Powder coating edge primer

摘要

Sheet molded compound articles which optionally can be in-mold coated have the edges and exterior margin surfaces thereof sealed with a water-free and solventless fine particle size powder coating. The coating thickness has a gradual and smooth transition from the sealed edge to the non powder coated exterior surface thereby eliminating the need for sanding. The desired method of application is by electrostatic spraying and the cured powder coating is free of pops. Application of the powder coating to the edge and margin portions of the sheet molded compound article includes heating at least the edges of the article near or above the cure temperature of a subsequently applied powder coating to degas the article, reducing the temperature of at least the edge and margin portions of the article to a temperature below the powder coating cure temperature, applying a fine size powder coating material to the edge and margin portion of the article and heating the applied powder coating to a temperature at or above the minimum cure temperature thereof.