Flexible blade coating

Flexible blades are often employed to spread liquid coating thinly onto a flat smooth substrate. In this study, we derive a fifth-order nonlinear ordinary differential equation for the thickness of a Newtonian coating and for the corresponding blade deflection. After solving this equation numerically, a graph is produced to help engineers predict the coating thickness. We find that blade deflection and coating thickness are governed by the blade angle and by a new dimensionless group called the blade flexibility. For values of blade flexibility less than one, the coating thickness matches that of a rigid blade. The results of this analysis provide an engineer with the ability to design a flexible blade configuration to deliver the desired coating thickness onto a substrate.