Abstract: Polypropylene (PP) material is widely used in industrial engineering industry due to its advantages of low density, high chemical stability and low cost. However, PP injection parts have problems of size shrinkage, warping deformation and recrystallization during production and storage. The shrinkage mechanism of polypropylene (PP) injection parts was analyzed reasonably, and the experimental scheme was designed for verification. Finally, the experimental results are analyzed and discussed in depth, and the shrinkage rules and influencing factors of polypropylene (PP) injection molded parts are summarized.

Key words: Polypropylene, Dimensional shrinkage, Shrinkage mechanism