| 摘要 |
Processes for coating metal or polymeric substrates are provided which inclu de the steps of: (a) applying a liquid basecoating composition to a surface of the substrate; (b) exposing the basecoating composition to air having a temperature ranging from about 10~C to about 50 ~C for a period of at least about 5 minutes to volatilize at least a portion of volatile material from t he liquid basecoating composition, the velocity of the air at a surface of the basecoating composition being less than about 0.5 meters per second; (c) applying infrared radiation and hot air simultaneously to the basecoating composition for a period of at least about 2 minutes, the velocity of the ai r at the surface of the basecoating composition being less than about 4 meters per second, the temperature of the metal substrate being increased at a rate ranging from about 0.4 ~C per second to about 1.2 ~C per second to achieve a peak substrate temperature ranging from about 120 ~C to about 165 ~C, such that a dried basecoat is formed upon the surface of the substrate; and (d) applying a powder topcoating composition over the dried basecoat.
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