Methods and systems for co-extruding multiple polymeric material flow streams into a mold cavity to produce a molded plastic article having an injection-formed aperture in gate region of the article are disclosed herein. A method includes providing a valve pin having a distal portion with a first diameter and a mid-portion with a second diameter smaller than the first diameter and providing a mold defining a cavity corresponding to a shape of a resulting molded plastic article. The mold has a recess aligned with a gate region of the mold, extending into the mold and configured to receive the distal portion of the valve pin when the distal portion of the valve pin extends beyond the gate region. The method includes advancing the distal portion of the valve pin into the recess until the mid-portion of the valve pin at least partially extends into the gate region, thereby establishing a flow path for a combined polymeric stream into the cavity at the gate region for forming a molded plastic article having at least one layer of a first polymeric material and at least one layer of a second polymeric material. The method also includes withdrawing the mid-portion of the valve pin from the gate region, thereby forming an injection-molded aperture in the resulting molded plastic article at the gate region.

A foam molding method includes: moving a screw backward to take air into a heating barrel through a nozzle part in a state in which a shut-off nozzle is opened, the shut-off nozzle that opens or closes the nozzle part for injecting the molten resin and is disposed on a heating barrel; closing the shut-off nozzle and moving the screw forward, to diffuse the air taken into the heating barrel, in the molten resin in the heating barrel; feeding the molten resin forward while dispersing the air as the air bubbles in the molten resin by moving the screw backward while rotating it in a state in which the shut-off nozzle is closed; and opening the shut-off nozzle, to inject the molten resin containing the dispersed air bubbles into the cavity.

A foam molding method includes: moving a screw backward to take air into a heating barrel through a nozzle part in a state in which a shut-off nozzle is opened, the shut-off nozzle that opens or closes the nozzle part for injecting the molten resin and is disposed on a heating barrel; closing the shut-off nozzle and moving the screw forward, to diffuse the air taken into the heating barrel, in the molten resin in the heating barrel; feeding the molten resin forward while dispersing the air as the air bubbles in the molten resin by moving the screw backward while rotating it in a state in which the shut-off nozzle is closed; and opening the shut-off nozzle, to inject the molten resin containing the dispersed air bubbles into the cavity.

An injection molding apparatus including: a valve pin driven by an actuator, the valve pin extending axially through at least a portion of the channel length of the fluid flow channel, the fluid flow channel including a throat, downstream flow of the injection fluid being restricted by a bulb portion of the pin, the valve pin having an intermediate position where downstream flow of injection fluid is unrestricted and a fully downstream position where downstream flow of injection fluid is stopped at both the gate and at the throat, wherein the actuator is driven by a valve assembly comprised of a spool mechanically driven by first and second actuators or solenoids that each separately engage the spool at opposing axial ends to effect movement of the spool back and forth between the drive fluid flow positions.

A molding system for applying moldable material to a pipe. An elongate mold has at least one elongate mold member movable relative another elongate mold member between open and closed positions. The mold includes a pipe support that extends generally radially into a mold cavity along a support axis. An inner end of the support is configured to support the pipe in a molding position in which an annular portion of the mold cavity extends circumferentially around the pipe. After moldable material in the annular portion of the mold cavity can support the pipe, the support is withdrawn from the mold cavity by moving outwardly along the support axis. An injector selectively dispenses additional moldable material into a space formed by the support in the existing moldable material.

A melt delivery body is disclosed for an injection molding apparatus. The melt delivery body includes a manifold, housed in a manifold plate, having a melt network with an inlet for receiving melt from a machine nozzle and an outlet substantially axially aligned with the inlet. The melt delivery body further including an in-line valve gated nozzle having a nozzle melt channel, a valve pin in the nozzle melt channel, and a valve pin actuator coupled to the valve pin and positioned substantially axially aligned with the in-line valve gated nozzle and between the manifold and the in-line valve gated nozzle for controlling the movement of the valve pin within the nozzle melt channel. The melt delivery body further including a biasing member for biasing the in-line valve gated nozzle towards the manifold.

A method and apparatus for producing hollow articles made of injection moulded plastic material by a mould having a die within which there is inserted a core, and at least one injector including a pin valve displaceable between a closing position and an opening position for injecting the pressurized plastic material into a space comprised between the die and the core. During the injection, any flexural deflection of the core is detected and the pin valve of the or of each injector is displaced in a controlled fashion to adjust a pressure and a flow rate of the injected plastic material, so as to reduce or eliminate such deflection of the core.

The disclosure relates to an injection nozzle (1) suitable for injection molding of thermoplastic materials, in particular polyolefin materials, the injection nozzle (1) comprising a housing (2) comprising a sleeve-shaped rear section (3) and a thereto coaxially arranged sleeve-shaped front section (4) surrounding a central passage (5) extending in an axial direction (z) forming part of a melt channel (6). In the central passage (5) a needle (7) is arranged movable in the axial direction (z) between a retracted open position and an extended closed position in which a gate (8) at a tip (9) of the front section (4) is closed by a front end (10) of the needle (7) in a sealing manner. A spacer (11) is arranged between the rear section (3) and the front section (4) defining a total length of the housing (2) in the axial direction (z).

The invention relates to a device for producing a knee spacer component by curing bone cement paste. The invention also relates to methods for producing knee spacer components using such a device.

The invention relates to a device for producing a knee spacer component by curing bone cement paste. The invention also relates to methods for producing knee spacer components using such a device.