A pressure controller for an injection molding machine capable of reducing variations of pressure in a mold in molding cycles and providing molded articles of stable quality is provided. The pressure controller includes an in-mold pressure estimation unit for estimating a pressure in the mold based on an injection pressure detected with an injection pressure detection unit, and an amount of movement of a screw detected with a screw movement amount detection unit, and an in-mold pressure control unit for controlling such that the estimated in-mold pressure becomes a set in-mold pressure after the pressure control is performed in a dwell step with an injection pressure control unit.

A pressure controller for an injection molding machine capable of reducing variations of pressure in a mold in molding cycles and providing molded articles of stable quality is provided. The pressure controller includes an in-mold pressure estimation unit for estimating a pressure in the mold based on an injection pressure detected with an injection pressure detection unit, and an amount of movement of a screw detected with a screw movement amount detection unit, and an in-mold pressure control unit for controlling such that the estimated in-mold pressure becomes a set in-mold pressure after the pressure control is performed in a dwell step with an injection pressure control unit.

An injection molding machine includes an injection apparatus having a screw rotation driving section for rotating a screw inserted to a heat sleeve and a screw forward/rear move driving section for forwardly or rearwardly moving the screw at least by a hydraulic cylinder, including a unique screw for which an L/D ratio between a screw length and a screw diameter is set as a specific value to the injection apparatus. The injection apparatus includes a cylinder attachment mechanism having a cylinder detachable section that provides the detachability of at least two or more different types of hydraulic cylinders adaptable to a molded piece that can be molded by the unique screw.

Disclosed herein is a process for producing marbled moldings, where a first molding compound and at least one further molding compound are injected from an injection unit of a screw injection molding machine into an injection mold, where the injection unit includes a barrel, a screw having a screw tip and a nozzle where the screw is rotatable and is disposed in the barrel so as to be movable between a forward position and a backward position, with a smaller distance between the screw tip and the nozzle in the forward position than in the backward position, and where the first molding compound includes a first polymer compound and a first colorant, and the at least one further molding compound includes a further polymer compound and optionally at least one further colorant.

Further disclosed herein is an apparatus for production of marbled moldings, and a process for producing the apparatus.

Disclosed herein is a process for producing marbled moldings, where a first molding compound and at least one further molding compound are injected from an injection unit of a screw injection molding machine into an injection mold, where the injection unit includes a barrel, a screw having a screw tip and a nozzle where the screw is rotatable and is disposed in the barrel so as to be movable between a forward position and a backward position, with a smaller distance between the screw tip and the nozzle in the forward position than in the backward position, and where the first molding compound includes a first polymer compound and a first colorant, and the at least one further molding compound includes a further polymer compound and optionally at least one further colorant.

Further disclosed herein is an apparatus for production of marbled moldings, and a process for producing the apparatus.

A shut-off nozzle includes a nozzle body portion having an in-nozzle flow path formed therein, and a needle valve that is inserted into the nozzle body portion coaxially with the nozzle body portion and is configured to open and close an outlet of the in-nozzle flow path. A cylindrical portion is formed in the vicinity of a tip portion of the needle valve. A cylindrical hole portion is formed in the vicinity of a tip portion of the in-nozzle flow path, the cylindrical hole portion being a cylindrical hole. The cylindrical portion is configured to be fitted into the cylindrical hole portion in a case where the needle valve is driven in a forward direction.

A shut-off nozzle includes a nozzle body portion having an in-nozzle flow path formed therein, and a needle valve that is inserted into the nozzle body portion coaxially with the nozzle body portion and is configured to open and close an outlet of the in-nozzle flow path. A cylindrical portion is formed in the vicinity of a tip portion of the needle valve. A cylindrical hole portion is formed in the vicinity of a tip portion of the in-nozzle flow path, the cylindrical hole portion being a cylindrical hole. The cylindrical portion is configured to be fitted into the cylindrical hole portion in a case where the needle valve is driven in a forward direction.

Plasticizing unit for a molding machine with an injection cylinder and an axially movable plasticizing screw arranged in the injection cylinder, wherein a filter device for filtering plasticized material, in particular plasticized plastic, is provided, which is or can be arranged axially movable in the injection cylinder.

Plasticizing unit for a molding machine with an injection cylinder and an axially movable plasticizing screw arranged in the injection cylinder, wherein a filter device for filtering plasticized material, in particular plasticized plastic, is provided, which is or can be arranged axially movable in the injection cylinder.

An injection apparatus of one embodiment includes a cylinder, a screw provided inside the cylinder, and a drive mechanism configured to rotate the screw, move the screw forward, and move the screw backward. The drive mechanism includes a piston having a piston rod and a rotating body which is arranged around the piston rod and is driven to rotate around a central axis of the piston rod as a rotation axis. A plurality of external teeth extending in the direction of the central axis of the piston rod are provided on the piston rod, and a plurality of internal teeth meshing with the external teeth are provided on the rotating body. Also, the screw is non-rotatably connected to a distal end side of the piston rod.