Mold Shrinkage of PPS Resin According to Injection Molding Condition for the Rectangular Specimen with Rectangular Hole

The molding shrinkage of polyphenylene sulfide resin was investigated in a rectangular specimen with a rectangular hole. The resins used were E1040S and E5060G. The flow patterns in the cavity were different for the two resins, and the mold shrinkage was smaller in E5060G than that in E1040S. Due to the shrinkage of the resin in the cavity, the outer dimensions decreased, but the inner dimensions increased, and the inner dimensions were more sensitive to the molding conditions. Among the dimensions of the specimen, shrinkage was small in the location close to the gate and large in the location far from the gate. In the case of the outer dimensions, the shrinkage in the flow direction was smaller than that in the direction perpendicular to the flow in both resins. In the mold shrinkage of the internal dimensions, E5060G had little shrinkage in the flow direction, but E1040S had little difference in shrinkage in the flow direction and the direction perpendicular to the flow. Due to shrinkage during molding, the outer and inner holes appeared in a rhombic shape, and the outer and inner rhombic shapes were reversed.