Manifold structure for pressure molding

Abstract

A system for pressure molding plastic material includes a source of hot flowable plastic material and a manifold for receiving hot flowable plastic material from the source and for transporting the hot flowable plastic material to a nozzle that is disposed within a nozzle cavity. A heater is provided to heat the nozzle and is positioned outside of, but close to, the nozzle cavity and includes at least one electrical supply wire. A shut-off seal is positioned within the nozzle cavity to seal the nozzle with respect to the wall defining the shut-off cavity. In addition, a secondary seal is most advantageously positioned between the shut-off seal and the heater for ensuring that any hot flowable plastic material that might leak through the shut-off seal does not come into contact with the electrical supply wire. This has been found to increase the reliability and operating life of conventional pressure molding systems.

Dependencies are inferred from the claim text.