Effects of drying conditions on the solvent diffusion process during coated fabrics curing

Fabric is a porous fiber material; it is not an impermeable substrate. To study the diffusion mechanism of polymethyl methacrylate (PMMA)/acetone coated glass fiber fabric solvent during curing, a drying model for the coated fabric was proposed based on the heat transfer equation, Fick diffusion equation and the coating solution volume with time relationship equation. This drying model was verified by confocal Raman spectroscopy. The impact of solvent mass fraction, drying temperature and air speed on solvent diffusion during curing was studied using the model. It was shown that the predicted solvent concentrations derived from the model were consistent with the experimental values. This model can be used to quantitatively calculate the solvent concentration at any position and at any time inside the coating film during the drying process. Moreover, it can also predict the curing time and residual solvent concentration required for the coating material to reach drying equilibrium. The fitting equations for solvent concentration, drying temperature, air speed and equilibrium drying time were obtained, which can provide a theoretical guidance for the optimized preparation, performance research and drying conditions of PMMA coated textile materials. The model can also be used for other coating formulations and fabrics, by simply changing the material parameters and geometric dimensions of both the coating solution and fabric.