Alternative to PTFE sealing ring?

Question

I need to suggest an alternative to solid PTFE as a sealing ring in a pharmaceutical production environment. I basically want all the good properties of Teflon but without it's porosity. Any ideas greatly recieved!!

The problem isn't the standard of seal, it's just because it's porous the stuff that's being processed seems to get trapped and because it's so hard to wet PTFE it can't be washed clean. I'm just doing this as a small part of a Masters project, I was just given the seal to work with, don't know much exact detail ofits use.

Answer 1

If you go to http://www.sealsales.com/ and select the various options under seal material you will see descriptions about each. You may find something there.

Edited Comment: Sorry I was looking under gaskets, seals are more specialised, but there may be something there: perhaps less porous teflon?

Answer 2

What do you mean by porosity of PTFE? I have been with pharma for 12 years and never faced the kind of problems you said. PTFE has got serious temperature limitations, otherwise it is very good. You can try silicon.

Answer 3

John Crane 7500 Virgin PTFE. Is not very pourous.

or

Kalrez.
http://www.dupontelastomers.com/Products/Kalrez/kalrez.asp

Answer 4

what kind of application? is it really the porosity of the Teflon? or are the seals leaking b/c of the overall seal design? can you try a seal grease? perhaps a silicone seal? more info, pls.

Answer 5

PVDF (Polyviniliden Fluoride ) In many aspects is similar or better and it is already used as a medical grade material for suture threads.
the most used polymer material in medical equipments is polycarbonate.
You may also consider silicone rubbers .