Utilization of PMOO in Determination of Optimum Parameters in Polymers' Injection Molding Process

In this paper, PMOO (probabilistic multi-objective optimization method) approach is utilized to perform the determination of optimum parameters in polymers’ injection molding process, which involves minimizing volume shrinkage, total warping deformation and shrinkage marks during ejection in addition to orthogonal experimental design. The variable parameters include mold temperature, melt temperature, holding pressure, holding time and cooling time. PMOO is a novel approach with both algorithm and viewpoint on “optimum point”, it puts forward a new concept of “preferable probability” to address the preference degree of an attribute of a candidate and the corresponding evaluation method. In PMOO, attributes of the alternative scheme are divided into two types, i.e., both beneficial type of attribute and unbeneficial (i.e., cost) type of attribute, the corresponding evaluation algorithms of their partial preferable probability are formulated quantitatively; the total preferable probability of each alternative scheme is product of all possible partial preferable probability, which is employed as the unique indicator to conduct the ranking of the optimization. In the polymers’ injection molding process, the volume shrinkage, total warping deformation and shrinkage marks during ejection are the optimal criteria to be minimizing; besides the range analysis of the total preferable probability of each alternative scheme is conducted. The result gives the optimum configuration for this polymers’ injection molding process.