Injection molding system having a valve member with a ribbed insulative portion.

摘要

A valve gated injection molding system having a novel valve member for large volume applications. The elongated valve member (66) has a ribbed insulative portion (94) between the main steel portion (96) and a conductive portion (98) adjacent the tip end (80). The conductive portion (98) provides more rapid cooling when the tip end (80) is seated in the gate in the closed position. The adjacent insulative portion (94) provides a thermal barrier to reduce heat flow along the valve member to the conductive portion (98). This combination avoids sticking of the tip end (80) when the mold opens and thus allows cycle time to be reduced. The conductive portion (98) has an integral beryllium copper plug (108) which is supported by radially extending ribs (102) of the insulative portion (94) to withstand continual repeated impact loading every time the gate is closed.