Patent ID: 8852486

Claim:
A method of making a gasket, the method comprising the steps of: providing a sheet of restructured filled PTFE; cutting a ring blank from the sheet of restructured filled PTFE; heating the ring blank to a gel point for the restructured filled PTFE; inserting the ring blank into a compression mold, which is at room temperature when the ring blank is inserted, and shaped to mold at least two concentric, raised sealing rings into each of a pair of opposing faces of the ring blank; the mold being further shaped to space the concentric rings apart from one another, separated by compressed regions; cooling the ring blank within the compression mold under pressure, at room temperature, until the ring blank forms a gasket defined by at least two concentric, raised sealing rings that are less dense and more compressible than the compressed regions that separate the rings; and removing the gasket from the compression mold.