Numerical simulation of visco-elastic-plastic fluid in the process of blade coating

The blade coating process involves continuously applying a thin molten polymer film onto a moving surface, with a stationary blade removing excess material to ensure a smooth, uniform layer. This study examines how coating thickness and blade load are affected by material parameters. The polymer is modeled as a non-Newtonian visco-elastic-plastic fluid. Flow equations based on fluid dynamics are simplified using lubrication approximation theory (LAT) and solved numerically in MATLAB using bvp4c . Key physical quantities such as pressure, pressure gradient, velocity profile, coating thickness, and load capacity are calculated and presented visually. Results show that increasing the Bingham number raises both coating thickness and blade load, while increasing the slip parameter raises coating thickness but reduces blade load. Specifically, for Bn = 2 , coating thickness increases 6.55% and blade load increases by 19.32%, compared to a Newtonian fluid. As slip parameter goes from 0 to 1.3 there is a 60.19% increase in coating thickness and a 31.44% decrease in blade load. These findings offer valuable insights into how visco-elastic-plastic rheology influences blade coating performance and can guide the optimization of coating quality and operational conditions in industry.