Improvements in and relating to electrostatic powder coating.

摘要

An electrostatic powder coating gun splits a pressurized gas-powder mixture into a plurality of separate electrostatically charged spray streams (26) to achieve a high degree of directionality and reduce deflection. The powder particles in the mixture may be electrostatically charged while inside one or more chambers (22) in the gun (18), either by an applied DC electrostatic field or by friction. The flow paths traversed by the spray streams (26) may be arranged and/or oriented so as to advantageously powder coat a particular surface configuration, such as the inside of a container. Alternatively, electrostatic charging of powder particles may occur via a plurality of electrodes (34) located external to the gun, with at least one external electrode associated with each spray stream (26). To further reduce deflection, the mixture may be sprayed from the gun in a pulsed manner. Additionally, the electrostatic fields created by the external electrodes (34) may be pulsed between an "off" and "on" condition during spraying.