Rheological insight of wall slippage and microrotation on the coating thickness during non-isothermal forward roll coating phenomena of micropolar fluid

Roll coating is important for coating industries, including wallpaper, magnetic records, photographic and plastic films, wrapping, adhesive tapes, magazines, books, etc. This theoretical study examines the non-isothermal, incompressible, steady flow of micropolar fluid inside a forward roll coating by using the lubrication approximation theory. Interesting engineering factors including pressure, roll-separating force, separation point, flow rate and power input are computed using a numerical technique, and further, the closed-form solutions for velocity, pressure gradient, temperature distribution and microrotation are also obtained. Graphs are used to show how the various parameters affect pressure, velocity, pressure gradient, shear stress and temperature distribution. Velocity profile, power input and separation points are the decreasing functions of the involved parameters. The fluid particle rotations increase the pressure distribution, leading to decreased coating thickness, which may help to improve the efficiency of coating process.

Automated summary

Roll coating is an important technique in the coating industry, used in applications such as wallpaper, magnetic records, photographic and plastic films. This theoretical study focuses on the flow of micropolar fluid in a forward roll coating, considering factors such as pressure, roll-separating force, separation point, flow rate, and power input. Numerical techniques are used to calculate these engineering parameters, along with obtaining closed-form solutions for velocity, pressure gradient, temperature distribution, and microrotation. Graphs are used to analyze the effects of various parameters on pressure, velocity, pressure gradient, shear stress, and temperature distribution. The study finds that velocity profile, power input, and separation points are decreasing functions of the parameters, and fluid particle rotations affect the pressure distribution and coating thickness.