| abstract |
An improved gasket particularly suitable for use in sensitive environments is disclosed. The preferred gasket of the present invention comprises at least one layer of a composite material of porous polytetrafluoroethylene (PTFE) polymer and resilient expandable microspheres. The composite material provides a number of significant advantages over existing PTFE and similar clean gaskets, including better seal under less compressive pressure, sufficient resilience to permit reuse, and retained porosity-allowing pressure equalization in the equipment to occur through the gasket itself. |