摘要 |
An injection molding apparatus includes a manifold having a manifold channel for receiving a melt stream from a source. A nozzle having a nozzle channel receives the melt stream from the manifold channel and delivers the melt stream to a mold cavity through a mold gate. A valve pin bushing is provided between the manifold and the nozzle and includes a bore for receiving a valve pin. A chamber is provided in said valve pin bushing and communicates with the bore. An inlet channel extends between an inlet, which is located in an outer surface of the valve pin bushing, and the chamber. A vent channel extends between the chamber and an outlet, which is located in the outer surface of the valve pin bushing. A forced fluid source communicates with the inlet channel to force fluid through the inlet channel, said chamber and the vent channel.
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