USPVI requirements for medical devices. It also provides low-friction and abrasion- resistance for elastomeric seals, magnets and motor cores. Explore how surface treatment helped improve electronic flow sensors. 

There are four primary applications; each with unique attributes:

Parylene C

  • Most-common application type
  • Provides a combination of physical properties and very low moisture permeability
  • Excellent resistance to chemicals and gases
  • Good electrical properties

Parylene N

  • Similar characteristics to Parylene C, but able to function up to 220° C without oxygen
  • Highly-dielectric properties
  • Most “conformable” of all of the dimer structures

Parylene D

  • Similar properties as above, but with the addition of 2 chlorine atoms to give greater thermal stability
  • The dimer with the lowest ability to confirm, also has some reduction in dielectric properties vs. C

Parylene HT

  • Lowest coefficient of friction of all parylene formulas
  • Based on alpha hydrogen atom with fluorine
  • Very low dielectric and most able to conform given extremely low molecular size

Essentially, Parylene delivers biocompatibility to the medical industry, and stability to the electronics, aerospace and automotive industries. See the parylene video below for additional application details. 

Interested in having a sample treated? Just fill out a parylene application worksheet for a recommendation.

Topics: parylene coating
1 min read

5 Quick Facts About PTFE- Filled Fluoroloy H (Rulon H)

By Dave Biering on October 6, 2015

PTFE- Filled Fluoroloy H (Rulon H)

Why should you choose Fluoroloy H over other PTFE blends? We’ve got the facts! Fluoroloy H (also known as Rulon H) is one over 300 unique Rulon formulas, and is top-rated for electrical properties. This material is a PTFE blend with a ceramic filler, which gives the material superior isolative properties. Other common filler options include graphite, metal oxides and even other polymers. Each formula is designed to accommodate different service requirements. 

Here are 5 quick facts you may not know:

5 Facts you may not know about Fluoroloy H:

  1. The material was originally developed for UHF heat-sinking applications, and now is most often used as inside connectors in high-powered microwaves.
  2. Rulon H is a common alternative to virgin and glass-filled PTFE. 
  3. It has a superior dielectric constant compared to standard Teflon, yet a higher rate of thermal conductivity (Fluoroloy H is 1.21 W/m C and virgin Teflon PTFE is 0.24 W/m C).
  4. Given its dielectric properties, Fluoroloy H generates and transfers heat much more efficiently than other materials.
  5. Rulon H is available in standard rod, sheet or tape, or is easily machined to create custom components. Download your free Plastic Machining Guide to explore our best practices for custom fabrication tips. 
  6. When choosing any PTFE, keep in mind that filled blends have a higher resistance to wear and deformation under load, while unfilled materials generally have a lower coefficient of friction/lower wear. 

Is Fluoroloy H the right material for your operating environment? Check out our Rulon Bearings Comparison Chart, or connect with an Expert to find out! TriStar is proud to be the exclusive, North American supplier of Rulon H.

Download our Machining Plastics White Paper
Topics: Fluoroloy
1 min read

Causes of Bearing Failure: New videos explain why metal bearings fail!

By Dave Biering on September 29, 2015

Video  - Why Do Metal Bearings Fail? Composite bearing solutions.

Metal bearings – what causes bearing failure, really? The short answer is that there is no short answer; bearings can fail from a multitude of reasons including corrosion, fatigue, lubrication, maintenance and more. Yet whenever there’s a failure, it’s important to uncover the root cause ― but it can be a complex discovery process. 

Until now.

Announcing TriStar’s new videos: Causes of Metal Bearing Failure, a four-part series that delves into common bearing problems, including:

  1. Lubrication – from choosing the wrong viscosity to overheated temperatures, incorrect lubrication is the #1 cause of bearing failure. This video highlights what you need to know to avoid lubrication issues. 
  2. Maintenance – metal bearings don’t always receive the care they need, particularly when they are located in a hard-to-reach assemblies. Explore why metal bearings contaminate and corrode without regular upkeep.
  3. Load – overloaded bearings (such as in gear boxes) is a problem that is more common than you might think. Review the conditions that can lead to brinneling and more. 
  4. Avoiding failure – Want to avoid all of the above pitfalls? Check-out how TriStar’s solutions can help you avoid the common causes of baring failure. With our self-lubricating composites, lubrication is a non-issue, and corrosion is a thing of the past.

Start uncovering how you can avoid the common causes of bearing failure! Check out the latest additions to our Bearing Video Learning Center! Or just ask the self-lubricating bearing experts for a recommendation!

Topics: Bearing Failure
1 min read

Rulon J vs. Teflon: An Aerospace Application

By Dave Biering on September 22, 2015

Blog_20150922

Takeoffs and landings, friction and fatigue, these are just a few of the demands on aerospace bearings. Should designers choose Rulon J tape or Teflon® tape for an aerospace bearing application? Which material can resist the challenges of wear and corrosion in aerospace and aviation? We tested both materials, and this is what we found.

A major manufacturer of helicopter components contacted us to improve the performance of the cowling rub strips on their helicopter body panels. The strips are riveted to the body panels of the copters, and are designed to stop the “rub” and wear caused by engine vibration.

Virgin Teflon tape worked in this application initially, but our client complained that it would eventually wear from the extreme friction that occurred over hundreds of takeoff and landing cycles. Each tape failure caused the copters to be pulled to the maintenance hangar, which resulted in lost flight time, and high Teflon replacement costs.

Rulon J, on the other hand, outperformed all tests and gave the client the extended wear they needed. Rulon J is a reinforced material that provides up to 3x the bearing service life of other materials. It also reduces friction and works well against soft mating materials such as composites, 316 stainless steel, aluminum, mild steel and brass. It is made of a specialized filler which gives it better tolerance and stability, even in the wide-ranging temperature conditions of a helicopter in flight.

The winner? Rulon J exceeded the applications requirements, in fact, all Rulon formulas can be etched with pressure sensitive adhesives (PSA) added. As an added bonus, Rulon tape provides a better sound barrier against engine noise. 

Choose Rulon J for:

  • Abrasion resistance
  • Lower maintenance
  • Grease-free operation
  • Reduction of stick/slip
  • Good noise insulation 

Do you know how to identify genuine Rulon from counterfeit? Read our technical white paper to find out how! Or request a quote for a custom width of Rulon J tape today!

Download our Rulon Bearings white paper

Topics: Rulon J
2 min read

Bearing Selection and Achieving the Right Press Fit

By Adrian Carrera on August 25, 2015

Bearing Selection and Achieving the Right Press Fit

I had a great conversation this week about bearing selection and the intricacies of finding the right press fit. As a quick review, press fit is defined as the value of interference between the shaft and the inside diameter of the bearing, or the housing bore and the outside diameter of the bearing when installed.

Why is press fit important in bearing selection? Check out a recent calculation for our Ultracomp composite material.

In order to generate a proper press fit for our Ultracomp product line, TriStar Plastics requires the housing bore dimension with tolerances, the shaft dimension with tolerances, along with the exposed applications temperature variations. The example below features an example of a press fit utilizing a housing bore of 0.5934/0.5941,” shaft 0.499/0.498 with the temperature varying from 68 deg. F to 200 deg. F.” 

To find the right press fit, you must also consider material creep and the vibration that occurs during rotational operation. Without the right fit, bearings can experience stress through extreme friction and heat due to thermal expansion, or they may be exposed to dust or other abrasive particles that are generated. Obtaining secure press fit also allows for torque transfer and for preserving axial location. Read about plastic custom fabrication in our Machining Plastics White Paper. 

Key considerations for a good press fit: 

  • Interference fit: Also known as a press fit or friction fit, is a fastening between two parts which is achieved by friction after the parts are pushed together, rather than by any other means of fastening.
  • Thermal expansion: The tendency of matter to change in volume in response to a change in temperature, through heat transfer. 
  • Running clearance: Is the calculated free space between either the shaft and the inside of the bearing, or the outside of the bearing and the housing. Running clearances can be affected dramatically by thermal cycling and, when combined with frictional heat, can be the difference between success or failure of the bearing.
  • Close In: For our Ultracomp products is a percentage of the material that will compress in on itself from the given restrictions on either the outside or inside diameter of the bearing. If close in is not properly calculated it could lead to bearing failure. Close in is determined by the bearing wall thickness, and shaft diameter. 

We can do a similar calculation for your application, just fill out a Design Worksheet! Or want to discuss your bearing selection with an Expert? Just Ask! 

Bearing Selection and Achieving the Right Press Fit

Topics: Bearing Selection
2 min read

3 Issues to Avoid with Corona Treatment of Films

By Dave Biering on July 7, 2015

3 Issues to Avoid with Corona Treatment of FIlms

Today we are talking films on Tech Talk ― as in corona treatment of ― not the latest “must- see” summer blockbuster (although we enjoy those, too!). So what do you need to know about corona treatment and successful treatment of films?

As you probably know, corona treatment can help you modify plastic films and other materials to render them more bondable, or to provide a longer lifespan. Corona plasma is a visible electrical discharge which is produced when a high-voltage and high-frequency electric potential comes in close to electrodes in the atmosphere. When the discharge occurs, ions and ozone are generated; the ozone compound is relatively short-lived and may dissociate to molecular oxygen (O2) and oxygen radical (O`). The oxygen radical then works to modify the polymeric film material. Explore corona treatment and other techniques in the Surface Modification Technical White Paper.

While corona treatment has a very-high success rate, there are three common challenges to be aware of:

  1. Blocking – As polar groups form during corona, they have a high attraction to the molecular level, yet this attraction can be greater than the internal bonds of the substrate. Under these circumstances, the substrate can delaminate when the product is unrolled. The tighter the roll is wound and the longer it sits in storage, the more severe the problem becomes. Blocking is particularly challenging when working with films at the center of the roll.
  2. Heat Sealing - Excessive corona treatment can lead to problems when attempting to heat seal the product.
  3. Additives - If the polypropylene or polyethylene contains additional components (such as slip additives or some processing aids), the effectiveness of the initial treatment is reduced over time. This is caused as the additives “bloom” to the surface and partially mask the polar groups formed during treatment. To avoid this challenge, it is best to treat these films at the point-of-use rather than at the point-of-manufacture.

Beyond film, corona treatment is also applied to other in-line processes such as foils, paper, webs and tape. Will it work for your materials? Fill out a Surface Modification Worksheet with your design specs and we’ll help you find out!

Tell us about your experience with Corona Treatment of films in the comment field below. Or, if you’re so inclined, share your list of favorite summer films! 

Topics: corona treatment
1 min read

How it Works: Conveyor Roller Bearing

By Dave Biering on June 30, 2015

3)	How it Works: Plastic Conveyor Roller Bearing

From food packaging and processing to general material handling, the conveyor roller bearing is an underrated superstar of the manufacturing floor. You might even consider it the heart of the whole conveyor assembly. But how does this essential bearing assembly work?

As the name suggests, conveyor roller bearings have a cylindrical shape and are designed to carry heavy loads, since the weight is evenly distributed over a large surface area. Also referred to as cylinder rollers, this bearing type can easily handle radial (but not thrust) loads. For a good fit, we always recommend choosing a conveyor roller bearing with the largest diameter at the shortest length in order to minimize roller deflection. For tight spots, needle bearings (a close cousin to roller bearings), offer a very small diameter design envelope.

Plastic roller bearings offer significant advantages over metal; they are lightweight, require no manual lubrication and do not rust or corrode after sanitation baths. And since they require less energy to turn, they can help you reduce energy costs. Roller bearings excel in virtually any manufacturing environment from cold rooms (explore how Ultracomp plastic bearings increased production for a manufacturer of in ice cream), to tough, heavy-vibration manufacturing areas. Ultracomp bearings are available in tube and sheet stock, or can be fabricated to your exact specifications (fill out a design worksheet for a custom quote).

See how plastic conveyor roller bearings work in our video:

Need more info? Connect with the Conveyor Roller Bearing experts!

Topics: conveyor roller bearing
1 min read

4 Factors that Impact Plane Bearings and P, V and PV (WATCH)

By Dave Biering on June 23, 2015

4 Factors that Impact Plane Bearings and P, V and PV

P, V and PV – how do they impact a plane bearing system? Let’s take a quick review of this important connection. Plane bearings are basically rolling element bearings in their simplest form; they provide good value, easy installation and serve a multitude of industries. And plastic plane bearings have the advantage of a self-lubricating design to reduce manual greasing costs. 

When choosing the right plane bearing for your application, we, of course, look at bearing load (P), relative velocity (V), temperature variations and environmental considerations. But there are 4 other factors that are critical to help determine a material’s ability to handle P, V and PV:

Since pressure (P) and velocity (V) do not occur independently, they should always be considered in tandem. After all, it is the combination of load and speed that generates frictional heat, and each material has a maximum PV rating. But we also must consider these key factors to determine the performance and longevity of a material as a plane bearing:

  • Ambient temperature - the higher the ambient temperature, the greater the reduction in capacity measurements.
  • Intermittent operation – consider that oscillating and reciprocating motion allows for higher P, V, and PV values.
  • Shaft materials – materials that are good thermal conductors allow for increased values.
  • Surface finish - a surface finish that is too smooth will generate higher friction (and more heat), which will lower values.

Got all that? For a quick review of the plane bearing and P,V, PV connection, watch this video demo (below). Or fill out a Plane Bearing Design Worksheet for a custom quote!

Topics: Plane Bearings
1 min read

Thermoset vs. Thermoplastic Bearings

By Dave Biering on June 16, 2015

 What is the difference between thermoset and thermoplastic bearings?

What is the difference between thermoset and thermoplastic bearings? 

This is a great question that came to us in a recent site visit. I thought I’d share the key differences between the two:

The primary difference between these two bearing materials is that thermoset plastics retain their solid state indefinitely, and include just a few trade names. Thermoplastic bearing materials can be heated and reheated many times to form new shapes. Thermoplastics are the largest groups of plastics and include PVC, PEEK, polyethylene, nylon, acetal, and acrylic. Thermoplastics are particularly good for machining into custom fabricated components (explore The Essential Guide To Machining Plastics)

Thermoset plastics: 

  • Do not melt since they chemically change in molding 
  • Are usually brittle and chip easily 
  • Include fillers 
  • Common formulas: 
    • Phenolic 
    • Epoxy 
    • PTFE 
    • Mycartas 
    • Melamines 

Thermoplastics: 

  • Largest class of plastics 
  • Melt and reform without any chemical change 
  • Filler options include: 
    • Glass fibers 
    • Carbon fibers 
    • Graphite 
    • Carbon 
    • Molybdenum disulfide 
    • PTFE

Still confused about these similar-sounding bearing materials? Connect with the thermoplastic bearings expert to answer your questions! 

Download our Machining Plastics White Paper

Topics: Thermoplastic bearings
1 min read

Q&A: What is the shelf life of PTFE and Rulon Materials?

By Dave Biering on June 11, 2015

Q&A: What is the shelf life of PTFE and Rulon Materials?

This was an excellent question from a customer wondering how long they could store non-etched Rulon materials. When handled and stored properly, Rulon has an unlimited shelf life. But when the material is etched, the answer is not quite as simple. 

When stored in normal warehouse conditions, all PTFE and Rulon materials have an unlimited shelf life. In fact, a common industry pun is that, at 85 years and counting, PTFE has “not been around long enough” to determine how long it will last! 

But etched-PTFE and Rulon are a different story. The etching process involves reducing the surface lubricity of the polymer in order to bond it to another material. For best results, etched materials must be stored in a black, UV-blocking bag or else the etch will degrade at about six months. The UV bag also protects Rulon materials from damaging ozone and heat exposure, which is common to a warehouse environment. With this protection, etched materials can last a year. 

To determine if your PTFE/Rulon material has degraded, we recommend two methods:

  • Look at the color ― if it has faded to a light brown/tan or has a marbled look, it is no longer a viable manufacturing material.
  • Try a droplet test – add a drop of water and if it rolls around in a ball the material is now hydrophobic and the etch has been lost. If it disperses, than the etch is still good hydrophilic and the material is good to go!

Still not sure about the shelf-life of your stored Rulon materials? Need a second opinion? Just connect with the official Rulon experts! 

Submit questions about your most challenging applications.

Topics: Rulon Materials
2 min read

Rulon AR and Rulon LR: Back to Basics

By Dave Biering on May 19, 2015

Rulon AR and Rulon LR:  Back to Basics

I’ve just returned from a few days of customer site visits, which is always a great experience. I enjoy touring the manufacturing plants and learning more about our customers and their bearing challenges. On this trip I was asked about Rulon AR and Rulon LR, two of the over 300 different formulas of Rulon bearing materials. Our customer had some old design prints on file, and could not find the original Rulon formulas specified on the prints. Turns out, their old designs specified Rulon A and Rulon LD; materials that are no longer in production, here’s what we reviewed:

Our client had been using Rulon A and Rulon LD; two of the original Rulon compounds that were in widespread use from 1950s through the mid-1980s. The materials (both maroon in color,) were actually remanufactured and renamed by Dixon in 1988; Rulon A became AR and Rulon LD became LR. At that time, it was discovered that a constituent of the maroon pigment was carcinogenic, so the necessary formulation changes were made. 

Although the formula changed nearly thirty years ago, the materials have retained their self-lubricating properties to deliver excellent wear and friction, plus their signature maroon color. In fact, both are NASA approved for use in LOX service.

Rulon AR 

The primary application is a seal or gasket material because it is flexible and responsive. Rulon AR is ideal for seals and the bonded coatings of slide surfaces. AR excels in automotive applications such as shaft seals and piston cups for gas meters, or anywhere where high physical properties are required.

Rulon LR

Is the go-to material for general purpose Rulon applications. Since the material is stiffer and has good deformation resistance it’s excellent for bearing or structural components.

Both Rulon AR and LR are versatile design materials with extremely low outgassing in vacuum service. They require a minimum 35RC hardness on mating hardware due to the abrasive nature of the filler and are available in rod, sheet, tube and Rulon tape. 

Here’s a handy Rulon comparison chart to help you review the exact specification of these unique materials. Have a question for our Experts? Submit them here! We’re happy to help!

Topics: Rulon LR Rulon AR
1 min read

Bearing Nomenclature 101: When to choose bearings vs. bushings?

By Dave Biering on May 14, 2015

Bearing Nomenclature 101: When to choose bearings vs. bushings?

When should you choose bearings vs. bushings? I’m often asked about bearing nomenclature (see our recent blog entry on plane bearings vs. plain bearings). So today let’s set the record straight on bearings and bushings:

A bearing is designed to “bear” or carry stress or loads in various design applications, but to add a layer of confusion, bushings are often referred to as plain bearings or sleeve bearings. Generally speaking, the difference between bushings and rolling element bearings in that bushings are designed as a single part, while bearings can have multiple parts.

Both bearings and bushings can be composed of metal or plastic composites, or a combination of the two. Plastic bearings provide the advantages of a self-lubricating design (never needs grease), plus corrosion and chemical resistance, and superior longevity and wear.

The automotive industry tends to use the terms bushing and bearings interchangeably, and they often employ bearings with a plastic-lined bearing with a bronze interlayer (such as TriSteel bearings). These bearings excel in heavy-duty sliding, oscillating and rotary applications, such as auto transmissions, shock systems and gear boxes.

Ultimately, your application requirements will dictate the bearing/bushing decision! Want to review bearing nomenclature? Or have a technical question answered? Get in touch with the bearing and bushing experts!

Bearing Selection: Get the Ultimate Plastic Bearing Design

Topics: Bearing Selection
2 min read

Engineered Plastic Components and the Cost vs. Performance Debate

By Dave Biering on May 12, 2015

When does the cost of machining expensive plastics outweigh the cost of traditional metals?

Thank you for your overwhelming response to our recent technical paper, Machining Plastics the Essential Guide to Tools and Techniques! We’ve heard from many of you stating that this guide to engineered plastic components has become a go-to resource for your machine shop. We’ve also had some follow-up questions about the cost vs. performance debate, especially with regard to more-expensive materials. When does the cost of machining expensive plastics outweigh the cost of traditional metals? Read on for more (and to view our relative cost of materials chart).

Plastics are an excellent replacement for bronze, stainless steel and cast iron, as they excel in high temperatures and extreme environments. But this level of performance can be costly, since engineered plastics are not inexpensive. Consider that PBI-Celazole is 25x the price of cold-rolled steel, and 15x more expensive than Type 303 steel. At these price points, it is critical to choose just the right engineered plastic for your application before beginning any machining.

At TriStar, our theory is that the cost of the material should be an investment in performance. Once you’ve reviewed the primary application conditions (environments, temperature requirements, mating hardware, etc.), and made a selection, you should next consider the cost of a material failure. A higher-quality material will provide a higher-quality part. And a higher-quality part can help you reduce in-field failures and costly recalls.

Here’s a quick review of the relative cost of plastic materials:

relative-cost-of-plastic-materials.png

Any of these materials can be machined, yet each offer unique attributes for certain conditions.  Want to explore the advantages and considerations for each?  Connect with our team for a review, or request a quote for engineered plastic components!  At TriStar, our goal is to help you find the best engineered plastic components for your application ― all at the best value!

 

 

Topics: engineered plastics
1 min read

Q&A: How can I correct a bearing failure of agitator steady bearings?

By Dave Biering on May 7, 2015

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Keep sending us your questions about bearing failure and other bearing challenges! Some of our best products were developed as a result of your toughest applications! 

This week’s question was submitted by a chemical company looking to replace their reactor agitator steady bearing used in industrial mixing and blending. The client had been using a 25% glass-filled Teflon bearing, but had a high bearing failure based on low wear properties. Add to that the fact that glass filled PTFE is not FDA acceptable and the customer had more than a wear issue. They needed a replacement bearing with FDA compliance and good friction rates. After reviewing the application, our team recommended durable, Rulon 1439 FDA-compliant steady bearings.

Rulon was chosen based on the following factors:

Rulon 1439 is an excellent material for submerged applications, as it is compatible with most lubricants and delivers better wear than most PTFE compounds. The material resists boiling temperatures and caustic washdown chemicals of FDA-compliant environments, plus it has a pleasing, stain-resistant white color. Rulon 1439 is an excellent replacement steady bearing in food processing mixing applications

Specifications below:

Rulon® 1439 Material Specifications

Color

White

Performance

Max Load "P" (psi) Mpa: 1,000/6.9
Max Speed "V" (fpm) m/s: 400/2.0
Max "PV" (psi-fpm) (Mpa • m/s): 10,000/0.35

Mating Surface Steel and Stainless Steel

Rb25 and higher

Environment

FDA compliant, steam, wet, dry, vacuum

Relative Rating (1=Low, 5=High)

Coefficient of friction: 3
Creep resistance: 4
Insulative property: Yes

Since moving from Teflon to Rulon, our client reports they have lowered bearing failure rates and increased production levels.

Learn more about Rulon applications in any of our Rulon technical white papers!

Topics: Bearing Failure
1 min read

Comparison of Underwater Bearings: Wood vs. Plastic

By Dave Biering on April 30, 2015

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We had an interesting call on our Ask the Experts line this week concerning underwater bearings and the benefits of wood vs. plastic in a hydro plant application. One surprising fact we reviewed is that like plastic, wood bearings are self-lubricating materials that never require greasing. Yet plastic bearings (such as Ultracomp 300) offer the advantages of dimensional stability in liquids, superior strength, and other benefits reviewed here in our comparison chart.

Wood bearings (also referred to as lignum vitae) are considered an “old-world” bearing material; there’s even evidence showing they were used as rudder bearings by Phoenicians boat builders 4500 year ago! Yet breakthroughs in composites have given plastic the edge in underwater propeller and rudder shafts, switching gear, water turbines, and even petrochemical and wastewater applications.The materials resist corrosion, never absorb water and deliver extended service life to help save on replacement costs.

See the differences:

AttributesWood BearingsUltracomp 300
PV rating 12,000 25,000
Max speed 500 sfpm wet 100 sfpm dry
Max load 1000 psi 14000 psi dry dynamic
Max operating temp -50 to +180F -375 to +325F
Friction 0.07-0.11 0.08-0.12
Tensile strength 1,100 psi 17,500
Specific gravity 1.2 1.35
Lubricant by weight 40% Proprietary
CTE 4.3 x 10-6 3.3 – 6.24 x 10-5
Permanent deformation
at 7500 psi load
.005" Nil

After reviewing this information, our caller determined that while wood bearings may still have a place in certain applications, plastic bearings were a superior choice for a hydro plant application. Want to see more technical specifications?  Check out our Materials Database. 

Topics: Underwater bearings
2 min read

4 Signs You’re Ready to Outsource Plastic Fabrication

By Dave Biering on April 14, 2015

4 Signs You’re Ready to Outsource Plastic Fabrication

Plastic fabrication is completely unlike metal fabrication; a fact that we covered indepth in our recent Machining Plastics technical white paper. After all, plastics melt and chip as you machine them, plus they can expand 5x or more beyond their original shape. Machining requires skill, experience and proper tooling in order to achieve the best value for your material investment. 

Given all the variables, when does it make sense to consider moving your plastic fabrication from in-house to outsourced? What criteria should you consider when making this important decision?

We’ve prepared 4 top signs to help you review. 

Consider outsourcing your plastic fabrication when:

1. You’re not certain if the material is genuine
How do you know if the material that you have paid for is indeed the genuine material (counterfeiting is a widespread problem, a topic we covered in this paper). Consider outsourcing with a reputable bearing supplier who will review relative costs, and is also an authorized dealer of the material you are interested in. Unfortunately, counterfeit materials are fairly common in the plastics industry, so learn how to recognize genuine and avoid counterfeit!
2. Heat levels are a mystery
Plastics melt! And any type of machining generates friction, thus heat. In essence, your cutting tool can quickly become a “melting tool” if you’re not careful. If you’re uncomfortable with the connections between heat and cutting speeds, tool selection, coolants and tolerances, it might be worth outsourcing your project.
3. Best practices for drilling, turning, threading and tapping are unknown
Which technique will provide an optimal component without stressing and distorting the material? Look for a machine shop that has an extensive inventory of equipment and a quick delivery. CNC turning, Swiss screw machines, and milling equipment are all key equipment for precision engineering – look for a fabricator who has them!
4. Your component requires secondary processing
Do you need to paint your component once it’s machined? Or adhere it to another piece? You may be interested in Surface Modification, a series of techniques that help to improve the application of secondary processes including paints and other coatings. This is a select service that is not readily available in the market.

Reach out to the plastic machining experts with your questions!

Topics: Plastic Fabrication
1 min read

Plastic Fabrication Review: Machining vs. Injection Molding

By Dave Biering on April 2, 2015

Plastic Fabrication Review: Machining vs. Injection Molding When it comes to plastic fabrication, there is not one simple, one-size-fits-all solution to creating your ideal custom part. Plastics machining offers many advantages (as we covered in our new technical paper), yet injection molding also has offers unique benefits.

So how do you decide between these two plastic fabrication techniques? Ultimately, your decision should come down to answering a couple of basic questions that will help you make the most of your material investment. Consider the following:

Plastic Fabrication Considerations:

  • What is the production quantity? 
    With injection molding, tooling can be expensive, so you need to be certain that the expensive tooling justifies the cost of the machined part. As a rule of thumb, we recommend injection molding for quantities over 5,000 pieces, and machining for anything under..
  • Are tolerances matched to the material? 
    Some materials cannot hold tolerances, which can impact their compatibility with injection molding. Read all about material selection and plastic machining in our new white paper: Machining Plastics: The Essential Guide to Materials, Tools & Techniques. 
  • How complex is the geometry? 
    If the part geometry very complex, you have many more fabrication options with machining vs. molding.
  • What is the stress on the material? 
    You need to determine if there are fillers in the resin you are using, since this will directly impact stress. 
  • What are the surface finish requirements? 
    This is particularly important in medical applications, where a proper finish is critical to the surface ID of the part. 

For a quick video review of this topic, check out the video (below). Of course, our Plastic Bearing Engineering Experts are always available to answer your questions too!

Topics: Plastic Fabrication
2 min read

Q&A - Bearing Selection Does Rulon W2 Require Grease?

By Dave Biering on March 31, 2015

Q&A  Bearing Selection Does Rulon W2 Require Grease?Lots of interesting bearing selection questions coming into our Ask the Experts portal - have you submitted your bearing design challenge? The latest query involves Rulon W2 in a wet application. Our partner wants to know if grease is required to maintain low friction.

Q: Our company is using Rulon W2 in a fluid application (fresh water, seawater, oil) for hydraulic and pneumatic components. The Rulon disc mates against 316 stainless steel hardware. Operating conditions are loads up to 500 psi, with intermittent high-speed cycling. 

Is lubrication needed between the Rulon disc and the stainless steel hardware?

A: Rulon W2 is actually designed for exactly this type of environment. It is a self-lubricating bearing material that never needs additional grease to perform in any application. It gives low friction against most materials, plus superior wear and good thermal dissipation in fresh water. In fact, Rulon W2 actually improves in performance when wet. The material does not expand and can help prevent shaft distress without any manual greasing needed - ever. 

Check out our complete Rulon Bearings Comparison Chart for details on Rulon bearing selection, or see the W2 specifications below. And thanks for the question!

Rulon® W2 Material Specifications

Color

Black

Performance

Max Load "P" (psi) Mpa: 1,000/6.9
Max Speed "V" (fpm) m/s: 400/2.0
Max "PV" (psi-fpm) (Mpa • m/s): 10,000/0.35

Mating Surface Steel and Stainless Steel

Rb35 and higher

Environment

Steam, wet, dry

Relative Rating (1=Low, 5=High)

Coefficient of friction: 2
Creep resistance: 4
Insulative property: No

Available Shapes and Sizes

Rod and Tube

Extruded up to 10' long
Molded up to 12" long
Extruded 2" max O.D.
Molded 47" max O.D.
Precision grinding or machining available for some sizes

Sheet and Tape

Tape 38" width max. Skived up to 1/4" thick
Molded up to 24" x 3" thick. Max thickness 3"
Precision grinding or machining available on thickness

Custom

Contact district sales manager
Full machining capabilities available

1 min read

What is a Plane Bearing? Or is it a Plain Bearing?

By Dave Biering on March 26, 2015

What is a Plane Bearing? Or is it a Plain Bearing? First let’s settle this important question, is it a “plane” bearing or a “plain” bearing? And survey says? Both spellings are correct, although this bearing supplier prefers plane bearing. 

Now that we have that settled, the question then becomes, what is a plane bearing exactly? We have the answer to that question, too!

A plane bearing is really a bearing in its simplest form; it is any non-rolling element bearing that is applied where two surfaces rub together. Common forms are flange or sleeve bearings, slide plates or friction bearings. Some applications call for a reinforced plane bearing with unique liners, while others demand a particular material surface finish as demonstrated in this video

Plane bearings are comprised of materials ranging from composites, bronze, and acetals to carbon alloy. Ultimately to get the right fit for your plane bearing application, consider:

  • Bearing load
  • Relative velocity
  • Operating temperature variations
  • Environmental conditions
  • Machinability
  • Cost

For more details, check out our popular Rulon plane bearings which excel in high-temperature, non-lubricated applications, or Ask an Expert for a recommendation.

Topics: Plane Bearings
1 min read

Causes of Bearing Failure – See the Video

By Dave Biering on February 19, 2015

Causes of Bearing Failure – See the VideoOf all of the questions we receive about bearings, one of the most-commonly asked is regarding the causes of bearing failure. Just why do bearings fail? 

Today, we address this complex topic with a new video.

Bearing failure can result from a host of many factors, ranging from temperature fluctuations, to alignment issues, a change in operating conditions, or even too much (or too little) bearing lubrication. But to avoid a bearing failure in the future, we need to examine the root cause. 

We wanted to share a Q&A on causes of bearing failure, particularly with rolling element vs. plane bearings.

(Watch the video below.)

Tell us about your experience with bearing failure. What was the cause? Need help solving a bearing challenge, just Ask an Expert.

Topics: Bearing Failure
1 min read

Q&A - Can you review amorphous vs. crystalline polymers?

By Dave Biering on February 12, 2015

The key attributes of crystalline vs. amorphous polymersA recent customer visit found us reviewing the attributes of amorphous vs. crystalline polymers. I thought I’d share the information as a good refresher on polymers and PTFE. 

So what are the key attributes of crystalline vs. amorphous polymers?

Crystallinity is one of the key properties of all polymers. Crystalline polymers are nearly linear in structure, which tends to be flexible and fold up to form tightly and packed. Processing time and temperature greatly influence the degree of crystallinity. These polymers have a higher level of shrinkage, are generally opaque or translucent, possess excellent chemical resistance, low friction, and superior wear resistance.

Conversely, amorphous polymers have low shrinkage, good transparency, gradual softening when heated (no distinct melting point), average or poor chemical resistance, high friction, and low wear resistance.

Here are some common materials of each:

Crystalline polymers

  • Polyethylene
  • Polypropylene
  • Acetals
  • Nylons

Amorphous polymers 

  • Polystyrene
  • Polycarbonate
  • Acrylic
  • ABS
  • SAN
  • Polysulfone
Want to learn more? Check out how crystallinity can help you Recognize Quality in PTFE Materials or Ask an Engineer for assistance!
Topics: polymer bearings PTFE
1 min read

Plasma Treatment of Medical Filters

By Dave Biering on January 8, 2015

Plasma Treatment of Medical FiltersIt is no secret that medical manufacturers are turning to plasma treatment to help them improve the performance of their products. Whether used to alter PEEK and PVC to accept time-released medications or even to improve a plastic-to-metal bond in medical tools; plasma treatment has virtually unlimited potential for the medical and pharmaceutical fields. 

Today I wanted to share how we treated blood filters that are used in orthopedic surgery. Our team is proud to help ensure patient safety by treating the filters that inhibit platelet clotting and assist with gas exchange during surgery.

Our client cited they were having difficulty ensuring that blood would adhere to the polymeric filter material during surgery. Without a good bond, there was a real chance that air bubbles could form during surgery, which could lead to the formation of potentially deadly blood clots. 

Through our plasma treatment, we were able to modify the filter so blood would “wet” and create an intimate contact with the tubing. Plasma treatment has resulted in the client’s filters now boasting a greatly-improved molecular adhesion. 

Learn more about changing medical plastics with plasma treatment (below).

Topics: Plasma Treatment
1 min read

3 Key Benefits of Surface Modification

By Dave Biering on December 9, 2014

TriStar Plastics Corp. - 3 Key Benefits of Surface ModificationReading through some of our older posts, I noticed that we received some great feedback on our coverage of Plasma Surface Modification Improves Drone Aerodynamics. A topic that is still timely today. In this instance, our client needed to improve the bond strength on the wing edge of their drones. The end result after plasma treatment was a superior bond adhesion that excelled at resisting wind forces.

Today I wanted to review 3 key benefits of surface modification for all industries.

Plasma surface modification is often described as a low-pressure gas with electricity running through it. It contains ions, free radicals, excited molecules and UV light. When exposed to an energy source such as electricity or microwave, it becomes a mix of ions, free electrons and other types of molecular fragments. The resultant plasma treatment removes all traces of organic contamination. 

When properly applied, plasma treatment can:

  • Microscopically modify the surface of a polymer substrate to improve mechanical bond strength without altering the haze, transmittance or clarity of the material 
  • Clean surfaces to improve the surface wetting and adhesion of paints, coatings and markings
  • Functionalize groups (carboxyl (HOOC-), carbonyl (-C=O-), hydroxyl (HO- and others) to the polymer substrate to significantly increase the surface energy for bonding; particularly in applications where aqueous-based adhesives require a bond strength that can’t be obtained with conventional cleaning techniques.

Surface modification can benefit industries ranging from medical and biotech, to electronics and even consumer goods. For additional benefits, get your free copy of our Surface Modification technical paper! Or just Ask an Expert for advice!

Topics: Surface Modification Plasma Treatment
1 min read

Rulon Bearings in Vacuum Applications

By Dave Biering on November 12, 2014

Rugged Rulon 1337 for slide pads and rolling element retainersRugged Rulon 1337 for slide pads and rolling element retainers

When a major manufacturer of vacuum chambers required a self-lubricating bearing to replace their failing metal components, we knew Rulon® bearings would fit the bill. Our Engineering Experts took a site visit to the client, and recommended Rulon 1337; a material that is comprised solely of FDA-compliant materials, and offers durability and extended service with most mating surfaces. 

Our client’s vacuum chambers are used in a range of applications from food processing to industrial testing. The systems remove air and gases via a suction pump, which, over time, can impact the structural integrity of chamber components. Rugged Rulon 1337 plastic bearings have promoted superior performance in two areas of this demanding application:

Slide pads provide superior support and service

Vacuum chamber bearings are generally constructed of stainless steel or bronze, which many designers mistakenly believe are superior materials. But Rulon 1337 bearings provide the rigid support and load capacity to excel as slide pads in X, Y, Z linear slides, and they rarely need replacement. Since switching to Rulon, our client notes the bearings have provided longer service in this low-pressure environment. 

Rolling element retainers have self-lubricating design

Our client also needed replacement retainers for their rolling element bearings, with a key requirement for maintenance-free service. Rulon 1337 has delivered again, as it features a self-lubricating design, compatibility with most mating surfaces plus good friction and thermal properties. With exceptional resistance to deformation plus solid construction, Rulon 1337 has solved these vacuum chamber challenges! 

Is Rulon 1337 the right choice for your application? Check out our Rulon Materials Comparison Chart to review exact specifications, or explore new applications in our Rulon Technical White Papers

Did you know that TriStar also offers Surface Modification of plastics via vacuum plasma? You can learn more by completing an Application Worksheet. 

Topics: Rulon Materials Rulon 1337
1 min read

Bearing Materials and Tribology Testing

By Dave Biering on November 4, 2014

Blog_20141104I had an interesting conversation with a manufacturer this week regarding bearing materials and tribology testing. With so many counterfeit bearing materials on the market, it is more important than ever to ensure that you are using genuine materials before you begin manufacturing to avoid application problems down the line.

In our call we spoke of the number of processors claiming to sell quality, original materials, yet in many cases, the materials are actually a blend of poor-quality resins. To complicate the situation even further, the counterfeits often look and feel just like the real deal. How can you avoid falling victim to these lesser materials? Consider the advantages of tribology testing to guarantee true authenticity.

Tribology characterizes the friction, lubrication and wear properties of polymers to predict how they will perform. Tribology also helps you comply with important industry standards such as EN, ASTM, CPSC and others. The testing is particularly critical in the medical, pharma and food processing industries where authenticity and sanitation must be guaranteed.

Look to Tribology testing to help you:

  • Guarantee that the material you purchase is authentic
  • Identify any material defects before production begins
  • Protect the end user of your product from underperforming bearings
  • Eliminate shipping defective products
  • Avoid costly product recalls

Want to explore the 7 key tribology tests that are required for polymer characterization? Download your free copy of our white paper, Rulon Bearings: How to Recognize Genuine and Avoid Counterfeit.

Tribology is just one of many analytical services that we offer. We can help you identify and validate any plastic material, and predict how it will operate in real-world conditions. Just Ask the Experts for a quote!

Topics: Composite Bearings Bearing Failure
2 min read

Common Causes of Bearing Failure

By Dave Biering on October 16, 2014

Common Causes of Bearing FailureWhy do bearings fail?

Unfortunately, there is not one simple, one-size fits all answer to this question. When we evaluate bearing materials for any application, we also examine why previous materials may have failed. We look at operating conditions, running temperatures, lubrication issues, fatigue factors and more to determine the root cause. It is the culmination of all of these ― plus many other factors ― that contribute to bearing service life. Here’s a quick review of common causes to help you avoid bearing failure in the future:

Although it can be difficult to determine the exact cause of a bearing failure, some major causes include:

  1. Bearing lubrication – without the right lubrication levels, bearings can overheat and wear prematurely, which can significantly increase your replacement and maintenance costs. Lubrication failures can result either by using the wrong lubricant, insufficient lubrication or even a total breakdown of lubrication. Another challenge with lubricated bearings is that the excess grease can attract dust and other contaminants which can reduce service lifetime. Self-lubricating plastic bearings eliminate all of these concerns since they run “dry” without any additional lubrication.
  2. Working conditions – What are the everyday conditions that your bearings are exposed to? Do they regularly encounter cleaning chemicals, corrosive salt water, construction dust or other debris? It is critical to match bearings to the correct working environment. For instance, Rulon J offers superior performance in a diverse range of applications. It gives good wear, friction and temperature stability, but is not the best choice for use in wet environments. Explore the benefits of Rulon J after treatment with Plasma Surface Modification.
  3. Shifting and misalignment – After hundreds of hours of use and stop/starts, equipment bearings can slide out of place. This can signal the end for metal bearings, while other materials are specially designed to accommodate shifting concerns. Ultracomp bearings, for instance, are a good choice for the construction, oil and gas and rail industries where heavy loads and constant use contribute to shifting.
  4. Temperature - Many designers still believe that a thicker bearing wall can resist higher temperatures than thin-walled plastic bearings. In fact, heat buildup is much more likely with thick-walled bushings. Consider plastic bearings for good heat dissipation and a higher-PV value.

Have you experienced a recent bearing failure? Share your experience here and we can help you explore different bearing options!

Topics: Bearing Failure Bearing Service Life
1 min read

Tech Tip: How do I measure the surface tension of plastics?

By Dave Biering on September 30, 2014

Measuring Surface AngleMeasuring surface tension can be done quite easily in the lab with the use of a goniometer (or surface contact meter). In fact, this is a key service of TriStar’s Surface Modification Division

The process begins by first measuring the baseline contact angles to determine the right surface modification method. Since the surface tension of liquids and the surface energy of materials must be matched, we add a droplet of water to the component to get the best reading. 

The component is then placed in a vacuum plasma chamber, treated, and read again to measure tension changes. After plasma cleaning, components are much more accepting of secondary treatments such as adhesion, ink stamping, overmolding and more. If the surface energy of the material is too low, then the coatings will not flow well and fisheyes, pinholes, gaps, or air bubbles will form. If the material surface energy is too high, then paints, inks and other coatings may bleed or be difficult to control. So accuracy is key!

Here’s a chart to help you review the different variables of untreated polymers:

Surface Energy and Contact Angles of Untreated Polymers

You might also want to check out this video for a demonstration (below), or feel free to reach out to the Surface Modification Experts!

Topics: Surface Modification
1 min read

Tips to Bond Silicone Rubber to Aluminum

By Dave Biering on September 23, 2014

Plasma cleaning of metal parts dramatically increases the success of overmolding.We’ve had a few questions lately about the best method of bonding rubber to aluminum before overmolding. It seems this bonding combination poses a tough challenge. And in many cases, we’re finding that companies want to achieve better bond strength without using harsh solvents. So how can you achieve one without the use of the other? Plasma cleaning is the answer.

Plasma vacuum cleaning prepares metal substrates by removing all contaminants without the use of solvents, and with no damage to the components. Plasma is a one-step and solvent-free process to improve bonding silicone rubber to aluminum ― or virtually any other material combination. Because when you begin with a spotless component you can dramatically increase the success of overmolding. 

You can check out our video for additional information or submit a Surface Modification Design Sheet to submit your specs for a quote. Learn how surface modification can also help prepare polymer substrates for bonding.

Topics: Surface Modification Bonding Plasma Treatment Rubber
1 min read

Ultracomp Conveyor Bearings Roll Along for the “Toy of the Century”

By Dave Biering on September 11, 2014

Ultracomp Conveyor Bearings Roll Along for the “Toy of the Century”Agriculture, railroad, construction and other heavy-duty applications are primary areas for Ultracomp bearings – but did you know that the material also helps the “Toy of the Century” meet their holiday production goals? Here’s how:

As the holiday gift-giving season revs into high gear, toy manufacturers look for every advantage to meet increased demand. After all, a breakdown on the production line can lead not only to costly repairs, but potentially missed shipments to toy retailers worldwide. 

When the maker of plastic building blocks approached us to replace their failing metal bearings on their conveyor systems, Ultracomp was the natural choice. Our client described how the blocks begin as granulated plastic and are sent to the high-temperature molding machine. Once molded, the blocks roll along to packaging where they are sorted by shape, color and size and packaged into specialized kits. The metal bearings our client had installed on the conveyors would seize up from the dust generated in molding. The dust adhered to the grease that was applied to the metal conveyor units. The grease also dripped onto the formed parts, which caused a serious quality control challenge.

Since switching to grease-fee Ultracomp bearings, our partner reports the conveyor belts resist plastic dust to run more efficiently and deliver better quality products. And unlike metal bearings, Ultracomp bearings resist friction and vibration and excel against the stainless components of the production line. 

We might even say that Ultracomp delivers the performance of the century to the “Toy of the Century!”

Have you seen the latest Ultracomp Video for more applications of this self-lubricating material? Check it out below!

Topics: Ultracomp Self-Lubricating Bearings
1 min read

Counterfeit Rulon Bearings and Material Failure – What can go wrong?

By Dave Biering on September 9, 2014

Counterfeit Rulon Bearings and Material Failure - Free White PaperHave you downloaded your free copy of our Rulon technical paper, How to Recognize Genuine and Avoid Counterfeit? This paper was developed as a resource to help you source quality components from the many bogus “Rulon” materials that have flooded the market in recent years. But you may wonder what can really go wrong with counterfeit materials ― we thought we’d provide a quick list of common failures:

Rulon is universally recognized as the gold-standard in bearing-grade materials, yet some processors claim they produce genuine Rulon when they are actually producing lesser-quality materials. To avoid these materials, you should consult a trusted source to ensure that the material is manufactured under proper controls. Without the right controls, counterfeit materials can lead to:

Mechanical failure:

  • Inconsistent friction levels
  • Lower levels of stability in high-temperature transitions
  • Chemical failure:
  • Lower resistance to corrosive agents
  • Reduction in material lifespan
  • Change in flammability properties

Electrical failure:

  • Changes to dielectric constant and surface sensitivity 
  • Reduction in arc resistance

Another good resource to help separate genuine from counterfeit is the Materials Database, which provides exact technical specifications. With due diligence, you can avoid the pitfalls of counterfeit materials. Because after all, Quality Control Begins with Precision Processing!

Topics: Rulon Bearing Failure Counterfeit Bearings
1 min read

Q&A – Machining plastics – what do I need to know?

By Dave Biering on September 2, 2014

Machining plastics – what do I need to know?This question came into our Ask the Experts portal and it bears repeating. There are many variables when it comes to machining plastics that one must consider, such as thermal expansion, the speeds and feeds of the machine, plus the need to use a coolant ― and choosing the right one ― to prevent melting. 

How can you avoid the machining pitfalls of chipping and threading? 

For many machinists, moving from metal to plastic can be a bit of an adjustment; particularly in determining heat tolerances. Each plastic is unique; some expand during the machining process, and then shrink again. Some require a dual approach; with an initial round of machining, followed by a cooling-off period, then a final round to complete any final cuts.

To help you through the process, we’ve prepared a machining video (see below) that is full of tips and tricks. Be sure to also check out the complete TriStar video library on YouTube for more timely information on plastics.

Topics: Manufacturing Plastics Machining
1 min read

Rulon Reels In Custom Fishing Components

By Dave Biering on August 28, 2014

Rulon Reels In Custom Fishing ComponentsHere’s a fishing tale about the one that didn’t get away! 

Our team worked with a high-end fishing manufacturer to design a whole new reel drag system. The drag is actually a slip-clutch assembly that allows the line to move freely under the pressure of a sudden hook or the pull of a large fish ― basically keeping the fish engaged while the line is hauled in. 

Why did we choose Rulon LR and Rulon J formulas for this unique clutch application? It all came down to matching the right compounds to the right surface materials.

The new clutch devices incorporate carbon composite bushings for the drag pin and drag washers. With this combination of Rulon materials, the reel now produces a very efficient and smooth transition during drag adjustments. Rulon has helped to increase the drag response time, given longer wear life and provided a competitive value.

Since this initial reel development, our Surface Modification team has also worked with other high-end manufacturers to bond washers to the reel’s metal substrates. 

An added bonus is that Rulon is a self-lubricating material that eliminates the need for manual greasing for the lifetime of the product

Ever wonder if the Rulon material that you have purchased is the “reel” deal? Get your free copy of our technical paper, How to Recognize Genune and Avoid Counterfeit! Or just Ask an Expert!

Topics: Rulon J Surface Modification Rulon LR
1 min read

Waterproof Bearings: CJ resists corrosion and moisture

By Dave Biering on July 22, 2014

Composite CJ bearings resists corrosion and moistureIs corrosion a problem in your marine bearing application?

Are excessive loads or speeds a challenge?

Need a material to resist sea spray, barnacle growth and other water hazards?

We have the answer to these marine bearing challenges.

The CJ bearing system might be the right fit ― it has even performed on elite America’s Cup vessels.  Designed as a replacement for bronze, steel, rolling element bearings and even other polymers, CJ is a simple, self-lubricating bearing solution for marine, construction, railroad and other heavy-duty applications.  Consider CJ bearings when loads are above 15,000 PSI and speeds are between 0-400 feet per minute.

CJ bearings NEVER absorb water, and excel in these marine environments:

Naval submarines

  • Fairwater plane pivot bearings

Self-unloading barges

  • Loading/unloading boom pivot bearings

Off-shore oil rigs

  • Spherical bearings on pipe handling devices
  • Door pivots on water bomber loading doors

Inboard/outboard motor

  • Stern drive pivot points – variable pitch prop pivots

Sail boats

  • Rudder bearings

Water attractions

  • Underwater animatronics and other entertainment applications

Explore the benefits of CJ bearings in our new video (below), or sail on over to the Materials Database for additional tech specs!

Topics: CJ Bearings Composite Bearings Marine Bearings
1 min read

Food Processing, Custom Plastic Fabrication & Frying – Oh my!

By Dave Biering on July 17, 2014

1)	Food Processing, Custom Plastic Fabrication & Frying – Oh my!Have you obtained your free copies of our Food Processing and Food Packaging technical white papers?   Here you’ll learn how food manufacturers are increasing production levels and improving safety ― simply by replacing traditional metal and bronze bearings with durable, value-driven composites and polymers.

Another unique food bearing challenge recently came through our custom fabrication shop when we developed Ultraflon components for a brand new French fry machine. 

Here’s how:

Our partner developed an all-new machine that converts granulated potatoes into crispy fries in just under a minute.  The process involves rehydration, pressing, cutting and frying of the potato product to achieve the perfect product consistency.  With special UL and NSF requirements in place, Ultraflon excelled as a structural and component bearing in this demanding, quick-fry application.  Ultraflon offers superior wear and extrusion resistance, plus low friction to accommodate the machine’s unique design envelope.

Want to explore custom components for your food application?  Check out our custom fabrication video or request a quote today

Topics: Food Custom Bearings
1 min read

Self-lubricating Bearings vs. Greased, Metal Bearings

By Dave Biering on June 24, 2014

Self-lubricating Bearings vs. Greased, Metal Bearings”Why do bearings fail?”  It is a pivotal question that we hear all too often.

Interestingly, one of the primary reasons for bearing failure is related to lubrication.  
Without proper lubrication, metal bearings can overheat and wear prematurely.  And by “proper lubrication” we are referring to a total lack of lubrication, use of the wrong type of lubricant, or even the evaporation that occurs through oxidation or environmental exposure.  Self-lubricating polymer bearings eliminate this concern entirely since they are oil-free.  So what are some other benefits of self-lubricating bearings over metal? 

No maintenance = cost savings

Plastic bearings are the no-maintenance replacement for bronze and metal-backed bearings.  Their oil-free/dry-running nature reduce time-on-maintenance and unplanned production stoppages when a bearing fails.

No grease = resistance to debris

Dirt and dust from agriculture, construction and other punishing environments are no match for self-lubricating bearings.  Since they run dry, they resist environmental debris.

High-tolerance = chemical and sanitation tolerance

In certain industries such as food processing and medical applications, regulations call for frequent wash downs.  Unlike metal bearings, plastic bearings easily tolerate these corrosive chemicals.

These are just a few of the many advantages of self-lubricating bearings.  Here’s how they work to eliminate greasing.

Interested in learning more?  Let our Experts answer your questions, or see an overview of self-lubricating bearings.

Topics: Plastic Bearings Self-Lubricating Bearings
1 min read

Meet TriStar’s Business Development Manager

By Dave Biering on May 27, 2014

Judy Cedrone - TriStar PlasticsJudy Cedrone solves bearing challenges and gives industry insight

“I love helping our engineering clients solve their tough bearing challenges,” says Judy Cedrone, Business Development Manager at TriStar Plastics, “and in this position, no two days ― or two applications ― are ever the same,” she adds with a smile.  

Serving over 70 industries for more than three decades, the TriStar team has mastered every type of bearing application ― from replacing tried-and-true automotive brake bearings to fabricating high-performance bearings for elite America’s Cup vessels.   “There is so much innovation in the marine industry right now,” says Judy, “and self-lubricating bearings such as the Ultracomp 300A give marine engineers an unbeatable combination of extended service and corrosion resistance for superior design flexibility.”

Judy recently celebrated her 26th year at TriStar, and has held several positions within sales and management.  She notes that she is just one of many employees with long tenure at TriStar, “Our customers are amazed at the continuity of care they receive from TriStar; even years after their initial contact with us, they can usually reach the same person to answer any questions.”   

Beyond helping customers solve tough engineering challenges, Judy loves “nature, hiking, and virtually all water activities ― especially kayaking,” from her base in North Carolina.  And she has a real soft spot for rescue dogs.  But it is her latest canine addition, Savannah, who has stolen Judy’s heart!

To find out how self-lubricating bearings can help your businessget in touch with Judy!
Topics: TriStar Self-Lubricating Bearings Marine Bearings
1 min read

Q&A - What is a sleeve bearing?

By Dave Biering on May 20, 2014

Sleeve BearingThis is a simple question that is worth repeating.  Sleeve bearings are the most common type of plane bearing, and are suitable for use in a range of applications.   Sleeve bearings are designed to carry linear, oscillating or rotating shafts, and function via a sliding action.  Plain and sleeve bearings are often compact and lightweight, and generally offer good value.   To compare various bearing configurations, see our recent post on common bearing types.    Where are sleeve bearings found?  

Common sleeve bearing applications include:

  • Auto industry - Transmission shafts, links, pins and crank components
  • Ag Industry – Linkage assemblies on attachments, steering gear
  • Off-road Industry – Clevis bearings for hydraulic cylinder pins
  • Marine industry - Steady bearings for drive shafts
  • Food industry - Processing and packaging applications where lift and tilt devices are used

Plain and sleeve bearings are also referred to as bushings or journal bearings.  For assistance in choosing the right sleeve, see our Rulon sleeve bearing selector chart.

Topics: Plastic Bearings Plastic Sleeve Bearings
2 min read

Q&A How do plastic bearings compare to standard metal bearings?

By Dave Biering on May 8, 2014

Plastic Bearings vs MetalIt is a question that is still widely debated ― how do plastic and metal bearing compare?   In some industries, plastic is regarded as a premium bearing material, while in others there is a prevailing misconception that plastic is inferior to metal.  We decided to compare the two by looking at a few of the key factors that determine bearing performance ― namely maintenance, durability and service life.  Here’s what we discovered:

Maintenance

Bearing lubrication is extremely important to overall performance, particularly at initial equipment start-up when machines are starting “dry.”   Without the right level of lubrication, aging and wear rates are accelerated. 

Plastic bearings have the maintenance advantage.  They have built-in lubrication properties so components are continuously greased from initial start-up.  Plastics resist the force of stick/slip to deliver longer wear without ever needing additional maintenance.

Conversely, metal bearings require regular manual greasing to reach the proper level of lubrication.  These greasing schedules are a burden to equipment maintenance crews, and contribute to a lower productivity as the manufacturing lines are halted for greasing. 

Durability

Another common misconception in bearing design is that thin-walled plastic bearings do not last as long as their thick-walled metal counterparts.  Nothing could be further from the truth.  Thin-walled bearings are able to dissipate heat, which extends their durability.  A thinner wall design also contributes to better clearance between shaft and bearing for lower friction levels.

Metal bearings are designed thickly to compensate for wear, but even with the extra material, the metal surface can fail.  Ultimately, bearing materials should be chosen based on their predicted wear, not on the thickness of the part.

Learn how reinforced plastic bearings extended wear and reduce costs in high-speed rotary applications.

Service

Generally speaking, plastic bearings routinely deliver longer service than oil-impregnated bronze bearings.  In fact, service life can be predicted through tribology testing, which measures friction and other properties of plastic materials in simulated industrial applications.  Tribology can also protect the end user of the material by ensuring that the components meet all applicable industry standards.   Metal bearings are not regularly tested for service life. 

Ask our Experts about the benefits of plastic bearing for your application.

Topics: Plastic Bearings Self-Lubricating Bearings Bearing Performance
2 min read

Common Types of Plastic Bearings

By Dave Biering on April 29, 2014

Types of plastic bearingsOur plastic bearing blog has covered hundreds of topics over the years ― everything from questions on the surface energy of plastics to the advantages of high-performance bearings aboard America’s Cup.   This week we wanted to take a “back-to-basics” approach by reviewing some of the common types of plastic bearings.

As a quick review, bearings enable rotational or linear movement, and are designed to reduce friction for easier movement and speed.  Here are 5 common configurations:

  1. Flange bearings

    20140429_flangeFlange bearings are designed to handle both axial and radial loads. In some designs the flange is also used as a locating mechanism to hold the sleeve portion in place. Flange bearings require a little more machining to the housing but can solve the unique load conditions of a shaft and some type of thrust surface.

  2. Mounted bearings

    20140429_mountedMounted bearings come in the form of pillow block or flange style housings. These can be in many different forms with 2, 3 or 4 mounting holes. Mounted bearings can be retrofit with several different plastic plane bearing materials to improve wear and reduce or eliminate lubrication.  

  3. Thrust bearings

    20140429_thrustIn plane bearing speak thrust bearings are simple washers made from any number of materials. These are generally thin, easy to install and prevent metal on metal contact in any thrust load conditions. Much simpler to use than ball or needle thrust bearings and do not require lubrication of any kind in most conditions.

  4. Sleeve bearings

    20140429_sleeveThe most common plane bearing, sleeve bearings, are simple ID/OD/Length cylinders that are designed to carry linear, oscillating or rotating shafts. The key to successfully designing a plastic sleeve bearing is paying attention to temperature, P, V and PV ratings for the material and match it with your application. Watch our video on designing plane bearings for more information on this process.

  5. Spherical bearings

    20140429_sphericalSpherical bearings are designed to allow for shaft misalignment, as they can rotate from two directions. Spherical bearings typically support a rotating shaft in the bore that calls for both rotational and angular movement. 

For applications with unconventional parameters, the above standard bearings may not be the right fit.  Instead, the best solution may be custom-fabricated bearings. 

See our Materials Database for more technical data on the above bearings, or just Ask an Expert!


Topics: Plastic Bearings Plastic Sleeve Bearings Flange Bearings
1 min read

Trilon Modified UHMW – Ideal for Custom Components

By Dave Biering on April 10, 2014

Trilon AR and FRA question was recently posted to our portal asking about Trilon as a custom component.  Trilon is a modified-UHMW that gives superior wear in highly-abrasive environments. The material is available in variety of formulas, and can be fabricated in the field, or easily customized in-house using carbide or diamond tools.  Trilon excels in industries where durability and longevity matter; including mining, pulp and paper, and timber handling.  Explore our Railroad White Paper to review how custom Trilon FR components delivered superior fire resistance to a mass transit system.

Both Trilon AR and FR give nearly double the wear life of virgin acetal, and up to four times the wear  of nylon.  And since Trilon has a dynamic friction of just .07, the material requires less energy to drive systems ― which can help lower your operating costs. 

Look to Trilon for:

  • Lightweight alternative to stainless steel (8x lighter)
  • Self-lubricating properties that “polish” mating materials to reduce friction
  • Abrasion, moisture and all-weather tolerance
  • Lower operating costs

Ask our design Experts for a quote on Trilon custom components today!

Topics: UHMW Trilon Custom Bearings
1 min read

Tech Tip: How do Self-lubricating Bearings Work to Eliminate Greasing?

By Dave Biering on March 11, 2014

Self-lubricating bearings

I read an interesting article recently that estimated up to 80% of all industrial bearing failures (catastrophic, functional and premature) are related to improper lubrication. The article listed a number of common challenges associated with manual greasing; everything from poor lubricant selection and incorrect application, to lubricant contamination and eventual degradation. Without the right level of lubrication, of course, bearing surfaces are less able to distribute heat, and are prone to failure from corrosion, friction and other issues.

This brought to mind a question we see often on our Ask the Expert portal ― how do self-lubricating bearings actually work to eliminate the need for manual greasing?

Polymer bearings possess inherent lubrication characteristics; in fact, manually greasing a self-lubricating bearing can actually deteriorate the material, since the grease becomes more of a lapping compound. The lapping action will attract debris and shorten wear life.  Check out our video below to learn more about how self-lubricating bearing systems work:

Could self-lubricating bearings be the right fit to replace your metal bearings?  Talk to our team and request a quote today!

Topics: Self-Lubricating Bearings
1 min read

Tech Tip: 5 Common Signs of Bearing Failure

By Dave Biering on January 28, 2014

5 Common Signs of Bearing FailureWhy do bearings fail? This is a common manufacturing question, but one that is not always easy to answer.  Failure can be a result of many factors; extreme working conditions, maintenance and lubrication schedules, or industry-specific demands.  Early indications of bearing failure can include machinery that is running unevenly, or at an exceptionally loud volume, or with reduced accuracy. There are also some visual signs to look for.

Here are 5 common signs of bearing failure:

  1. Abrasion - Generally caused by excessive wear and friction against mating hardware.
  2. Creep - Occurs when there is slipping at the surface fitting.
  3. Flaking - Particle flaking is common with rolling element bearings.
  4. Seizure - This often occurs when bearings are overheated from continuous rotation.
  5. Excessive loads - A bearing with an overloaded capacity is susceptible to premature wear and fatigue.

In most cases, we’ve found that there is an inherent rush to just replace the faulty bearing and move on with production. There’s no time to analyze the root cause of the failure. But by taking the time to understand the cause, you can actually extend the life of the bearing and prevent long-term damage to your equipment. We suggest instituting a regular inspection schedule to avoid bearing failure before it ever happens.

Trying to identity a bearing failure in your application? Our engineering experts can guide you to an answer.

Topics: Bearing Failure Plastic Bearings
1 min read

Q&A: How can I Bond Rulon? See a Demonstration!

By Dave Biering on October 8, 2013

Bonding Rulon® to steel, aluminum and other substrates can be easily achieved, however, surface preparation is critical in order to achieve the best bond strength.  One material that is specially formulated for bonding is Rulon 142, which is etched on one side.  The material was developed primarily for machine tools and is known for superior performance in linear bearings and slides.

Watch this demonstration to learn about the proper techniques for preparing, bonding, and finishing  Rulon 142 and other formulas. 

Or just Ask the Experts in the TriStar Lab for a specific recommendation on your material; we are here to offer assistance!

Topics: Bonding Rulon
1 min read

TriSteel Self-Lubricating Bearings for Automotive Applications

By Dave Biering on September 10, 2013

Self-lubricating Bearings for Automotive ApplicationsAuto design manufacturers are constantly seeking new solutions to help improve the safety and performance of their vehicles.  Innovations in 4-wheel drive controls, CVTs (continuously variable transmissions), clutch systems and dual-mass flywheels are helping to meet those goals.  But these components have also increased the demand for heavy-duty sliding, oscillating and rotary bearings.  TriSteel bearings are designed to excel in automotive applications:

  • Dual-layer design gives many options for outer-shell structural support and polymer liners
  • Self-lubrication gives manufacturers maintenance-free design options
  • Exceptional capacity for tolerating side loads
  • PEEK/Stainless bearings are an excellent substitute for applications in high temperature chemical valves and pumps.
  • Good vibration resistance for auto undercarriage components

Want to learn about other applications for TriSteel bearings?  See our video in the TriStar Video Learning Center to learn more!

Share your experience with reinforced bearings!

Topics: TriSteel Automotive
2 min read

Reinforced Plane Bearings: The Pros and Cons of Different Liners

By Dave Biering on September 3, 2013

Blog 20130903bIn our last post we reviewed the key questions to ask when selecting a liner material for reinforced bearings. Ultimately, the final selection will depend on the exact parameters of your application (load, speed and temperature), and we also recommend that you review the size and shape, plus cost and machinability of your material.   When you’ve evaluated all of these factors, here are some liner option to consider, and common uses of each:

PT
Low friction, high PV, high speed, no lubrication required, high-operating temperature.   An enhanced-wear PTFE liner for use in lubricated and dry environments. With lubrication, PV ratings can exceed 1,000,000.

Uses: Material handling, agriculture, and hydraulics. The PTS version is lead-free for use in food-grade applications.

AC
Good for use in lubricated or dry environments, and offers high PV. With lubrication, PV ratings can be met without limitations. Lubrication reservoirs are available on the liner to produce a constant storage and pumping action for better hydrodynamic film generation. 

Uses: mining equipment, chassis components

PE
Operates with or without lubrication, high PV, and high temperature. With lubrication, PV ratings can exceed 1,000,000. Lubrication reservoirs are available to produce a constant storage and pumping action for better hydrodynamic film generation; reservoirs unnecessary in dry applications.

Uses: chemical pumps and valve bushings

PR and P4
Good for high-speed reciprocating, self-lubricating, high-temperature and high-load applications. Liner is designed specifically for high-frequency dither applications. 

Uses:  valves, shock absorbers, hydraulic controls – both lubricated and dry

AT
High-PV and high-speed applications, and this liner will run with zero lubrication. Liner thickness allows for secondary machining to accommodate misalignment.

Uses:  ski lift chair clip bearings, lift and tilt on medium-speed and mid-load applications.

TriSteel reinforced bearings are metal-backed and contain various self-lubricating liner materials that are sintered to the substrate for longer wear.  Read about our newest variation, TriSteel P4.

Interested in learning more about reinforced bearings?  Submit your design specs or request a quote!

Topics: TriStar Material Selection
1 min read

Rulon Bearing Tape = 500x Industry Standard for Wear Resistance

By Dave Biering on June 18, 2013

Rulon Bearing TapeWe recently answered a question via our Ask the Experts forum from a client searching for a tape with outstanding wear qualities.  Rulon tapes outperform all products in their category.  In rotation tests, this material offered 500x  wear resistance, and very low friction.  Rulon tapes are available in both low temperature acrylic and high-temperature, clean-release silicone adhesive.

Rulon® tapes are manufactured from skived, PTFE films and are available in thicknesses ranging from 0.002 in. to 0.260 in. Standard widths are 6” or 12” and custom widths are available.   All tapes can be chemically etched to provide a bondable surface and just the right tack strength. 

Consider Rulon tape for use in liners, and chute and rail coverings.  You can also review our Rulon Comparison Chart for specifications on different grades

Topics: Material Selection Rulon Materials High Performance Materials
1 min read

Machining Rulon® - 8 Techniques to Finish Stock Material

By Dave Biering on May 28, 2013

Machining Rulon - 8 Techniques to Finish Stock Material

You’ve identified the ideal Rulon formula for your application, and now need some advice on achieving the best machining technique to fit your application.Before you start experimenting, here are some of the most-common machining methods.

Rulon can be finished by using the following techniques:

  • Cutting
  • Sawing
  • Centerless Grinding
  • Tapping and Threading
  • Reaming
  • Turning and Machining
  • Screw Machining
  • Etching

SURFACE SPEED (F.P.M.): 400 for RULON®

As a rule, we recommend a machining surface speed (F.P.M) of 400. A feed rate of .004 to .006 in. per revolution is ideal when working with stock of 0.125 in. diameter or smaller; the bar will have to be supported during forming either through a center hole or on the side opposite the tool. Very small diameter pieces may require a much larger diameter ground rod to form the required diameter just prior to cut-off. Keep in mind that standard screw machines generally limit bar length to 12’.

Rulon Machining Guidelines

For more on machining plastics, check out our machinining slide presentation or grab our free machining white paper

We can also help you alter the surface of your material to improve adhesion properties of paint or other coatings. Learn more about the advantages of Surface Modification.

Custom Plastic Fabrication: Get the Guide! 

Topics: Rulon Materials Plastics Machining
1 min read

Rulon Plane Bearings and Coefficient of Friction

By Dave Biering on April 16, 2013

Q: We are designing plane bearings made of Rulon®, what are some key considerations in terms of coefficient of friction?
 
A:   This is a question that we hear often regarding Rulon, Ultraflon and other PTFE-filled materials.   The short answer is that these design materials are exceptions to the general rules of friction.  With most materials, you can presume that higher loads and higher speeds would mean higher friction.  But with PTFE-filled materials, the opposite is true; the higher the load and speed, the lower the friction. This is important to keep in mind when designing, since surface contact area can be reduced dramatically to optimize friction properties.  
 
We’ve prepared a Coefficient of Friction video that covers this topic in much greater detail, but also invite you to reach out to Our Experts to review your application needs.

Topics: Rulon Materials Composite Bearings
1 min read

Recognizing The Three Types of Bond Failure

By Kevin Smith on March 26, 2013

Blog 20130326In the last few weeks we’ve reviewed the importance of having a good bond adhesion in order to ensure proper device performance.  But it is just as important to be able to recognize an adhesive bond failure.   So what should you be looking for?

There are 3 primary types of bond failure: adhesive, cohesive, and substrate.

Adhesive

This is the most common failure when bonding dissimilar materials.  The adhesive (glue, paint, coating, tape, etc.) has more chemical and/or mechanical attraction to one substrate than the other.  When the bonded material is submitted to lap-shear testing (pulled apart by hand), the two pieces come apart and all (or most) of the adhesive remains on one substrate.  This is referred to as “delamination.”

adhesiveCohesive

This is most common failure when the adhesive is too weak for the intended application. As shown below, the adhesion to the substrates is greater than the structural integrity of the adhesive.  This can occur with “soft” adhesives like certain urethanes and silicones.  It can also occur if the adhesive bond-line is applied too thick.

cohesiveSubstrate Failure

This is the best type of failure. It simply indicates that the strength of the adhesive bond and the adhesive itself (and the correct amount applied) is the right formula for the application.

substrateWe can help you avoid a surface bonding failure. Just Ask an Expert!  


1 min read

Preparing Fluoropolymers for Bonding With Plasma Treatment

By Kevin Smith on March 19, 2013

PTFE MoleculeWe are often asked about which method is best for preparing fluoropolymers for a bonding applicationThe most critical step is bonding is to ensure that you begin with a clean surface.

Fluoropolymers are a group of polymers in which all, or most, of the hydrogen has been replaced with fluorine. They have a wide range of mechanical, frictional, chemical, and electrical properties which make them ideal for a many different applications. However, these properties result in such low surface energy levels they are difficult to bond without surface pretreatment.

Sodium-etch solutions are one common surface treatment used for bonding, but they have significant disadvantages.  The wet chemicals are expensive and dangerous, do not coat uniformly, and are very difficult to dispose of.   A better method of preparing polymers for bonding is by plasma treatment

The TriStar team has had good results with surface treatment of fluoropolymers such as FEP,PFA, Tefzel®, and PTFE (Teflon®) with gas plasma.  If an appropriate process is used, the surface of the fluoropolymer is chemically modified and becomes water-wettable, printable and bondable with structural adhesives. The plasma treatment is uniform, dry (no wet chemistries), efficient, and safe. And the process is earth-friendly with no disposal issues.

Wondering if plasma is the right treatment for your bonding challenge?  Reach out to our team to learn more

Topics: Surface Modification
1 min read

Plasma Surface Modification vs. Corona Treatment

By Kevin Smith on March 12, 2013

Plasma Vs. CoronaA question was posed to our Ask the Experts line wondering about the differences between plasma surface modification and corona treatment.  While there are a variety of surface modification techniques to help achieve desired results, today we’ll compare some of the key advantages and considerations of plasma treatment vs. corona treatment.

Plasma can readily prime any surface for adhesion, painting, coating or printing applications.  Plasma is a good option for components that require a longer treatment hold before moving to the next step in manufacturing. Other key advantages of plasma treatment include:

  • Good surface chemistry selectivity
  • Enhanced control of gas type, flow, pressure and concentration
  • Three-dimensional treatment  
  • Earth-friendly process that uses no damaging solvents

Considerations

  • Price is relative to system size; as the system size increases the price increases
  • Throughput is restricted by batch-to-batch logistics
  • In-house systems can be very costly; it most cases outsourcing is a better value

Corona discharge is a form of plasma at standard atmospheric pressure and is normally used with in-line processes such as plastic film, which is where treatment shines.  Key advantages include:

  • Price of purchasing a system for in-house treatment
  • Systems are robust and easy to maintain
  • User-friendly

Considerations

  • Lack of surface chemistry selectivity
  • Limited polymer choice
  • reatment is two-dimensional

See our video for additional information on the strengths and advantages of Surface Modification.

See also: Compare Plasma Treatment vs Corona Treatments.

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1 min read

Plasma Surface Modification – How does the process work?

By Kevin Smith on January 22, 2013

I often receive calls asking to explain, “How does a low-pressure plasma tool actually work?”  I thought I’d share a diagram that we often use to explain the process.  The plasma process is widely used to critically clean and functionalize the surface of components.   After a plasma treatment, components are able to better accept paints, adhesives, inks and coatings.

Simply put, plasma treatment is the grafting of chemical functional groups to the polymer backbone by first removing an elemental component, then replacing it with a functional element.

Plasma Treatment Process

Plasma processing is done in a controlled environment at sub-atmospheric pressure, specifically, a partial pressure (vacuum) with only a particular process gas (or groups of gases) present. The process gas is excited with a high frequency field causing the gas molecules to ionize. This increases the energetic free radicals which react with the molecules on the surface of the material being treated. This reaction includes physical bombardment, oxidation, grafting, cross-linking and even polymerization of the surface molecules.

This is just a quick overview of the process.  Reach out to our Surface Modification Experts for additional information to learn how plasma modification can benefit your manufacturing processes.

Topics: Surface Modification
1 min read

Increasing adhesion on hard-to-bond materials like Delrin

By Kevin Smith on December 4, 2012

Blog 20121204Question: How do I bond Delrin to other materials?

Delrin (also known as Acetal, Polyocymethylene (POM), polyacetal, and polyformaldehyde) is an engineered polymer that is commonly used in the manufacturing of precision parts.  It is a fairly rigid plastic that exhibits low friction and maintains good dimensional stability and good abrasion resistance.  It also has low moisture absorption, good heat resistance, and (like most plastics) is a good dielectric.


Unfortunately, like many engineered and high performance polymers, it can be very difficult to bond, especially with conventional adhesives.  However, Delrin can be made easily bondable with any number of simple pretreatments such as chemical etching, flame treatment, or surface roughening (abrasion).  Of these treatments, the most effective is a plasma treatment to clean and functionalize the material.  Although a corona treatment can be effective, it does not offer the same level of uniformity or treatment lifetime that can be achieved with a low-pressure (vacuum) plasma treatment.  In the case of Delrin, and many other engineered or high-performance polymers, an oxygen plasma treatment may be all that is required to make the material bondable with conventional epoxies, urethanes, or cyanoacrylate adhesives.

Is Delrin right for your next application?  Consult our Experts to find out more!

Topics: Material Selection Surface Modification
1 min read

What is a fluoropolymer?

By Dave Biering on November 13, 2012

This is a question that often appears on our Ask the Experts form.  In fact, we’ve produced a fluoropolymer video (at right) to help you compare and contrast the different materials.  Fluoropolymers are a family of materials that are based on an atomic structure around fluorine carbon.  Different variations can be formulated by adding or subtracting fluorine through other bonds such as chlorine, ethylenes and other chemical agents.

Fluoropolymers come in several forms:

  • Granulate
  • Melt-processable
  • Films
  • Paste
  • Dispersions

Fluoropolymers are lightweight and durable, and resist heat, moisture and chemicals.  To learn more about the varieties available and different processing techniques, watch our video or contact our technical team for more information.

Topics: Fluoropolymers
1 min read

5 Common Gases to Render Polymer Surfaces Hydrophilic

By Kevin Smith on October 23, 2012

Functional groups via plasma processing

Plasma TreatmentsHere is a quick review of five gases that create polar entities on a polymer surface to render it hydrophilic (or wettable):

  1. Oxygen - generally the most effective process gas for increasing surface energy – it creates carbonyl, carboxyl, ester, ether, hydroxyl, and hydroperoxyl functional groups, among others.
  2. Nitrogen - create amino groups, although the specific composition and density differ
  3. Ammonia - like nitrogen, ammonia creates amino groups with varying compositions and density
  4. Argon - the free radicals produced by argon, while promoting crosslinking, are also long-lived; thus, when a treated part is removed from the plasma chamber and exposed to the atmosphere, oxygen-containing groups (predominantly hydroperoxyl groups, it is believed) form.  These may subsequently react with the adhesive to create a covalent bond at the interface.  
  5. Air - is a very complex process gas, and produces all of the functional groups produced by the other four gases.  

The best technique to analyze the chemistry of the functional groups on a polymer surface is an electron spectroscopy; our Surface Modification team is also available to help.

Topics: Surface Modification
1 min read

PTFE-filled Fluoroloy H

By Dave Biering on October 16, 2012

Rulon White PaperI recently had a call about Fluoroloy H from one of our engineering partners.  Fluoroloy H is also known as Rulon H, and is one of the leading PTFE-filled products in terms of electrical properties.

The material is a unique combination of both ceramics and PTFE, and was originally developed for UHF heat-sinking applications.   It gives a slightly-better dielectric constant compared to standard Teflon, and has about 8x the thermal conductivity of virgin PTFE.  It is easy to machine and is available in rod, sheet and tape.

Fluoroloy has high insulative properties, and is widely used in the microwave industry as an alternative to virgin and glass-filled PTFE.

Did you know there are over 300 varieties of Rulon?  Download your free copy of our Rulon Whitepaper to learn more about the most-common formulas.

Topics: Rulon Materials
1 min read

Turcite Materials – Common Applications

By Dave Biering on August 7, 2012

Q&A  Can you tell me about the acetal Turcite for industrial use?  What are some common applications?

Turcite™ is a family of materials made from both Acetal resins and PTFE.  The acetal-based Turcite products are known for exhibiting good strength and stiffness, dimensional stability, resistant to abrasion with very low stick-slip in dynamic applications.

Turcite A and X are the most popular of the acetal-based versions where copolymer resins are blended with low friction and wear additives.

Turcite A and X are common to many industrial applications since they are chemically inert to most solvents.  They are a good choice for enhanced extrusion resistance in dynamic load applications. 

The other side of the Turcite family are modified PTFE materials used for both bearing and seal applications. Turcite B is a popular linear bearing material for the machine tool industry and there are many Turcite grades used in industrial seals, wipers and wear rings for hydraulic and pneumatic cylinders, valves and other control devices.

 Ask Our Experts for more information on Turcite, or consult our Materials Database.

            ™ - Turcite is a registered trademark material from Trelleborg.

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Topics: Material Selection Q&A
1 min read

Plasma Modification – The Basics: Oxidizing species

By Kevin Smith on July 17, 2012

Our Surface Modification team is often asked about the benefits of low-pressure plasma treatments.  Plasma offers many advantages to industries ranging from medical and biotech to aerospace and automotive.   For the next few weeks, I’ll touch on some of the basics that are helpful to know when considering plasma treatment for your application. 

Oxidizing species such as air, oxygen, water vapor, or nitrous oxide are often used as processing gases in low-pressure (vacuum) plasma systems to remove organic contaminates and to leave functional oxygen-containing groups on the surface of the device and/or material being treated.  These groups greatly enhance wetting and improve the bond-strength of adhesives, inks or paints, tapes, encapsulation/potting resin, and coatings.

Reducing gas species such as hydrogen or methane (often mixed with argon, helium, or nitrogen) may be used to remove organic contamination from substrates that may be sensitive to oxidation.  This chemistry may also be used to partially substitute hydrogen atoms for fluorine or oxygen on the surface of polymer substrates.  The noble gas species, such as argon or helium, are chemically inert so they do not combine or become part of the surface chemistry.  Instead, they transport energy to break chemical bonds in polymer chains.  Broken polymer chains result in dangling bonds which recombine with other reactive sites, resulting in significant molecular restructuring and/or crosslinking.  The creation of dangling bonds allows for chemical grafting reactions to occur.

Have questions on plasma processing?  Consult our Experts to learn more.  

Topics: Surface Modification

Plastic Bearings and Coefficient of Friction

By Dave Biering on May 29, 2012

We all realize that friction generates heat, and heat can be problematic for plastic plane bearings. So how can you choose the right plastic bearing material for a high-friction environment?  Which materials will give you the longest wear?  Our video below reviews key design considerations such as temperature, load, and speed, plus surface finish, hardness and more. 

To learn more or for guidance on your specific application, just reach out to our Experts; we can help you select the right material.  

Topics: Material Selection
1 min read

Machining UHMW – Points to Consider

By Dave Biering on May 1, 2012

A customer recently asked us for tips on machining UHMW materials to better hold tolerances. UHMW is a very unstable material to machine, since it has roughly 12x the thermal expansion of steel. 

Some of the key factors that we like to review include the size and geometry of the part, the speeds and feeds of the machine, plus the types of coolants to use (and those to avoid). With the right technique in place, chipping, threading and other challenges can be avoided. 

We’ve created a video to provide even more machining tips. Or our in-house machining experts are always available to help you troubleshoot, and can point you to our “Machining Plastics" seminar.

Custom Plastic Fabrication: Get the Guide!

Topics: Plastics Machining
1 min read

What are some advantages of using polymer materials for gears?

By Dave Biering on April 17, 2012

Polymer gears are commonplace in many industries and applications.

Polymer gears are commonplace in many industries and applications. The advantages of a polymer gear include noise reduction, self lubricating features, dramatic weight reduction and cost savings. From paper mill gears to drive gears in copiers, polymer gears have been successfully used for years.

But everything you know about metal gear design gets thrown out the door with polymers. There are many different factors that have to be considered when designing gears out of plastics including thermal expansion and contraction, physical strength, moisture absorption and possible chemical exposure.

Typical polymers for gears are cast nylons, injection molded nylons, polyester and acetal. Various fillers help to strengthen the base polymers such as glass and carbon fiber, aramid fibers and other additives are used to improve lubricity. More recently high end polymers like PEEK and Torlon have been used to make high temperature gears or gears where exceptional strength is required.

No matter what the material, designing polymer gears will require some extra thought and a change from the norm. Tooth profiles and overall height may need to be changed to accomodate bending forces. Contact conditions at the root of the tooth may need modifications from the norm. Flex strength of the polymer will definitely come into play so input and output torque requirements will need to be reviewed closely.

While there are a lot of advantages to polymer gears you can't overlook the basic differences between steel gears and polymer gears. Material choice and adherence to design changes required to address the physical, thermal and wear requirements of the gear must all be looked at closely.

TriStar has several thermoplastic and thermoset materials used frequently for gears and our engineering department can help you in this process. Have more questions? Just ask! 

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Topics: Misc Products

Q&A: Which material do you recommend for small construction equipment? Our cast nylon bearings are not lasting as long as we’d like.

By Dave Biering on April 3, 2012

This question was posed to us from a manufacturer of small excavators, the kind you often see in the consumer rental market.  Cast nylon is a good material for farming and construction, but with some drawbacks when it comes to moisture absorption and UV stability.  Depending on where you use them, nylon is good for cable sheaves, but for pivot points, we recommend these materials for top performance.

Topics: Construction Q&A CJ Bearings Ultracomp

TriSteel PE Metal-Backed Bearings

By Dave Biering on March 20, 2012

I recently had a call about our TriSteel line of bearings.  TriSteel PE bearings are specifically-designed for high-temperature and corrosive environments. Using a PEEK liner and stainless steel backing, this PE bearing can withstand temperatures up to 485°F in the most corrosive environments

Tri-Steel™ PE Series Bearings are ideal for application such as:

  • Pump shaft bearings
  • Valve stem bushings
  • Oven bearings
  • Tenter frame bushings
  • Automotive applications

Want more details about TriSteel?  View our video, below.

Topics: TriSteel Bearings
1 min read

Q&A: Treating Acrylic with Plasma

By Kevin Smith on February 28, 2012

Question:

We are attempting to bond two machined pieces of acrylic together to form a microfluidic device. I know that direct plasma bonding of acrylic won't work, but that plasma treatment of the acrylic can lead to a much better seal/bond when using an adhesive (e.g., epoxy).

Can you recommend a good starting place for a plasma surface treatment of acrylic, such as gases, ballpark power value, time, etc.?

Answer:

It is true that acrylic bonding is easily achieved via solvent and/or heat welding, but if the material is be bonded by applying a conventional cyanoacrylate or epoxy, a quick pretreatment with vacuum plasma can – as you mentioned – significantly improve the strength of the bond.  In the case of treating acrylic, the preferred treatment gas is oxygen. The power required is minimal as is the processing “plasma on” time.  It can be easy to “over process” some materials; this is true with acrylic.  The amount of time that the devices are processed in the chamber can depend on the type of system used, the amount of gas flow, and the load size.  For a full load of devices in a medium-sized chamber, a treatment time of 5 minutes should be fine; however, you should test random samples with a goniometer (or Dyne pens) to make sure that the treatment is uniform and effective.

Slight adjustments to power and time will help you optimize the process for your parts and volumes.

TriStar can assist in the plasma recipe development process; just contact us to discuss your application and production requirements.  As a side note, since you will be using pure oxygen as a process gas, it is important (from a safety standpoint) that your plasma system is equipped with a vacuum pump that is either a dry (scroll) or is lubricated with PFPE (Fomblin or Krytox) oil.  Vacuum pumps used for plasma systems should not be lubricated with conventional hydrocarbon oils if oxygen is used as a processing gas.

Do you have a question about bonding your application?  Our surface modification team can help find a solution!

Topics: Surface Modification Q&A
1 min read

Q&A: Is there a seal material that will operate at 600° continuously?

By Dave Biering on February 7, 2012

This question was posed to us from an aerospace client.   Temperature is always a big issue in aerospace, particularly in military aircraft and vehicles.  And continuously maintaining 600° can be a challenge, given that the materials that resist such high temperatures are usually more rigid.

TriStar has a range of high-pressure, high temperature seals available.   More details, including the key considerations to help you improve performance in seal material, are available in our video.  Or let us review your design specs, and we’ll help you match the right polymer to the right hardware.

Topics: Material Selection Q&A

Q&A: How do I identify which Rulon material I have?

By Dave Biering on January 24, 2012

With over 300 different types of Rulon available, this is a question that we hear quite often.  TriStar is the official North American distributor of Rulon, so we have the in-house experts to help you identify and source the right material for your application.

View our video to learn about identifying the three most commonly-used Rulon materials, or download our Rulon white paper now for more information.  At TriStar, we realize the best performance begins with the right material selection.

Topics: Rulon Materials Rulon Plane Bearings Q&A
2 min read

Material Selection Process (MSP)

By Dave Biering on December 13, 2011

What type of material should I use?  Can you review the pros and cons for this application?  What are the technical specs?  

These are just some of the questions we are often asked on our Ask the Experts forum.  Since selecting the right material is crucial to the ultimate performance of your application, TriStar offers an on-line Materials Selection Database.  But here are some key considerations to help you find just the right solution:

  • Physical Requirements

Is the part being designed going to be in a tensile, compressive or flexural state? All plastics will vary in their inherent strengths and with the addition of reinforcing additives we can change these strengths to meet specific demands.

  • Temperature

All plastics are impacted by ambient heat and have a maximum continuous service temperature. The maximum continuous service temperature is not a melting point, but is the highest temperature at which a material will retain physical integrity. Important: Note that elevated tempera­tures impact material properties in a negative manner and should be carefully reviewed before use.

  • Temperature Variation

All plastic materials have coefficients of thermal expansion. Measured in in/in/°F, plastic materials vary greatly not only from each other, but in some cases ten times that of metallic counter parts. As a result, we consider temperature variations. Components should be designed to meet required service temperature. Not doing so may result in premature failure.

  • Environmental Conditions

Always consider the following environmental conditions under which the material must operate:

- Contact with debris such as sand, grit or dust

- Contact with chemicals such as strong acids, bases and caustics

- Contact with water, constant spray or wash downs

- FDA or USDA compliance

- Thermal/electrical conductivity or insulation

- Radiation exposure

- Microwave exposure

  • Other important considerations

- Size and shape availability

- Material cost/economy

- Machinability

- Standard or custom runs

- Custom compounds

TriStar’s custom solution experts are always available for consult.

Topics: Material Selection
1 min read

Trilon AR

By Dave Biering on October 25, 2011

I recently received a call on Trilon AR, one of our newer materials.  Trilon AR is a modified UHMW compound available in rod or sheet form. It is a good option for chain guides, gears, sprockets and bearings.  Trilon excels in mining, pulp and paper, and timber handling applications.

Other key attributes:

Features:

  • Extreme abrasion resistant
  • Does not absorb moisture
  • Self-lubrication
  • Lowest friction

Benefits:

  • Long wear
  • Low operating cost
  • Machinable
  • Good in all weather
  • UV resistant

 Consult our team to see if Trilon AR would be a good fit for your application.

Topics: Misc Products
1 min read

Benefits of Plasma Cleaning

By Kevin Smith on October 4, 2011

  • Remove organic contaminants by chemical reaction (O2) or physical ablation (Argon plasma)
  • Eliminate the use of chemical solvents as well as storage and disposal of solvent waste
  • Clean surfaces with microscale porosity or microchannels not suitable for solvent cleaning due to surface tension limitations
  • Render most surfaces hydrophilic; decrease water droplet contact angle and increase surface wettability
  • Promote adhesion and enhance bonding to other surfaces
  • Prepare surface for subsequent processing (e.g. printing, painting, coating, potting)
  • Clean surface without affecting the bulk properties of the material
  • Can treat a wide variety of materials as well as complex surface geometries; examples include:
    • Semiconductor wafers and substrates (Si, Ge)
    • Glass slides and substrates
    • Optics and optical fibers
    • Oxides (quartz, indium tin oxide (ITO), TiO2, Al2O3); mica
    • Gold and metal surfaces
    • Atomic force microscopy (AFM) cantilever tips

Tell us about your experience with plasma cleaning.

 

Topics: Surface Modification Plasma Treatment
1 min read

Q&A: Why are PTFE Teflon prices going through the roof?

By Dave Biering on March 9, 2011

All of us in the fluoropolymer business are suffering what could be called a perfect storm of bad news! First, the raw material situation. One of the key ingredients in the processing of fluoropolymers is a mineral called fluorspar. This is a material that is critical in the production of not only fluoropolymers but pharmaceuticals, hydrofluoric acid, refrigerants and any other product that requires a fluorine based stock. China controls most of the worlds resources on this mineral and it became part of a war of words and ultimately manipulation in the world market. Countries, including the USA, are now scrambling to reopen old or open new mining resources of this critical mineral. So this shortage, as well as a worldwide surge in demand for fluoropolymers and a reduction in processors of the PTFE resin, all leads  to this very difficult situation. The bad news is there is no end in sight. The EU has declared fluorspar to be on it’s worldwide shortage list until 2030. So we all  will have to deal with this out of control pricing escalation for years to come. Best if you call Tri Star and place blanket orders for your requirements for the future!!

Topics: Material Selection Rulon Materials
1 min read

Plane bearings for a wet environment

By Dave Biering on September 22, 2010

Over the summer — at the height of boating season — I was asked how to choose the right bearing for use in a wet environment.  As a whole, plastics do not do well in wet applications; most traditional polymers tend to absorb moisture and saturation. Nylon materials, for instance, are susceptible to humidity and swelling issues.  Even those polymers that do well in water can usually withstand freshwater only, not saltwater. 

So what are your bearing choices for a wet environment application?  Polyesters and Acetron materials hold up well.  And our marine clients have done extremely well with Ultracomp for their rudder bearings, since they are durable and excel in linear, oscillating and rotary applications.  Our CJ product line is another good choice, since they remain dimensionally stable in liquid.  No matter what material you choose, we recommend that you avoid graphite, because it gives a cathodic charge in saltwater.

Very few PTFE-based materials excel in water, but we can help you find the right one for you freshwater, saltwater, DI, or chemical blend submerged applications.
Topics: Material Selection CJ Bearings Ultracomp Marine
1 min read

TriStar Plastics Named Exclusive Distributor by Saint-Gobain

By Richard Cedrone on July 20, 2010

Rulon, Rulon Bearings, Fluoroloy

TriStar Plastics today announced it has been named as the exclusive, North American distributor of the Rulon®, Rulon® Bearings and Fluoroloy® family of bearing products by Saint-Gobain Performance Plastics. This exclusive agreement is the culmination of a nearly 30-year partnership between TriStar and Saint-Gobain. "We are honored to broaden our relationship with Saint-Gobain through an exclusive parnership agreement," said Richard Cedrone, CEO of TriStar Plastics. "The Rulon solution offers unique benefits to our customers across a broad-range of industries, including food and beverage, agriculture, medical device and manufacturing. This partnership is a natural step in allowing us to better serve our customers."

Rulon and Fluoroloy bearing materials excel in heavy-duty and high-load applications by offering a combination of low coefficient of friction and excellent abrasion and corrosion-resistance. They also outperform and outlast other materials, including metal, and are self-lubricating for enhanced efficiency and reduced maintenance costs.

"At a time when equipment manufacturers are looking for a competitive edge and a way to reduce expenses, TriStar brings a tremendous amount of knowledge to the table," said Victor Lapinski, North American Distribution Manager at Saint-Gobains' Seals Division. "Their technical expertise, multiple distribution centers, and commitment to customer service make them an ideal choice and an elite business partner." The agreement is effective immediately.

Rulon - Quality Assurance Begins With Precision Processing

Topics: Rulon Materials Rulon Plane Bearings Announcements
1 min read

Torlon is for Punishing Environments

By Dave Biering on June 16, 2010

Torlon® is a high-strength plastic, and is among the most expensive on the market. Torlon can be injection molded, compression molded, and extruded, and is ideally suited for severe service environments. Applications include pump components, valve seats, bearings, rollers, high temperature insulators, electronic equipment, compressor components, and bearing cages.

The main characteristics of Torlon are a high maximum allowable service temperature, excellent mechanical strength and creep resistance over a wide range of temperatures, extremely low coefficient of linear thermal expansion, low flammability, exceptional resistance against high-energy radiation, moderate chemical and hydrolysis resistance, and excellent UV resistance. And Torlon is excellent at maintaining physical properties.

We've got a range of Torlon grades available for your application:

● 4203 and 4503 - structural/insulating grade offering good insulating properties, low thermal expansion, moderate coefficient of friction

● 4301 and 4501 - extrusion most popular - gives excellent wear, reduced coefficient of friction, little to no stick slip, flex modulus over 1 million psi

● 4540 - bearing grade for extreme wear life - insulating materials (primarily structural): aluminum, and stainless steel

● 5530/4XG - excellent electrical insulating properties, good wear resistance, abrasive towards mating surfaces, moderate dynamic coefficient of friction

● 4XCF - another good bearing material in hi-temp applications, high stiffness, lowest coefficient of thermal expansion of any standard polymer shape, non-abrasive

Tell us about your experience with Torlon.

Topics: Misc Products
1 min read

PTFE Slipper Seals

By Dave Biering on March 3, 2010

Our team has seen a spike in interest in slipper seals.

Slipper seals, made from filled PTFE, are designed to act as a low friction interface between a static elastomer expander and the dynamic mating surfaces. i.e shaft or bore. With filled PTFE like our Ultraflon, slipper seals offer exceptional wear life, extrusion resistance, low friction and elimination of stick slip. Slipper seals can be used in both hydraulic and pneumatic applications, lubricated or dry and across a broad temperature range. Since these seals depend on the elastomer for their energizing function, the temperatures will depend on the operating capabilities of that elastomer.

PTFE slipper seals are made in a variety of geometries and cross sections to accommodate the design envelope. There are piston seals, rod seals, wiper seals and a variety of supporting components to make up a complete cylinder design. Tri Star has seal engineers on staff to assist in the design of your slipper seal requirements.

You know the drill - if you have a question, Ask The Experts!

Topics: Misc Products
1 min read

More on Crystallinity of PTFE

By Dave Biering on February 2, 2010

Previous blog addressed importance of crystallinity control on PTFE as it relates to porosity, changes in physical strength and dielectric values. More Tri Star testing has shown better detail on the effects of processing and crystallinity. Specific gravity is the primary gage of crystalline or amorphous stages of polymers. In the case of PTFE the range is generally between 2.1 and 2.3 for unfilled resin. Testing showed that at 2.1 SpG the crystallinity of the molded product was approximately 38%. At 2.13 it was 47%, 2.15- 53%, 2.17 - 60%, 2.2 - 70%. Remember, the higher the crystallinity the lower the flex life, higher compressive stress, lower recovery, more permeability and lower wear life.

Another part of the equation has to do with microvoids as it relates to crystallinity. Microvoids are generally a result of poor attention to preforming conditions and to a lesser extent the sintering process. Microvoids, or porosity, have a direct bearing on crystallinity. As an example, a low microvoid material at 2.13 SpG would be 47% crystalline. However, if processing problems occur and void content grows you could see a substantial increase in crystallinity. At a 1% microvoid level the 2.13 sample at 47% crystallinity would increase to 53%. Doesn't sound like much but could have a great influence on the properties and wear of the material. Additionally, at 1% void content the dielectric strength of the PTFE would drop from it's normal 500 v/mil to 320 v/mil. This is significant when considering PTFE as a dielectric insulator. For more information on the importance of quality in PTFE, contact TriStar via this blog site or our website.

Topics: Misc Products
1 min read

Which Plastics are Biocompatible?

By Dave Biering on December 21, 2009

Which plastics are biocompatible?

The growth of plastics in medical devices is growing exponentially around the world. Plastics are regulated like any other materials that may come in contact with human tissue or fluids and that usually falls under testing procedures issued under USP or ISO10993.

There are three time scales for biocompatible devices:

  1. Limited - Less than 24 hour exposure
  2. Prolonged - 24 hours to 30 day exposure
  3. Permanent -  30 days and longer.

When determining biocompatibility, devices are categorized as follows:

  1. Surface Devices - Items such as electrodes for monitoring, contact lenses, catheters, endotracheal tubes, sigmoidoscopes and similar devices.
  2. Externally Communicating Devices - such as laprascopes, blood administration devices, pacemakers, oxygenators and the like.
  3. Implant Devices - such as orthopedic pins or plates, heart valves, grafts, stents and similar devices.

Testing of these devices includes mechanical, thermal, chemical tests as well as systemic injection, intracutaneous and implantation. All of these must be done before a plastic component can be approved.

Typical materials for biocompatible applications include medical grades of PVC and Polyethylene, PEEK, Polycarbonate, Ultem PEI, Polysulfone, Polypropylene and Polyurethane.

For more specific information on biocompatible materials as well as special plasma preparation treatments of all of these materials, contact TriStar Plastics at www.tstar.com and visit our Video Learning Center.

Have a question about surface  modification? Ask our experts!

Topics: Surface Modification Q&A Medical
1 min read

Surface Energy of Plastics

By Frank Hild on December 16, 2009

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When working with any polymer, if the material surface energy is relatively low, then any coating will not flow well and fisheyes, pinholes, gaps, or air bubbles will form. If the material surface energy is too high, then the paint, ink, or coating may bleed or be difficult to control. Therefore, the surface tension of the liquid and the surface energy of the material must be matched for the application.

The dynamics of wetting (watch video) are described below:

Spreading = A - ( B + C )

Where:

  • A = surface energy of solid (given below)
  • B = surface tension of liquid
  • C = surface energy of solid-liquid interface

If Spreading is:

  • Negative. Then, liquid will bead up.
  • Zero to Postive. Then, liquid will spread.
Surface Energy of Plastic

Visit our Video Learning Center or our Surface Modification product pages for more.

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Topics: Surface Modification
1 min read

Tivar HOT - High Temperature UHMW

By Dave Biering on December 8, 2009

Tivar HOT is a unique UHMW grade that has a dramatically higher continuous operating temperature (275F) than standard UHMW. Tivar HOT still has excellent wear and abrasion resistance, doesn't absorb moisture, has excellent chemical resistance and meets FDA, USDA and 3A guidelines.

We have found this product to be excellent for higher temperature zones in food processing and packaging equipment but it has also proven to be a great material in down-hole oil drilling applications!

It's a pretty diverse material! If you need excellent abrasion resistance, low friction, self lube bearing material with all of the other attributes mentioned, consider Tivar HOT from TriStar

Our video (below) has some more information about Tivar Hot.

Topics: Misc Products
1 min read

Fluoroloy H Dielectric Insulator Material

By Dave Biering on December 7, 2009

Fluoroloy H Dielectric Insulator Material

Fluoroloy H, aka Rulon H, is an interesting combination of ceramics and PTFE. This unique dielectric material is used inside connectors for high power applications.

The Fluoroloy H material has a slightly better dielectric constant compared to standard Teflon but has a higher rate of thermal conductivity. This allows the heat being generated at the center conductor to transfer to the outer conductor more efficiently, which in turn increases the power level efficiencies of the connector.

The thermal conductivity of Fluoroloy H is 1.21 W/m C and virgin Teflon PTFE is 0.24 W/m C. Fluoroloy H is easy to machine, similar to virgin or glass filled PTFE. Available in rod, sheet and tape.

For improved dielectric properties as well as heat sink properties, Fluoroloy H from TriStar Plastics is a unique design option.

If you are interested, learn some more about fluoropolymers (see embedded video below) or if you have a question that's driving you crazy - Ask The Experts!

Custom Plastic Fabrication: Get the Guide!

 

Topics: Fluoroloy
1 min read

Effect of Crystallinity on Physical Properties of PCTFE at Liquid Oxygen Temperatures (-320F)

By Dave Biering on December 7, 2009

PCTFE has long been the go to material for valve seats, seals and gaskets used in cryogenic applications. But one thing that makes PCTFE unique is that it can be processed to meet a broad molecular state, i.e. crystalline or amorphous. PCTFE is a melt fluoropolymer and when molded in either sheet, rod or tube form it can be set at a specific crystalline state through a unique quenching process. This process is not as easily manipulated with extruded PCTFE rod so if you are looking for controlled molecular values you need to consider molded product.

As an example of some of the differences in physical properties between the amorphous PCTFE and crystalline PCTFE, consider these values:

Property differences between amorphous PCTFE and crystalline PCTFE

Crystalline/amorphous values are monitored by specific gravity and performance in cryogenic service utilizing amorphous grades of PCTFE has been well documented in terms of service life, sealability and property retention.

Ask The Experts at TriStar for more information on how PCTFE can be "custom tailored" to your application through molecular manipulation!

Topics: Material Selection Misc Products
1 min read

Q & A: Can I use gamma radiation to sterilize a Teflon part?

By Dave Biering on December 7, 2009

The first part of the answer is we need to know what kind of Teflon. DuPont's family of Teflon products includes a number of different materials. PTFE is the best know of this family and the answer to your question for this material would be NO! PTFE does not hold up well at all in gamma radiation. As an example, 4Mrads of exposure reduces the tensile strength of the PTFE to 2% of it's original value.

A better fluoropolymer for gamma irradiation would be DuPon'ts Tefzel product which is known by the chemical moniker of ETFE. In vacuum or air irradiation, Tefzel maintains a high level of physical integrity after long exposures.

Another fluoropolymer that does well in gamma is PCTFE, formerly known as Kel-F. PCTFE has minimal property loss even after doses of 16-18Mrads of exposure. Rates of property loss in all main categories are less than 30% which is quite good for fluoropolymers.

TriStar Plastics has more information on different methods of sterilization and how it affects most medical grade polymers. Ask The Experts - you'll still like them when they're angry (but they won't be)!

 

gamma
Topics: Surface Modification Q&A
2 min read

Plasma Adhesion Promotion on Polycarbonate

By Frank Hild on November 23, 2009

This study examined the relative adhesion difference between untreated polycarbonate (PC), mechanically roughened PC, and plasma treated PC. It appears that plasma surface modification of PC based polymers is a viable way to enhance adhesion prior to bond-up, lamination, or overmolding. This study observed approximately a 459% increase in lap shear bond strength after plasma treatment.

Polycarbonate is a specific group of thermoplastics. They are called polycarbonates because they are polymers having functional groups linked together by carbonate groups in a long molecular chain.

Polycarbonate

The most common type of polycarbonate plastic is one made from Bisphenol A, in which groups from Bisphenol A are linked together by carbonate groups in a polymer chain. This polymer is highly transparent to visible light and has better light transmission characteristics than many kinds of glass. Polycarbonate can be mechanically bonded by standard methods. It can also be cemented by using a solvent such as methylene chloride or adhesives such as epoxy, urethane and silicone. Polycarbonate and also be ultrasonically welded. Yet, solvent based adhesive can contaminate sensitive devices. Moreover, ultrasonic welding requires tight tolerances and smooth contaminate-free surfaces. The plasma treatment prior to bonding with common adhesive has shown an effective way to bond PC without solvent based adhesive or technically difficult, sonic welding.

A plasma is a quasineutral cloud of ion, electrons, and radicals. The diffuse cloud is capable of doing chemistry on the surface of materials that is unique, providing wettable or adherent surfaces on materials that are otherwise inert.

The PC samples in this study were subjected to a specific plasma gas mixture to induce and adherent surface for a structural epoxy adhesive. The results are as follows:


  Untreated PC Mechanically Roughened PC

Plasma Treated PC
Process 1

Plasma Treated PC
Process 2
Contact Angle 98 degrees 64 degrees 22 degrees 14 degrees
Pull Strength 113.5 psi 211.7 psi 634.3 psi 594.6 psi
Extension 0.0264" 0.0335" 0.0779" 0.0741"
Failure Mode Adhesion
(delamination)
Adhesion
(delamination)
Adhesion
(delamination)
Adhesion
(delamination)

In summary, polycarbonate can be bonded using mechanical or solvent chemical methods. Yet, it has been proven that plasma surface modification is a viable, environmentally friendly, invisible treatment that can enhance the bonding performance significantly. If you would like more information about this process or other processes, please contact us at www.tstar.com.

Topics: Surface Modification
1 min read

Gamma Radiation Effects on Polymers: Part 1

By Frank Hild on October 21, 2009

Gamma Radiation is commonly used to sterilize polymer devices. But some polymers do not hold up well to this form of sterilization.

The following plastics cannot be sterilized by radiation:

* Polyacetals (turns to dust)
* Polyacetals(turns to dust)
* Polypropylene (unstabilized)
* Teflon (turns to wax)
* PVDF

Polypropylene Syndrome

* Natural unstabilized PP undergoes a slow degradation process after irradiation where over two years the elongation may drop from 600% to zero and parts will shatter
* PP is both crosslinked and scissioned
* Embrittlement and discoloration can occur
* Radiation stable PP is available

Polyethylene

* Polyethylene is predominantly crosslinked but acceptable to irradiation
* LDPE < LLDPE < HDPE < UHMWHDPE
* PE can be stabilized to make it gamma stable

If you are unsure if your material will hold up to this sterilization technique, please visit the TriStar Plastics Corp. website for contact information.

Topics: Surface Modification
1 min read

Recognizing Quality in PTFE Materials

By Dave Biering on September 29, 2009

Molecular weight and crystallinity are two factors in PTFE that determine many of it's performance qualities. Both of these properties are highly dependant on the sintering operation of the PTFE production. If the material is cooked (sintered) too long or at too high a temperature it can degrade the polymer. Molecular weight is a measure of the polymer chain length and it affects flex life, tensile strength and elongation. As molecular weight increases so do these properties and paying attention to gel temperatures and dwell times during sintering is extra critical.

Crystallinity of PTFE can vary considerably depending on processing. This value can be seen in small variations in the specific gravity although in practice most PTFE materials fall in the 50-60 percent crystalline percentage. Increasing crystallinity decreases flex life, increases compressive stress and decreases recovery values, permeability and wear life. Other properties of PTFE, such as thermal, chemical, electrical and friction, are not generally affected by crystallinity changes.

So, sintering and other processing steps do a make a difference in deterimining the quality of PTFE. If you need to maximize the performance of your PTFE parts, including Rulon, Fluorosint, Ultraflon or even generic products, be sure you contact Tri Star Plastics first. We can help you select the right material and the right process.

Topics: Misc Products Rulon Materials Rulon Plane Bearings
2 min read

Q & A about Rubber Overmolding

By Frank Hild on August 3, 2009

Q: I have a question for you. We are anodizing some aluminum parts per Mil A 8625F, Type 2, Class I and it appears to be getting somewhat poor results. I wanted to get your take on this surface chemistry that we are trying to bond to. Here are some brief notes. Hopefully this is enough info for you to comment on.

Mil A 8625F, Type 2, Class 1Type II: Sulfuric Acid anodizing Class 1: This means that the anodize is not dyed or pigmented.

There is also a secondary operation of sealing:

per Mil A 8625F, Type 2, class 1, Section 3.8.1:

"When class 1 is specified, sealing shall be accomplished by immersion in a sealing medium such as a 5 percent aqueous solution of sodium or potassium dichromate (ph of 5.0 to 6.0) for 15 minutes a 90C to 100C, in boiling deionized water, cobalt or nickel acetate, or other suitable chemical solutions..."

We are trying to bond a peroxide cured silicone to this treated aluminum surface. I am not familiar with the sealing process as described above. Can you give me some insight on this?

A: Sulfuric anodize, commonly referred to as Type II anodizing, is formed by using an electrolytic solution of sulfuric acid at room temperature and a current density of 15 to 22 Amps per square foot. The process will run for 30 to 60 minutes depending on the alloy used. This will produce a generally clear coating, depending on sealing, a minimum of 8µm thick. One third of the coating thickness will build up per surface and 2/3 will be penetration. Sulfuric anodize coatings are often sealed to enhance corrosion resistance, lock in dyes, or both. Hot water seals produce the clearest sulfuric anodize while sodium dichromate yields a yellow-green appearance but is generally a better seal. Sulfuric anodizing is rather tolerant of aluminum alloys for anodizing with the exception of high-silicon die-cast alloys such as 380. The less alloying elements there are the higher the clarity and depth of color of the anodize coating.

The best adhesion is reached when each bonding aluminum atom carries a single reactive group. Even at room temperature, acetic acid or fatty acids can easily pass through a coating infiltrating chemical bonds by advanced attack and leading to adhesion failure. The aluminum atom progressive binds with reactive groups which then leave and the bond fails.

Hope that helps! If you want your questions answer - Ask The Experts!

Topics: Surface Modification Q&A
1 min read

Accelerated Aging Discussion

By Frank Hild on June 2, 2009

Determining the effects of aging on a package/product in real time is a lengthy process that would severely delay market introduction of new products. Therefore, a standardized test methodology was developed to accurately evaluate the environmental effect of storage on a package/product during its expected usable shelf life. Accelerated aging, which subjects samples to elevated temperatures for specific periods of time, is used to simulate the effects of real-time aging and provides data which allows the manufacturer to accurately predict the effect of real-time aging on his package/product. A product can be released to market based upon successful accelerated aging of the package/product that simulates the period claimed for product expiration. (1 year, 2 years, etc.) Concurrent with the accelerated aging process, the manufacturer should still conduct real-time studies in order to substantiate the data generated during the accelerated aging process.

* Standard Test Method: ASTM F1980; Accelerated Aging of Sterile Medical Device Packages

Methodology: Accelerated aging techniques are based on the assumptions that the chemical reactions involved in the deterioration of materials follow the Arrhenius reaction rate function. This function states that a 10° C increase or decrease in the temperature of a homogenous process, results in approximately a two times or ½ time change in the rate of a chemical reaction.

Definition of variables:
AAR : Accelerated Aging Rate
AATD : Accelerated Aging Time Duration
DRTA : Desired Real Time Aging
AAT : Accelerated Aging Temperature
AT : Ambient Temperature
Q10 : Accelerated Aging Factor
Q10 = 2 - industry standard
Q10 = 1.8 - more conservative option

Equations:
Step 1. AAR = Q10^ ((AAT - AT) /10)
Step 2. AATD = DRTA / AAR

Example: Time duration calculation for accelerated aging of a medical product:
One year shelf study at 55° C, where ambient temperature is 22° C and Q10= 2

Equation Sample Data
AAR = Q10 ^ ((AAT -AT) /10)
AAR = 2 ^ ((55 - 22 / 10) = 9.85
DRTA = 1 year x 365 = 365 days
AATD = DRTA / AAR
AATD = 365 / 9.85 = 38 days
NOTE: 55° C and Q10 =2 are the most commonly used factors for medical devices and medical packaging components.
Still need some questions answered? Ask The Experts!

Topics: Surface Modification
1 min read

Rulon 142

By Dave Biering on February 2, 2009

Blog_20090202

Rulon 142 is an excellent material for high load, high speed linear guideway liners for machine tools.

Commonly used as an inexpensive insurance policy to possible lube failures on machines, Rulon 142 is bonded to the dynamic component on the X-Y-Z tables of some of the world's leading machinery builders.

Rulon 142 is also an excellent material for rebuilding machine tools where the efficiency and tolerances have been lost over time.

Easy to install using CE211 or CE211FC adhesives available from stock. Rulon 142 is commonly used as an cost effective alternate to Turcite B and is fabricated using the same techniques.

For more information, visit our Rulon 142 web page and be sure to check out our Shooting Star Archives for a number of articles on Rulon and more!

Rulon - Quality Assurance Begins With Precision Processing

Topics: Rulon Materials