A mold apparatus for forming a molded part includes a mold body, a mold cavity formed in said mold body, a plurality of valve gates associated with said mold body, and a controller in communication with said plurality of valve gates. The controller is programmed to time opening of each valve gate based on a selected flow rate required to eliminate weld lines in the product.

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 mold apparatus for forming a molded part includes a mold body, a mold cavity formed in said mold body, a plurality of valve gates associated with said mold body, and a controller in communication with said plurality of valve gates. The controller is programmed to time opening of each valve gate based on a selected flow rate required to eliminate weld lines in the product.

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.

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.

Systems and methods for controlling the closing speed of valve gated nozzles are disclosed. In one embodiment, a hot runner have a valve gated nozzle including a valve stem movable between an open position and a closed position is provided. The valve stem is moved at a first speed for a first portion of valve stem closure and a second speed for a second end portion of the valve stem closure.

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.

Apparatus and method for performing an injection molding cycle using the apparatus where the apparatus comprises: a manifold, a pneumatic actuator driven by a pneumatic valve assembly, the actuator driving a valve pin between a gate closed position and a maximum injection fluid flow position, the pneumatic valve assembly having a spool supported within a cylinder driven by a drive device that is supported solely by and translates together with the spool, a controller that instructs the pneumatic valve assembly to cause the actuator to drive the valve pin either upstream or downstream to selected positions or at selected velocities during the course of a single injection cycle based on a feedback signal indicative of position of the pin or actuator or pressure of an injection fluid material.

A method for injection molding of plastic material by means of at least one injector whose pin valve can be displaced between a fully closed position and a maximum open position in a controlled fashion according to a position and speed of the pin valve. During displacement of the pin valve from the fully closed position to the maximum open position, and/or vice versa, the pin valve is stopped in intermediate positions and the displacement speed thereof is uniform and constant. An initial opening step at maximum speed and one or more steps of inversion of the motion of the pin valve can be provided for.