Abstract:
An apparatus for electrostatically coating an object using electrostatically charged powder grains. The invention improves upon the spray bell sprayer by having a fixed hollow shaft providing a central supply line for the powder grains, the spray bell rotates about the hollow shaft and a plurality of compressed air nozzles pass radially into the hollow shaft.
Abstract:
The invention relates to a process and an apparatus for applying two or more colors of paint by applying a first paint to at least part of a substrate, followed by a second and, if desired, further different-colored paints to different parts of the substrate and hardening the applied coats of paint by baking, which comprises applying the second and if desired the further different-colored paints without interim baking of the first paint to the preselected different parts of the substrate using electrostatic atomization at stationary atomizer edges involving transport of the paint particles in an electric field and, after the first and subsequent paints have been applied, hardening all coats of paint together by baking.
Abstract:
Objects are coated using electrostatically charged powder grains by feeding an air-powder mixture to a spray bell, fanning out the flow of the air-powder mixture and centrifuging the powder particles off the spray head. The powder particles are conveyed onto the object to be treated by applying an electric field between the spray bell and the object. A fluidized flow of powder, that is, a flowable mixture of air and powder, is supplied at low speed to the spray bell, accelerated minimally when passing into the rotating bell, then accelerated by the bell to 500 to 6000 rpm, transported to the rim of the bell and there centrifuged off.
Abstract:
Process for electrostatically coating objects with a fluid, for instance liquid paint, by applying a high voltage to a spray bell and by feeding the fluid to a revolving, driven spray bell. The flow-rate of the fluid supplied to the center of the spray bell is decelerated nearly to zero when it enters the bell, then the rate of the fluid is increased by being accelerated by the bell to 15,000 to 60,000 rpm, and the fluid thereupon is centrifuged off the spray rim of the bell and is guided to the object to be coated.