Abstract: A process for injection molding of thermoplastic materials which includes a nozzle body having a bore to provide a flow path for molten thermoplastic. One end of the nozzle body is adapted for connection with a sprue of an associated mold body, and the other is adapted for connection with an end of an associated injection molding machine. The nozzle body has a shut-off valve fluid pin housing adapted for reciprocating movement in the nozzle bore to control the flow of plastic through the nozzle body. The shut-off valve fluid pin housing also includes a body having an adjustable fluid pin with a tip portion and a fluid passage formed in the body and open at the tip portion and the other end of the fluid passage communicating with a source of two pressurized fluids, one in vapor and liquid phase and another in gas.

Abstract: A nozzle for injection molding of thermoplastic viscous fluid materials which includes a nozzle body having a bore to provide a flow path. One end of the nozzle body is adapted for viscous fluid connection with a sprue of an associated mold body, and the other end is adapted for viscous fluid connection with an end of an associated injection molding machine. The nozzle body includes within its bore, a shut-off valve non-viscous fluid pin housing assembly which is adapted for reciprocating movement in the nozzle body. The fluid pin housing has a tip portion and a non-viscous fluid passage formed in the housing and open at the tip portion and the other end of the non-viscous fluid passage communicating with an associated source of pressurized non-viscous fluid. An actuator is provided for reciprocating within the nozzle body of the shut-off valve fluid pin housing to an open or closed position controlling the flow of viscous plastic through the nozzle body.