positioned between end walls 146 148 end wall 146 includes an inlet 150 for receiving a workpiece 152 such as a continuous strand or wire substrate an outlet 154 is provided in end wall 148 respective vortex generators 156 158 are connected proximate inlet and outlet 150 154 specifically vortex generator 156 comprises inner and outer tubes 160 162 mounted around inlet 150 a pressurized air inlet 164 communicates with an annular space 166 between inner and outer tubes 160 162 pressurized air inlet 164 is preferably connected in a generally tangential manner to outer tube 162 to promote an annular or swirling type of flow pattern within space 166 likewise vortex generator 158 at outlet 154 comprises inner and outer concentric tubes 168 170 mounted around outlet 154 a pressurized air inlet 172 communicates with an annular space 174 located between inner and outer tubes 168 170 and is again connected in a manner which induces a generally circular or swirling flow pattern around annular space 174 preferably this circular flow pattern is induced in the same direction within each vortex generator 156 158 and exits vortex generators 156 158 within coating area 144 while continuing to move in a generally swirling path as indicated schematically by arrows 176 preferably a powder fluidizing bed 180 is provided for producing a cloud of electrostatically charged powder which then follows the swirling flow path 176 and swirls around workpiece 152 while generally being drawn or electrostatically attracted to workpiece 152 and thereby coating the same powder fluidizing bed 180 more specifically comprises a bed of powder 182 that may be continuously or intermittently supplied by a conduit 186.