Spin and Spray Coating

August 10, 2005

l Patent No. U.S. 6,352,747 B1
PPG Industries, Cleveland, OH, has been granted a patent for a process for coating a surface on a spinning substrate wherein a liquid coating material is dispensed onto the surface of the spinning substrate through a dispenser radially from the center to the edge or from the edge to center above the surface. After application of the coating material, the coating is cured. The improvement comprises: dispensing the liquid coating through a nozzle in the dispenser onto the substrate, wherein said substrate to be coated has a curved surface having a base curvature other than zero, to produce a circular spray pattern of dispensed liquid having an outside diameter of up to 1.2” while maintaining the dispenser nozzle at a constant distance from 0.3” to 0.6” from the curved surface of the substrate for the entire distance from the center to the edge or from the edge to the center of the curved surface of the substrate, thereby reducing the amount of coating material used.