Journal of the Korean Society for Precision Engineering (한국정밀공학회지)

Korean Society for Precision Engineering (한국정밀공학회)
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Development of Injection Mold for Subminiature Lenses Using Shell Runners Containing Multiple Holes

다공성 박판형 러너를 사용한 초소형 렌즈 사출금형 개발

  • Yoon, Seung Tak (Department of Mechanical System Design Engineering, Seoul National University of Science and Technology) ;
  • Park, Keun (Department of Mechanical System Design Engineering, Seoul National University of Science and Technology)
  • 윤승탁 (서울과학기술대학교 기계시스템디자인공학과) ;
  • 박근 (서울과학기술대학교 기계시스템디자인공학과)
  • Received : 2015.08.31
  • Accepted : 2015.09.15
  • Published : 2015.11.01
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Abstract

This study aims to develop an efficient mold structure for the injection molding of a subminiature lens, using shell-type runners instead of traditional cylindrical runners. While the shell runner has the advantage of shorter cooling time due to its thinner geometry, this smaller thickness causes an increase in injection pressure. In this study, the design of the shell runner was modified to contain multiple holes for the purpose of reducing injection pressure. Numerical analyses were performed for shell runners of various hole-shapes, and the resulting filling and cooling characteristics were discussed; the rhombic hole showed the best result for both filling and cooling characteristics. Subsequently, injection molding experiments were performed using an injection mold fabricated based on the rhombic design. The lens parts were successfully molded with highly-reduced cycle time and without degradation of part quality.

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References

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