Elastomers and Composites

The Rubber Society of Korea (한국고무학회)
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Coater Die Design and Coating Quality Evaluation in the Machine Direction of Slot Coating Through Computer Simulation

컴퓨터 해석을 통한 Slot 코팅공정에서 운전방향의 코팅품질 평가 및 다이 설계

  • Kim, T.H. (Department of Mechanical System Design Engineering, Seoul National University of Science and Technology) ;
  • Lee, D.Y. (Department of Mechanical System Design Engineering, Seoul National University of Science and Technology) ;
  • Sung, D.J. (Narae Nanotech Co.) ;
  • Lyu, M.Y. (Department of Mechanical System Design Engineering, Seoul National University of Science and Technology)
  • 김태훈 (서울과학기술대학교 기계시스템디자인공학과) ;
  • 이두이 (서울과학기술대학교 기계시스템디자인공학과) ;
  • 성달제 (나래나노텍(주)) ;
  • 류민영 (서울과학기술대학교 기계시스템디자인공학과)
  • Received : 2013.10.07
  • Accepted : 2013.10.29
  • Published : 2013.12.31
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Abstract

Slot coating has been widely spread in photo resist coating on glass for flat display monitor. High quality of coating is required as high quality of image in display is needed. Coating quality in the slot coating is divided into nozzle direction quality and machine direction quality. Nozzle direction quality is related to flow uniformity inside the die whereas machine direction quality is related to die lip design and operational conditions. In this study coating uniformity in the machine direction of slot coating has been investigated through computer simulation. Die lip angle and die lip length were considered as outside die geometry and coating speed was considered as operational condition. Coating behavior has been analyzed and coating quality has been evaluated through computer simulation. Coating thickness decreased and coating uniformity increased as coating speed increased. However, the stability of meniscus formation was reduced and subsequently coating stability was reduced as coating speed increased. Coating thickness deviation decreased as die lip angle increased in down stream die. Coating thickness decreased and time to reaching steady state increased as increased die lip length in down stream die.

슬롯코팅은 평판 디스플레이의 부품을 위해 유리에 감광제를 코팅방법으로 많이 쓰이고 있다. 갈수록 고화질의 디스플레이가 요구됨에 따라 코팅의 고품질도 요구되고 있다. 슬롯코팅에서 코팅의 품질은 노즐방향의 코팅 균일성과 운전방향의 코팅 균일성으로 평가된다. 노즐방향의 코팅 균일성은 코터다이 내부의 설계에 의존되며 운전방향의 코팅 균일성은 코터다이 외부의 모양과 운전조건에 의존된다. 본 연구에서는 스롯코팅에서 운전방향의 코팅 균일성에 대해서 컴퓨터해석을 통하여 조사하였다. 해석에서 다이 외부의 형상으로 다이 립 각도와 길이를 변수로 하였고, 운전조건으로는 코팅속도를 변수로 하여 코팅 현상을 분석하고 코팅의 품질을 평가하였다. 코팅속도가 커질수록 코팅두께가 얇아지며 코팅의 균일성이 증대되었으나 maniscus형성이 불안정하여 코팅의 안정성은 감소되었다. Down stream 다이 립 각도가 커질수록 코팅두께의 편차는 작아졌으며, Down stream 다이 립 길이가 길수록 코팅 두께는 얇아졌고 안정적인 코팅이 이루어지기까지의 시간이 길어졌다.

Keywords

References

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