Abstract: The molding process of Toyota logo was analyzed using computer aided engineering(CAE), and the reasons for the appearance of sink mark and warpage were studied. To resolve the molding quality defects, the location of gating system and the wall thickness were adjusted. It was found that it did not work in changing the location of gating system, whereas a reduction of wall thickness was effective. When the central thickness was decreased to 3.6 mm, the maximum sink index decreased from 4.493 % to 3.886 %, the changing of sink index was more smoothly, and the value of warpage decreased from 0.4816 mm to 0.2414 mm.

Key words: wall thickness, computer aided engineering, injection molded plastics part, modification