UHMW vs. PTFE

There are few questions we dread more than the customer asking about a PTFE truck liner. While the error is understandable – in natural form both UHMW polyethylene and PTFE are white colored plastic, if PTFE were ever used as a truck liner the cost would be many 10s of thousands of dollars and the liner would be worn to bits in short order! Yet, monthly we receive inquiries from customers who simply don’t know any better asking for that. We believe it’s important to discuss the distinction, and some similarities, between the two plastics.

Similarities:

Both plastics in their natural form are white and both are widely stocked by most plastics distributors. Both plastics are known for having a very low coefficient of friction and net zero water absorption. They’re both available in 48″ wide plates and in common thicknesses from 1/8″-2″ (and beyond). Both plastics are FDA/CFIA compliant in their natural form. Both plastics can be modified with a variety of fillers or additives. However, that’s where the similarities end.

Differences:

There are so many differences between the products that a list is the best way to explain:

  • PTFE is substantially much more expensive than UHMW
  • PTFE can only handle about 1/5th the load of UHMW
  • PTFE is more slippery than UHMW (despite both having a low coefficient of friction)
  • UHMW has far better wear properties than PTFE
  • UHMW is typically stocked in 48″ x 120″ sheets where PTFE comes in 48″ x 48″ plates
  • PTFE withstands over 4x the temperature UHMW can in continuous operation

So if UHMW is less expensive, handles more wear, and more load…Where do you use PTFE? The answer is pretty simple: 1.) when it’s spec’d in or 2.) when one of its differing properties from UHMW makes it the better choice. For example, if you’re machining some bushings for use in a 400 degree Fahrenheit environment you would go with a PTFE product vs. a UHMW product which would simply melt. As well, if the application demands bearing pads with dynamic sliding (think telescope mounts) then PTFE is the better choice due to its phenomenal low coeffecient of friction. If in doubt, simply contact Redwood Plastics and Rubber and we’ll lend a hand!