Injection molding apparatuses and methods wherein a valve pin is controllably driven upstream and downstream along an axis between a first closed position where the tip end of the valve pin obstructs the gate to prevent the injection fluid from flowing into the cavity, a full open position and one or more intermediate positions, wherein the valve pin is drivable to be disposed or held in a selected intermediate position for a selected period of time during the course of an injection cycle where the tip end of the valve pin restricts flow of injection fluid through the gate to the mold cavity.

A method and apparatus for performing an injection molding cycle comprising drivably interconnecting a valve pin to an electric motor actuator and controllably operating the electric motor to drive the valve pin at one or more reduced rates of upstream or downstream travel based on either detection of the position of the pin or actuator or on a preselected length of time at which to drive the valve pin.

Provided is an injection molding device, including an injection port arranged on an upper mold base; an upper mold arranged in the upper mold base, wherein at least one ejection port, a gasket groove and a gasket are provided and the ejection portion is connected to the injection port; a lower mold base operatively aligned with or separated from the upper mold base and provided with at least one gas passage for the gas to enter or exit; and a lower mold disposed on the lower mold base. The lower mold base is aligned with or separated from the upper mold base, the lower mold is provided with a mold cavity and at least one shaped air path is provided to connect the mold cavity with the gas passage. The lower mold is a porous material and has a plurality of pores. Gas is pre-injected into the mold cavity through the gas passage and at least one air path to maintain a preset pressure inside the mold cavity. Gas is spewed out through the plurality of pores, thereby causing a finished product to exit the mold cavity. In addition, the present disclosure also provides an injection molding method.

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 method and apparatus for producing hollow articles made of injection moulded plastic material by a mould having a die within which there is inserted a core, and at least one injector including a pin valve displaceable between a closing position and an opening position for injecting the pressurized plastic material into a space comprised between the die and the core. During the injection, any flexural deflection of the core is detected and the pin valve of the or of each injector is displaced in a controlled fashion to adjust a pressure and a flow rate of the injected plastic material, so as to reduce or eliminate such deflection of the core.

An injection molding machine includes a cylinder that accommodates a molten resin, a discharging nozzle, a piston that discharges the molten resin from the discharging nozzle, and one or more processors configured to execute the following functions. The functions include calculating a target pressure at which a flow rate of the molten resin discharged from the discharging nozzle becomes an indicated flow rate, controlling a pressure of the molten resin in the cylinder such that the pressure becomes the target pressure, acquiring a temperature of the molten resin in the cylinder, and acquiring a pseudo-plastic viscosity corresponding to the temperature of the molten resin. The target pressure is calculated based on the indicated flow rate, the temperature of the molten resin, the pseudo-plastic viscosity, and the size of the discharging nozzle.

A predetermined mold gap is provided beforehand between a movable mold and a stationary mold of a mold by a mold clamping device. A mold clamping pressure is set to zero, and a predetermined back pressure is set for the movable mold. Subsequently, the injection device is caused to start injection of the molten resin into the mold for which the mold gap, the mold clamping pressure, and the back pressure have been set. When a predetermined injection end condition set beforehand is satisfied as a result of progress of an injection filling process, a filling end process of ending the injection filling process is performed.

An injection device according to one embodiment of the present invention monitors the linear torque of a linear motor and the rotary torque of a rotary motor using a first detection unit for detecting the linear torque and a second detection unit for detecting the rotary torque while controlling the linear motor and the rotary motor so that a bush is spline-fitted to a screw.

An injection molding apparatus and method of fabricating a molded part are provided. The apparatus may include a barrel, a nozzle enclosing an end of the barrel and defining an opening in fluid communication with an inside of the barrel, and an extrusion screw positioned at least partially inside the barrel and rotatable relative to the barrel. The extrusion screw may include a screw tip. Relative axial movement between the barrel and the extrusion screw may open or close the opening of the nozzle to permit or prevent, respectively, material flow through the opening of the nozzle. The method may include clamping a mold, opening a nozzle, rotating the extrusion screw to pump a molten material into the mold until the mold is filled, closing the nozzle, and unclamping the mold to release a molded part.

An injection molding machine having vent mechanism includes a plastication device, an injection device, a junction, a vent-up sensor, and a controller. The vent-up sensor detects vent-up. When the vent-up is detected, the controller switches from normal conditions to vent-up suppression conditions. The vent-up suppression conditions have at least one of the followings: increasing a rotational speed of the plastication screw to be higher than that in the normal conditions; using retreat-metering when the retreat-metering is not performed in the normal conditions, wherein in the retreat-metering, in addition to a pressure of the resin material, a force in a retreat direction is applied to the injection plunger to move the injection plunger at a predetermined retreat speed in the metering; and increasing the retreat speed of the injection plunger to be higher than that in the normal conditions when the retreat-metering is performed in the normal conditions.