Rohm and Haas Company

Morton International, Inc.

Grant E Schlegel

Paul R Horinka

Gregory R Mill

Andrew T Daly

Joseph J Kozlowski

Michael Louis Spera

Carryll A Seelig

Gordon L Tullos

Todd M Bender

John R Petro

A method of providing a powder coating to MDF substrate panels wherein, by the differential treatment of the front and back surfaces of these panels, both surfaces can be coated at the same time and the effects of moisture and other volatile outgassing is controlled in such a way as to provide a blemish-free front facing surface with a minimal, but nonetheless acceptable, amount of blemishes on the opposite or back surface. Differential treatment is achieved by preparing each surface using different grades of sand-paper, applying different amounts of curing energy, whether infra-red or thermal, or by applying different thicknesses of coating to each surface.

Differential processing of powder coated substrates

The present invention provides smooth and even ultraviolet (UV) cured powder coatings for wood comprising one, two or three layers of one or more waterborne stains, or clear or tinted waterborne basecoat coatings and one or more topcoat layers of clear or tinted clear powder coatings made from one or more than one free radical UV curing resin, one or more than one photoinitiator, and one or more than one post-blend dry flow additive, such as fumed alumina. The coatings of the present invention have a natural wood appearance, are foam free and fully coat substrates at powder coating thicknesses ranging from 0.5 mil (12.7 &#x3bc;m) to 2.0 mil (50.8 &#x3bc;m). Accordingly, the coatings will fully and evenly coat uneven, beveled and/or routered substrate surfaces, including open grain natural wood substrates, such as oak. In addition, the present invention provides a method for making coatings comprising applying one or more waterborne stain to the wood to form a stain layer, drying or curing the said stain layer, sanding or grinding to de-nibb the said stain layer, applying clear or tinted UV curing coating powder to the stained substrate, flowing out the applied coating powder to form a continuous film, and UV curing the film formed from the powder.

Ultraviolet radiation cured powder coatings for stained wood

Machine-profiled edges and corners and other surface discontinuities of heat sensitive workpieces such as wooden cabinet doors are uniformly covered by a coating powder applied electrostatically to the back side of the workpiece first, allowing the powder to wrap around the edges toward the front side, and then applying the coating powder electrostatically to the front side and fusing or fusing/curing the coating powder.

Process for coating cabinet doors

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Macungie, PA, United States of America

Grant E Schlegel