The general principle of producing anodic oxide film of anodized aluminum plate is to take the aluminum plate as the anode, place it in the electrolyte solution, and make use of the electrolytic effect to make its appearance cause the process of alumina film.

The selection of electrolyte in Changshu oxidation plant mainly depends on the different requirements of oxide film application. For example, for the thick film with the intention of decoration, wear resistance and corrosion resistance, the selected electrolyte shall have a slightly soluble effect on the oxide film. In order to obtain a thin and fine oxide film, the electrolyte that is almost insoluble in the oxide film is selected. The commonly used anodizing electrolytes in industry include sulfuric acid, oxalic acid, chromic acid and some sulfonic organic acids.

The anodizing manufacturing methods of aluminum plate in Changshu oxidation plant are complicated. According to the current mode, they are divided into DC anodizing, AC anodizing, and pulse current anodizing, which can shorten the production time to reach the required thickness, the film is thick, uniform and fine, and the corrosion resistance is significantly improved; According to the electrolyte, there are: sulfuric acid, single acid, chromic acid, mixed acid and natural coloring anodizing with sulfonic organic acid as the main solution; According to the properties of the film, it can be divided into: general film, hard film (thick film), porcelain film, bright polishing layer, barrier layer of semiconductor effect and other anodic oxidation.

Among many anodizing methods in Changshu oxidation plant, DC sulfuric acid anodizing method is the most widely used, because it has the anodizing treatment suitable for aluminum and most aluminum alloys; The film is thick, hard and wear-resistant, and better corrosion resistance can be obtained after sealing the hole; The film is colorless, transparent, strong adsorption capacity and easy to color; Low processing voltage and low power consumption; The processing process does not need to change the voltage cycle, which is conducive to continuous production and complete operation automation; Compared with chromic acid, sulfuric acid has the advantages of less personal damage, wide supply and low price. This method is mostly used in the construction of aluminum profile appearance treatment production lines in China.