Manufacturing Process

Tinplate is produced from low-carbon cold-rolled steel. The substrate is cleaned electrolytically, pickled, and electroplated in an acidic tin bath (fluoborate or stannous sulfate) at current densities of 10–40 A/dm². Tin coating weight is controlled by the current and line speed (0.5–11.2 g/m²). The strip is then reflowed by induction heating above 232°C to brighten the surface. This is followed by passivation (chromate or cathodic dichromate) and oiling. For DR (Double Reduced) material, an additional cold rolling pass (15–30% reduction) is applied after annealing to increase strength.