Determining Cavitation Count and Cycle Time in Multi Cavity Injection Molds
Determining cavitation count and cycle time requires balancing thermal cooling physics against clamping limits, runner shear, and capital amortisation curves.
Internal Cavity Pressure
Meaning
Real time force measurements taken from inside the mould provide direct feedback on the state of the polymer during the injection and packing stages. Monitoring internal cavity pressure allow moulders to detect variations that external machine sensors might miss. This data is the most accurate indicator of part quality and consistency.
Sensor Placement
Transducers are usually located behind an ejector pin or in the cavity wall near the end of the flow path. The internal cavity pressure measured at these points reveals if the mould has been completely filled and properly packed. Strategic placement ensures that the most critical areas of the part are monitored.
Quality Correlation
Part weight and dimensions are directly linked to the peak force reached during the cycle. When the internal cavity pressure stays within a specific window, the likelihood of producing a defect like a short shot or a sink mark is greatly reduced. It provides a digital fingerprint for every good part made.
Process Control
Advanced machine controllers use the feedback from these sensors to adjust the switchover point or the holding pressure in real time. This automated response to the internal cavity pressure compensates for variations in material viscosity or ambient conditions. It ensures a stable process over long production runs.