Roll coating analysis of a second-grade material

Abstract

In this study, the lubrication approximation theory is used to provide numerical results in roll coating over a moving flat porous web. The rate of injection at the roll surface is assumed equal to the rate of suction on the web. The second-grade fluid is used, which reduces with appropriate modifications to the Newtonian fluid model. Results are obtained in such quantities as coating thickness, split location, pressure distribution, stresses, forces, the power input to the roll, and adiabatic temperature rise between the coating roll and the coated web. Some of these results are shown graphically. It is found that material parameters β and Reynolds number are the parameters to control flow rate, coating thickness separation points, separation force, power input, and pressure.