Low-stress molded gasket and method of making same

摘要

A molded discrete low stress gasket is constructed of restructured filled PTFE for use in corrosive or severe chemical environments under relatively low bolt loads. The gasket has a gasket surface and includes a raised outer sealing ring and a raised inner sealing ring. The gasket may constructed from a restructured filled PTFE material, with the sealing rings deforming at lower pressures than the remaining portions of the gasket.

主权项

1. 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.