Tinplate, also known as tinplate, refers to the quality of low-carbon steel plate coated with a layer of tin metal materials, the thickness is generally 0.1 ~ 0.4mm. In practice, a wide range of applications, can be made into a variety of different types of food, beverage canned category, daily cosmetics category, medicine and various packaging containers.
Tinplate according to its tin plating process can be divided into two types, namely hot dip tinplate and electrolytic tinplate. Hot-dip tinplate is made by tin-coating process, and its application is limited. Electroplating tinplate also known as cold plating tinplate, the use of electroplating process in the steel substrate evenly plated tin film. Electroplated tinplate mainly alkaline electrolysis, sulfate electrolysis, halogen plating and borofluoride electroplating method and several other types.
According to the different thickness of the front and back of the thin steel plate, the tinplate can be divided into two types: the thick tin and the thick tin. Equal thickness tin is the same as the front and back of the thin steel plate, while the difference between the front and the back of the tin plating is different. Taking into account the printing surface with a thick coating of the protective layer, you can use the thin side of the tin surface for the printing surface, rather than the printed surface with a thick tin layer. This can save a lot of expensive tin. Some countries simply do not tin, or even both sides are not tin, both sides with paint to replace the tin layer. But the coating process requires a higher, must have a good anti-rust protection, otherwise it will affect the appearance of the container quality.
Under normal circumstances, the surface of the tinplate coated with a layer of cottonseed oil or dioctyl phenate, the purpose is to prevent the sheet in the storage process of rust and transport friction. At present, the domestic production of tinplate dioxin dioctyl ether, oil content that is: Q said clean, low oil content; Z said recoating, that is, high oil. In order to control the degree of surface oxidation, improve the carbonization capacity, to prevent surface discoloration and affect the printing color effect, after tinning to passivation treatment. Passivation of sodium carbonate cathode treatment, sodium dichromate impregnation passivation, chromic acid impregnation passivation, sodium dichromate cathode passivation, etc., code were 411,100,300,311,314. The larger the number, the greater the amount of electricity, the higher the surface chromium content.
At present, the domestic use of tinplate printing materials, for many high-grade printing materials imported materials, according to the Japanese industrial standards (JISG 3303), the type of steel and chemical composition and tinplate tin in the amount of attachment.
Due to the type of steel, with its different performance. Because of the corrosion resistance of MR steel plate is good, it is generally used for food packaging containers. If the corrosion resistance requirements higher, the choice of MC steel plate.