OPTIMIZATION OF SINGLE-ZONE DRYING OF POLYMER SOLUTION COATINGS TO AVOID BLISTER DEFECTS

ABSTRACT

The optimal conditions for drying polymer-solvent coatings result from a trade-off between minimizing the residual solvent level and creating defects. Blistering defects can be caused by boiling the solvent within the coating. In this paper, we use a detailed drying model with automated constrained optimization to find optimal drying conditions for prototypical coatings that minimize the residual solvent without blistering the coating. The drying oven is assumed to have a single zone with fixed residence time. The optimal drying conditions include the oven air temperature and substrate-side and coating-side heat transfer coefficients The latter are constrained to physically reasonable values. According to our results, the optimal coating-side heat transfer coefficient is always equal to or greater than the optimal substrate-side heat transfer coefficient.