Abstract
Roll coating is a common technique for applying thin coating films on continuous substrates, e.g., papers and foils. Key advantages are the comparatively simple technology and the possibility of coating thin films using highly viscous fluids. Since roll coating is a self-metered process, the prediction of film thicknesses is of fundamental interest for industrial process control. In the present work, a new analytical approach for the prediction of the film thickness in roll coating with deformable rolls and negative gaps is developed. This method is based on the fluid dynamic theory of lubrication approximation. The film thickness is calculated depending on the geometry of the rolls (including the elasticity of the rubber), the fluid properties of the applied film and the roll velocities. This is gained by using boundary conditions for pressure and—in contrast to former literature—for force. The quality of the predicted results is validated with experimental data from literature. The comparison shows good agreement and thus the derived analytical model offers new possibilities for predicting film thickness and understanding of the associated influence parameters.
Similar content being viewed by others
Explore related subjects
Discover the latest articles, news and stories from top researchers in related subjects.References
Greener, J, Middleman, S, “Theoretical and Experimental Studies of the Fluid Dynamics of a Two-Roll Coater.” Ind. Eng. Chem. Fundam., 18 35–41 (1979)
Savage, MD, “Mathematical Models for Coating Processes.” J. Fluid Mech., 117 443–455 (1982)
Benkreira, H, Edwards, MF, Wilkinson, WL, “A Semi-empirical Model of the Forward Roll Coating Flow of Newtonian Fluids.” Chem. Eng. Sci., 36 423–427 (1981)
Benkreira, H, Edwards, MF, Wilkinson, WL, “Roll Coating of Purely Viscous Liquids.” Chem. Eng. Sci., 36 429–434 (1981)
Mmbaga, JP, Hayes, RE, Bertrand, FH, Tanguy, PA, “Flow Simulation in the Nip of a Rigid Forward Roll Coater.” Int. J. Numer. Meth. Fluids, 48 1041–1066 (2005)
Han, SK, Shin, DM, Park, HY, Jung, HW, Hyun, JC, “Effect of Viscoelasticity on Dynamics and Stability in Roll Coatings.” Eur. Phys. J. Special Top., 166 107–110 (2009)
Szczurek, E, Dubar, M, Deltombe, R, Dubois, A, Dubar, L, “New Approach to the Evaluation of the Free Surface Position in Roll Coating.” J. Mater. Proc. Technol., 209 3187–3197 (2009)
Carvalho, MS, Scriven, LE, “Three-Dimensional Stability Analysis of Free Surface Flows: Application to Forward Deformable Roll Coating.” J. Comput. Phys., 151 534–562 (1999)
Coyle, DJ, “Forward Roll Coating with Deformable Rolls: A Simple One-Dimensional Elastohydrodynamic Model.” Chem. Eng. Sci., 43 2673–2684 (1988)
Carvalho, MS, Scriven, LE, “Effect of Deformable Roll Cover on Roll Coating.” Tappi J., 77 201–208 (1994)
Carvalho, MS, Scriven, LE, “Flows in Forward Deformable Roll Coating Gasp: Comparison between Spring and Plane-Strain Models of Roll Cover.” J. Comput. Phys., 138 449–479 (1997)
Carvalho, MS, “Effect of Thickness and Viscoelastic Properties of Roll Cover on Deformable Roll Coating Flows.” Chem. Eng. Sci., 58 4323–4333 (2003)
Gostling, MJ, Savage, MD, Young, AE, Gaskell, PH, “A Model for Deformable Roll Coating with Negative Gaps and Incompressible Compliant Layers.” J. Fluid. Mech., 489 155–184 (2003)
Cohu, O, Magnin, A, “Forward Roll Coating of Newtonian Fluids with Deformable Rolls: An Experimental Investigation.” Chem. Eng. Sci., 52 1339–1347 (1997)
Devisetti, SK, Bousfield, DW, “Fluid Absorption During Forward Roll Coating of Porous Webs.” Chem. Eng. Sci., 65 3528–3537 (2010)
Bohan, MFJ, Fox, IJ, Claypole, TC, Gethin, DT, “Numerical Modelling of Elastohydrodynamic Lubrication in Soft Contacts Using Non-Newtonian Fluids.” Int. J. Numer. Methods Heat Fluid Flow, 12 494–511 (2002)
Lécuyer, HA, Mmbaga, JP, Hayes, RE, Bertrand, FH, Tanguy, PS, “Modelling of Forward Roll Coating Flows with a Deformable Roll: Application to Non-Newtonian Industrial Formulations.” Comput. Chem. Eng., 33 1427–1437 (2009)
Kang, Y-T, Lee, K-Y, Liu, T-J, “The Effect of Polymer Additives on the Performance of a Two-Roll Coater.” J. Appl. Polym. Sci., 43 1187–1195 (1991)
Lee, JH, Han, SK, Jung, HW, Hyun, JC, “Ribbing Instability in Rigid and Deformable Forward Roll Coating Flows, Ribbing Instability in Rigid and Deformable Forward Roll Coating Flows.” Korea-Aust. Rheol. J., 22 75–80 (2010)
Ascanio, G, Carreau, PJ, Brito-de la Fuente, E, Tamguy, PA, “Forward Deformable Roll Coating at High Speed with Newtonian fluids.” Trans. IChemE, Part A Chem. Eng. Res. Des., 82 390–397 (2004)
Durst, F, Grundlagen der Strömungsmechanik—Eine Einführung in die Theorie der Strömungen von Fluiden. Springer, Berlin (2006)
Hertz, H, “Über die Berührung fester elastischer Körper.” J. Reine Angew. Math., 92 156–171 (1881)
Parish, GJ, “Measurements of Pressure Distribution Between Metal and Rubber Covered Rollers.” Br. J. Appl. Phys., 9 158–161 (1958)
Parish, GJ, “Apparent Slip Between Metal and Rubber-Covered Pressure Rollers.” Br. J. Appl. Phys., 9 428–433 (1958)
Thomas, HR, Hoersch, VA, “Stresses Due to the Pressure of One Elastic Solid Upon Another, One Elastic Solid Upon Another.” University of Illinois, Engineering Experimental Station, Bulletin no. 212, pp. 66-99 (1930)
Hannah, M, “Contact Stress and Deformation in a Thin Elastic Layer.” Q. J. Mech. Appl. Math., 3 94–105 (1950)
Parish, GJ, “Calculation of the Behaviour of Rubber-Covered Pressure Rollers.” Br. J. Appl. Phys., 12 333–336 (1961)
Coyle, DJ, Macosko, CW, Scriven, LE, “Film-Splitting Flows in Forward Roll Coating.” J. Fluid Mech., 171 183–207 (1986)
Decré, M, Gailly, E, Buchlin, JM, “Meniscus Shape Experiments in Forward Roll Coating.” Phys. Fluids, 7 458–467 (1995)
Becerra, MZ, Oldrich, JR, Azevedo, LFA, Carvalho, MS, “Measuring the Velocity Field in Film-Splitting Flows of Newtonian Liquids.” AIChE J., 53 281–289 (2007)
Ascanio, G, Ruiz, G, “Measurement of Pressure Distribution in a Deformable Nip of Counter-Rotating Rolls.” Mess. Sci. Technol., 17 2430–2436 (2006)
Hooke, CJ, “The Elastohydrodynamic Lubrication of a Cylinder on an Elastomeric Layer.” Wear, 111 83–99 (1986)
Author information
Authors and Affiliations
Corresponding author
Additional information
This paper was presented at the 16th International Science and Technology Symposium, September 9–12, 2012, in Atlanta, GA (USA).
Rights and permissions
About this article
Cite this article
Willinger, B., Delgado, A. Analytical prediction of roll coating with counter-rotating deformable rolls. J Coat Technol Res 11, 31–37 (2014). https://doi.org/10.1007/s11998-013-9506-2
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11998-013-9506-2