Optimization of cooling pipe system for plastic injection molding

This paper proposes an optimization methodology to decide layouts and shapes of cooling channels in a plastic injection molding die for reduction of molded defects in plastic products. In a cooling process of plastic injection molding, non-uniform temperature distribution causes some molded defects in molded products; such as warps and cracks. The most effective factor to affect the temperature distribution is cooling channels. In the proposed method, the design problem of cooling channels is formulated as the multi-objective optimization problem adopted two objective functions to evaluate the temperature distribution and the cooling rate in the die. Then, the cooling channels arrangements are taken as the design variables. An optimum layout of cooling channels is obtained from the approximated design space that is constructed by the results of numerical simulation based on the design of experiment.