Impacts of operating variables in forward roll coating process of viscous hybrid nanofluid

Abstract

Roll coating plays a significant role in various coating industries such as magnetic records, wallpapers, wrapping, adhesive tapes, books and magazines, photographic and plastic films. The thin layer coating of a magnetohydrodynamic (MHD) viscous hybrid nanofluid by passing through the space between two co-rotating rolls has been studied in an isothermal and incompressible analysis. The governing equation of mass and momentum are obtained then dimensionless using lubrication approximation theory (LAT). The velocity, pressure gradient, and pressure distribution are determined by the exact solution. Using Simpson’s (3/8) rule for numerical integration, the complex integral is examined. Important engineering parameters including power and roll separating force delivered by the rolls to the fluid are also estimated numerically. Raising the volume fraction of nanoparticles raises the pressure distribution and pressure gradient while having little effect on the velocity profile. It seems that the magnetic field and hybrid nanofluid, both seem very advantageous for the efficient roll coating process, controlling the separation force, power input, and distance between the attachment and separation point.