A method and system for co-injection molding of two molten plastic materials that allows monitoring and utilization of injection pressure and optionally melt pressure and/or flow front pressure during an injection run. A controller alters the injection pressure so as to achieve and maintain optimal or desired ratios of injection pressure, and optionally melt pressure and/or flow front pressure, of the two molten plastic materials. This allows for more precise part manufacture, including reducing the thickness of a skin or shell layer compared to a core layer of a molded part.

The present invention offers a technique for providing assistance in setting at least one of the temperature of a nozzle and the temperature of a cylinder. A control device for an injection molding machine includes a monitoring part configured to monitor, during a filling step of filling the inside of a mold device with a molding material, a change in the filling pressure acting on the molding material.

With respect to a controller of an injection molding machine, the injection molding machine includes an injection member provided inside a cylinder to heat a molding material and an injection drive source to fill the molding material into a mold device by moving the injection member forward. The controller includes a limiting part that limits a movement of the injection member forward in a pressure-holding process of controlling an injection drive source so that an actual value of a filling pressure acting on the molding material from the injection member becomes a set value, and a determining part that determines an appropriateness of a setting to be used by the limiting part based on information of a sensor provided in the mold device.

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.

Systems and approaches for controlling an injection molding machine having a mold forming a mold cavity and being controlled according to an injection cycle include injecting a molten polymer into the mold cavity according to a startup profile. A first sensor is used to measure at least one variable during the startup profile. The startup profile is terminated upon the at least one variable exceeding a first threshold. The molten polymer is then injected into the mold cavity according to a primary injection profile.

A hydraulic system for a cyclically operating shaping machine includes at least one hydraulic drive unit for cyclically driving a component of the shaping machine at a start time; at least one pump; and at least one hydraulic accumulator which can be discharged for driving the at least one hydraulic drive unit and which can be charged up by operation of the at least one pump. An open-loop or closed-loop control unit is also provided for control of the at least one pump. The open-loop or closed-loop control unit is adapted to operate the at least one pump continuously until the start time of the at least one hydraulic drive unit to charge up the at least one hydraulic accumulator until the start time of the hydraulic drive unit.

An additive injection system for use in injection molding machines to inject additive materials, such as fluids or powders, downstream of a nozzle of the injection molding machine. The additive injection unit has an additive tank to store or contain additive material and additive injectors that inject an additive material into an injection molding machine. A pump pumps the additive material from the tank through a common manifold connected to the additive injectors to be injected into the injection molding machine. A controller controls operation of the additive injection device and one or more sensors coupled to the additive injection device can provide feedback to the controller.

In one aspect, there is provided an injection molding system configured to operate in a plurality of cycles. The system comprises, amongst other things, a controller that is configured for performing a comparison of a variable pressure setpoint with a target pressure value. The controller is configured to, when the target pressure value is less than the variable pressure setpoint by at least a predetermined lower bound, (i) decrease the variable pressure setpoint to a reduced variable pressure setpoint and (ii) not further decrease the variable pressure setpoint from the reduced variable pressure setpoint until the pump assembly operates for a plurality of stabilizing cycles at the reduced variable pressure setpoint.

A method of influencing a backpressure length and/or a screw return speed in an axially extending plasticizing cylinder of a plasticizing unit for an injection moulding machine including a plasticizing screw arranged displaceably and rotatably in a cylinder bore of the plasticizing cylinder. Metering of plastic granulate fed to the plasticizing unit is carried out in dependence on the desired backpressure length in the plasticizing unit, and the plasticizing unit is operated in underfed mode.

A controller for an injection molding system is in communication with a melt flow control unit, a gas assist control unit, and a gas counter pressure control unit. The controller can effect real-time adjustments to gas assist pressure and/or gas counter pressure as a function of melt pressure or flow front position.