Injection molding has been applied to manufacturing for various products for years. However, due to the requirement of high precision for modern products, the product development is still very challenge. Conventionally, people used to utilize the packing pressure technology (either enlarge packing pressure or extend the packing time) to enhance the dimension quality, but it is not always useful. In this study, first we have applied CAE technology to analyze why the conventional packing pressure is not always effectively. The reason is that the compiled injection system with different thickness along the product will cause non-uniform shrinkage all the time. It is not easy to compensate using packing pressure skill. Furthermore, we have applied 3D volume shrinkage compensation method (3DVSCM) to reduce the warpage defect based on a mobile phone benchmark. Results show that through various packing pressure operations the dimension deviations at different regions can be compensated simultaneously, no matter the region has higher or lower shrinkage. It is also tested under various operation conditions, such as different injection times, melting temperatures, mold temperatures, and so on. The modification is always so effectively. That means the high dimension quality demand is possible obtained utilizing 3D volume shrinkage compensation method under suitable process condition setting.
SPE Technical Papers , Paper No. 78, pp.1-6 (2017).