Design & Manufacturing

Korean Society of Die & Mold Engineering (한국금형공학회)
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A study on the weld-strength in two-shot molding

이중 사출시 발행하는 Weld-line의 강도 연구

  • Jang, Min-Kyu (Graduate School of Mechanical Engineering, Pukyong National University) ;
  • Kim, Chang-jin (School of Mechanical Engineering, Pukyong National University) ;
  • Choi, Hea-Suck (Han Il E Hwa Co., LTD, R&D Center-Design Team) ;
  • Jeong, Yeong-Deug (School of Mechanical Engineering, Pukyong National University)
  • 장민규 (부경대학교 대학원 기계공학과) ;
  • 김창진 (부경대학교 기계공학부) ;
  • 최해석 (한일이화(주) 중앙연구소) ;
  • 정영득 (부경대학교 기계공학부)
  • Accepted : 2015.05.28
  • Published : 2015.06.12
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Abstract

In injection molding, many kinds of defects have occurred because of a characteristic of plastics injection molding. Weld line is one of the defects is formed when separated melt fronts recombine together during the mold filling stage. That is one of problems in injection molding. Weld lines in the appearance of plastics parts can deteriorate visible quality. And most importantly, the local mechanical strength in the weld line area can be significantly weaker. It could be one of the most problems for structural applications. In this study, the mold available two-shot-molding of same polymers have been designed, and a series of experiment about tensile strength in weld line area has been conducted using Taguchi's design of experiment to optimize injection molding conditions decreasing of weld strength and find out a factors affected weld strength in two-shot- molding.

Keywords

References

  1. Allen Y.Peng, David C, Hsu and Wen-Hsien Yang, Prediction of the Weld-line-induced strength reduction for Injection-Molded Plastics Parts, ANTEC 2006, pp. 719-722, 2006.
  2. Tomari, K., Fracture Toughness of Weld lines in Thermoplastics Injection Molding, Polym. Eng. Sci., vol. 30, p. 931, 1993.
  3. Liu Chuntai, Shen Cahngyu, "The Influence of Meeting Angle on the Weld Line Strength in Injection Molded Short-fiber-reinforced Polyanide 66", ANTEC 2005, pp. 879-883, 2005.
  4. TAO C. CHANG, ERNEST FAISON, Optimization of Weld Line Quality in Injection Molding Using an Experimental Design Approach, Jounal of injection molding technology, Vol. 3, No.2, pp. 61-66, 1999.
  5. Kevin R.Quinn, James A.Duffy, and Chris S.Ellis, Reinforced Thermoplastics : Understanding Weld Line Integrity, Jounal of injection molding technology, Vol.1, No.2, pp. 123-129, 1997.
  6. T. Semba, Weld line strength in PC/ABS Injection Molding, intern. polymer Processing, Vol.14, No.4, p. 365, 1999. https://doi.org/10.3139/217.1547
  7. Rover A. Malloy, Plastics Part Design for Injection molding, Hanser public, p. 54, 1994.