Patent ID: 8758863

Claim:
A method for coating a substrate with a deposition material comprising a powder, comprising the steps of: (a) applying a pre-deposition treatment to the deposition material, wherein said applying a pre-deposition treatment step comprises a step of de-agglomerating the deposition material; (b) directing the deposition material onto the substrate by means of electrostatic charging, wherein the deposition material is directed into a flow path of a nozzle of an electrostatic charging unit through a plurality of powder inlets positioned around the flow path of the nozzle, at least one powder inlet forming an acute angle with the flow path of the nozzle, wherein main feed air is directed into the flow path of a nozzle of the electrostatic charging unit through a booster air inlet positioned in the flow path at a position that is upstream of the position in the flow path of the plurality of powder inlets, and wherein additional air is directed tangentially into the nozzle through a plurality of vortex inlets downstream of the position in the flow path of the plurality of powder inlets, each vortex inlet connecting at a tangential angle to the nozzle, whereby a vortex is created within the nozzle by air entering the nozzle through the plurality of vortex inlets; and (c) applying a sintering treatment to the substrate whereby the deposition material is adhered to the substrate.