DEVICE FOR POWDER COATING FOR THREE-PIECE CANS

摘要

L-2003 An apparatus for coating the inside of tubular members, more specifically can bodies, which are open at opposite ends. The apparatus includes a supply tube and a return tube which are spaced apart to have received therebetween the tubular member to be coated. In each of the supply tube and the return tube there is positioned a corona electrode, the corona electrodes being in alignment wherein powder supplied to the interior of the tubular member is both initially charged as it passes through the supply tube and is further charged within the tubular member by an electrical field which exists between the two corona electrodes and the tubular member. Powder is supplied to the supply tube through a small diameter passage as compared to the diameter of the supply tube and there is provided a diverter which effects radially outward flow of incoming powder so that the powder is concentrated substantially adjacent the inner surface of the supply tube so that the powder delivered to the tubular member flows substantially entirely along the inner surface of the tubular member. The apparatus permits the provision of a thin coating on the tubular member which is uniform in thickness at opposite ends thereof.