Patent ID: 6579575
Filing Date: 2003-06-17
Classification: B05D,F26B

Abstract:
A process for coating a metal substrate, comprising the steps of:(a) applying a liquid basecoating composition to a surface of the metal substrate; (b) applying a first infrared radiation at a power density of 30 kilowatts per meter squared or less and a first air simultaneously to the basecoating composition for a first period of about 30 seconds or more, a first velocity of the air at the surface of the basecoating composition being about 4 meters per second or less, a first temperature of the metal substrate being increased at a first rate ranging from about 0.05Â° C. per second to about 0.3Â° C. per second to achieve a first peak metal temperature ranging from about 30Â° C. to about 60Â° C., such that a pre-dried basecoat is formed upon the surface of the metal substrate; (c) applying a second infrared radiation and a second air simultaneously to the basecoating composition for a second period of about 15 seconds or more, a second velocity of the air at the surface of the basecoating composition being about 4 meters per second or less, a second temperature of the metal substrate being increased at a second rate ranging from about 0.4Â° C. per second to about 1.2Â° C. per second to achieve a second peak metal temperature of the substrate ranging from about 60Â° C. to about 80Â° C., such that a dried basecoat is formed upon the surface of the metal substrate; and (d) applying a powder topcoating composition over the dried basecoat.