Study on residual stresses of thinwalled injection molding.pdfVIP

EUROPEAN POLYMER JOURNAL European Polymer Journal 41 (2005) 2511–2517 /locate/europolj Study on residual stresses of thin-walled injection molding Tong-Hong Wang, Wen-Bin Young * Department of Aeronautics and Astronautics, National Cheng Kung University, Tainan 70101, Taiwan, ROC Received 4 December 2003; received in revised form 6 April 2005; accepted 11 April 2005 Available online 22 June 2005 Abstract The residual stresses of the thin-walled injection molding are investigated in this study. It was realized that the behavior of residual stresses in injection molding parts was affected by different process conditions such as melt tem- perature, mold temperature, packing pressure and filling time. The layer removal method was used to measure the resid- ual stresses at a thin-walled test sample by a milling machine. This simple method was demonstrated to be adequate for a thin-walled part. Moldings under different conditions were investigated to study the effects of the process conditions on the residual stresses of a thin-walled product using the elastic and viscoelastic models. The mold temperature was found to affect the size of the core region and residual stress on the surface layer of a thin-walled part in our studied range. The packing pressure was insensitive to the residual stresses in the studied high-pressure ran