An injection device includes a heating cylinder having a gas injection port, a screw, a gas supply device and a control unit. The interior of the heating cylinder is divided into a plasticization zone on an upstream side, a starvation zone on a downstream side of the plasticization zone, and a compression zone on the downstream side of the starvation zone. The gas injection port is provided with an injection valve, and gas is supplied into the heating cylinder in the starvation zone. The heating cylinder includes a pressure sensor. The control unit is configured to control the injection valve based on a resin pressure detected by the pressure sensor.

Disclosed herein is a novel shut-off nozzle for use with an injection molding system for creating and injecting foaming polymers to form products and other components. The shut-off nozzle is designed to increase cell nucleation during the foaming process, increase the pressure drop rate as the polymer is injected into a mold, and stop drooling of the foamed polymer at the end of an injection cycle. The shut-off nozzle includes an angled shut-off needle, which significantly reduces the amount of waste in each injection cycle and a water-cooling circuit to rapidly cool and solidify the molten polymer remaining in the shut-off nozzle at the end of each injection cycle.

An apparatus having a first portion including a first front wall, a first rear wall, and a bottom wall integrally coupled to the first front wall and the first rear wall, and pivotal pin structures integrally coupled to and extending from the first rear wall. The apparatus includes a second portion having a second front wall, a second rear wall, and a top wall integrally coupled to the second front wall and the second rear wall, and pin holders integrally coupled to and extending from the second rear wall and at an offset angle with reference to the top wall. The pivotal pin structure includes a base support connected to the first rear wall and a shaft connected to the base support, and the pin holder defines an opening sized and shaped to accept the shaft. The first and second portions are sized and shaped to be pivotally movable between open and closed configurations.

With respect to a controller of an injection molding machine, the injection molding machine includes an injection member provided inside a cylinder to heat a molding material and an injection drive source to fill the molding material into a mold device by moving the injection member forward. The controller includes a limiting part that limits a movement of the injection member forward in a pressure-holding process of controlling an injection drive source so that an actual value of a filling pressure acting on the molding material from the injection member becomes a set value, and a determining part that determines an appropriateness of a setting to be used by the limiting part based on information of a sensor provided in the mold device.

Disclosed herein are novel methods for forming a polymer part including providing an injection molding system with a shut-off nozzle, where the shut-off nozzle includes a main body, a nozzle tip body, a flow path through the main body and the nozzle tip body, a nozzle tip, and a shut-off mechanism. The nozzle tip includes an internal passage and a cooling mechanism. The shut-off mechanism includes a passageway intersecting the flow path at an angle and a pin positioned in the passageway. The method further includes the steps of initiating an injection molding cycle by injecting molten polymer through the shut-off nozzle into a cavity of a mold, actuating the shut-off mechanism to move the pin in the passageway into the intersection of the passageway and flow path, and initiating the cooling mechanism to solidify molten polymer in the nozzle tip to form a solid slug.

A system is described comprising an actuator with a piston linearly movable and a needle shutter connected to the piston for regulating the injection flow of molten material from a nozzle into a mold. By a supply circuit pressurized fluid is brought to the piston to move it back and forth. A solenoid valve is connected to the supply circuit and configured so that in resting condition it leaves open a fluid drainage path for bringing the shutter to a closing position.

Disclosed herein are novel methods for forming a polymer part including providing an injection molding system with a shut-off nozzle, where the shut-off nozzle includes a main body, a nozzle tip body, a flow path through the main body and the nozzle tip body, a nozzle tip, and a shut-off mechanism. The nozzle tip includes an internal passage and a cooling mechanism. The shut-off mechanism includes a passageway intersecting the flow path at an angle and a pin positioned in the passageway. The method further includes the steps of initiating an injection molding cycle by injecting molten polymer through the shut-off nozzle into a cavity of a mold, actuating the shut-off mechanism to move the pin in the passageway into the intersection of the passageway and flow path, and initiating the cooling mechanism to solidify molten polymer in the nozzle tip to form a solid slug.

An apparatus having a first portion including a first front wall, a first rear wall, and a bottom wall integrally coupled to the first front wall and the first rear wall, and pivotal pin structures integrally coupled to and extending from the first rear wall. The apparatus includes a second portion having a second front wall, a second rear wall, and a top wall integrally coupled to the second front wall and the second rear wall, and pin holders integrally coupled to and extending from the second rear wall and at an offset angle with reference to the top wall. The pivotal pin structure includes a base support connected to the first rear wall and a shaft connected to the base support, and the pin holder defines an opening sized and shaped to accept the shaft. The first and second portions are sized and shaped to be pivotally movable between open and closed configurations.

Disclosed herein are novel methods for forming a polymer part including providing an injection molding system with a shut-off nozzle, where the shut-off nozzle includes a main body, a nozzle tip body, a flow path through the main body and the nozzle tip body, a nozzle tip, and a shut-off mechanism. The nozzle tip includes an internal passage and a cooling mechanism. The shut-off mechanism includes a passageway intersecting the flow path at an angle and a pin positioned in the passageway. The method further includes the steps of initiating an injection molding cycle by injecting molten polymer through the shut-off nozzle into a cavity of a mold, actuating the shut-off mechanism to move the pin in the passageway into the intersection of the passageway and flow path, and initiating the cooling mechanism to solidify molten polymer in the nozzle tip to form a solid slug.

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.