Abstract: A powder spray apparatus and method for operating it comprise a spray booth having a floor. A spray gun is associated with the spray for directing a spray of powder of a particular color toward a workpiece. Overspray is redirected by limiting exhaust air from the flowing into an air-entrained powder separation system. An inlet to the separation system includes a sump for capturing powder from the floor of the spray booth when the floor is cleaned during a color changeover. The powder deposited in the sump is recirculated to a powder reservoir for later reuse.

Abstract: Apparatus for electrostatic spray painting having a painting chamber to which is connected a spray gun fed by a paint powder delivery system. A powder supply provides a high potential across the painting chamber and the spray gun to develop an electrostatic field to pull the paint powder ejected by the spray gun toward a workpiece positioned within the paint chamber. A humidity sensor is located in proximity with the paint powder delivery system for detection of an amount of moisture. A humidity signal is produced in response to the sensed humidity. A remote computer may be connected to receive a plurality of process condition signals including the humidity signal and to provide a display indicative thereof.