Abstract
In this study, a strategy for designing optimal shim configuration inside a slot die is suggested to assure the uniform coating flow distribution of various non-Newtonian shear-thinning liquids at the die exit in a slot coating system. Flow patterns of non-Newtonian liquids inside the slot die, via three-dimensional computations, have been compared using various shim geometries which can adjust the flow region in a slot manifold. The rather non-uniform (parabolic) velocity distributions of shear-thinning liquids at the die exit under the basic shim condition could be effectively flattened by the modification of shim geometry without the change of die manifold structure. Dimensions of hybrid shims for controlling flow features at edge and center regions within slit channel are positively tuned, according to the shear-thinning level of coating liquids.
This is a preview of subscription content, log in via an institution to check access.
References
Ahn, W.-G., S.H. Lee, J. Nam, and H.W. Jung, 2015, Effect of flow rate variation on the frequency response in slot coating with upstream sloped die geometry, Korean J. Chem. Eng. 37, 1218–1221.
Bhamidipati, K.L., S. Didari, P. Bedell, and T.A.L. Harris, 2011, Wetting phenomena during processing of high-viscosity shearthinning fluid, J. Non-Newton. Fluid Mech. 166, 723–733.
Byun, C.W., 2012, Slot die, Korea Patent 2012014511.
Carvalho, M.S. and H.S. Kheshgi, 2000, Low-flow limit in slot coating: Theory and experiments, AIChE J. 46, 1907–1917.
Cohen, E.D. and E.B. Gutoff, 1992, Modern Coating and Drying Technology, 1st ed., VCH Publishers, New York.
Gates, I.D., 1999, Slot coating flows: Feasibility, quality, PhD Thesis, University of Minnesota.
Han, G.H., S.H. Lee, W.-G. Ahn, J. Nam, and H.W. Jung, 2014, Effect of shim configuration on flow dynamics and operability windows in stripe slot coating process, J. Coat. Technol. Res. 11, 19–29.
Higgins, B.G. and L.E. Scriven, 1980, Capillary pressure and viscous pressure drop set bounds on coating bead operability, Chem. Eng. Sci. 35, 673–682.
Jeon, S.W., Y.W. Son, S.M. Kang, and H.M. Lee, 2013, Slot die coater for production of electrodes, Korea Patent 20130110507.
Kistler, S.F. and P.M. Schweizer, 1997, Liquid Film Coating, Chapman and Hall, London.
Koh, H.J., I. Kwon, H.W. Jung, and J.C. Hyun, 2012, Operability window of slot coating using viscocapillary model for carreautype coating liquids, Korea-Aust. Rheol. J. 24, 137–141.
Lee, K.Y. and L.D. Liu, 1989, Design and analysis of a dual-cavity coat-hanger die, Polym. Eng. Sci. 29, 1066–1075.
Lee, S.H., H.J. Koh, B.K. Ryu, S.J. Kim, H.W. Jung, and J.C. Hyun, 2011a, Operability coating windows and frequency response in slot coating flows from a viscocapillary model, Chem. Eng. Sci. 66, 4953–4959.
Lee, S.H., H.J. Koh, S.H. Shim, H.W. Jung, and J.C. Hyun, 2011b, An optimal die design for the coating uniformity of non-Newtonian liquids in slot coating process, Korean Chem. Eng. Res. 49, 314–319.
Lee, S.H., S.J. Kim, J. Nam, H.W. Jung, and J.C. Hyun, 2014, Effect of sloped die lip geometry on the operability window in slot coating flows using viscocapillary and two-dimensional models, J. Coat. Technol. Res. 11, 47–55.
Matsubara, Y., 1979, Geometry design of a coat-hanger die with uniform flow rate and residence time across the die width, Polym. Eng. Sci. 19, 169–172.
McKelvey, J.M. and K. Ito, 1971, Uniformity of flow from sheeting dies, Polym. Eng. Sci. 11, 258–263.
Nam, J., L.E. Scriven, and M.S. Carvalho, 2009, Tracking birth of vortex in flows, J. Comput. Phys. 228, 4549–4567.
Park, S.H., C.G. Lee, and Y.H. Lim, 2014, Movable member for slot die coater and slot die coater for production of electrodes using the same, Korea Patent 20140089035.
Pearson, J.R.A., 1964, Non-Newtonian flow and die design, Trans. J. Plastics Inst. 32, 239.
Romero, O.J., L.E. Scriven, and M.S. Carvalho, 2006, Slot coating of mildly viscoelastic liquids, J. Non-Newton. Fluid Mech. 138, 63–75.
Ruschak, K.J. and S.J. Weinstein, 1997, Modeling the secondary cavity of two-cavity dies, Polym. Eng. Sci. 37, 1970–1976.
Sartor, L., 1990, Slot coating: Fluid mechanics and die design, PhD Thesis, University of Minnesota.
Tanwar, J., M. Vinjamur, and L.E. Scriven, 2007, Design principles of integrated vacuum slot arrangement, AIChE J. 53, 572–578.
Tsuda, T., 2009, Dynamic response analysis and control of slot coating, J. Fluid Sci. Tech. 4, 735–745.
Yuan, S.L., 1995, A flow model for non-Newtonian liquids inside a slot die, Polym. Eng. Sci. 35, 577–586.
Author information
Authors and Affiliations
Corresponding authors
Additional information
These authors contributed equally
Rights and permissions
About this article
Cite this article
Jin, G.L., Ahn, WG., Kim, S.J. et al. Effect of shim configuration on internal die flows for non-Newtonian coating liquids in slot coating process. Korea-Aust. Rheol. J. 28, 159–164 (2016). https://doi.org/10.1007/s13367-016-0015-6
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s13367-016-0015-6