| 摘要 |
<p>In order to apply a strip-shaped powder layer onto the inside of a can body to cover a welding seam of the can body in a controlled manner, the can body is moved in a predetermined direction over a spraying head transporting the powder, due to the kinetic energy imparted thereto by a moving air current, to an elongated opening of the spraying head. This elongated opening flow communicates with a spray chamber of the spraying head and is located opposite the welding seam of the can body. While the can body moves past the spraying head there is formed a strip-shaped powder layer at the welding seam without any cloud formation of the powder in the spray chamber. Advantageously, a vacuum action is applied immediately adjacent the outlet opening where the powder conveyed by the moving air current is introduced as a bundled powder jet into the spray chamber of the spraying head, so that the bundled powder jet entering this spray chamber is retained in its jet-like configuration through removal of the air current serving as carrier air for the powder particles. In this way, the powder particles are not deflected out of their intended flight path or trajectory towards the welding seam.</p> |
