GB591877A - Electroplating apparatus - Google Patents

Abstract

591,877. Electroplating - apparatus; electrodeposition of tin. IMPERIAL CHEMICAL INDUSTRIES, Ltd. March 30, 1945, No. 8074. Convention date, March 30, 1944. [Class 41] Metal strip to be plated is passed across the top of a tank and between a pair of rolls 6, 7 at the exit end, a resilient sealing member 10 being provided between the tank and the lower roll to minimize loss of solution. The sides of the tank are extended to at least the height of the top of the strip. Escaped solution is caught in a tray and returned by pump to the tank. The anodes 3 of the metal to be deposited are supported on conducting supports 2 beneath the strip. The upper roller 6 is of metal and forms the current connection to the strip. The bottom roll is of some material resistant to the electrolyte, e.g. rubber. Similar rolls 4, 5 with sealing member may be provided at the entrance end. In the apparatus shown, two plating units are separated by an intermediate chamber 21 provided with driving rolls 22 and 23. The guide rolls 4, 5 ; 6, 7 are driven by some means not sufficiently positive to cause slipping on the strip. The walls 24 and 25 shield the roll 23 from the plating effects and slow down the motion of the solution. Alternatively, a succession of tanks may be provided with external driving rolls. By providing the upper rolls 4, 6 also with sealing members, the electrolyte level may be raised above the strip and both sides may be plated at once, upper anodes also being provided in this case. A stannous-chloride, sodium fluoride bath of pH about 3 may be employed for tin plating.