The influence of mold design and process parameters on dimensional shrinkage of perfluoroalkoxy alkane injection molding parts

Abstract

In mass production, injection molding plays a vital role in manufacturing various parts with complex settings. As perfluoroalkoxy alkane (PFA) injection‐molded products are widely used in immersion system, dimensional quality needs more attention. However, there is limited research on the dimension defects of PFA injection‐molded products. This study focused on the influence of mold design and process parameters on PFA part shrinkage, using mold flow simulation and orthogonal testing separately. Several gate locations and sizes were simulated to minimize shrinkage in mold design. Displacements varied with gate locations, and shrinkage decreased with larger gate sizes. The Taguchi method analyzed process parameters' impact on shrinkage. The results indicated that the injection rate had the most significant effect on the shrinkage of tube length, while melt temperature, holding pressure, and screw speed affected the shrinkage of tubes' outside diameter. Different flow directions exhibited variance in shrinkage. Using max–min normalization, the two shrinkage values reached 0.00972, whereas the smallest value obtained in the orthogonal experiment was 0.1545 in run 3. Thus, optimizing mold design and process parameters were two effective methods to reduce shrinkage. This study reduced shrinkage and improved the quality of PFA injection molding parts for semiconductor systems.