Journal of the Korean Society of Manufacturing Process Engineers (한국기계가공학회지)

The Korean Society of Manufacturing Process Engineers (한국기계가공학회)
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A Study on Injection Molding Analysis of a Plastic Rack Gear

플라스틱 랙기어의 사출성형 해석에 관한 연구

  • Kim, Hyung-Kook (School of Smart Mechanical & Automotive Engineering, Changwon Moonsung University)
  • 김형국 (창원문성대학교 스마트기계자동차공학부)
  • Received : 2020.05.05
  • Accepted : 2020.05.29
  • Published : 2020.08.31
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Abstract

This study investigates the injection molding of a plastic rack gear and focuses on deflections in the part. The causes of deflections were found and resolved through a trade-off study by injection molding analysis. Based on a warpage analysis, the fiber orientation was found to be a dominant factor in the occurrence of deflections. Changes in the part design and various injection conditions were analyzed for their effects in reducing deflections. Based on the trade-off study, a new part bottom design, injection time, and melt temperature were recommended. A trial injection was done for the new plastic rack gear, and measurements showed that its flatness surpassed that of the original part and met the specified requirement. The short injection time, low melt temperature, and symmetric similar configuration of the part contributed to the reduction in deflections. Therefore, optimized gate design and injection conditions as well as a new part design were validated through injection molding analysis in this study.

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References

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