Elastomer gaskets are known for their superb sealing capability but are more susceptible to chemicals. PTFE is chemically inert but is a difficult material when it comes to sealing. The best characteristics of both materials are brought together in the Tri-Bond® gaskets.
The thin PTFE lining on the outside is taking care of the chemical resistance of the gasket while the flexible elastomer inside covers its sealing capabilities. The combination of these features makes this the ultimate pharmaceutical gaskets.