Slot coating flows of non-colloidal particle suspensions

Slot coating is used in the manufacturing of functional films, which rely on specific particle microstructure to achieve the desired performance. Final structure on the coated film is strongly dependent on the suspension flow during the deposition of the coating liquid and on the subsequent drying process. Fundamental understanding on how particles are distributed in the coated layer enables optimization of the process and quality of the produced films. The complex coating flow leads to shear-induced particle migration and non-uniform particle distribution. We study slot coating flow of non-colloidal suspensions by solving the mass and momentum conservation equations coupled with a particle transport equation using the Galerkin/Finite element method. The results show that particle distribution in the coating bead and in the coated layer is non-uniform and is strongly dependent on the imposed flow rate (wet thickness). (c) 2016 American Institute of Chemical Engineers AIChE J, 63: 1122-1131, 2017