Pulsed cooling control for improving part warpage in injection molding process

In this study, the mold operation fluid will be controlled for observing the cooling efficiency of conventional cooling and pulsed cooling. The cooling techniques will be compared under varying mold temperature, coolant temperature, melt temperature, and flow rate. A mold structure was built using stainless steel 420. The cavity plate contains two cavities. Each cavity will be used for one type of part thickness. Results show that by appropriately controlling the fluid in pulsed cooling, the cooling rate can be improved from 0.552 °C/s to 0.755 °C/s and the warpage can be reduced by 20%. Moreover, as compared with conventional cooling, pulsed cooling can reduce warpage by 20% because pulsed cooling can maintain a stable heating/cooling temperature history and offer sufficient cooling to reduce warpage.