Mathematical analysis of a non-Newtonian polymer in the forward roll coating process

Abstract

This article describes the development of a mathematical model of forward roll coating of a thin film of a non-Newtonian material when it passes through a small gap between the two counter-rotating rolls. The conservation equations of mass, momentum, and energy in the light of LAT (lubrication approximation theory) are non-dimensionalized and solutions for the velocity profile, flow rate, pressure distribution, pressure, forces, stresses, power input to the roller, and temperature distribution are calculated analytically. It is found that by changing (increasing/decreasing) the value of material parameters, one can really control the engineering parameters like, stress and the most important the coating thickness and is a quick reference for the engineer working in coating industries. Some results are shown graphically. From the present study, it has been established that the material parameter is a device to control flow rate, coating thickness, separation points, and pressure distribution.

Operational Stability Analysis on the Roller-Coating Process for a Roll Coating-Simulation Test Equipment

“…The steady-state response of the unbalanced mass to the whole is obtained by solving the Equation (8). Let q(t) = Γ b 0 e jΩt (q 0 is a complex number), q 0 is…”

“…While it only considered symmetry as a case, the asymmetry was not discussed in detail. Taking the rolling process into account, Muhammad Zahid [8] described the process of extruding a film into a non-Newtonian fluid by establishing a roll coating model between the two counter-rotating rollers. The result indicates that the coating parameters could be controlled by changing the values of the material parameters, which provided a quick and convenient reference for the coating process.…”

Theoretical Analysis of Magnetohydrodynamical Waves for Plasma based Coating Process of Isothermal Viscous-Plastic Fluid

“…Surface coating using a fluid film is common in the magnetic tape, photographic, wrapping industries, polymer sheet, hot rolling, glass-fabric, wire drawing, as well as for manufacturer of paint and paper, to protect a large surface region with one/many uniform layers [1][2][3][4]. Despite the fact that the products utilized in various coating sectors vary greatly, while the same basic technologies are used to create the necessary coatings.…”

Coating of a viscoplastic material onto a moving porous web during forward roll coating process: A theoretical study

“…Zahid et al 16 use lubrication approximation theory to find the coating thickness of third grade fluid during roll coating process. The development of a mathematical model of forward roll coating of a thin film of a non-Newtonian material when it passes through a small gap between the two counter-rotating rolls under lubrication approximation theory has been discussed by Zahid et al 17 Z. Xie et al 18 studied the micro interface lubrication regimes of water lubricated bearing. They also investigate the static and dynamic lubrication parameters of the floating ring bearing in.…”