Meaning
Calculated mathematical area under the cavity pressure curve during the filling and packing phases represents the total force applied to the polymer over time. Monitoring the real-time pressure integral helps determine the weight and dimensional stability of the molded part before it is ejected. This calculation is a primary metric for quality control in precision moulding.
Process Calculation
The machine controller integrates the pressure sensor readings from the start of injection until the gate freezes. This value corresponds to the amount of polymer packed into the cavity during the cycle. If the value falls below the threshold, the machine flags the part as a short shot, while values that exceed the upper limit indicate that the part has been overpacked and might flash.
Tooling Action
High-precision systems use the integral value to open a reject gate on the conveyor line, directing out-of-spec parts to a scrap bin. This automated action prevents defective parts from being shipped to the customer. It reduces the need for manual inspection.
Sensor Control
Sensor performance affects the calculation, which is highly dependent on the position and sensitivity of the transducers. Any sensor drift or thermal shift will alter the integral calculation. This requires regular calibration.
