Polytetrafluoroethylene (PTFE) polymers are well known for chemical resistance, low friction, dielectric constant, purity and broad temperature range. A second generation of granular PTFE resins has been specially designed to provide additional characteristics while maintaining all of the basic properties of PTFE. The new properties, which include resistance to permeation and creep, discussion. weldabilifi, increased dielectric breakdown strength and smooh surface are reviewed in the following discussion.