DRYING MECHANISM OF COATED FILM OF POLYMER SOLUTION

Abstract

Drying of coated film of polyvinylalcohol (PVA) aqueous solution is studied theoretically and experimentally, focusing on the diffusion process of water and the volumetric shrinkage of film occurring by evaporation of water. The diffusion coefficients were measured over the whole range of concentration by three methods, and drying experiments of coated films using hot air were performed. Numerical solutions were obtained from a set of transport equations for water using the observed diffusion coefficients and were compared with the experimental results.