Meaning
Instrumentation using quartz crystals to generate electrical charge under mechanical force provides high-speed measurement of mould cavity activity. Known for their rapid response times, piezo pressure sensors are installed directly within the mould steel to monitor the force exerted by the polymer melt during the injection cycle. These devices convert physical force into a proportional electrical signal, which is then processed by a controller.
This real-time pressure profile allows manufacturers to monitor the consistency of each injection cycle.
Cavity Monitoring
Continuous pressure data provides an accurate representation of what occurs inside the mould cavity. By utilizing piezo pressure sensors, the system can detect subtle variations in viscosity or fill rate. This data allows the machine to make real-time decisions, such as switching from injection to packing based on actual cavity pressure.
Defect Prevention
Variations in cavity pressure can indicate the presence of moulding defects before parts are ejected. Data from piezo pressure sensors can automatically trigger a sorting gate to isolate parts that do not meet the pressure threshold. This automation prevents short shots or overpacked parts from reaching the final packaging line.
Sensor Installation
Placing the measuring elements requires precision machining of the mould plates. These piezo pressure sensors are typically mounted behind ejector pins or directly in the cavity wall. This placement protects the sensitive electronic components from the high temperatures and corrosive gases generated by the polymer.
