| 摘要 |
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.
|
