Anodizing is an electro-chemical conversion process. The surface of the metal is converted to aluminum oxide as a result of reactions going on at the anode in an acidic solution.
After cleaning and etching, aluminum profiles are immersed in sulfuric acid solution under controlled parameters. An electric current flows through the solution to produce an aluminum oxide film, which is extremely hard, durable and corrosion resistant.
Aluminum profiles are then electro or dye colored to obtain aesthetic colors such as light, medium and dark bronze, silver, gold, etc.
Sealing is the final stage in anodizing process and it is done in hot water solution. The purpose of sealing process is to close porous aluminum oxide layer after the anodizing step in order to enhance the durability of the finishing.