Process and apparatus for pipe seal manufacture

摘要

Process for forming an annular member by extruding a thermoplastic profiled strip at an elevated temperature. Prior to cooling the strip, the still-molten ends undergo in-line compression molding to form an annular member having a joint section. The cross-section of the annular member is continuous in the joint section and the remainder of the body. Preferably, the extrudate may contain a thermoplastic elastomer, more preferably a thermoplastic vulcanizate formed by a dynamic vulcanization process. During the extrusion and compression molding processes, the extrudate may be supported on a rotatable turntable, or alternately on a rotatable molding cylinder.