Journal of Coatings Technology and Research

, Volume 14, Issue 5, pp 1003–1013 | Cite as

Trailing edge formation during slot coating of rectangular patches

  • D. Maza
  • M. S. CarvalhoEmail author


Different products, such as adhesives, pharmaceutical patches, batteries, and fuel cell membranes, require coating discrete patches onto moving substrates. For coating rectangular patches, intermittent slot die coating is the preferred method. The patches can be obtained by rapidly starting and stopping the flow out of the coating die. Controlling the flow start-up and shutdown to produce sharp and uniform leading and trailing edges of each patch is challenging. Different ways to control the liquid feeding are used to optimize the process. Even if the start-up and shutdown of the feeding system are well designed, the transient flow in the coating bead contributes to the formation of nonuniform leading and trailing edges of coated patches. In this work, we analyze how the operating conditions, die geometry, and liquid properties affect the coating bead breakup process and the trailing edge configuration. The process is directly related to the contact line dynamics. The results show that the uniformity of the trailing edge of each coated patch can be improved by changing the die shoulder angle and wetting characteristics of the die surface.


Intermittent coating Slot coating Contact line Finite element method 



This work was funded by CNPq (Brazilian Research Council), FAPERJ, and the Industrial Partnership for Research in Interfacial and Materials Engineering (IPRIME) of the University of Minnesota.


  1. 1.
    Schmitt, M, Scharfer, P, Schabel, W, “Slot Die Coating of Lithium-Ion Battery Electrodes: Investigations on Edge Effect Issues for Stripe and Pattern Coatings.” J. Coat. Technol. Res., 11 57–63 (2014)CrossRefGoogle Scholar
  2. 2.
    Kim, S, Kim, JH, Ahn, KH, Lee, SJ, “Rheological Perspectives of Industrial Coating Process.” Korea Aust. Rheol. J., 21 83–89 (2009)Google Scholar
  3. 3.
    Milbourn, TM, Barth, JJ, “Method of Applying Discrete Coating Patches on a Moving Web,” U.S. Patent, 5360629, 1994Google Scholar
  4. 4.
    Watanabe, M, Ueyama, Y, Nakamura, T, Ohana, Y, Hayashi, T, “Intermittent Coating Apparatus, Intermittent Coating Method and Manufacturing Method of Battery Electrodes, and Non Aqueous Electrolyte Cell,” U.S. Patent, 5824156, 1998Google Scholar
  5. 5.
    Iwashita, Y, Endo, S, Morimoto, K. “Intermittent Coating Method and Apparatus Therefor.” U.S. Patent, 5989622A, 1999Google Scholar
  6. 6.
    Schmitkons, JW, Turner, J, Zupan, MP, Rivas, A, Benecke, J, Cieplik, A, Burmester, T, Boger, B, “Snuff Back Controlled Coating Dispensing Apparatus and Methods.” U.S. Patent, 5733597A, 1998Google Scholar
  7. 7.
    Sakai, Y, Yoshikawa, T, Akinori, I, “Intermittent Coating System and Intermittent Coating Method.” U.S. Patent, 6455105B1, 2002Google Scholar
  8. 8.
    Szczepaniak, W, Janssen, F, Blum, J. “Device for Linear Adjustment of Machine Component, Has Adjustment Unit that is Acted on Adjustment Tape for Bending Motion, So that the Machine Component is Moved Relative to the Bearing on Linear Guide Portions.” DE Patent App. DE102012110305A1, 2014Google Scholar
  9. 9.
    de Vries, I, “Intermittent Slot Die Coating of Low Viscous Solutions,” 17th International Coating Science and Technology Symposium (ISCST 2014), San Diego, CA, USA, 2014Google Scholar
  10. 10.
    Yang, CK, Wong, DSH, Liu, TJ, “An Experimental Study on Discrete Patch Coating.” Ind. Coat. Res., 5 43–58 (2004)Google Scholar
  11. 11.
    Schmitt, M, Diehm, R, Scharfer, P, Schabel, W, “An Experimental and Analytical Study on Intermittent Slot Die Coating of Viscoelastic Battery Slurries.” J. Coat. Technol. Res., 12 927–938 (2015)CrossRefGoogle Scholar
  12. 12.
    Christodoulou, KN, Scriven, LE, “Discretization of Free Surface Flows and Other Moving Boundary Problems.” J. Comput. Phys., 99 39–55 (1992)CrossRefGoogle Scholar
  13. 13.
    de Santos, JM. “Two-Phase Cocurrent Downflow Through Constricted Passages.” Ph.D. Thesis. University of Minnesota, MN, USA 1991Google Scholar
  14. 14.
    Romero, OJ, Carvalho, MS, “Response of Slot Coating Flows to Periodic Disturbances.” Chem. Eng. Sci., 63 2161–2173 (2008)CrossRefGoogle Scholar
  15. 15.
    Maza, D, Carvalho, MS, “Transient Response of Two-Layer Slot Coating Flows to Periodic Disturbances.” AIChE J., 61 1699–1707 (2014)CrossRefGoogle Scholar

Copyright information

© American Coatings Association 2017

Authors and Affiliations

  1. 1.Department of Mechanical EngineeringPontificia Universidade Catolica do Rio de JaneiroGavea, Rio de JaneiroBrazil

Personalised recommendations