Transactions of the Korean Society of Mechanical Engineers A (대한기계학회논문집A)

The Korean Society of Mechanical Engineers (대한기계학회)
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Numerical Analysis of Mold Deformation Including Plastic Melt Flow During Injection Molding

플라스틱 유동을 고려한 사출성형 충전공정 중 금형의 변형 해석

  • Jung, Joon Tae (School of Mechanical Engineering, Chonnam Nat'l Univ.) ;
  • Lee, Bong-Kee (School of Mechanical Engineering, Chonnam Nat'l Univ.)
  • 정준태 (전남대학교 기계공학부) ;
  • 이봉기 (전남대학교 기계공학부)
  • Received : 2014.02.21
  • Accepted : 2014.05.08
  • Published : 2014.07.01
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Abstract

In the present study, a numerical analysis of an injection molding process was conducted for predicting the mold deformation considering non-Newtonian flow, heat transfer, and structural behavior. The accurate prediction of mold deformation during the filling stage is important to successfully design and manufacture a precision injection mold. While the local mold deformation can be caused by various factors, a pressure induced by the polymer melt is considered to be one of the most significant ones. In this regard, the numerical simulation considering both the melt filling and the mold deformation was carried out. A mold core for a 2D axisymmetric center-gated disk was used for the demonstration of the present study. The flow behavior inside the mold cavity and temperature distribution were analyzed along with the core displacement. Also, a Taguchi method was employed to investigate the influence of the relevant parameters including flow velocity, mold core temperature, and melt temperature.

본 연구에서는 사출성형 충전공정 중 금형의 변형을 예측하기 위하여 비뉴턴 유동, 열전달, 구조해석이 함께 고려된 수치해석 연구를 수행하였다. 정밀 사출성형 금형을 설계/제작하기 위해서는 충전공정 중에 발생하는 금형의 변형을 정확하게 예측하는 것이 중요하다. 이와 같은 금형의 국부적인 변형은 다양한 요인에 의해 발생할 수 있으나, 용융된 고분자 수지의 유동에 의한 압력이 가장 큰 원인 중의 하나로 여겨지고 있다. 따라서, 본 연구에서는 2 차원 축대칭 형상의 단순 원형 디스크 제품의 금형을 모델링하고 이에 대한 수치해석을 수행하였다. 이를 바탕으로 금형 내부의 고분자 수지의 유동 특성과 금형 변형량, 온도 분포에 대한 분석을 수행하였다. 또한 다구치 방법을 기반으로 한 실험계획법을 도입하여 유동 속도, 금형 온도, 고분자 수지의 온도가 금형 변형에 미치는 영향을 파악하였다.

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References

  1. Zhao, J., Mayes, R. H., Chen, G., Xie, H. and Chan, P. S., 2003, "Effects of Process Parameters on the Micro Molding Process," Polym. Eng. Sci., Vol. 43, No. 9, pp. 1542-1554. https://doi.org/10.1002/pen.10130
  2. Tsai, K. M., Hsieh, C. Y. and Lo, W. C., 2009, "A Study of the Effects of Process Parameter for Injection Molding on Surface Quality of Optical Lenses," J. Mater. Process. Technol., Vol. 209, No. 7, pp 3469-3477. https://doi.org/10.1016/j.jmatprotec.2008.08.006
  3. Baek, S. B., Park, K., Youn, C. H. and Ra, S. W., 2010, "Study on Improvement of Dimensional Accuracy of a Precision Plastic Screw Under Various Injection-Molding Conditions," Trans. Korean Soc. Mech. Eng. A, Vol. 34, No. 10, pp. 1549-1554. https://doi.org/10.3795/KSME-A.2010.34.10.1549
  4. Giacomin, A. J., Hade, A. J., Mix, A. W., Chen, Y. C., Liao, H. C. and Tseng, S. C., 2011, "Core Deflection in Injection Molding," J. Non-Newton. Fluid Mech., Vol. 166, No. 16, pp. 908-914. https://doi.org/10.1016/j.jnnfm.2011.04.005
  5. Li, X., Zhao, G., Guan, Y. and Li, H., 2009, "Research on Thermal Stress, Deformation, and Fatigue Lifetime of the Rapid Heating Cycle Injection Mold," Int. J. Adv. Manuf. Technol., Vol. 45, No. 3-4, pp. 261-275. https://doi.org/10.1007/s00170-009-1969-z
  6. Lee, S. H., Min, B. H. and Kim, B. G., 2002, "Optimizing the Injection Molding Process for Cooling Filter Using Computer Simulation and Taguchi Methods," IE Interfaces, Vol. 15, No. 3, pp. 263-267.
  7. Yu, L., Koh, C. G., Lee, L. J. and Koelling, K. W., 2002, "Experimental Investigation and Numerical Simulation of Injection Molding with Micro- Features," Polym. Eng. Sci., Vol. 42, No. 5, pp. 871-888. https://doi.org/10.1002/pen.10998
  8. Chiang, H. H., Hieber, C. A. and Wang, K. K., 1991, "A Unified Simulation of the Filling and Postfilling Stages in Injection Molding. Part I: Formulation," Polym. Eng. Sci., Vol. 31, No. 2, pp. 116-124. https://doi.org/10.1002/pen.760310210

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