A method and system for adjusting melt pressure in an injection molding material that allows calculating a melt pressure of a molten plastic material to be injected and based on the calculated melt pressure and a desired melt pressure adjusting operation of an injection molding machine. This control of an injection molding cycle using the method and system of plastic melt pressure determination allows production of parts of increased quality and consistency.

In a method for operating an injection moulding machine in the absence of a backflow barrier, plastic melt is injected by a plasticising device into a cavity in a screw antechamber of a plasticising screw adapted to rotate about a longitudinal axis and to move translationally by a drive unit during an injection phase and a holding-pressure phase. A rotational drive of the drive unit is controlled such that a speed of the plasticising screw causes overlay of a backflow of the plastic melt from the screw antechamber back into screw threads of the plasticising screw by an opposing delivery flow as a result of a rotation of the plasticising screw due to a translational injection movement of the plasticising screw. A differential flow is established from the backflow and the opposing delivery flow and influenced at least during the injection phase by influencing the speed of the plasticising screw.

A method for producing an optical article having a Fresnel microstructure and an injection molding system for producing such an article. The method includes heating and cooling a mold and applying a pressure to a thermoplastic material during injection molding of the optical article to facilitate formation of the Fresnel microstructure.

A device for assisting molding condition determination includes a molding state data adjustment amount obtaining unit and a molding condition element adjustment amount obtaining unit. The molding state data adjustment amount obtaining unit obtains, using a first learning model, a molding state data adjustment amount having a value equivalent to a difference between molding state data detected by a sensor and a molding state data target value. The molding condition element adjustment amount obtaining unit obtains, using a second learning model, an adjustment amount for a molding condition element corresponding to the molding state data adjustment amount.

A method for controlling an injection molding process based upon an actual plastic melt pressure including identifying an optimal actual plastic melt pressure curve over time based on a baseline cycle, and adjusting in a subsequent cycle an injection pressure in order to cause a monitored pressure of the molten thermoplastic material to follow the optimal actual plastic melt pressure curve over time. A method for controlling an injection molding process based upon an plastic melt pressure setpoint adjusted using a cavity pressure, wherein the cavity pressure is multiplied by a process factor. Further, a method for controlling an injection molding process using real time cavity pressure including identifying an optimal cavity pressure curve over time based on a baseline cycle and adjusting, in a subsequent cycle, an injection pressure in order to cause a monitored cavity pressure to follow the optimal cavity pressure curve over time.

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 for producing an optical article having a Fresnel microstructure and an injection molding system for producing such an article. The method includes heating and cooling a mold and applying a pressure to a thermoplastic material during injection molding of the optical article to facilitate formation of the Fresnel microstructure.

A method is provided for controlling an injection molding system, which includes a mold having an inner surface defining at least two groups of cavities, each group of cavities defining precisely one cavity with one pressure sensor at the inner surface. Each group of cavities is at least partially surrounded by a tempering unit that provides an energy flow to the surrounded cavities. According to the method, a pressure is determined in each group of cavities of the at least two groups of cavities. A reference pressure is determined for each group of cavities. A difference between the reference pressure and the pressure in at least one group of cavities is determined and controlled to become minimum by manipulating the energy flow of the tempering unit.

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.

An injection molding apparatus including a mold, an injection device and a specific volume sensing module is provided. The injection device is adapted to inject a material into the mold. At least parts of the specific volume sensing module are disposed at the mold, wherein the specific volume sensing module is adapted to sense an actual specific volume of the material in the mold. In addition, an injection molding method is also provided.