In plastic injection molding there is ideally no irregular filling in the molded product. Since filling irregularity must be evaluated by the physical characteristics and internal state of the molded product, characteristics that reflect the internal state properly must be measured. In this study to evaluate the uniformity of mold filling patterns with polycarbonate, a transparent resin, we measured the RGB optical density values of light transmitted through a polarizing plate, and compared uniformity of the transmitted density by parameter design techniques, using molding conditions as factors and analyzing the results by the MT method. Evaluation of transmission density through the polarizing plate was able to detect filling irregularities and transmission variations more sensitively than evaluation of transmission density without the polarizing plate.
