The original surface of aluminum profiles generally has a self oxidation film, and even slight scratches may occur during raw material transportation. Before surface treatment of aluminum, aluminium profiles go through processes such as processing, forming, heat treatment, and storage, as well as some of dust sticking. In order to improve the decorative effect of surface treatment and ensure the smooth progress of subsequent aluminum surface treatment main process anodizing, surface pretreatment of aluminum is indispensable. The alkaline washing process involves placing aluminum profiles in a strong alkaline solution mainly composed of sodium hydroxide for etching reaction. The purpose of this process is to further remove surface impurities, thoroughly remove the natural oxide film on the aluminum surface, and expose the metal substrate, laying a good foundation for the subsequent surface treatment technology of anodizing to generate a uniform anodized film. If…