Abstract:
An injection molding machine that uses a mold and a native controller to operate according to an original mold cycle to mold plastic objects is retrofitted with a retrofit controller; the retrofitted machine uses the mold and the retrofit controller to operate according to a retrofit mold cycle to mold plastic objects.
Abstract:
A method and a machine account for changes in material properties of molten plastic material during an injection run. A change in a control signal is calculated by a controller during the injection molding run. If the change in the control signal indicates a change in material flowability, the controller alters a target injection pressure to ensure that molten plastic material completely fills and packs a mold cavity to prevent part flaws such as short shots or flashing.
Abstract:
A process of forming molded articles using an injection molding apparatus is provided. The process includes providing a thermoplastic material to the injection molding apparatus. The thermoplastic material is heated such that the thermoplastic material is in a molten state. The molten thermoplastic material is injected into at least one mold cavity of the injection molding apparatus using an injection element. A melt pressure of the thermoplastic material filling the at least one mold cavity is monitored using a sensor. The sensor provides a signal indicative of melt pressure in the cavity to a controller. The controller controls the injection element thereby changing melt pressure of the thermoplastic material filling the at least one mold cavity based on the signal to reach a target cavity pressure. A molded article is formed by reducing a mold temperature of the thermoplastic material within the at least one mold cavity.
Abstract:
A method and a machine that account for changes in material properties of molten plastic material during an injection run. If viscosity of the molten plastic material changes during an injection run, a controller alters a step time of the injection cycle to ensure that molten plastic material completely fills and packs a mold cavity to prevent part flaws such as short shots or flashing.
Abstract:
A method of detecting and compensating for a non-operational mold cavity in an injection molding apparatus having a plurality of mold cavities and an injection molding screw or ram includes injecting, via the injection molding screw or ram, a molten thermoplastic material into the plurality of mold cavities. The method includes measuring a first process parameter of the injection molding apparatus at a pre-determined time during or after the injecting. The method also includes determining, based on the first process parameter, whether one or more mold cavities of the plurality of mold cavities are non-operational. Then, when it is determined that one or more mold cavities are non-operational, the method includes automatically adjusting the first process parameter or a second process parameter of the injection molding apparatus.
Abstract:
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.
Abstract:
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.
Abstract:
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.
Abstract:
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.
Abstract:
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 extruding a molten polymer according to an extrusion profile and measuring at least one variable during the extrusion profile with a first sensor. At least one extrusion operational parameter is adjusted based on the measured variable. The extrusion profile is terminated upon the molten polymer exceeding a first threshold, and the molten polymer is injected into the mold cavity according to an injection profile via a screw that moves from a first position to a second position. Upon completion of the injection profile, a recovery profile commences in which the screw is moved to the first position.