Systems and approaches for controlling a molding machine having a mold forming a mold cavity and being controlled according to a mold cycle include injecting a molten polymer into the mold cavity. A first and a second sensor are used to obtain first measurements of respective first and second variables during the injection cycle. The second sensor is positioned downstream from the first sensor. The first and second sensors are used to obtain second measurements of the respective first and second variables during the injection cycle. A first difference value is determined between the first measurements of the first and second variables. A second difference value is determined between the second measurements of the first and second variables. The first and second difference values are compared, and at least one control parameter is adjusted based on a difference between the first and the second difference values.

A method for manufacturing a glass plate equipped with a vehicle window-type resin frame includes performing injection molding of the resin frame by using two shaping molds having a cavity configured for the resin frame, disposing the glass plate inside the shaping molds such that the glass plate is retained by a retaining part that is adjacent to the cavity of the shaping molds, and injecting a resin into the cavity, wherein there is at least a partial gap between the glass plate and the retaining part, in a state in which the shaping molds are clamped together.

A technique for providing assistance in setting the time to increase the clamping force is provided. A control device of an injection molding machine includes a clamping control part and a monitoring part. The clamping control part is configured to change, in a filling step of filling the inside of a mold device with a molding material during clamping, a set value of clamping force from a first set value to a second set value that is larger than the first set value, at a predetermined pressurizing timing in the middle of the filling step. The monitoring part is configured to monitor changes in the actual value of the clamping force due to changes in the set value of the clamping force.

Injection molding of plastic materials by an apparatus comprising at least one injector including a valve pin displaceable in a controlled manner between a closed position and an open position by an electric rotary actuator. At least one step is provided of detecting the value of the torque developed by the electric rotary actuator when the valve pin is in the path from the closed position to the open position, and the torque value detected is used to pilot the molding process.

In a method for operating an injection moulding machine in the absence of a backflow barrier, plastic melt is injected by a plasticising device into a cavity in a screw antechamber of a plasticising screw adapted to rotate about a longitudinal axis and to move translationally by a drive unit during an injection phase and a holding- pressure phase. A rotational drive of the drive unit is controlled such that a speed of the plasticising screw causes overlay of a backflow of the plastic melt from the screw antechamber back into screw threads of the plasticising screw by an opposing delivery flow as a result of a rotation of the plasticising screw due to a translational injection movement of the plasticising screw. A differential flow is established from the backflow and the opposing delivery flow and influenced at least during the injection phase by influencing the speed of the plasticising screw.

Injection molding of plastic materials by an apparatus comprising at least one injector including a valve pin displaceable in a controlled manner between a closed position and an open position by an electric rotary actuator. At least one step is provided of detecting the value of the torque developed by the electric rotary actuator when the valve pin is in the path from the closed position to the open position, and the torque value detected is used to pilot the molding process.

An injection molding machine includes a cylinder; a screw; a rotary driving unit; a reciprocation driving unit; a pressure detector that detects a pressure of a molding material in front of the screw; a control unit that performs a first type of plasticizing process where the screw is moved backward to a predetermined position and rotated at the predetermined position to transfer the molding material forward to reserve the molding material in front of the screw, performs a first type of filling process where the screw is moved forward to inject the molding material reserved in front of the screw in the first type of plasticizing process from the cylinder to be filled in a mold unit, monitors the pressure in the first type of filling process by the pressure detector, and corrects the setting of the first type of filling process based on a monitored result.

In order to improve the consistency of molded products as viscosity shifts throughout a run, a controller of an injection molding machine executes a calibration cycle in accordance with a mold cycle. The controller analyzes a plurality of sensed melt pressure values during the calibration cycle to determine one or more calibration metrics. The controller then uses the calibration metrics when executing each mold cycle of the run. More particularly, during each mold cycle of the run, the controller detects a plurality of sensed melt pressures prior to and during a fill phase of the mold cycle and compares the plurality of sensed melt pressures to the one or more calibration metrics to predict cavity pressure for a pack and hold phase of the mold cycle. The controller then adjusts a set point pressure for the pack and hold phase based on the predicted cavity pressure.

An injection molding machine, and a method of controlling the injection molding machine, can prevent a molding defect. The injection molding machine can mold a product for each execution of a molding cycle through an injecting process of injecting a material into clamped molds, a dwell process of controlling dwell pressure of the material in the molds, and a cooling process of cooling the material in the molds, the injection molding machine including a mold opening amount sensor and a controlling unit, the mold opening amount sensor being configured to detect a mold opening amount of the molds, the controlling unit being configured to control clamping force of the molds and the dwell pressure based on the mold opening amount during the molding cycle.

An injection molding apparatus including:

a valve pin driven by an actuator, the valve pin extending axially through at least a portion of the channel length of the fluid flow channel, the fluid flow channel including a throat, downstream flow of the injection fluid being restricted by a bulb portion of the pin, the valve pin having an intermediate position where downstream flow of injection fluid is unrestricted and a fully downstream position where downstream flow of injection fluid is stopped at both the gate and at the throat, wherein the actuator is driven by a valve assembly comprised of a spool mechanically driven by first and second actuators or solenoids that each separately engage the spool at opposing axial ends to effect movement of the spool back and forth between the drive fluid flow positions.