Optimization of a Reinforcing-Rib Design for ABS and High Glossy Surfaces of Plastic Parts

Abstract

The goal of this study is to determine the optimum value of design variables in mixed conditions of the thickness, height and draft angle of reinforcing ribs within an objective limit in ABS resin and a high glossy surface. For this purpose, we investigated the actual depths of sink marks on the surface of the specimen that was manufactured with an injection mold specifically for this study. A response surface methodology with the Box-Behnken design was used to analyze the real depths with combinations of the thickness, height and draft angle of the ribs. The result shows that the most influential factor to increase the shrinkage is the thickness of ribs and that the optimum value of the rib thickness is a multiple of 0.31 of the section thickness. It was found that the rib height and rib draft angle are not factors that can change the sink amount.