Style Glass Filled PTFE (polytetrafluoroethylene) is a high molecular weight polymer and one of the most versatile plastics known to man. This PTFE sheet is filled with 25% glass fibers by weight. The filled material significantly reduces cold flow and creep and increases wear resistance compared to unfilled PTFE sheet. It can handle a very broad range of chemicals with the exception of molten alkali metals and elemental fluorine. This style is suitable for service at temperatures from the cryogenic range up to 500°F.