Fluidised bed for electrostatic coating - coats earthed workpiece immersed in fluidised powder using low voltage electrodes

摘要

The fluidised bed for electrostatic workpiece coating, reduces coating time and danger of ignition of the fluidised coating powder is eliminated. Relatively low voltages and high powder concentrations can be used. The earthed workpiece (6) is immersed in the fluidised layer (5) itself, which accommodates also the charging and the opposite electrodes (7). The electrically charged powder particles are deposited on the workpiece. The opposite electrodes ensure constant charging of the powder particles independently of the workpiece (6) within the fluidised layer. The voltage on the electrodes is disconnected or reduced to a low, non dangerous value before immersion of the workpiece and for the duration of coating.