GB237328A - Improvements in or relating to the manufacture of tin-plate - Google Patents

Abstract

237,328. Harris, G. M. April 17, 1924. Pickling; tinning.-In a process for the manufacture of tin plate the plates are black annealed, black pickled, and swilled, the plates then being dried in such a manner that they do not reach a temperature substantially exceeding 100‹ C.; the dried plates are then passed to the cold rolling plant, then prepared for tinning, and finally tinned. The black annealing follows directly the hot-rolling, shearing, and opening. The annealed plates are fed one at a time from a table A by a sucker C to an inclined guide D, whence they slide into the pickling vat E containing sulphuric acid. The plates are then fed by rubber-covered rollers G to a water bath K, being swilled by sprays H to remove the acid, and are delivered by further rolls G to the drying rollers L, covered with a thick layer l of porous absorbent material such as felt, the interiors of the rolls being steam heated, so that the absorbed moisture is driven off from the felt, which on further rotation of the rollers is re-applied to fresh plate surfaces. The dried plates are then fed by rolls M on to the conveyer N and conveyed to the tinning apparatus. The bath K may contain a solvent such as potassium bichromate, which precipitates colloidal ferric hydroxide. According to the first Provisional Specification, the plates are dried by passing them through tanks, the bottoms and sides of which are heated by superheated steam, oil, or other medium. Air heated to about 100‹ C. may also be blown into the tanks. Specifications 5649/82, 4732/00, and 13703/14 are referred to.