A strain gauge nozzle adapter that may be placed between a barrel end cap and a nozzle body of an injection molding system, the strain gauge nozzle adapter having a strain gauge pin that measures strain within the strain gauge nozzle adapter for use in approximating conditions within an injection molding system, such as pressure or the location of a melt flow front. The strain gauge nozzle adapter may include a plurality of strain gauge pins. An alternative material insert in the strain gauge nozzle adapter may surround a strain gauge pin to amplify meaningful measurements obtained by the strain gauge pin so that noise measurements do not compromise the accuracy of approximation of conditions within a mold.

In one aspect, a method of molding a multilayer article comprises causing a surface layer material injection unit to commence injecting a surface layer material into a mold cavity via a surface layer material channel. Then, an internal layer material injection unit commences injecting an internal layer material into the mold cavity an internal layer material channel. Then, during application of a hold pressure upon the surface layer material in the surface layer material channel and with the surface and internal layer material injection units in fluid communication with one another, a pullback stroke is effected at the internal layer material injection unit. After a delay interval, at least one physical parameter indicative of a post-pullback pressure of the internal layer material is detected, and an indicator of pullback effectiveness is generated based on the post-pullback pressure indicated by the at least one physical parameter relative to a threshold pressure.

A plasticizing device includes: a material storage unit having a charging port and configured to store pellet-shaped resin pellets; a plasticizing unit having a supply port in communication with the charging port and configured to plasticize at least a part of the resin pellets to generate a shaping material; a coupling pipe having a coupling path coupling the charging port and the supply port; a first material sensor configured to detect a remaining quantity of the resin pellets in the coupling path; and a control unit. The material storage unit includes a material supply mechanism configured to supply the resin pellets to the coupling path, and when the remaining quantity of the resin pellets detected by the first material sensor is less than a first reference value, the control unit controls the material supply mechanism to supply a predetermined quantity of the resin pellets to the coupling path.

Systems and approaches for controlling an injection molding machine having a first configuration and a mold forming a mold cavity and being controlled according to an injection cycle include obtaining a pattern for a portion of an injection cycle of an injection molding machine having a second configuration and operating the injection molding machine having the first configuration to inject a molten material into the mold cavity. While operating the injection molding machine having the first configuration, the obtained pattern is used to control a portion of the injection cycle.

Systems and approaches for controlling an injection molding machine having a first configuration and a mold forming a mold cavity and being controlled according to an injection cycle include obtaining a pattern for a portion of an injection cycle of an injection molding machine having a second configuration and operating the injection molding machine having the first configuration to inject a molten material into the mold cavity. While operating the injection molding machine having the first configuration, the obtained pattern is used to control a portion of the injection cycle.

Systems and approaches for controlling an injection molding machine having a mold forming a mold cavity and being controlled according to an injection cycle include obtaining a pattern for the injection cycle, operating the injection molding machine to inject a molten material into the mold cavity, and measuring a cavity pressure value of the mold cavity during the mold cycle. Upon measuring a nominal cavity pressure value, a pattern recognition portion of the injection cycle that is at least partially dependent on the obtained pattern commences where a driving force being exerted on the molten material is adjusted such that the measured cavity pressure matches the obtained pattern for the injection cycle.

Systems and approaches for controlling an injection molding machine having a mold forming a mold cavity and being controlled according to an injection cycle include obtaining a pattern for the injection cycle, operating the injection molding machine to inject a molten material into the mold cavity , and measuring a cavity pressure value of the mold cavity during the mold cycle. Upon measuring a nominal cavity pressure value, a pattern recognition portion of the injection cycle that is at least partially dependent on the obtained pattern commences where a driving force being exerted on the molten material is adjusted such that the measured cavity pressure matches the obtained pattern for the injection cycle.

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.

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.