Abstract: The injection molding process of a thick-section part was simulated by using a Moldflow software. On the base of an orthogonal experiment and the multiple evaluation indicators reflecting the shrinkage and warpage of the part, the influences on filling time, melt temperature, packing time, packing pressure and cooling time by mean value analysis and range analysis were investigated, and then these processing parameters were optimized by a comprehensive scoring method. The results indicated that the warpage and shrinkage could be reduced by improving the packing time and packing pressure. A series of optimum processing parameters were achieved as filling time of 2.5 s, melt temperature of 280 ℃, packing time of 130 s, packing pressure of 110 MPa and cooling time of 40 s. When being injection molded with such optimized processing parameters, the part presented a distinct decrease in quality looseness by 6.66 %, volume shrinkage by 7.90 %, plane error by 12.5 % and warpage by 20.83 %. The thick-section part exhibited an improvement in total quality due to the CAE-based optimization combined with the orthogonal experiment.

Key words: thick-section part, injection molding, orthogonal experiment, processing parameter, multi-objective optimization