High-speed powder coating without spray guns using UV/EB technology

Presently, the traditional market of electrostatic powder coatings is growing only slowly. New promising applications for powder coatings with a big market potential are high-speed processes with velocities above 2 m/s combined with compact coating and curing systems, for example for the coating of wood-based materials. New surface qualities and the possibility to integrate these techniques into fast production flows can be expected. The existing powder coating techniques cannot meet these demands. This paper presents a new high-speed powder coating technique which works without spray guns. By this new method, coatings with uniform film thickness may be applied with at the same time high transfer efficiency, low contamination and robust powder recovery. The demands for high process speeds with melting and cross linking times of only a few seconds can especially be met by using radiation melting and curing processes like, e.g., IR, UV or EB techniques. An additional advantage of UV/EB-curing is the low thermal load on the workpieces during melting and curing.