Hot Tinning Plating Production ProcessAuthor : hani Time : 2019/06/10
What is tinplate? How about the production process of hot tinning?
By hot dipping or electrolytic processing, the process of making the surface of cold rolled sheet firmly adhere to a layer of dissimilar metals is called plating process.
Tin-plated thin steel wrench is called tinplate, commonly known as tinplate.
Tin is one of the elements with strong chemical stability. Its relative atomic weight is l18.7 and density is 7.3g/cm3.
The melting point is 232 C. Tin is almost insoluble in dilute solutions of sulfuric acid, nitric acid, and hydrochloric acid. Its plasticity is better than steel, it is non-toxic and harmless to the human body.
Tin-plated sheets are mainly used in cans, food boxes, boxes, etc. Tin-plated rice is delivered in sheets or rolls.
Hot-dip and electroplating are two main production methods of tinplate. In hot-dip tin plating, the strip is hot-dipped on the surface of the strip through a molten tin bath. In tin plating, the strip steel is electroplated on the surface of the strip steel by the electrolytic method through an electrolytic cell.
The coating is thicker in hot-dip plating. The amount of tin plating per unit area is more than 25g/m2.
And the coating is not uniform. Usually, hot-dip tin plating is only used in single sheet or narrow band tin plating units with low speed and low productivity. The process flow of hot-dip tin plating is as follows:
Raw material, electrolytic pickling, high-pressure water washing, solvent treatment, hot tinning, oil treatment, alkali washing, oil removal, polishing, and finished product inspection
Hot-dip tin-plated base plate is first cleaned by white pickling, slight oxide film and oil stain on the surface, or electrolytic pickling in the hydrochloric acid tank to quickly remove oxide scale on the surface. The temperature of tin bath in the tin plating bath is 300-400 C. Before entering the tin trough, the original plate first passes through the flux through to remove the oxide film on the surface. The steel plate from the tin trough needs to pass through the palm oil trough (oil temperature 235-240 C) to prevent tin oxidation and maintain the melting state so that the excess tin can be extruded by the tin plating roll. Then the grease is washed by the washing machine and polished by the polishing machine, a tin plate with a smooth surface can be obtained.