Design & Manufacturing

Korean Society of Die & Mold Engineering (한국금형공학회)
권호 표지

A study on light weighted injection molding technology and warpage reduction for lightweight automotive head lamp parts

자동차 헤드램프 부품의 경량화 사출 성형기술 및 변형 저감에 관한 연구

  • Jeong, Eui-Chul (Molds and Dies Technology Group, Korea Institute of Industrial Technology) ;
  • Son, Jung-Eon (Molds and Dies Technology Group, Korea Institute of Industrial Technology) ;
  • Min, Sung-Ki (CHANGDAE Precision Company) ;
  • Kim, Jong-Heon (CHANGDAE Precision Company) ;
  • Lee, Sung-Hee (Molds and Dies Technology Group, Korea Institute of Industrial Technology)
  • 정의철 (한국생산기술연구원 금형기술그룹) ;
  • 손정언 (한국생산기술연구원 금형기술그룹) ;
  • 민성기 (창대정밀 기술연구소) ;
  • 김종헌 (창대정밀 기술연구소) ;
  • 이성희 (한국생산기술연구원 금형기술그룹)
  • Received : 2019.05.09
  • Accepted : 2019.06.30
  • Published : 2019.06.30
Download PDF
⟨ Previous Next ⟩

Abstract

In this study, micro cellular injection molding of automobile head lamp housing with uneven thickness structure was performed to obtain improvement on deformation and light-weight of the part. The thickness of the presented model was uniformly modified to control the deformation of the molded part. In order to maximize the lightweight ratio, the model having an average thickness of 2.0 mm were thinly molded to an average thickness of 1.6 mm. GFM(Gas Free Molding) and CBM(Core Back Molding) technology were applied to improve the problems of the conventional foam molding method. Equal Heat & Cool system was also applied by 3D cooling core and individual flow control system. Warpage of the molded parts with even cooling was minimized. To improve the mechanical properties of foamed products, complex resin containing nano-filler was used and variation of mechanical properties was evaluated. It was shown that the weight reduction ratio of products with light-weighted injection molding was 8.9 % and the deformation of the products was improved from the maximum of 3.6 mm to 2.0 mm by applying Equal Heat & Cool mold cooling system. Also the mechanical strength reduction of foamed product was less than 12% at maximum.

Keywords

Acknowledgement

Supported by : 중소벤처기업부

References

  1. J.J. Lee, S.W. Cha, S.Y. Kim, "Effect of Gas amount on Viscosity Change in Microcellular Plastics," KSME annual conference, pp. 1114-1119, 2004.
  2. S. Leicher, J. Will, H. Haugen, E. Wintermantel, "MuCell(R) technology for injection molding: A processing method for polyether-urethane scaffolds," Journal of Material Science, pp. 4613-4618, 2005.
  3. B.J. Jeon, S.W. Cha, R. Zafar, "A Study on Foaming Method of Microcellular Foaming Plastics," KSPE annual conference, pp. 425-426, 2007.
  4. Tomoki Mori, Hidetomo Hayashi, Masami Okamoto, Satoshi Yamasaki, Hiroshi Hayami,"Foam processing of polyethylene ionomers with supercritical CO2," Composites: Part A, Vol. 40, pp. 1708-1716, 2009. https://doi.org/10.1016/j.compositesa.2009.08.018
  5. Shia-Chung Chen, Hai-Mei Li, Shyh-Shin Hwang, Ho-Hsiang Wang, "Passive mold temperature control by a hybrid filming-microcellular injection molding processing," International Communications in Heat and Mass Transfer, Vol. 35, pp. 822-827, 2008. https://doi.org/10.1016/j.icheatmasstransfer.2008.03.013
  6. J.D. Yoon, S.W. Cha, H.J. Kim, "Effect of Microcellular Foaming Process on the Impact Strength of Polypropylene," KSME annual conference, pp. 1084-1088, 1999.
  7. Y.D. Hwang, S.W. Cha, C.J. Kim, "Impact Strength as Foaming Magnitude of Microcellular Foamed Plastics," KSPE annual conference, pp. 341-345, 2001.
  8. Shia-Chung Chen, Won-Hsion Liao, Rean-Der Chien, "Structure and mechanical properties of polystyrene foams made through microcellular injection molding via control mechanisms of gas counter pressure and mold temperature," International Communications in Heat and Mass Transfer, Vol. 39, pp. 1125-1131, 2012. https://doi.org/10.1016/j.icheatmasstransfer.2012.06.015
  9. H.K. Kim, S.W. Cha, W.C. Jung, "Warpage reduction of glass fiber reinforced plastic through MCPs applied injection molding process," KSAE annual conference, pp. 1222-1223, 2013.
  10. S.H. Cho, H.K. Kim, S.W. Cha, "Warpage Reduction and Mechanical Properties of the Microcellular Foaming Glass Fiber Reinforced Plastic," KSPE annual conference, pp. 120-121, 2014.
  11. S.W. Kim, S.W. Cha. K.H. Kim, "Research of foaming characteristics by MCPs using supercritical fluid according to foaming temperature and thickness," KSPE annual conference, pp. 997-998, 2013.
  12. H. Hassan, N. Regnier, C. Pujos, E. Arquis, G. Defaye, "Modeling the effect of cooling system on the shrinkage and temperature of the polymer by injection molding," Applied Thermal Engineering, Vol. 30, pp. 1547-1557, 2010. https://doi.org/10.1016/j.applthermaleng.2010.02.025
  13. H. Hassan, N. Regnier, C. Lebot, C. Pujos, G. Defaye, "Effect of cooling system on the polymer temperature and solidification during injection molding," Applied Thermal Engineering, Vol. 29, pp. 1786-1791, 2009. https://doi.org/10.1016/j.applthermaleng.2008.08.011
  14. H. Hassan, N. Regnier, C. Le Bot, C. Pujos, G. Defaye, "3D study of cooling system effect on the heat transfer during polymer injection molding," Int. J. Therm, Vol. 49, pp. 161-169, 2010. https://doi.org/10.1016/j.ijthermalsci.2009.07.006
  15. Y. Liu, M. Gehde, "Evaluation of heat transfer coefficient between polymer and cavity wall for improving cooling and crystallinity results in injection molding simulation," App. Therm, Vol. 80, pp. 238-246, 2015. https://doi.org/10.1016/j.applthermaleng.2015.01.064