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

The Korean Society of Mechanical Engineers (대한기계학회)
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Study on Improvement of Dimensional Accuracy of a Precision Plastic Screw Under Various Injection-Molding Conditions

사출성형 조건에 따른 정밀 플라스틱 나사의 형상정밀도 향상에 관한 연구

  • Baek, Soon-Bo (Graduate School, Seoul Nat'l Univ. Tech.) ;
  • Park, Keun (School of Mechanical Design and Automation Engineering, Seoul Nat'l Univ. Tech.) ;
  • Youm, Chung-Ho (Graduate School, Seoul Nat'l Univ. Tech.) ;
  • Ra, Seung-Woo (Research Center, Seoul Metal Co. Ltd.)
  • 백순보 (서울산업대학교 원) ;
  • 박근 (서울산업대학교 기계설계자동화공학부) ;
  • 염충호 (서울산업대학교 원) ;
  • 나승우 ((주)서울금속 기술연구소)
  • Received : 2010.05.13
  • Accepted : 2010.08.02
  • Published : 2010.10.01
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Abstract

Recently, plastic screws have replaced metal screws because of the former's light weight, thermal and electrical insulating properties, and anticorrosion characteristics. Plastic screws are usually produced by injection molding, which involves material shrinkage during the solidification of the polymer. This shrinkage results in the degeneration of the dimensional accuracy. In the present study, the effect of injection-molding conditions on the dimensional accuracy of plastic screws was investigated through a numerical simulation of injection molding; on the basis of this simulation, we could determine the mold-design parameters. The design of experiment was applied in accordance with the numerical analysis in order to optimize the injection-molding conditions with a view to improving the dimensional accuracy of the precision plastic screw.

플라스틱 나사는 경량성, 내식성, 열 및 전기절연성이 우수하여 최근 금속나사 대체용도로 사용 되고 있다. 플라스틱 나사는 사출성형에 의해 제작되며 성형과정에서 수축이 발생하여 형상정밀도가 저하된다. 특히 소형 정밀나사의 경우 마이크로미터 단위의 정밀도를 요구하는 관계로 소성가공에 의해 제작되는 금속나사를 대체하기 위해서는 많은 어려움이 따른다. 본 연구에서는 사출성형 공정의 수치해석을 통해 금형설계 인자를 결정하였고, 실험계획법을 적용하여 변형량을 최소화하기 위한 성형조건을 도출함으로써 플라스틱 나사의 형상정밀도 향상을 위한 연구를 수행하였다.

Keywords

References

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  1. Numerical Analysis of Mold Deformation Including Plastic Melt Flow During Injection Molding vol.38, pp.7, 2014, https://doi.org/10.3795/KSME-A.2014.38.7.719
  2. Thermal-Fluid Coupled Analysis for Injection Molding Process by Considering Thermal Contact Resistance vol.35, pp.12, 2011, https://doi.org/10.3795/KSME-A.2011.35.12.1627