GB368727A - Process and apparatus for electroplating - Google Patents

Abstract

368,727. Electrodeposition of metals. CELLULOID CORPORATION, 290, Ferry Street, Newark, New Jersey, U.S.A. Oct. 9, 1930, No. 30314. Convention date, Oct 9, 1929. [Class 41.] In the electrodeposition of metals on articles by successive passages through or immersions in a plating bath, electrolyte is applied to the articles while out of the bath to prevent stratification of the deposits. The invention is particularly applicable to the plating of large drums and endless belts used in casting films of cellulose derivatives. In the apparatus shown in the Figure, the belt 13 to be plated passes over pulleys 2, 3 and a centrally-disposed upper pulley, not shown, above which is situated a sprinkler to which electrolyte is pumped from the vat. The upper pulley is adjustable. The belt 13 is guided within the bath by side members depending from a sheet 15 above the belt. The lower surface of the belt is polished by reciprocating brushes 21. Electric contact to the belt is made by brushes 45. Anode rods of 49 are mounted in notched supports 47 and are connected to a bus-bar 50. The belt is further polished by a rotary brush 38, the bristles of which are arranged in spiral form, so as to prevent formation of scratch lines. The brushes 21 may also be provided with staggered bristles for this purpose. The electrolyte is circulated to and from the vat past baffles 70, 74. Scum is removed by a pipe 53. The speed of the belt should be such that the interval between successive immersions is not more than one minute. The pulleys are flanged and may be provided with circumferential flutings ; they may be covered with hard rubber, cellulosic material or a phenol-aldehyde resin. In a modification, the vat slopes upwardly on each side from the centre where a third pulley is provided. In another modification the belt passes at the bottom round a single large pulley mounted in a vat of semicircular section. The pulley may be provided with blocks, shims, or an adjustable rim. The plating metal may be nickel or copper or both metals in succession. A belt may be made wholly by electrodeposition the cathode being prepared to facilitate removal of the deposit.