Enhancing blade coating performance through oldroyd 8-constant fluid modeling and slip analysis

The phenomenon of blade coating (BC) has been explored by using the Oldroyd 8-constant fluid model. The blade coating (BC) involves the application of a liquid layer for protection on a continuously moving substrate via a leveling blade. The Oldroyd model is developed using lubrication approximation principles, leading to a set of fourth-order differential equations. The study calculates various parameters such as stream function, fluid flow velocity, pressure gradients, overall pressure, and mechanical properties related to different coating techniques. These parameters are determined using the Newton-Raphson method and the fourth-order Runge-Kutta technique. The findings are presented through graphical and tabular formats, highlighting the influence of material parameters in the viscoelastic fluid model on BC's physical characteristics. When the Oldroyd 8-Constant fluid model is applied with a slip value of 0.1, there is a significant increase in pressure – up to 364 % in the exponential coater and 340 % in the plane coater, compared to using a Newtonian fluid. Implementation of slip effects leads to increment of coating thickness by 9 % and 9.2 % for the plane and exponential coaters, respectively. Furthermore, the blade load in the plane coater decreases by 71.3 %, and the exponential coater sees a reduction of 72.4 % in blade load, compared to the use of a Newtonian fluid. This investigation provides valuable insights into BC processes, with important implications for their industrial applications.