What are the tin plating processes?

Tin coating has good stability, strong corrosion resistance and discoloration resistance, non-toxic, soft and good weldability and ductility, so it is widely used in industry. Tin plating on iron and steel products is a cathode coating, which can resist most forms of corrosion only when the coating is basically non-porous. However, under sealed conditions, the tiny tin layer can play a very good protective role, and the products generated with organic matter are non-toxic, so tin plating is often used in steel strip production and can-making industry. Hot dip plating process is often used in early tin plating, which consumes a lot of energy, and it is not only difficult to obtain uniform and flat coating, but also easy to waste tin. Basic tin plating, neutral tin plating and acid tin plating have been successfully studied and applied to production practice steadily. Sodium hydroxide and potassium hydroxide are usually used as complexing agents in alkaline tin plating solution. Since the 1940s, alkaline tin plating solution has replaced almost all the older tin plating processes. With the in-depth research and development of additives, especially the extensive use of decorative tin particles, tin plating with acidic stannous sulfate has made great progress. Adding antioxidants and other additives to simple sulfuric acid and stannous sulfate solution can obtain a matte or bright coating with good quality. Although fluoborate tin plating process has advantages, it is not recommended for environmental protection. In addition, in order to obtain a well-bonded tin coating on lead-based or zinc-based substrates, neutral tin plating electrolyte was used and developed.