Tinplate (commonly known as tinplate) refers to a steel plate with a thin layer of metal tin on the surface. Tinplate is made by rolling low carbon steel into a steel plate about 2mm thick, pickling, cold rolling, electrolytic cleaning annealing, flattening, trimming, and then cleaning, electroplating, soft melting, passivation treatment, oiling and shearing into a tinplate plate product. The tin used for tinplate is high-purity tin (Sn>99.8%). The tin layer can also be applied by hot dip plating. The tin layer of the tinplate obtained by this method is thicker, the amount of tin is large, and no purification treatment is required after tin plating.

Tinplate has the advantages of being odorless, non-toxic, light in weight, and easy to process and shape. Printing different patterns can also beautify the product, so it has been widely used in the food canning industry, electronic devices, chemical paint and other industries. In the production process of tinplate, after the strip steel is tinned and reflowed, in order to prevent the tin layer from oxidizing and yellowing during storage or coating baking, and to improve the tinplate's anti-sulfur properties, the tinplate must be passivated.

PRODUCTION PROCESS

The tinplate consists of five parts, from the inside to the outside, the steel substrate, the tin-iron alloy layer, the tin layer, the oxide film and the oil film.

The production process of tinplate mainly includes electroplating tin, reflowing, cathode passivation and oiling. The electroplating tin process deposits a layer of metallic tin on the cold-rolled plate. The reflowing process forms a very thin tin-iron alloy layer between the cold-rolled substrate and the pure tin layer. The cathode passivation treatment and the oiling process form a passivation film and an oil film respectively.