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.

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.

A method of monitoring and controlling a molding clamping 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 mold while it is closing from a first strain gauge, identifying a deviation from a target strain profile based on the output from the first strain gauge, determining that the deviation exceeds the deviation limit, and adjusting the rate or force of clamp movement. The target strain profile may have a first portion relating to a clamp closing process, a second portion relating to a filling process, and a third portion relating to a clamp opening process. The first portion relating to the clamp closing process may include an intermediate portion relating to a coining process having an intermediate clamp force setpoint.

An injection molding machine includes a cylinder that accommodates a molten resin, a discharging nozzle, a piston that discharges the molten resin from the discharging nozzle, and one or more processors configured to execute the following functions. The functions include calculating a target pressure at which a flow rate of the molten resin discharged from the discharging nozzle becomes an indicated flow rate, controlling a pressure of the molten resin in the cylinder such that the pressure becomes the target pressure, acquiring a temperature of the molten resin in the cylinder, and acquiring a pseudo-plastic viscosity corresponding to the temperature of the molten resin. The target pressure is calculated based on the indicated flow rate, the temperature of the molten resin, the pseudo-plastic viscosity, and the size of the discharging nozzle.

An injection molding apparatus, comprising: an injection molding machine; a distribution manifold having a distribution channel, a clamp device arranged to clamp together, under a selected clamp force, a mold system having a plurality of mold cavities one or more first downstream channels fluidly coupled to the distribution channel; one or more first gates arranged to deliver injection fluid to a first cavity; one or more second downstream channels fluidly coupled to the distribution channel; one or more second gates arranged to deliver injection fluid to a second cavity; a control system adapted to: instruct the first upstream valve and a second upstream valve; and at least one downstream valve having a valve pin having a control surface for controlling flow of injection fluid.

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.

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 electric injection molding machine includes an injection apparatus including a screw configured to inject a resin, a driving direction conversion part configured to move the injection apparatus forward and backward in an axial direction of the screw, and a first motor coaxially connected to a rotation shaft of the driving direction conversion part, the first motor being configured to drive the driving direction conversion part. The first motor includes a motor connection part, the motor connection part being configured to connect a second motor to the first motor coaxially with the driving direction conversion part on a side of the first motor opposite to a side thereof on which the driving direction conversion part is connected thereto, the second motor being configured to drive the driving direction conversion part in an interlocking manner with the first motor.

A method and system for co-injection molding of two molten plastic materials that allows monitoring and utilization of injection pressure and optionally melt pressure and/or flow front pressure during an injection run. A controller alters the injection pressure so as to achieve and maintain optimal or desired ratios of injection pressure, and optionally melt pressure and/or flow front pressure, of the two molten plastic materials. This allows for more precise part manufacture, including reducing the thickness of a skin or shell layer compared to a core layer of a molded part.

When an injection molding machine performs molding, the mold clamping force on the mold is adjusted on the basis of a mold displacement of the mold or the injection peak pressure and injection foremost position so that the molding is performed without causing flash and by an appropriate mold clamping force with which energy can be reduced. The amount of mold displacement and also the injection peak pressure and the injection foremost position are monitored during automatic operation. If there occurs no mold displacement change exceeding a threshold or if there occurs no injection peak pressure anomaly or injection foremost position anomaly exceeding thresholds, the automatic operation is continued. If the mold displacement change occurs or if the injection peak pressure anomaly and the injection foremost position anomaly occur, the operation of the injection molding machine is stopped.