Journal of the Korean Society for Precision Engineering (한국정밀공학회지)

Korean Society for Precision Engineering (한국정밀공학회)
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Investigation of Weldline Strength with Various Heating Conditions

국부 금형가열에 조건에 따른 사출성형품 웰드라인의 강도 고찰

  • Park, Keun (Mechanical Design and Automation Engineering, Seoul National Univ. of Technology) ;
  • Sohn, Dong-Hwi (Mechanical Design and Automation Engineering, Seoul National Univ. of Technology) ;
  • Seo, Young-Soo (Mechanical Design and Automation Engineering, Seoul National Univ. of Technology)
  • 박근 (서울산업대학교 기계설계.자동화공학부) ;
  • 손동휘 (서울산업대학교 기계설계.자동화공학부 원) ;
  • 서영수 (서울산업대학교 기계설계.자동화공학부 원)
  • Published : 2010.01.01
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Abstract

Weldlines are generated during the injection molding process when two or more melt flows are brought into contact. The weldlines are unavoidable in the cases of presence of holes or inserts, multi-gated delivery systems, significant thickness change, etc. At the welded contact region, a 'V'-shaped notch is formed on the surface of the molded part. This 'V'-notch deteriorates not only surface appearance but also mechanical strength of the molded part. To eliminate or reduce weldlines so as to improve the weldline strength, the mold temperature at the corresponding weld locations should be maintained higher than the glass transition temperature of the resin material. The present study implements high-frequency induction heating in order to rapidly raise mold surface temperature without a significant increase in cycle time. This induction heating enables to local mold heating so as to eliminate or reduce weldlines in an injection-molded plastic part. The effect of induction heating conditions on the weldline strength and surface appearance of an injection-molded part is investigated.

Keywords

References

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