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SCO is an independent consulting office specializing in the areas of polymer processing and fiber formation by providing consulting services and software development.
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Computer Simulation of Coater Dryer (Part 1) & (Part 2) |
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[Computer Simulation of Coater Dryer (Part 1), Japan Plastics, Vol.56, No.12, P.90 (2005) & Computer Simulation of Coater Dryer (Part 2), Japan Plastics, Vol.57, No.1, P.175 (2006)]
Film coating is an important process for film processing, where polymer-solvent solution is coated on plastics films etc., and continuously passing through dryer(s) the solvent is evaporated. The coating process is applied to the production of adhesive tapes, photo-films, wrapping films, magnetic tapes, dry film resist (DFR) used for producing printed circuit boards, etc. To analyze the drying process of the coated film, it is necessary to consider heat transfer in the base film and the coated film (solution layer) together, and mass transfer in the coated film accompanying evaporation of the solvent at the surface. It could be said this is a complicating and interesting problem. The present writer already published an article about drying in a coater dryer (its abstract is included in this collection of abstracts). Important difference of the present article from the previous one is the method of obtaining the diffusion coefficient in coating liquid. The diffusion coefficient is one of the most important factors that control the drying process. In short, the diffusion coefficient is decided by fitting experimental data, in the previous model. Contrary to the previous model, the diffusion coefficient is derived by calculation using physical properties in the present model. Namely, no experimental data is necessary to simulate the drying process, but depending on the circumstances, getting all necessary physical properties is quite difficult. From practical point of view, both of these two models have advantages and disadvantages, and using these models on a case-by-case basis will be wise. To calculate the diffusion coefficient, Vrentas-Duda free volume theory [24], [25] is adopted in the present model. In this chapter, theoretical equations, simulation program based on the present model and its calculation example are presented, mentioning the previous model. [24] Duda, J. L., Vrentas, J. S., Ju, S. T. and Liu, H. T., AIChE J., 28 (2), 279 ('82) [25] Zielinski, J. M. and Duda, J. L., AIChE J., 38 (3), 405 ('92) |