| 摘要 |
<p>A hollow object, consisting of a flat base with a rim, is suspended so the base is vertical, and is then sprayed with electrically-charged enamel powder. During spraying, a gas stream is directed onto the lowest inner part of the rim, and a second, local spraying operation is then used to coat the lowest part of the rim with powder. An auxiliary spraying operation may also be used to coat the inner surface of the highest part of the rim, but the latter is pref. coated during the main spraying operation. The pref. plant uses a conveyor for the vertical suspension of the objects, while they travel past nozzles spraying powder onto the base and the inner surface of the upper rim; another nozzle blows a gas stream onto the lowest inner part of the rim. The lowest part of the rim is then coated by yet another nozzle. Used for the electrostatic spraying of enamel powder, e.g. onto the lids of kitchen stoves. The influence of gravity normally prevents a uniform powder coating; the invention eliminates this problem.</p> |
