Abstract: The present invention provides an electrically heated nozzle for injection molding which is insulated to prevent conduction of electricity and loss of thermal transmission to the casing, wherein at least a part of the electrical insulation comprises a layer of dielectric insulator material with an electrical resistance wire wound spirally thereabout and another dielectric insulator layer thereover. Also disclosed is a method for making such a nozzle which includes the steps of applying a first insulator layer, winding electrical resistance wire about the first insulator layer, applying a second insulator layer, and applying a casing layer thereover. The first and second insulating layers may be provided by spraying or through telescoping, self-supporting sleeves.

Abstract: The present invention provides an electrically heated nozzle for injection molding which is insulated to prevent conduction of electricity and loss of thermal transmission to the casing, wherein at least a part of the electrical insulation comprises a layer of dielectric insulator material with an electrical resistance wire wound spirally thereabout and another dielectric insulator layer thereover. Also disclosed is a method for making such a nozzle which includes the steps of applying a first insulator layer, winding electrical resistance wire about the first insulator layer, applying a second insulator layer, and applying a casing layer thereover. The first and second insulating layers may be provided by spraying or through telescoping, self-supporting sleeves.

Abstract: An injection molding hot runner nozzle includes a nozzle body comprising a nozzle core, a nozzle tip, and a melt passage extending through the nozzle body for conveying melt from a manifold through the nozzle tip and to a gate of a mold cavity. A cylindrical sleeve is disposed around the nozzle body, the sleeve being slidably removable from the nozzle body. A wire heating element for heating melt in the melt passage is is spirally wound about the sleeve. A temperature sensor comprising a wire is spirally wound about the sleeve.

Abstract: The present invention provides an electrically heated nozzle for injection molding which is insulated to prevent conduction of electricity and loss of thermal transmission to the casing, with an electric heater and sensor that are wrapped around substantially the same portion of a melt channel of the nozzle.

Abstract: The present invention provides improved heated manifolds, heaters and nozzles for injection molding, having a high strength metal skeleton infiltrated with a second phase metal having higher thermal conductivity. Also disclosed is method of forming a manifold, heater or nozzle preform and infiltrating the preform with a highly thermally conductive material. The invention also provides a method of simultaneously infiltrating and brazing injection molding components of similar or dissimilar materials together.

Abstract: A mold gate insert includes a mold gate insert body, which is comprised of a material having a high thermal conductivity, and a thermal insulation element, which is nested in the mold gate insert body. The thermal insulation element is provided to abut a nozzle seal and align the nozzle with a mold gate. The amount of heat transferred from the nozzle to the mold gate insert is reduced by the thermal insulation element.

Abstract: The invention relates to an injection molding apparatus including a mold block, a nozzle, a gating system and a slug heater. The mold block defines a mold cavity having a mold cavity inlet. The nozzle has a nozzle inlet. The nozzle inlet is fluidically connectable downstream from a melt source. The nozzle inlet is upstream from the mold cavity inlet. A melt flow passage extends from the nozzle inlet to the mold cavity inlet. The gating system includes a valve pin and an actuator. The valve pin is movable between an open position wherein melt flow is permitted into the mold cavity, and a closed position wherein the valve pin blocks the melt flow passage to prevent melt flow into the mold cavity. The actuator is operatively connected to the valve pin to move the valve pin between the open and closed positions.

Abstract: The present invention provides an electrically heated nozzle for injection molding which is insulated to prevent conduction of electricity and loss of thermal transmission to the casing, with first and second electric heaters which can operate independently or simultaneously to heat the melt channel of the nozzle.

Abstract: The present invention provides improved heated manifolds, heaters and nozzles for injection molding, having a high strength metal skeleton infiltrated with a second phase metal having higher thermal conductivity. Also disclosed is method of forming a manifold, heater or nozzle preform and infiltrating the preform with a highly thermally conductive material. The invention also provides a method of simultaneously infiltrating and brazing injection molding components of similar or dissimilar materials together.

Abstract: The present invention provides improved heated manifolds, heaters and nozzles for injection molding, having a high strength metal skeleton infiltrated with a second phase metal having higher thermal conductivity. Also disclosed is method of forming a manifold, heater or nozzle preform and infiltrating the preform with a highly thermally conductive material. The invention also provides a method of simultaneously infiltrating and brazing injection molding components of similar or dissimilar materials together.

Abstract: The present invention provides an electrically heated nozzle for injection molding which is insulated to prevent conduction of electricity and loss of thermal transmission to the casing, with an electric heater and sensor that are wrapped around substantially the same portion of a melt channel of the nozzle.

Abstract: A mold gate insert includes a mold gate insert body, which is comprised of a material having a high thermal conductivity, and a thermal insulation element, which is nested in the mold gate insert body. The thermal insulation element is provided to abut a nozzle seal and align the nozzle with a mold gate. The amount of heat transferred from the nozzle to the mold gate insert is reduced by the thermal insulation element.

Abstract: The present invention provides an electrically heated nozzle for injection molding which is insulated to prevent conduction of electricity and loss of thermal transmission to the casing, with first and second electric heaters which can operate independently or simultaneously to heat the melt channel of the nozzle.

Abstract: An injection molding apparatus and method for multi-layer molding of preforms and closures has a central melt channel, an annular melt channel radially spaced from the central melt channel, and an annular ring channel surrounding the central melt channel. The central melt channel has a first portion for flow of a first material, a second portion for flow of the first material and a second material, and a flow extension connecting the first portion and the second portion. The flow extension has a flow opening in communication with the annular ring channel for flow of the second material. The apparatus and method also include a cavity for receiving flow of the first material and the second material from the central melt channel, and for receiving flow of the first material from the annular melt channel. In addition, the apparatus and method include a melt passage having a first melt portion in communication with the central melt channel, and a second melt portion in communication with the annular melt channel.

Abstract: An injection molding apparatus and method for multi-layer molding of preforms and closures has a central melt channel, an annular melt channel radially spaced from the central melt channel, and an annular ring channel surrounding the central melt channel. The central melt channel has a first portion for flow of a first material, a second portion for flow of the first material and a second material, and a flow extension connecting the first portion and the second portion. The flow extension has a flow opening in communication with the annular ring channel for flow of the second material. The apparatus and method also include a cavity for receiving flow of the first material and the second material from the central melt channel, and for receiving flow of a third material from the annular melt channel.

Abstract: The present invention provides an electrically heated nozzle for injection molding which is insulated to prevent conduction of electricity and loss of thermal transmission to the casing, with first and second thermocouples for sensing temperature of the nozzle, the two thermocouples are independent so they can act either independently or simultaneously to sense temperature conditions in the melt channel of the nozzle.

Abstract: The present invention provides improved heated manifolds, heaters and nozzles for injection molding, having a high strength metal skeleton infiltrated with a second phase metal having higher thermal conductivity. Also disclosed is method of forming a manifold, heater or nozzle preform and infiltrating the preform with a highly thermally conductive material. The invention also provides a method of simultaneously infiltrating and brazing injection molding components of similar or dissimilar materials together.

Abstract: The present invention provides an electrically heated nozzle for injection molding which is insulated to prevent conduction of electricity and loss of thermal transmission to the casing, with first and second electric heaters which can operate independently or simultaneously to heat the melt channel of the nozzle.

Abstract: The present invention provides improved heated manifolds, heaters and nozzles for injection molding, having a high strength metal skeleton infiltrated with a second phase metal having higher thermal conductivity. Also disclosed is method of forming a manifold, heater or nozzle preform and infiltrating the preform with a highly thermally conductive material The invention also provides a method of simultaneously infiltrating and brazing injection molding components of similar or dissimilar materials together.

Abstract: A melt transfer system is provided for a stack mold. The melt transfer system includes first and second transfer bushings arranged in opposing platens of the mold. Each transfer bushing defines a portion of a runner passage communicating at shear gates disposed in a shearing surface that is parallel to the direction of opening and closing movement for said platens in order to shear the melt when the platens are moving from a closed position to an open position. In another aspect, the shearing surfaces are normal to the direction of movement of the platens and at least one of the transfer bushings is rotatable relative to the platen for shearing the melt. In another aspect, a transfer bushing is provided having a core formed of an insulative material and a shell formed of a conductive material. The core defines a channel for conducting melt between a shear gate at one end of the channel and an aperture at another end of the channel.