Electrolytic coloring of anodic aluminum oxide film

Electrolytic coloring film refers to the oxide film that is electrolytically colored by DC or alternating current in a solution containing metal salts on the basis of a transparent anodic oxide film electrolyzed by sulfuric acid once. Also called secondary electrolytic membrane in Japan. It means that anodic oxidation is called primary electrolysis, and electrolytic coloring is called secondary electrolysis. Multicolor technology, which has been popularized in industry, can get many colors in an electrolytic coloring tank. This is a new electrolytic coloring method using interference light effect. Because electrolytic adjustment is added before electrolytic coloring, it is also called three-stage electrolytic method in Japan.

Electrolytic coloring film is far superior to the colored film in weather resistance, light resistance and service life, and its energy consumption and coloring cost are far lower than that of the whole colored film, so it has been widely used in the coloring of architectural aluminum profiles. After Japan's Asada method came out and industrialized in 1960s, AC electrolytic coloring technology took the lead because of its good oxide film performance, convenient industrial control and low operating cost, and became the first choice for anodizing film coloring of aluminum profiles. Electrolytic coloring technology has been tested by industrial practice and has been continuously developed and improved. The coloring power supply is updated, the bath composition is stable, the process is more mature, the cost is continuously reduced and the scale is expanding day by day. The electrolytic coloring technology has made great progress in theory and practice, especially in anodic oxidation electrolytic coloring engineering. Today's industrialized technology can't be mentioned in the same breath as the early literature patents, and several summary monographs on electrolytic coloring of aluminum anodic oxide film have been published abroad.