Proceedings of the Korean Society for Technology of Plasticity Conference (한국소성가공학회:학술대회논문집)
- 2003.05a
- /
- Pages.363-370
- /
- 2003
Shrinkage in Injection molded Part for Operational Conditions and Resins
성형조건과 수지의 종류에 따른 사출 성형품의 성형 수축
Abstract
Shrinkage of injection molded parts is different form operational conditions of injection molding such as injection temperature, injection pressure and mold temperature, and mold design such as gate size. It is also various for different resins which have crystalline structure or not. In this study part shrinkage was investigated for various operational condition and resins; PBT for crystalline polymer, and PC and PMMA for amorphous polymer was used in experiment. Crystalline polymer shows higher part shrinkage by about three times than amorphous polymer. Part shrinkage increased as injection temperature and mold temperature increased and injection pressure decreased. Part shrinkage decreased as gate size increased since the pressure delivery is mush easier for large gate size. Part shrinkage according to the gate location was that the position in the part with close to the gate showed large shrinkage and this phenomenon might be occurred by residual stress.
Keywords
- Part Shrinkage;
- Operational Condition;
- Injection Temperature;
- Mold Temperature;
- Injection Pressure;
- Gate Size