GB561670A - Improvements relating to the production of chemical coatings on ferrous surfaces - Google Patents

Abstract

561,670. Coating ferrous metal. PYRENE CO., Ltd., (Parker Rust-Proof Co.). Aug. 11, 1942, No. 12667/43. Divided out of 561,504. [Class 82 (ii)] In the production of a corrosion-resistant and paint-holding coating on a ferrous surface by the chemical reaction of a coating solution applied by spraying, immersion of the surface in the solution or causing the solution to flow over the surface, the coating action is accelerated by the action of rollers having yielding surfaces which move in contact with, and at the same surface speed as, the surface to be coated, some of the rollers being positively driven so that they convey the sheet forward as well as accelerating the coating, the rollers pressing their solution into contact with the surface to be coated without exerting any scrubbing action. The sheets 1, fed by conveyer rollers 2, enter a chamber 3 containing pairs of rubber-covered rollers 4 which grip both sides of the sheets and convey them forwards and while the sheets are in this chamber they are sprayed with water from nozzles 7 in transverse pipes 15 and fed from pipes 5, 6. The sheets emerge on to conveyer rollers 11 and are carried into a chamber 12 where they are sprayed with a phosphate solution from nozzles 13 and are engaged by rubber-covered rollers 14 arranged singly or in pairs, there being thirty pairs of rolls and thirty single rollers. The nozzles are fixed to transverse pipes 16 arranged in groups of ten pipes each fed by a header 17 through a pipe 23, fed by a pipe 18 through a pump 21 from a tank 19. The solution runs off the sheets on to inclined parts 24 of the chamber 12 or on to a hood 25 and thence into troughs 26 from which it overflows into a V-shaped settling chamber 27. Sludge is removed from the chamber by a pump 29. The coated sheets pass through a chamber 32 where they are washed by water from nozzles 35 and thence into a chamber 41 where they are sprayed with dilute chromic acid by nozzle 43. Other coating solutions, e.g. those described in Specification 362,956, may be used. Specifications 346,401 and 386,739** are also referred to.