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

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.

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