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 controller for an injection molding system is in communication with a melt flow control unit, a gas assist control unit, and a gas counter pressure control unit. The controller can effect real-time adjustments to gas assist pressure and/or gas counter pressure as a function of melt pressure or flow front position.

A method is disclosed of controlling a plant for dehumidifying and/or drying plastic material in granular and/or micro-granular and/or powder and/or flake or similar form, this plant including a process fluid generator and at least one dehumidifying/drying hopper for feeding a respective user machine associated with the plant and including a melting device for melting the plastic material and a moulding device for moulding, in particular by injection moulding and/or blow moulding and/or compression moulding, the plastic material. The method of controlling includes the steps of detecting in the user machine a pressure (P.sub.pwp) of the plastic material in melted state and modifying at least one process parameter (D.sub.p) of the plant on the basis of the detected value of this pressure (P.sub.pwp).

An injection-molding method is provided in which in a first injection-molding step at least one first material component (17) is injected into a mold cavity (4) of an injection mold (3). The first injection-molding step is terminated when a condition pertaining to a first material volume that has been injected in the first injection-molding step has been met. This condition can be, for example, a minimum filling level which is caused in the mold cavity (4) by a material volume from the at least one first material component (17) that in the first injection-molding step has been injected into the mold cavity (4). When the minimum filling level can be detected or confirmed, for example with the aid of a sensor (10), the first injection-molding step is terminated and a second injection-molding step can optionally be started.

Embodiments within the scope of the present disclosure are directed to external sensor kits that may be included in new injection molds or retrofitted into existing injection molds in order to approximate conditions within a mold, such as pressure or the location of a melt flow front. Such kits are designed to amplify meaningful measurements obtained by the external sensor kit so that noise measurements do not prevent the approximation of conditions within a mold. In some embodiments within the scope of the present disclosure, an external sensor kit includes a strain gauge sensor, a coupon, a support bracket, and a hammer. The strain gauge sensor is placed on a surface of the coupon and measures the strain in the coupon.

A remote controller can be provided on any apparatus that employs feedback control from a native controller to add functionality to the apparatus where the native controller is not capable of providing such functionality independently.

In order to improve the consistency of molded products as viscosity shifts throughout a run, a controller of an injection molding machine executes a calibration cycle in accordance with a mold cycle. The controller analyzes a plurality of sensed melt pressure values during the calibration cycle to determine one or more calibration metrics. The controller then uses the calibration metrics when executing each mold cycle of the run. More particularly, during each mold cycle of the run, the controller detects a plurality of sensed melt pressures prior to and during a fill phase of the mold cycle and compares the plurality of sensed melt pressures to the one or more calibration metrics to predict cavity pressure for a pack and hold phase of the mold cycle. The controller then adjusts a set point pressure for the pack and hold phase based on the predicted cavity pressure.

A pressure measurement device mountable to an injection unit that injects molding material of an injection molding machine, and an injection molding machine are provided. The pressure measurement device includes: a measurement cylinder mounted to the injection unit and through which the molding material injected by the injection unit flows; a plurality of dies mounted to the measurement cylinder and through which the molding material flows, and having different specifications; a flow path switching pin that selectively switches a discharge destination of the molding material to any one of the plurality of dies; and a pressure sensor that measures a pressure of the molding material in the measurement cylinder.

In one aspect, there is provided an injection molding system configured to operate in a plurality of cycles. The system comprises, amongst other things, a controller that is configured for performing a comparison of a variable pressure setpoint with a target pressure value. The controller is configured to, when the target pressure value is less than the variable pressure setpoint by at least a predetermined lower bound, (i) decrease the variable pressure setpoint to a reduced variable pressure setpoint and (ii) not further decrease the variable pressure setpoint from the reduced variable pressure setpoint until the pump assembly operates for a plurality of stabilizing cycles at the reduced variable pressure setpoint.

In one aspect, there is provided an injection molding system configured to operate in a plurality of cycles. The system comprises, amongst other things, a controller that is configured for performing a comparison of a variable pressure setpoint with a target pressure value. The controller is configured to, when the target pressure value is less than the variable pressure setpoint by at least a predetermined lower bound, (i) decrease the variable pressure setpoint to a reduced variable pressure setpoint and (ii) not further decrease the variable pressure setpoint from the reduced variable pressure setpoint until the pump assembly operates for a plurality of stabilizing cycles at the reduced variable pressure setpoint.