A PTFE Rotary Lip Seal is a seal that features a lip on the ID that seals dynamically on a shaft and metal casing on its OD to press-fit into a bore. A gasket is sandwiched between layers of sealing lips and the can to seal off the potential leak path.
This 42 page guide includes the following topics and more:
How They Work
Why PTFE
Fillers Employed with PTFE Resins
PTFE Radial Lip Seal Design
Design Principles Employed in PTFE Radial Lip Seal Design