Systems and methods for controlling injection molding using predicted cavity pressure

An injection molding system comprising:

• an injection molding machine including:
• a pressure sensor configured to sense a melt pressure of a thermoplastic material;
• and
• a controller operatively connected to the injection molding machine, the controller configured to:
• execute a calibration cycle in accordance with a mold cycle using the injection molding machine;
• analyze a plurality of melt pressure values sensed by the pressure sensor during the calibration cycle to determine one or more calibration metrics;
• execute a mold cycle run using the injection molding machine;
• and
• during each mold cycle of the run:
• detect a plurality of melt pressure values sensed by the pressure sensors prior to and during a fill phase of the mold cycle;
• compare the plurality of sensed melt pressures to the one or more calibration metrics to predict a cavity pressure during a pack and hold phase of the mold cycle;
• and
• adjust a set point melt pressure for the pack and hold phase of the mold cycle based on the predicted cavity pressure to provide an optimal pack and hold phase pressure which accounts for changes due to viscosity and environmental variation to improve product quality.