At present, the application of single color anodized aluminum alloy building profiles in practice has been significantly reduced, and the electrolytic colored oxide film, organic colored oxide film, porcelain oxide film, hard oxide film, imitation stainless steel oxide film based on it has been widely used. For the oxide film coloring technology, the factors affecting the oxidation coloring of aluminum profiles
are as follows:
Influence of impurities in electrolytic solution
The coloring degree of aluminum profile products mostly depends on the formation quality of oxide film. Therefore, in sulphuric sour anodic oxidation solution, the influence of impurities on the oxide membrane can not be ignored, the impurities are mainly copper, iron, aluminum and other metal ions and organic impurity pollutants, to remove in time, to maintain the normal range of use of the solution.
(1) Copper ions will be replaced and deposited on the surface of the aluminum profile, causing loose holes in the oxide film, and reducing the transparency, corrosion resistance and electrical insulation performance. Therefore, the contents of copper ions is not allowed to surpass 0.02g/L.
(2) Chloride ions come from tap water or the cooling water after the cooling pipe is broken. The content of chloride ions should be lower than 0.2g/L, otherwise the oxide film generated will be rough and loose, and the surface of aluminum profile will be eroded (breakdown) in serious cases.
(3) Aluminum ion electrolyte aluminum ion is gradually increased, when the content is greater than 25g/L, the conductivity of the electrolyte decreases, the surface of the parts appear white spots or blocky white spots, and make the adsorption capacity of the film layer decreased, staining is difficult.
(4) Iron ions in the iron ion electrolyte are not allowed to exceed 0.2g/L, otherwise dark stripes will appear.
(5) Organic impurities will hinder the formation of oxide film, film adsorption of oil, so that the color is not uniform, the appearance of spots.