Answered: College: Plastic Block Questions

I was wondering if Polyurethane would be a legal meterial to be used within the plastic block?

  • Andrew

No, Polyurethane would not be considered legal under this rule.

Thanks Karthik!

What about PTFE or Teflon?

  • Andrew

You’re welcome!

PTFE (Teflon) is not permitted.

Wow, didn’t expect that one.

I guess its worth asking again UHMW is still a legal material for this correct? Because on a wear level UHMW is stronger than PTFE and UHMW is a plastic as well along with Teflon and PTFE according to my understanding of their properties. Can you elaborate more as to why Teflon and PTFE are not permitted but UHMW is (If it still is of course)?

  • Andrew

UHMW is legal.

Teflon (PTFE) is near the bottom of the triboelectric series, thus is very susceptible to becoming electrically charged via friction. Thus the use of Teflon is not permitted for safety issues.

Ahh Ok I understand now, Thank you! I will account for this in designing!

  • Andrew

You’re welcome!

Alright Karthik sorry to keep asking questions, I’m doing lots of research on plastics lately and which would be best for our application.

I have a few more I have found:

Chemraz, Kalrez, and Aegis.

Would any of these be legal?

  • Andrew

No. “Rubbery” plastics are not allowed. That is not within the intent of this rule.

Alright, I shall continue my search!


You’re welcome.