Optimization of coating film deposition when using an automated high throughput coating application unit

Optimization of coating film deposition using an automated combinatorial film deposition system was carried out using an experimental design approach. In this study, a D-optimal response surface design was used. Numerical factors (dispense volume, doctor blade speed, contact time between doctor blade. and coating materials) and categorical factors (doctor blade movement, pattern of drops, and number of drops for each patch) were used as input variables. The models obtained for dry film thickness difference for model coating formulations having two different viscosities (90 mPa.s and 220 mPa.s) were significant. Optimum combinations of these factors were used to minimize dry film thickness variation to 7.5 mu m and to 2.5 mu m for formulations with viscosity 90 mPa.s and 220 mPa.s, respectively, and for both formulations the coatings obtained were acceptable with respect to length and width. (C) 2006 Elsevier B.V. All rights reserved.