Abstract: In a vent type injection molding machine having a screw contained in a heating cylinder, there are provided a plurality axially spaced apart vent openings located at intermediate points of the heating cylinder for venting inside of the heating cylinder to the outside and control means for selectively opening and closing the vent openings in accordance with the position of the screw in the heating cylinder or the pressure of a thermoplastic resin injected by the injection molding machine.

Abstract: Method for improved melt quality of thermoplastics processed in reciprocating-screw molding, especially optical injection molding processes. In a reciprocating-screw injection-drive unit (4) is a barrel (53) and screw (15). Screw (15) is double flighted throughout its melting or transition zone (2), to form melt channel (48) and solids channel (50) separated by melt-filtering flight element (47), and kept in fluid communication by melt-transfer apertures (47 or 55 or 56) or substantially nonvertical ramped barrier flight geometry (not shown). The largest energy input for melting is directly provided by thermal conductivity, via electrical resistance heating elements.

Abstract: A control method of an injection molding machine is implemented so that a screw is rotated at a predetermined speed in the reverse direction to a rotational direction in a measuring process in the whole or partial stroke of an injection process in the case where an in-line screw type injection molding machine is controlled. With the control method, when the screw is moved forward in the injection process, apparent position of a ridge of the screw in a predetermined position of a heating cylinder becomes stationary.

Abstract: An injection apparatus of a plunger type for injecting reinforced materials such as BMC is of a single barrel type or a double barrel type comprising a rotatable plunger disposed in the barrel. A check valve means for preventing a back flow of the materials in a metering process is provided such that it is closed when the plunger is actuated to move axially for injection.

Abstract: A drive apparatus useful in screw injection molding apparatus is disclosed. The apparatus is particularly useful when both axial and rotational movements are required because the invention discloses a construction that reduces the wear attributed to sealing gaskets of relatively large diameter which are subjected to rotational stresses and relatively high linear velocities. In the injection molding embodiment described in detail, the extruder screw is rigidly attached to a drive piston that has both axial and rotational movements. Concentric to that drive piston is a drive cylinder tha has only axial movement yet is connected to the drive piston such that the piston is able to rotate freely relative to the cylinder but may move axially only when the cylinder moves. Thus, the sealing gaskets of the drive cylinder are free of rotational stresses which extends the useful life of the sealing gaskets.

Abstract: The present disclosure is directed to a method of injection molding PVC products from powdered raw material, while employing an injection molding machine having a plasticizing unit having a rotary screw and a rotary screw and an injection unit having a screw which both rotates and reciprocates. The powdered raw material is subjected firstly to a prejellifying treatment during forced transportation through the plasticizing unit in which it is heated and brought to agglomerate in a relatively short time and the agglomerate is subjected to a vacuum after the prejellifying treatment and its introduction into the injection unit at an absolute pressure of less than 50 kPa.

Abstract: An injection apparatus of a plunger type for injecting reinforced materials such as BMC is of a single barrel type or a double barrel type comprising a rotatable plunger disposed in the barrel. A check valve means for preventing a back flow of the materials in a metering process is provided such that it is closed when the plunger is actuated to move axially for injection.

Abstract: A metering system of an injection molding machine which uses a numerical control unit (10), having a torque limit function, in order to control a rotating speed and a back pressure of a screw (1) in accordance with a screw position.The numerical control unit (10) reads out, from a non-volatile memory (14), a screw rotating speed command value and a torque limit value in accordance with a screw position detected by an encoder (P1), and outputs the readout screw rotating speed command value and torque limit value to a second servo motor (M2), which rotates the screw (1), and to a first servo motor (M1), which drives the screw (1) in the axial direction, respectively.

Abstract: In order to obtain an injection drive apparatus which is low-priced, can produce a great output torque, and has a satisfactory acceleration/deceleration characteristic, in an injection-molding machine which performs injection by driving a screw by means of servomotors, one or more ball screws (7), used to drive a screw (2) in the axial direction, are driven by means of a plurality of servomotors (M1, M2), a position detector (P1) for detecting the screw position is provided only for one servomotor (M1), and the servomotors (M1, M2) are provided individually with power amplifiers, which are controlled by means of one control circuit so that the individual servomotors (M1, M2) are controlled in synchronism with one another.

Abstract: A large-output injection/measurement mechanism of an injection molding machine, which uses measurement and injection servo motors as its drive source. A plurality of ball screws are rotatably provided between front and rear plates of the injection molding machine and are coupled to the injection servo motor. Ball nuts engaged with the plurality of the ball screws are fixed on a pressure plate. The pressure plate is coupled to the measurement servo motor through a spline shaft and a rotational drive pipe spline-coupled thereto. The spline shaft is fixed on a screw sleeve rotatably fixed to the pressure plate. A screw fixed to the pressure plate is driven by the servo motors, thereby performing injection and measurement of a molding material.

Abstract: An injection molding machine includes an injection mold assembly, an injection molding unit, and a drive for inserting the injection molding unit on and withdrawing it from the injection mold assembly. The injection molding unit includes a carrier block, a plasticizing cylinder projecting into a central longitudinal bore of the carrier block, a feed screw coaxially received in the plasticizing cylinder, and a coupling for releasably axially immobilizing the plasticizing cylinder in the carrier block. The coupling has a plurality of locking bolts radially slidably supported on radial guide faces of the carrier block. The locking bolts have a locking position in which they project into a circumferential locking groove of the plasticizing cylinder and an unlocking position in which the locking bolts are, by a drive, radially withdrawn from the circumferential locking groove.

Abstract: A screw-rotating/injection mechanism of an injection molding machine has a screw shaft (1) having a rear portion thereof connected to a drive shaft (1') which is rotatably fixed to a pressure plate (4). A nut (6) which is spline-coupled to a spline shaft (5) constituting a rear portion of the drive shaft (1') is driven by a screw rotating motor (M1) through a first transmission unit (9, 10, 13, 15) to rotate the screw shaft (1). A ball screw (8, 8') threadedly engaged with a ball nut (7, 7'), fixed to the pressure plate (4), is driven by an injection servo motor (M2) through a second transmission unit (11, 11', 14, 16) to move the screw shaft (1) forward, thereby performing injection.

Abstract: An injection molding apparatus including a power transmission device is provided for axially moving a screw by a rotational force of a motor received through a first clutch. During non-injection/non-metering, the motor is driven to cause an energy accumulation device to accumulate energy through a second clutch. During injection, a driving force of the motor and the energy accumulated in the energy accumulation device achieve high-pressure, high-speed injection with good response characteristics.

Abstract: An exhaust gas treating device for injection molding machines, in which a vent port of a vented injection machine is connected to a vacuum and an exhaust gas treating mechanism for treating the gas discharged from the vent port characterized in that a mist separator, the vacuum pump, an air-water separator and a deodorizing unit are disposed in the above-mentioned order from the vent port side and in communication with the vent port.

Abstract: A molding apparatus for molding a pressurized plastic material of the nature of ground meat or other food such as ground fish and the like in which the apparatus comprises a movable mold having a mold opening for receiving a pressurized charge of the material, with the mold being movable between mold opening filling and article discharge positions, an entrance to the mold opening at the filling position, means for directing the pressurized charge through this entrance at the filling position and into the mold opening and vent means spaced from the mold opening entrance for venting from the mold opening air displaced by the pressurized charge entering the mold opening. The vent means comprises a plurality of elongated slots extending from the mold opening in the filling position on the side opposite to the mold entrance and exhausting to the exterior of the apparatus.

Abstract: Injection blow molding equipment for the production of hollow articles wherein cores are axially inserted in blow molds and blank molds is disclosed. Compact core assemblies and fluid supply systems integral with the platens allow the mold parts to be mounted on the surfaces of opposed, relatively movable platens. Partible neck rings associated with each core open divergently outwardly as the blow mold and core separate, to shorten machine cycle time. A manifold, supplied with cooling fluid from the periphery of a core mounting plate, distributes heat transfer fluid to the core assemblies for cooling the neck rings. In one embodiment, mating blow mold sections are mounted on contra-oscillatable mounting members and are opened and closed by arcuate movement of the mounting members.