ELECTRODEPOSITION COATING APPARATUS

An apparatus used in the electrodeposition coating of a continuous sheet of metal as it travels in a horizontal pathway between a pair of electrically charged electrodes and through a bath of liquid coating solution that is continuously circulated to the bath through a pair of liquid seals which are disposed adjacent opposing, aligned openings through which the sheet of metal enters and exits a chamber containing the bath. The liquid seals are each comprised of a pair of nozzles for directing converging streams of liquid coating solution against the traveling sheet of metal in the direction of the chamber and have a three-fold purpose. They are designed to, (I) prevent the escape of liquid coating solution from the chamber through the openings, (II) provide a liquid support for the sheet of metal at the openings in the opposing end walls of the chamber, and (III) direct fresh liquid coating solution along the sheet of metal into the critical area or space between the electrodes to maintain and keep uniform in this area, the concentration of the liquid coating solution that becomes diluted as the coating material of the solution adheres to the sheet of metal during its travel between the electrodes. A pair of blow off nozzles are supplied adjacent and outside each of the liquid seals to direct air, under pressure, angularly against the sheet of metal in the direction of the chamber to aid in the prevention of the escape of liquid coating solution from the apparatus, to provide an additional fluid bed for supporting the sheet of metal and to minimize and control the thin film of liquid coating material which adheres by surface tension to the sheet of metal.