A method for increasing the injection speed of a melted plastic injection device for injecting said melted plastic into a molding cavity (51), said injection device comprising: a first cylinder (1) provided with a tubular casing (2) defining a first inner diameter d.sub.1, and a first piston (3) slidable inside said tubular casing (2), adapted to be loaded with melted plastic and to inject said melted plastic toward the molding cavity (51); a second cylinder (21) constrained to the first cylinder (1) and provided with a second piston (23) which rod (24) is connected to the first piston (3) and is adapted to actuate said first cylinder (1) during an injection operation; the method comprising the steps of: releasing second cylinder (21) and first cylinder (1) by extracting the first piston (3) from the tubular casing (2); coaxially inserting a tubular body (12), defining a second inner diameter d.sub.3 which is smaller than the first inner diameter d.sub.1, into the tubular casing (2); disconnecting the first piston (3) from the rod (24); connecting a third piston (13) to the rod (24), said third piston (13) being sized to slide inside said tubular body (12); constraining second cylinder (21) and first cylinder (1) by inserting the third piston (3) into the tubular casing (2).

A melt dispenser for plastic molding comprises a barrel unit removably mountable to a drive unit. A feed screw is received within a barrel of the barrel unit and is rotated by the drive unit to dispense molten molding material through an outlet of the barrel. A coupling mechanism can be engaged to hold the barrel unit against the drive unit and on to connect the screw to the drive. The coupling mechanism is operable by an actuator.

An injection molding machine with an injection system and a clamping system. The injection system may include a removable injection module defining a portion of the material flow path. The injection module may include all of parts that come in contact with the material between the material source and the mold. The injection module may include a valve arrangement movable between a fill position to load the injection module with material and an inject position to eject material from the injection module into the mold. The actuators for the injection module may be supported on the machine rather than the injection module. The clamping system may include a platen linear actuator to open and close the mold, and a hydraulic clamping system to apply clamping force to the closed mold. The hydraulic clamping system may include a free-float valve manifold assembly that selectively places the hydraulic cylinders in free-float mode.

An injection molding machine with an injection system and a clamping system. The injection system may include a removable injection module defining a portion of the material flow path. The injection module may include all of parts that come in contact with the material between the material source and the mold. The injection module may include a valve arrangement movable between a fill position to load the injection module with material and an inject position to eject material from the injection module into the mold. The actuators for the injection module may be supported on the machine rather than the injection module. The clamping system may include a platen linear actuator to open and close the mold, and a hydraulic clamping system to apply clamping force to the closed mold. The hydraulic clamping system may include a free-float valve manifold assembly that selectively places the hydraulic cylinders in free-float mode.

A micro moulding machine and process for forming small plastic parts for the medical device industry. The machine adds heat in two steps to a precision sized plastic pellet and then displaces the entire pellet volume into the mould cavity. A substantial amount of heat is added to the pellet by forcing it through an orifice very near the gate of the mould. The pneumatic pressure to drive the pellet through the orifice is controlled to regulate the amount of heat introduced into the pellet.

A micro moulding machine and process for forming small plastic parts for the medical device industry. The machine adds heat in two steps to a precision sized plastic pellet and then displaces the entire pellet volume into the mould cavity. A substantial amount of heat is added to the pellet by forcing it through an orifice very near the gate of the mould. The pneumatic pressure to drive the pellet through the orifice is controlled to regulate the amount of heat introduced into the pellet.

The present invention relates to an injection molding apparatus with a spherical rotor. The injection molding apparatus includes an injection oil cylinder, an injection base frame, a motor, a transmission mechanism, bases, radial thrust bearings, a hopper, a machine barrel, an electric heater, a moving oil cylinder, a gear and a plunger. The apparatus further includes a plasticizing rotor and the plasticizing rotor includes a hemispherical rotor and a cylinder integrated with the hemispherical rotor. Continuous external thread grooves are provided on the hemispherical rotor. The machine barrel includes a hemispherical plasticizing cavity and an injection barrel. The hemispherical rotor is located in the hemispherical plasticizing cavity and is rotatable. The hopper is installed on the plasticizing cavity. The apparatus with the spherical rotor has the advantages of strong plasticizing, pulverizing and extruding ability, good quality of molded products and the like.

The present invention relates to an injection molding apparatus with a spherical rotor. The injection molding apparatus includes an injection oil cylinder, an injection base frame, a motor, a transmission mechanism, bases, radial thrust bearings, a hopper, a machine barrel, an electric heater, a moving oil cylinder, a gear and a plunger. The apparatus further includes a plasticizing rotor and the plasticizing rotor includes a hemispherical rotor and a cylinder integrated with the hemispherical rotor. Continuous external thread grooves are provided on the hemispherical rotor. The machine barrel includes a hemispherical plasticizing cavity and an injection barrel. The hemispherical rotor is located in the hemispherical plasticizing cavity and is rotatable. The hopper is installed on the plasticizing cavity. The apparatus with the spherical rotor has the advantages of strong plasticizing, pulverizing and extruding ability, good quality of molded products and the like.

A screw can be driven along an axial direction of a heating barrel and rotatable. An injection piston drives the screw along the axial direction. An injection hydraulic cylinder is partitioned into a first chamber in which pressured hydraulic oil for driving the injection piston is supplied and a second chamber from which hydraulic oil is discharged, and drives the injection piston in the axial direction by hydraulic pressure. A first oil discharge port is blocked by the injection piston when the injection piston advances to a holding pressure switching position. A second oil discharge port can discharge the hydraulic oil from the front chamber regardless of the position of the injection piston. The first oil discharge port is disposed at a position opposed to the first oil discharge port across a center axis of the injection hydraulic cylinder, and is connected to the first oil discharge port.

A feedstock delivery system for injection molding includes a vessel unit that includes a vessel with an internal volume and an inlet for receipt of a feedstock. First and second dispensing units are alternatively connectable to the vessel unit and each include first and second ends, first and second valves, and a buffer chamber. The first end is connectable to the dispensing unit such that the buffer chamber is in communication with the internal volume of the vessel. The second end is connectable to an injection mold and defines an outlet of the feedstock delivery system. The outlet is in communication with the buffer chamber, and the buffer chamber is positioned between the first and second valves. The buffer chamber of the first dispensing unit defines a first chamber volume, and the buffer chamber of the second dispensing unit defines a second chamber volume greater than the first chamber volume.