Filled TFE Anti-Extrusion Rings For O-ring Packings and Other Seals

Filled tetrafluoroethylene (TFE) backup rings offer superior resistance to extrusion, wear, deformation and cold flow in dynamic and static O-ring sealing applications. TFE compounds consisting of various concentrations (5 - 60%) of inorganic fillers such as glass, molybdenum disulphide, graphite and bronze are the most commonly used materials for backup rings. An important consideration in the use of these filled materials is that hard mating surfaces be used to minimize abrasive wear. However, recently developed organic-type fillers have extended the utility of filled backup rings to applications involving non-hardenable mating surfaces such as hard anodized aluminum and titanium.