Plastic injection molding is a popular process in the plastic industry, and it is one of the popular polymer processing operations in the plastic industry today. However, least of skill of making a mold and injection molding machine can cause the defect quality of product occurred. There are a few types of plastic part defects such as warpage, shrinkage and weld line. The purpose of the project is to see what happen to the plastic parts produce when the injection molding machine runs for some cycle. This research is to investigate the plastic part defect in term of warpage and shrinkage using coordinate measuring machine (CMM) and how the cooling cycle can affect the product quality. This study used polypropylene (PP) as the plastic material. From the data collected, we can conclude that the most significant defect in plastic part is warpage and shrinkage. This defect is reflected to the mold temperature. We can find that, in proper cooling in mold directly affect to the product quality.
