A control device for an injection molding machine including a cylinder into which a resin is supplied and a screw that moves forward and rearward and rotates inside the cylinder, includes a metering control unit that performs metering of the resin inside the cylinder by controlling forward rotation and rearward movement of the screw until the screw has been moved rearward to a predetermined metering position, based on predetermined metering conditions, a rearward movement speed acquisition unit acquiring a rearward movement speed of the screw, a speed determination unit that determines a suck back speed for causing a resin pressure to reach a target pressure, based on the rearward movement speed acquired during metering by the rearward movement speed acquisition unit, and a suck back control unit causing the screw to move further rearward based on the suck back speed, after the screw has reached the predetermined metering position.

A control device for an injection molding machine that performs a metering of a resin while the resin is being melted inside a cylinder, includes a pressure acquisition unit that acquires a pressure of the resin, a reverse rotation control unit that causes a screw to be rotated in reverse so as to reduce the pressure of the resin, after the screw has been moved rearward to a predetermined metering position, a judgment unit that judges whether or not the pressure of the resin has reached a predetermined rearward movement initiation pressure, after the reverse rotation of the screw is started, and a rearward movement control unit which causes the screw to be moved rearward, in the case it is judged that the pressure of the resin has reached the rearward movement initiation pressure.

A control device for an injection molding machine is equipped with a pressure acquisition unit that acquires a pressure of a resin, a reverse rotation control unit that causes a screw to be rotated in reverse, after the screw has reached a predetermined metering position, a measurement unit that measures an elapsed time or a rotation amount of the screw from when the screw has reached the predetermined metering position, and a rearward movement control unit that initiates sucking back of the screw in an overlapping manner with the reverse rotation of the screw, in the case that a predetermined rearward movement initiation time has elapsed, or in the case that the screw has been rotated by a predetermined rearward movement initiation rotation amount, from when the screw has reached the predetermined metering position.

A control device for an injection molding machine is equipped with a pressure acquisition unit that acquires a pressure of a resin inside a cylinder, a reverse rotation control unit that causes a screw to be rotated in reverse based on a predetermined reverse rotation condition so as to reduce the resin pressure after having moved the screw rearward to a metering position, a compensation amount calculation unit that calculates a compensation amount to be made with respect to the reverse rotation condition, based on the resin pressure inside the cylinder acquired by the pressure acquisition unit when the reverse rotation of the screw is stopped, and a predetermined compensation function, and a compensation processing unit configured to compensate the reverse rotation condition based on the compensation amount calculated by the compensation amount calculation unit.

A computer-implemented simulation method for use in a molding process by a computer process is disclosed. The method includes steps of specifying a simulating domain comprising a mold cavity and a barrel of an injection machine, wherein the barrel is configured to connect to the mold cavity; creating at least one mesh by dividing at least part of the simulating domain; specifying boundary conditions of the mesh by taking into consideration at least one motion of a screw in the barrel; and simulating a first injection-molding process of a molding material by using the boundary conditions to generate a plurality of molding conditions.

A method and system for adjusting melt pressure in an injection molding material that allows calculating a melt pressure of a molten plastic material to be injected and based on the calculated melt pressure and a desired melt pressure adjusting operation of an injection molding machine. This control of an injection molding cycle using the method and system of plastic melt pressure determination allows production of parts of increased quality and consistency.

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.

A method of monitoring and controlling a sequential valve gate molding apparatus in an injection molding or other molding process is disclosed. The method includes creating a target strain profile, receiving a deviation limit, receiving a change in strain relating to a first valve gate from a first strain gauge, identifying whether a deviation exists from a first portion of the target strain profile based on the output from the first strain gauge, determining whether any existing deviation exceeds the deviation limit, and adjusting the position of a first valve gate pin in the first valve gate if it does. The method may further include control of subsequent valve gates. Multiple strain gauges may be used to control a single valve gate, and/or each strain gauge may control more than one valve gate.

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.

A computer-implemented simulation method for use in a molding process by a computer process is disclosed. The method includes steps of specifying a simulating domain comprising a mold cavity and a barrel of an injection machine, wherein the barrel is configured to connect to the mold cavity; creating at least one mesh by dividing at least part of the simulating domain; specifying boundary conditions of the mesh by taking into consideration at least one motion of a screw in the barrel; and simulating a first injection-molding process of a molding material by using the boundary conditions to generate a plurality of molding conditions.