Ribbing instability in rigid and deformable forward roll coating flows
- Authors
- Lee, Je Hoon; Han, Sang Kwon; Lee, Joo Sung; Jung, Hyun Wook; Hyun, Jae Chun
- Issue Date
- 3월-2010
- Publisher
- KOREAN SOC RHEOLOGY
- Keywords
- ribbing; forward roll coating; wavelength; severity; viscoelasticity; roll deformability; coating window
- Citation
- KOREA-AUSTRALIA RHEOLOGY JOURNAL, v.22, no.1, pp.75 - 80
- Indexed
- SCIE
SCOPUS
KCI
OTHER
- Journal Title
- KOREA-AUSTRALIA RHEOLOGY JOURNAL
- Volume
- 22
- Number
- 1
- Start Page
- 75
- End Page
- 80
- URI
- https://scholar.korea.ac.kr/handle/2021.sw.korea/116912
- ISSN
- 1226-119X
- Abstract
- Dynamics and ribbing instability for Newtonian and viscoelastic liquids have been investigated in both rigid and deformable forward roll coating flows. Especially, the role of viscoelasticity of coating liquids and roll deformability or hardness on the coating flow has been scrutinized. Coating thickness at steady uniform states and wavelength and severity at unstable ribbing states have been measured, incorporating thickness measurement device and two-roll coating equipment. Relationship between wavelength and severity in ribbing instability strongly depends on the viscoelasticity as well as other operating conditions such as capillary number, coating gap, and roll deformability. Coating windows demarcating uniform and ribbing instability are considerably reduced by increasing viscoelasticity and decreasing roll deformability. In other words, ribbing is aggravated as the viscoelasticity of coating liquids that can generate the extensional property in film splitting region rises or roll deformability decreases, leading to higher severity and narrower wavelength.
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Collections - College of Engineering > Department of Chemical and Biological Engineering > 1. Journal Articles
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