Tech Talk Blog

Tivar® HOT is a good alternative when standard UHMW is unable to withstand your operating temperature.  As the name implies, it is engineered to withstand high operating temperatures up to 220°F.  It is a diverse material that can be modified to fit a broad scope of applications.

Tivar HOT has near-zero water absorption, so it can be used in scalding and submerged applications.  It gives superior wear and chemical resistance, offers good impact strength, low friction, and is self-lubricating. It is also incredibly abrasion-resistant.

Tivar is a good solution for food processing and packaging equipment.  It meets FDA/USDA guidelines and is 3A Compliant.  We see it used in the production of sugar and candy.  Also many industrial applications such as pipe saddles, hopper liners, and conveyor guides.

It is available in sheet, rod or tube form, can be made to order, and is easily machined.  We can custom fabricate a part to match your print.

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.

Here’s a quick review of the different categories of plastics:

Plastics are classified into two categories:

1)      Thermoset – is any material that, once heated, cannot be reheated or reformed (Examples: Bakelite, Melamine, Teflon, Torlon, Celazole, glass epoxy systems, phenolic, Micarta

2)   Thermoplastic – any material that can be heated and reheated to make a finished part or stock shape (Examples: PVC, PEEK, polyethylene, nylon, acetal, acrylic)

Plastics also break down into two subcategories:

1)      Amorphous – Which is see-through or

2)      Crystalline – Not see-through.

The molecular structure is very important to the performance properties of any plastic material.

In processing, thermoset materials can only be compression or transfer molded. The process usually requires extremely high pressures and elevated temperatures. Thermoset materials usually require some form of reinforcement for stability and strength.

Thermoplastics can be extruded, injection molded, compression molded, blow molded, thermo formed, bonded to substrates, stamped and machined. And with thermoplastics, we have the ability to include additives to enhance properties like wear, fire resistance, electrical properties, and improvements in impact strength.  We can also reinforce with additives like glass fibers, carbon fibers, Kevlar, graphite, calcium carbonate.

We also classify by temperature:

1)      Commodity Plastics – lower cost and performance, typically doesn’t work above 200° F, good chemical resistance

2)      Engineering Plastics – 300° F limit, generally more versatile, used in structural and wear applications, available with enhancements

3)      High Performance Plastics -  most expensive, handle high temperatures over 300° F, associated with the most extreme operating conditions – thermally stable, excellent inherent wear properties, broad chemical resistance.

Our team is always looking at new alloys, new fillers, and extending chemistries to make new polymers.

Did you realize there are probably over 300 types of Rulon? Rulon is a self-lubricating material that can almost be considered “generic” in some ways.  It is a PTFE material with various fillers; it is the type and amount of filler that makes each variation of Rulon unique.

When choosing Rulon, we ask:

1) What is the application function – bearing? Seal? Gasket? Some materials can be used for all applications.

2)  What is the temperature? -400 to +550 is the general range Rulon can accept. For design purposes, we need to know how much press fit and close in to account for in the gradient.

3)  What is the environment? Some types are made for FDA or USDA environments or for resisting abrasion. Most PTFE materials don’t do well in water, but a few do.

4)  What is the speed? All types of Rulon can take 400/500 feet per minute without lubrication; but we need the load to be a bit more accurate. Rotating? Oscillating? Linear?

5)  What are the loads on that bearing? Most can handle 1000 psi, but others can withstand higher levels.

6)  What type of hardware (consider temperature)? Only a few types of Rulon can work with stainless steel.

7)  What is the surface finish? 8-16 rms on the shaft is recommended, but for holding purposes, we would suggest 32 rms.

We can help you choose the right Rulon for your application.