Virgin PTFE has the smallest friction coefficient. It also has an almost universal chemical compatibility, and a very wide temperature range (either low or high temperature, from -200°C up to +250°C).
However, it has a poor wear resistance and creeps under load. To overcome these problems, Techné proposes PTFE charged with bronze, carbon, glass, graphite, MoS2, etc.
PTFE is often machined to make back up rings.
When PTFE is part of a sealing system, it is often associated with a rubber expander (or a metal spring) to give it a better elasticity. Virgin PTFE is FDA and/or USP class VI approved.