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A Study on the Optimization of the Dimensional Deviation due to the Shortening of the Cycle Time for Rear Cover of Mobile Phone

휴대폰 후면 커버의 공정시간 단축에 따른 치수 편차의 최적화에 관한 연구

  • Kim, Joo-Kwon (Department of Mechanical Engineering, Pukyong National University) ;
  • Kim, Jong-Sun (Molds and Dies Technology Group, Korea Institute of Industrial Technology) ;
  • Lee, Jun-Han (Molds and Dies Technology Group, Korea Institute of Industrial Technology) ;
  • Kwak, Jae-Seob (Department of Mechanical Engineering, Pukyong National University)
  • 김주권 (부경대학교 기계공학과) ;
  • 김종선 (한국생산기술연구원 금형기술그룹) ;
  • 이준한 (한국생산기술연구원 금형기술그룹) ;
  • 곽재섭 (부경대학교 기계공학과)
  • Received : 2017.09.26
  • Accepted : 2017.11.22
  • Published : 2017.12.31

Abstract

In this study, we investigated the optimization of process conditions by using the Six Sigma process, design of experiment (DOE) method and response surface method (RSM) to resolve dimensional deviation and appearance problems arising from the shortened process time of the mobile phone rear cover. The analysis of the trivial many was performed by 2-sample T-test and cooling time, and mold temperature and packing pressure were selected as the vital fews affecting the overall width of the product. The optimal conditions of the process were then studied using the DOE and the RSM. We analyzed the improvement effects by applying the selected optimal conditions to the production process and the results showed that the difference between the mean value and target value of the overall width stood at 0.01 mm, an improvement of 88.89% compared to current process that fell within the range of standard dimension. The short-term process capability stood at $4.77{\sigma}$, which implied an excellent technology level despite a decrease by $0.22{\sigma}$ compared to the current process. The difference in process capability decreased by $2.44{\sigma}$ to $0.41{\sigma}$, showing a significant improvement in management capability. Ultimately, the process time of the product was shortened from 18.3 seconds in the current process to 13.65 seconds, resulting in a 34.07% improvement in production yield.

Keywords

References

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