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Investigation of the Part Shrinkage in Injection Molding for Class Fiber Reinforced Thermoplastics

유리섬유가 첨가된 수지에서 사출성형품의 성형수축에 관한 연구

  • 모정혁 (서울산업대학교 대학원) ;
  • 류민영 (서울산업대학교 금형설계학과)
  • Published : 2004.10.01

Abstract

The shrinkages of injection molded parts are different in molding operational conditions and mold design. It also differs from resins. The shrinkages of injection molded parts fur PBT (polybutylene terephthalate), PC (polycarbonate), and glass reinforced PBT and PC have been studied for various operational conditions of injection molding. The part shrinkage of crystalline polymer, PBT was higher than that of amorphous polymer, PC by about two times. The part shrinkages of both polymers decreased as glass fiber content increases. Higher injection temperature and lower injection pressure resulted in a higher shrinkage in both PBT and PC resins. As mold temperature increases the part shrinkage of PC decreased. However, the part shrinkage of PBT increased as mold temperature increases. The part shrinkages of PBT and PC resins decreased as gate size increases since the pressure delivery is mush easier for a larger gate size. The part shrinkage of flow direction was less than that of the perpendicular direction to the flow for both pure and glass fiber reinforced resins. The part shrinkage at the position close to the gate was less than that of the position far from the gate.

Keywords

References

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  2. Processability and Mechanical Characteristics of Glass Fiber and Carbon Fiber Reinforced PA6 for Reinforcement Content vol.50, pp.3, 2015, https://doi.org/10.7473/EC.2015.50.3.184
  3. Prediction of Mechanical Property of Glass Fiber Reinforced Polycarbonate and Evaluation of Warpage through Injection Molding vol.38, pp.6, 2014, https://doi.org/10.7317/pk.2014.38.6.708
  4. A Study on the Warpage of Glass Fiber Reinforced Plastics for Part Design and Operation Condition: Part 1. Amorphous Plastics vol.36, pp.5, 2012, https://doi.org/10.7317/pk.2012.36.5.555