on the weld seam 12 or by maintaining the weld seam hot so that sticking of the particles 21 on the seam 12 takes place the spray nozzle 27 can be connected directly with the supply conduit 14 whereas the connection can be made in an arcuate portion 29 of the conduit 14 for interruption of the powder stream 28 a further conduit 30 is provided and opens into the arcuate portion 29 the conduit 30 can deflect by a fine air jet the particles 21 in the absence of a container or can body 4 through the conduit 14 toward the recess 15 the powder particles 21 thrown by the spray nozzle 27 on the weld seam and not adhering to the seam are aspirated into the recess or spray chamber 15 because of the low pressure in the latter and transported by suction through the conduit 18 to the processing device 8 for preventing accumulation of the particles 21 falling on the bottom of the recess 15 especially when additional air is blown through the conduit 30 a further suction opening 31 can be provided in the recess 15 fig5 shows the embodiment of fig4 from above the distance between the guide plates 25 substantially corresponds to the width of the powder strip to be produced on the container.