An injection molding machine includes a first reservoir cylinder and a second reservoir cylinder to which a molten resin is supplied, a first injection member provided inside the first reservoir cylinder and configured to push out the molten resin in the first reservoir cylinder, a second injection member provided inside the second reservoir cylinder and configured to push out the molten resin in the second reservoir cylinder, and an injection cylinder to which the molten resin in the first reservoir cylinder and the molten resin in the second reservoir cylinder are supplied. Upon supply of the molten resin from the first reservoir cylinder to the injection cylinder, the injection molding machine supplies the molten resin to the second reservoir cylinder, and upon supply of the molten resin from the second reservoir cylinder to the injection cylinder, the injection molding machine supplies the molten resin to the first reservoir cylinder.

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.

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.

A shut-off nozzle includes a nozzle body, a rotary valve, and a reinforcement member. The nozzle body has a nozzle internal flow path formed therein, and a valve insertion hole is opened from a lateral surface of the nozzle body. The rotary valve includes a cylindrical portion to be fitted into the valve insertion hole, and an operation shaft portion having a small diameter. A through hole is opened in the cylindrical portion, and the nozzle internal flow path is opened and closed according to a rotation position of the rotary valve. The reinforcement member includes a cylindrical reinforcement portion to be inserted into the valve insertion hole, and a shaft hole through which the operation shaft portion passes is opened in the cylindrical reinforcement portion. The cylindrical reinforcement portion is inserted into the valve insertion hole so as to be on an outer side of the cylindrical portion of the rotary valve.

A shut-off nozzle includes a nozzle body, a rotary valve, and a reinforcement member. The nozzle body has a nozzle internal flow path formed therein, and a valve insertion hole is opened from a lateral surface of the nozzle body. The rotary valve includes a cylindrical portion to be fitted into the valve insertion hole, and an operation shaft portion having a small diameter. A through hole is opened in the cylindrical portion, and the nozzle internal flow path is opened and closed according to a rotation position of the rotary valve. The reinforcement member includes a cylindrical reinforcement portion to be inserted into the valve insertion hole, and a shaft hole through which the operation shaft portion passes is opened in the cylindrical reinforcement portion. The cylindrical reinforcement portion is inserted into the valve insertion hole so as to be on an outer side of the cylindrical portion of the rotary valve.

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.

The device for implementing the method comprises an extruder (10) supplied with a material, at least a first cylinder (11) and a second cylinder (12), at least a first mould (13) and a second mould (13), a circuit (14) connecting the extruder to the cylinders and the cylinders to the moulds, and means for extraction (18, 19, 19) of the moulded item.

The device for implementing the method comprises an extruder (10) supplied with a material, at least a first cylinder (11) and a second cylinder (12), at least a first mould (13) and a second mould (13), a circuit (14) connecting the extruder to the cylinders and the cylinders to the moulds, and means for extraction (18, 19, 19) of the moulded item.

A shut-off nozzle includes a nozzle body portion, a needle valve, and a needle driving mechanism including a cylinder mechanism and a spring holder. The nozzle body portion includes a valve housing and the valve housing has a needle hole, into which a rear end portion of the needle valve is insertable, and a spring holder hole. The spring holder is inserted in the spring holder hole in a direction orthogonal to the axial direction in a state in which slide in the axial direction is allowed, and both ends of the spring holder are fixed to the cylinder mechanism. A central portion of the spring holder presses the rear end portion of the needle valve. Enlargement portions are formed in both side surfaces of the valve housing continuous with the spring holder hole.

A method for producing gramophone records by injection moulding, comprises the steps of heating polymeric material to liquefy said material, supplying liquid polymeric material under pressure from a feed zone to a space between two mould parts via a nozzle. The liquid polymeric material is passed through a single passage located in one of the mould parts and forced under pressure through the nozzle into said space. Polyethylene terephthalate isophthalic acid modified copolymer is used as said polymeric material.