Meaning
Real-time monitoring of ejection forces utilizes transducers positioned directly behind the pin assembly in an injection mold. Ejector pin sensing allows the machine controller to detect the amount of resistance encountered as the part is pushed out of the cavity. It detects issues such as part sticking or pin breakage.
Process Control
Force feedback provides a clear signal of the demolding conditions. If the ejection force increases over a series of cycles, it indicates that the mold surface is fouling or that the venting is clogged. This data allows for the automation of a shutdown sequence before a part sticks and causes a double-hit on the next shot.
Continuous logging of these values helps establish a baseline for normal tool operation.
Defect Detection
Stress marks or pin push-through on the part surface correlate with high pressure readings. When the polymer has not cooled sufficiently, it remains soft and susceptible to deformation from the pins. Monitoring the force profile ensures that the part has reached the required structural integrity before the mold opens.
Lower Benefit
Lower downtime results from early intervention. Preventive action taken when a sensor triggers an alarm avoids the high cost of a crashed tool. The investment in sensor hardware pays for itself by extending the life of the ejector system.
