An injection molding method includes: a plasticizing process of feeding a resin pellet and additive components to a heating cylinder including a screw that can rotate around a rotation axis and can advance and retreat along the rotation axis, and generating molten resin by rotating the screw in a normal direction; and an injection process of injecting to a cavity the molten resin containing the additive components. In the plasticizing process, retreat operation of forcibly retreating the screw is performed at a predetermined velocity by a predetermined stroke or a predetermined time.

A method is described for operating an injection moulding machine, which has one or more movable machine parts which can be moved by suitable drives along specifiable travelling distances. Movement of a movable machine part is repeated cyclically. In order to reduce the movement times of the movable machine parts to a minimum, provision is made for one or more of the movable machine parts to successively reduce the power reserves of one or more of the drives associated with a movable machine part, until a specifiable minimum of power reserve is reached, wherein the minimum can be zero. In each cycle, the power reserve of the drive or drives is determined and is successively reduced, in particular from cycle to cycle. A movable platen, an ejector, a core puller, a plasticizing screw and/or an injection piston can be provided as movable machine part.

An injection molding machine uses a controller to effectively control its operation. The controller may determine and/or receive information regarding the machine's maximum load capacity, and may also determine a current operational load value of the machine. The controller also may determine a number of set points used to operate the machine. The controller may cause the machine to operate at these set points, thereby resulting in the machine operating at or below the maximum load value by adjusting any number of machine parameters associated with the injection molding machine.

An injection molding machine uses a controller to effectively control its operation. The controller may determine and/or receive information regarding the machine's maximum load capacity, and may also determine a current operational load value of the machine. The controller may cause the machine to operate at any number of combinations of settings of operational parameters which result in the machine operating at or below the maximum load value by adjusting any number of machine parameters associated with the injection molding machine based on feedback sensors measuring real-time operating conditions of the machine.

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.

An injection molding system comprised of: an injection machine having a barrel and a screw for injecting an injection fluid, a distribution manifold, a valve associated with a corresponding one of one or more downstream gates, a sensor adapted to sense and generate a signal indicative of pressure of the injection fluid in the barrel or an inlet that delivers injection fluid from the barrel to the manifold, and a controller receiving the signal generated from the sensor and including instructions that use the signal as a control value to adjust, during the course of an injection cycle, positioning or velocity of one or more of the valve pins.

A method and apparatus for injection molding of plastic material into a cavity of a mold by means of at least one injector whose opening and closing occurs through an electronic control unit and wherein an undesired opening of the mold caused by any overpressure of the plastic material injected into the cavity of the mold is detected by means of transducers and corrected by means of the electronic control unit. The transducers are arranged outside the cavity of the mold.

A molding system for applying moldable material to a pipe. An elongate mold has at least one elongate mold member movable relative another elongate mold member between open and closed positions. The mold includes a pipe support that extends generally radially into a mold cavity along a support axis. An inner end of the support is configured to support the pipe in a molding position in which an annular portion of the mold cavity extends circumferentially around the pipe. After moldable material in the annular portion of the mold cavity can support the pipe, the support is withdrawn from the mold cavity by moving outwardly along the support axis. An injector selectively dispenses additional moldable material into a space formed by the support in the existing moldable material.

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.

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.