Tech Talk Blog

TriStar’s Enhanced Materials Division (EMD) offers advanced technologies like plasma surface treatment and specialized polymer filtration membranes. While these capabilities are incredibly valuable in the right applications, we believe they are just one small part of the overall value an engineering team like TriStar EMD can provide.

In this blog post, we explore why value-added engineering services are the key to unlocking the full value of advanced materials enhancement processes.

For a more in-depth look at the Enhanced Materials Division and what it can do, please see our guide here.

Engineering Services That Enable a Strategic Approach to Material Selection and Enhancement

Examples of challenges where an expert materials engineering team can prove invaluable include:

1. Identifying and addressing the root cause of issues that emerge in the manufacturing process itself—like a lubricant that is preventing subsequent application of paint.
2. Identifying better materials that allow critical components to last longer, fail less frequently, and achieve improved functional characteristics.
3. Studying critical product or manufacturing failures to begin identifying a solution when in-house engineers aren’t quite sure what’s wrong.

When approaching any of these challenges, TriStar emphasizes an organization-wide commitment to a hands-on, consultative engineering approach. In short, this means offering clients a collaborative process focused on addressing specific, ground-level engineering pain points. Rather than sell a particular material or enhancement as a catch-all solution, our goal is to study specific use cases and identify the materials capable of delivering the greatest possible full-life cycle value in their intended application.

The Enhanced Materials Division represents the leading edge of our culture of value-added engineering. By combining access to TriStar’s deep arsenal of materials (many of which can solve challenging engineering problems “off the shelf”) and advanced enhancement processes like plasma surface treatments (which can be used to customize materials for unique application requirements), EMD can offer clients a portfolio of capabilities that are more valuable than the sum of their parts.

We start by studying specific application problem areas and how they could potentially be solved using one of our many polymer and composite materials. These materials can be specified to deliver commonly required characteristics such as:

• The ability to resist corrosion, even in salty, wet, or chemically caustic environments.
• Reduced vibration/friction to improve noise, service-life, and maintenance needs.
• Self-lubrication—lubrication failure is the number one cause of, for example, bearing failure.

If the application requires material characteristics that cannot be fulfilled by our stock polymer materials, advanced processes like plasma surface treatment can be used to provide carefully targeted enhancements. EMD also can fabricate custom materials when needed, even for applications like specialized filtration membranes which require precision down to the tens of nanometers.

EMD’s engineering services tie this entire process together. Why? Because most manufacturing or product development organizations cannot afford to maintain in-house expertise on every potentially valuable material or material enhancement process.

In many cases, product engineers simply don’t know if materials that could solve their problem even exist. In others, they may be unsure how the limitations of one material can be mitigated. Or whether the cost differential of a more advanced material choice will be justified by the value it delivers to product performance and reliability. In any of these cases, TriStar EMD can step in to provide an expert engineering team with a wealth of experience tailoring advanced material solutions to tough engineering problems.

EMD engineering services provide clients with true end-to-end solution engineering that draws on our deep knowledge of advanced materials, our in-house capabilities to perform enhancements like plasma surface treatments, and our ground-level experience across a broad range of industries. When clients engage with us, they don’t need to have any pre-existing understanding of processes like plasma treatment—they only need to come with a problem that needs solving.

Learn More About Working with an Advanced Materials Engineering Team

At TriStar, we believe that material selection matters. And our EMD team represents the culmination of that belief in our own organization.

The EMD team is passionate about learning the specifics of every client application and can commonly be found studying issues onsite when needed. In our experience, this commitment to value-added solutions engineering almost always pays off in the long run. The right materials selection can almost always help critical components and products perform better and more reliably. And in some cases, it can solve problems that client engineering teams didn’t even know they had!

For a more in-depth look at TriStar EMD, please see our guide here. Or, if you prefer to reach out to EMD directly to begin discussing how we can help solve your toughest engineering challenges, just use the button below.

A membrane is a thin material that allows some substances through while keeping others out. But with precision engineering, membranes can be configured to achieve precise filtration outcomes which are essential in industries ranging from food & beverage to in vitro diagnostics.

This blog post provides an introduction to filtration membranes and how they work. Advanced polymer membranes are just one offering from TriStar’s Enhanced Materials Division (EMD) — you can learn more about EMD and how it works here.

What are polymer filtration membranes?

A polymer filtration membrane is a thin sheet of polymer material whose microporous structure has been engineered to achieve a precise filtration outcome. Different materials and microporous properties (like pore size) can be used for different filtration applications.

The pores in specialized membranes are often measured in the tens of nanometers! This means that they can be used to filter incredibly small contaminants, like microorganisms, tiny particulate, or natural organic material. By combining different pore sizes in different membrane layers, filtration can be specified even more precisely.

The ability to flexibly configure polymer membranes is the main reason why you will find them in so many different industries. They are used in water purification, inside fuel cells and batteries, and in advanced medical diagnostic equipment, just to name a few examples.

Common Polymers for Filtration Applications

• PTFE
• PES
• PVDF
• Nylon
• Polypropylene

How TriStar Helps Clients Implement the Right Filtration Membrane for the Job

Filtration membranes represent a substantial engineering challenge for many product development teams. They require specialized knowledge, precision fabrication capabilities, and careful alignment to each unique application. In our experience, advanced filtration challenges require more than an “off the shelf” membrane material. Success requires an in-depth, consultative engineering approach.

For example, TriStar EMD worked with client engineers to perfect a High-Performance Liquid Chromatography (HPLC) system. In this case, analysis of the application determined that a novel material was required, and TriStar created one for the job: Ultraflon M18+. This hyper-hydrophilic material allowed for more precise control over liquid and gas flow within the HPLC system. You can learn more about this application in our case study here.

Our guide here provides a deeper look at how TriStar EMD provides value-added engineering to help clients get the most out of advanced materials like filtration membranes.

Or, if you’re interested in discussing how we can help develop the right membrane for your filtration challenge, we encourage you to reach out using the button below.

What are plasma surface treatments and how can they help materials and components perform their best in demanding applications?

By altering the properties of materials at a molecular level, surface treatments can deliver precision-engineered properties which can be carefully tailored to unique operational challenges.

Plasma surface modification is just one type of advanced material enhancement technology offered by TriStar’s Enhanced Materials Division. For a deeper look at how our consultative engineering approach unlocks the power of advanced material enhancement capabilities like plasma, please see our guide here:

Plasma Surface Treatments 101

While the underlying science of plasma surface modification is complicated, engineering teams don’t need to be plasma experts to employ this technology. A plasma treated material is enhanced at a facility like TriStar EMD’s laboratory before being shipped out to be used as normal in the end product or application.

To achieve a successful result, the most important factor is matching the correct plasma treatment and material to the unique challenges of each use case. Once the optimal treatment process is identified, plasma-modified materials can integrate at scale with your supply chain, with treated materials delivered as required.

How does plasma surface modification work?

The steps below describe TriStar’s low-pressure “vacuum plasma” methodology. This type of process can be used with a wide array of materials including ceramics, polymers, elastomers, and metal assemblies. And it’s far more environmentally friendly than traditional, solvent-based solutions like acetones or sodium.

1. Materials are placed into a vacuum chamber which is reduced to ultra-low pressure.
2. A mix of gases is injected into the chamber and ionized.
3. Ions react with the surface of the material in the chamber.

By varying plasma type, pressure, and the length of time the treatment is applied, different results can be achieved. Plasma surface treatments are used in a variety of industries and niche applications; typical examples include:

• Improving the bonding property of a surface to improve adhesion of paints, inks, molding, and other coatings.
• Micro-cleaning a surface for ultra-hygienic standards and enhanced wetting of adhesives and over-molded elastomers.
• Improving hydrophobic or hydrophilic properties.

Learning More About Plasma Surface Treatments from TriStar’s Enhanced Materials Division

TriStar’s Enhanced Materials Division has extensive experience working with client engineers to understand how specific problems can be solved with  plasma-based treatments. These clients don’t necessarily come to TriStar knowing they need plasma—only with a problem that needs to be solved with better materials.

Because plasma surface treatments can be applied to a variety of materials to enhance their functional properties, they offer the most value when paired with a careful material selection process. The right material selection can solve a variety of common issues, while plasma treatments are used to achieve additional, targeted enhancements suited to the application at hand. Once the right materials and plasma treatment are identified, TriStar can perform all modifications using our in-house plasma laboratory.

For a deeper look at plasma surface treatments, we recommend this tech talk with EMD Principal Engineer Frank Hild. Or, if you’re interested in reaching out to the TriStar team to discuss a specific plasma treatment challenge, download our worksheet to get started.

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.

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.

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!

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.

Visit our Video Learning Center or our Surface Modification product pages for more.