Abstract: A radial seal ring has a frame or reinforcement, a body of an elastomer, and a seal lip of a low friction material such as a fluorine containing resin, particularly PTFE, adhered to the body. The seal lip extends radially of the body to provide a portion unadhered to the body and which has an annular recess in the surface thereof which faces toward the body. The recess is located adjacent to a peripheral edge of the body and defines a controlled region of deflection of the lip seal. The annular recess is formed during molding by pinching a preformed disc of the lip seal between an annular rib of the mold and an opposed surface of the mold.

Abstract: The seal ring is molded by positioning a frame or reinforcement in one part of an opened mold, and positioning a low friction material disc on a clamping surface of the same part of the mold. The mold is closed with a second part so that between 30% and 70% of the disc is clamped and squeezed between opposed surfaces of the mold parts, and the reinforcement or frame is held in position in the closed mold. A vacuum is drawn in the mold, and an elastomer is injected to form a body or lip connecting the reinforcement to the disc. The molded ring is removed from the mold and excess lip material and at least the portion of the disc which was clamped are cut off to form the finished seal ring. The low friction material disc can contain PTFE.