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.

A process includes: supplying a main resin from outer and inner flow channel, to a joined flow channel at a predetermined supply velocity for a predetermined time; supplying a second resin from a middle flow channel to the joined flow channel simultaneously with the main resin at a predetermined supply velocity for a certain time within the predetermined time; and sliding a shut-off pin to bring the pin forefront to a predetermined position near an outlet of the inner flow channel, open to the joined flow channel, before the second resin is supplied, or during a time starting after a time from the start of the second resin supply and ending with the termination of the supply, so that the velocity of main resin supply from the inner flow channel to the joined flow channel is reduced to a predetermined level by adjusting the degree of aperture for the outlet.

Apparatus and method for detecting a position of an actuator piston driving a valve pin in an injection molding system. The apparatus includes an actuator housing having a body portion, surrounding an axial bore, of a substantially non-magnetic and/or magnetically permeable material, a piston, movable within the axial bore for driving a valve pin, the piston including a magnetic member generating a magnetic field such that axial movement of the piston in the bore modifies the magnetic field according to the position of the piston relative to a detection position, and a magnetic field detector attached to an exterior surface of the body portion at the detection position for detecting the magnetic field associated with the position of the piston and generating an output signal determined by the piston position.

An injection molding apparatus including an actuator interconnected to a rod or valve pin having a smooth continuous cylindrical outer surface and one or more discontinuous or relieved or relieved portions formed as discontinuities in the cylindrical outer surface and adapted to be disposed within a fluid flow channel, the one or more discontinuous or relieved portions being configured and arranged along the axial length of the pin or rod such that the flow of injection fluid over or past the one or more discontinuous or relieved portions is modified to flow at substantially different rates or velocities or in substantially different flow patterns relative to rate or velocity or pattern of flow of injection fluid over or past the smooth continuous cylindrical outer surface.

There is provided a mold stack (100). The mold stack (100) comprises a core insert assembly (102), the core insert assembly (102) for defining an inner portion of a molded article to be molded. The core insert assembly (102) includes a sensor assembly (120) configured to measure the in-mold pressure using entire active surface of the core insert assembly (102).

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.

An injection molding machine includes an edge gate nozzle with a nozzle body having a primary melt channel and a nozzle head having first and second secondary melt channels that feed melt to first and second nozzle tips. First and second heaters are disposed in the nozzle head to provide heat to the secondary melt channels. In some embodiments, the heaters are positioned adjacent to the secondary melt channels, with first heater is closer to the first secondary melt channel than to the second secondary melt channel. In some embodiments, the heaters are positioned adjacent to the nozzle tips, with the first heater closer to the first nozzle tip than to the second nozzle tip. In some embodiments, each heater is adjacent to both the respective nozzle tip and secondary melt channel. In some embodiments, each heater is individually controllable.