GB734364A - Improvements in or relating to the production of metal strip - Google Patents

Abstract

734,364. Coating with metals. BRENNAN, J. B. Dec. 29, 1952, No. 32851/52. Class 82 (2). [Also in Group XXII] A method of forming a metal strip comprises directing, e.g. spraying, a stream of metallic particles towards a pair of converging moving surfaces, e.g. rolls, and towards a bite between such surfaces so that the particles coated on the moving surfaces are pressed together in the bite to produce a coherent metal strip. A pair of rolls 11, 12 are positioned in an opening 13 on one wall of a chamber 10 and sealing means, e.g. rubber strip, around the opening 13 seal the rolls in the opening. Cooling fluid may be introduced into the rolls via their shafts. A nozzle 18 for spraying plastic metal particles P, e.g. of bronze, steel or aluminium, towards the roll bite is mounted in the chamber 10 and scraper knives 21 bear on the rear surfaces of the rolls to remove the deposited metal particles. An electro-conductive heating coil 29 heats the particles to the required plasticity. To prevent the metal particles from adhering to the rolls the roll surfaces are chromium-plated or graphite coated or the rolls may be formed of graphite. Sizing rolls 22 and 23 are positioned adjacent the scrapers for compacting and sizing the strip. Spray nozzles 24 and 25 cool the strip 19 and a further pair of rolls 26, 27 size and pass the strip to an annealing chamber 28. In a modification, metal particles Z fall from a hopper 31 through an induction coil 32 on to converging driven rolls 35 and 36 which press the plastic particles together to form a metal sheet 37. In another modification a pair of anodized aluminium bands 41 and 42 are led around rolls 43 and 44 and metal particles Y are sprayed on to the converging bands from a nozzle 45. Guide-plates 46, 47 limit the size of the sheet formed between the bands. A laminated composite strip may be formed by passing a band of steel, aluminium, paper, asbestos or other fibrous material around one of the rolls, heating the outer surface of the band by an electric coil, cooling the inner portion of the band by a cooling shoe and spraying metallic particles on to the heated portion of the band. When using paper or other fibrous material the band must be cooled immediately after depositing the plastic metal particles. The porous metal strips may be used for electrodes for electrolytic devices, e.g. condensers and for bushings or bearings or transformer laminations. To aid in starting the formation of the strip a " bait " is inserted between the rolls and the metal particles are first deposited on the " bait " as it is drawn from the rolls. Specification 548,023, [Group III], is referred to.