Abstract: A gate adapter for use in a hot runner co-injection molding system includes a hollow gate adapter body defining a gate outlet at a free end thereof. At least a pair of nozzle assemblies is disposed in the adapter body, each of nozzle assemblies having an inlet end in fluid communication with a source of liquid extruded material and an outlet end in the adapter body. At least a pair of nozzle passages is formed in the adapter body and extends from the outlet of the nozzle assemblies to a passage outlet adjacent the gate outlet. A valve stem is disposed adjacent each of the passage outlets and is operable to selectively allow flow from the passage outlets to the gate outlet. The nozzle passages extend for a short predetermined distance within the adapter body to minimize heat transfer.

Abstract: A mold bushing for injecting plastic material into a mold cavity. The bushing member has a one-piece body member with a central passageway for a shut-off gate pin member and a separate and distinct passageway for the molten plastic material. In one embodiment, a tip member is positioned on the end of the body member and has a material discharge chamber. A gate or orifice opened and closed by the pin member is positioned either in the tip member or the mold. A wear bushing member can be positioned in the discharge chamber or the end of the body member to support the end of the pin member and prevent the flow of plastic material into the central passageway. The body member is heated by an annular cast heater member or the like. In an alternate embodiment, the body member has an extension which partially fills the discharge chamber and the wear bushing is a cylindrical member positioned at the discharge end of the central passageway.

Abstract: Mold bushings or nozzles for gas-assisted injection molding processes are disclosed. The devices include movable shut-off mechanisms which selectively facilitate or prevent the passage of molten plastic material into mold cavities. One or more apertures, such as holes, openings, channels, slits, slots, and the like, are provided at or adjacent the end of the pin members or at the end of the devices. The apertures are thin or small and have dimensions which will allow the passage of gas and at the same time prevent the plastic material from plugging or clogging them.

Abstract: A mold bushing for injecting plastic material into a mold cavity. The bushing member has a one-piece body member with a central passageway for a shut-off gate pin member and a separate and distinct passageway for the molten plastic material. A tip member is positioned on the end of the body member and has a material discharge chamber. A gate or orifice opened and closed by the pin member is positioned either in the tip member or the mold. A wear bushing member is positioned in the discharge chamber or the end of the body member and acts to support the end of the pin member and prevent the flow of plastic material into the central passageway. The body member is heated by an annular cast heater member or the like. The wear bushing member can be indexed for proper positioning relative to the body member and the plastic flow passageway. The wear bushing member preferably has a body portion which partially fills the discharge chamber in the tip member.

Abstract: A mold bushing for injecting plastic material into a mold cavity. The bushing member has a one-piece body member with a central passageway for a shut-off gate pin member and a separate and distinct passageway for the molten plastic material. A tip member is positioned on the end of the body member and has a material discharge chamber. A gate or orifice opened and closed by the pin member is positioned either in the tip member or the mold. A wear bushing member is positioned in the discharge chamber or the end of the body member and acts to support the end of the pin member and prevent the flow of plastic material into the central passageway. The body member is heated by an annular cast heater member or the like. The wear bushing member can be indexed for proper positioning relative to the body member and the plastic flow passageway. The wear bushing member preferably has a body portion which partially fills the discharge chamber in the tip member.

Abstract: Mold bushings or nozzles for gas-assisted injection molding processes are disclosed. The devices include movable shut-off mechanisms which selectively facilitate or prevent the passage of molten plastic material into mold cavities. One or more apertures, such as holes, openings, channels, slits, slots, and the like, are provided at or adjacent the end of the pin members or at the end of the devices. The apertures are thin or small and have dimensions which will allow the passage of gas and at the same time prevent the plastic material from plugging or clogging them.