Modeling of Infrared Drying of Polymer Solutions

This work presents the dynamic modeling of drying behavior of polymer solutions in an infrared-convective oven. Two study cases were considered for the drying process. The first one deals with the drying of a coated polymer solution on a fixed substrate while the second one includes drying of the same solution on a moving substrate in an infrared (IR) oven. Both models involve simultaneous heat and mass transfer equations that describe changes in the solvent concentration and the polymer temperature during the drying process. The set of partial differential equations (PDEs) arising from the mass and energy balances constitute a highly nonlinear system due to inter-dependence of the thermodynamic and transport properties of polymer solutions. The models were numerically solved and were validated using published experimental data. The models were employed to simulate the drying of a polyvinyl acetate coating (in toluene) on a polyester substrate. Results obtained from the derived model demonstrated the importance of parameters such as web velocity, heater temperature, and inlet air velocity in the IR drying process. In general, high temperature and air velocity cause rapid drying of the polymer coating, while high substrate velocity resulted in drying. This model can be applied on any industrial applications that include continuous IR drying process of polymer-coated layers to predict the drying behavior of the coated product.