Controlling the warpage of plastic parts in injection molding process using the variation in coolant temperature of core and cavity

The warpage which has been occurred in the injected molded parts has always been a problem, as it may affect the function of the part and make it unusable. The main factors which has some effects on warpage of parts are the differential cooling, differential shrinkage, orientation effects and corner effects. According to the part each one of these effects may has the most impact on the warpage of the part. The most important reason which creates shrinkage in the parts is the difference between the temperatures of two sides of the molds (core side and cavity side), it is possible to minimize this shrinkage by decreasing this differential temperature. After a couple of analysis in Moldflow software it’s been shown that the differential cooling has the most influence on warpage of the part. It is possible to control the differential cooling with the coolant temperature which inters to the cooling channels of the mold. In order to find the optimized coolant temperature for both sides of the mold to decrease warpage of the part, a DOE analysis has been prepared. It’s been shown that the difference between the temperatures of the sides of the mold has much more influence than the average temperature of these sides on the warpage of the parts.