The alkaline cleaning process involves immersing Aluminum Extrusion Profile in a strongly alkaline solution primarily composed of sodium hydroxide to initiate an etching reaction. The purpose of this treatment is to further remove dirt from the surface of the Aluminium Profile, thoroughly eliminate the natural oxide film on the aluminum surface, thereby revealing a pure metal substrate. This lays a solid foundation for subsequent uniform conductivity during anodizing and the formation of a uniform anodic oxide film. If the duration of alkaline cleaning is appropriately extended, it can also make the surface of Aluminium Profiles Window and Door more even, uniform, and smooth, eliminating minor roughness marks on the aluminium surface such as mold marks, dents, scratches, etc. A longer period of alkaline cleaning can achieve a uniformly soft reflective surface without strong glare. However, it is also important to note that excessive alkaline cleaning is wasteful for aluminium profiles and can cause dimensional deviations in the profiles. Moreover, it may reveal inherent internal structural defects.
