Elastomers and Composites

The Rubber Society of Korea (한국고무학회)
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A Study on the Warpage in Injection Molded Part for Various Part Designs and Non Reinforced Resins

비 보강 수지의 종류와 사출성형품의 설계에 따른 휨의 연구

  • Lee, M. (Graduate School of Industry, Seoul National Univ. of Technology) ;
  • Kim, J.H. (Graduate School of NID Fusion Technology, Seoul National Univ. of Technology) ;
  • Park, S.R. (Graduate School of NID Fusion Technology, Seoul National Univ. of Technology) ;
  • Lyu, M.Y. (Department of Product Design and Manufacturing Engineering, Seoul National Univ. of Technology)
  • 이민 (서울산업대학교 산업대학원) ;
  • 김지현 (서울산업대학교 NID융합기술대학원) ;
  • 박서리 (서울산업대학교 NID융합기술대학원) ;
  • 류민영 (서울산업대학교 제품설계금형공학과)
  • Published : 2009.12.31
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Abstract

Most of the plastics products are being manufactured by injection molding. Warpage in injection molded affects the product dimension and it causes assembling problem. In this study, warpages in the injection molded part been studied. Specimens are rectangular flat shapes with and without ribs. Amorphous polymers (PC and ABS) and crystalline polymers (PP and PA66) were used for material. Flat shape with ribs showed higher warpage than flat shape without ribs by 6 to 9%. The specimens with ribs that are located parallel to the flow direction has higher warpage than specimens with ribs that are located perpendicular to the flow direction by 25 to 39%. Crystalline polymers have higher warpage than amorphous polymers by 23 to 67%. Warpage decreases as packing time increases and it increases as injection temperature increases.

플라스틱 제품 중 대부분은 사출성형 공정에 의해 이루어지고 있다. 사출성형품에서 휨은 제품의 치수에 영향을 미치며 또한 조립시의 문제점으로 작용한다. 본 연구에서는 사각 Flat한 시편과 여기에 리브가 수지 흐름방향으로 시편, 리브가 수지 흐름방향의 수직으로 있는 시편에 대해서 사출성형 후 휨에 대해서 연구하였다. 비 보강된 비결정성 수지 (PC, ABS) 와 결정성 수지 (PP, PA66)에 대해서 휨을 비교 하였다. 제품형상이 Flat한 시편보다 평판에 리브가 있는 시편에서 휨이 6~9% 더 많이 발생하였다. 그리고 리브가 수지 흐름방향의 수직으로 놓여있는 시편보다 수지 흐름방향으로 놓여있는 시편에서 휨이 25~39% 더 많이 발생하였다. 또한 비결정성 수지보다는 결정성 수지에서 휨이 23~67% 더 많이 발생하였다. 성형조건에 따른 영향은 보압시간이 증가 할수록 휨이 감소하였고 수지온도가 증가 할수록 휨은 증가하였다.

Keywords

References

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