Variation of coating thickness in blade coating process of an upper-convected Jeffery’s fluid model

Abstract

The coating process is significant in terms of its practical applications in the field of paint and electronics industries. The coating process offers a protective layer in paints; however, it stores information in electronics industries. Current study gives insight on the blade coating analysis by passing an upper convected Jeffery's material through the narrow gap between the moving substrate and a fixed blade. The basic flow expressions were simplified by utilizing lubrication approximation theory, and then solved using the perturbation analysis and numerical shooting technique. The study discussed the effects of material parameters in both cases of plane and exponential coaters. The variations of Weissenberg number, viscosities ratio and normalized coating thickness on the maximum pressure, pressure gradient, coating thickness, pressure, and load are presented through graphs and in a tabular manner. In addition, the perturbation results were validated by comparing with the numerical outcomes and found an excellent agreement. It is noted that increasing both the Weissenberg number and viscosities ratio resulted in reduced coating thickness and increased blade load, hence were the controlling parameters, as they certified the coating quality and life of the substrate. Besides, the parameters had significant impacts on the velocity and pressure profiles. In addition, maximum pressure was directly proportional to the Weissenberg number and viscosities ratio.

Transparent, Robust, and Photochemical Antibacterial Surface Based on Hydrogen Bonding between a Si-Al and Cationic Dye

“…Generally, the thickness of the coating is determined by the characterizations of the solution, velocity of the moving substrate, and blade angle (Figure S10). , The thickness ( t ) of the coating can be calculated by the Landau–Levich–Derjaguin model as follows: where κ –1 is the capillary length and Ca is the capillary number. κ –1 estimates the relative effects of the Laplace pressure and hydrostatic pressure and is defined as κ –1 = (γ/ρg) 1/2 .…”

“…Generally, the thickness of the coating is determined by the characterizations of the solution, velocity of the moving substrate, and blade angle (Figure S10). 44,45 The thickness (t) of the coating can be calculated by the Landau−Levich−Derjaguin model as follows: 46 t Ca…”

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