Patent ID: 7384671
Filing Date: 2008-06-10
Classification: B05C,B05D,Y10T

Abstract:
1. An apparatus for performing a process for forming a coating on a substrate, including: a fluidising chamber for establishing a fluidised-bed comprising a fluidising gas and a powder coating composition, thereby effecting tribostatic charging of the powder coating composition, means for immersing the substrate wholly or partly in the fluidised bed, whereby tribostatically charged particles of the powder coating composition adhere to the substrate, the substrate being either electrically isolated or earthed, an electrically conductive electrode, to which a voltage is applied, positioned to influence the extent to which charged particles adhere to a region of the substrate, means for applying the voltage to the electrode, means for withdrawing the substrate from the fluidised-bed and means for forming the adherent particles into a continuous coating over at least part of the substrate, the apparatus being arranged such that the maximum potential gradient existing in the fluidised bed is below the ionisation potential of the fluidising gas.