Conventional drying usually involves the evaporation of water from a solid particulate material such as paper fibers, wet sand, etc. In this process, the first stage of the drying involves evaporation of water from the interstitial spaces between the particulate material. The final stages of drying can involve the removal of water dissolved in the solid or trapped in the particles.

In contrast to conventional drying, drying related to polymers usually refers to the removal of a solvent from a homogeneous polymer solution in which the polymer is dissolved or molecularly distributed in the solvent. This type of drying is associated with the production of polymer films and coatings as well as non-latex based paint. In some ways, the production of films and coatings from latex polymers follows the mechanisms associated with conventional particulate drying. In recent years, there has been a significant shift from the production of polymeric coatings and polymers from the use of polymer solutions to the utilization of latex polymers. This change has been driven by environmental concerns related to non-aqueous solvents.

The Center has developed several models to describe the drying of polymer solutions to produce coatings and films. These models involve the complex coupling of molecular diffusion in the polymer with mass transfer in the vapor phase above the solution as well as heat transfer to the solution from the surroundings. These models are numerical solutions of the basic partial differential equations, which can then be used to predict concentration and temperature as a function of position and time in the coatings or films. Complexities such as the change in the dimension of the film as well as the interaction of several solvents as well as several layers of different polymers have been investigated. These models have been particularly useful to the industrial Partners of the Center for the analysis of the production of films and coatings in conventional convection drying ovens as well as the newly developed gap dryer.

In addition to the models, the Center has developed experimental techniques to measure the needed mass transfer and thermodynamic information to model drying processes. The Center has also conducted research on the reduction of defects in polymer coatings and films produced through such drying operations.