The effect of anodized industrial aluminium extrusion has a lot to do with the electric current density. In a certain condition, with the current density increases, the growth rate anodized film increases too, but anodized time decreases and meanwhile the film is porous and easily colored, the hardness and wear resistance goes up. If the current density is too high, it will be affected by the joule heat, which will increase the temperature of the surface of the parts and the temperature of the local solution. The dissolution rate of the membrane will rise, and the possibility of burning the parts will be burned. The current density is too low, and the film growth rate will be slow, meanwhile, the film's dense, hardness and wear resistance are lower. Under the condition of normal temperature (about 20 ℃), except the special process formulation, the electric current density of industrial aluminum profiles and industrial aluminum alloy extrusion should be controlled between 1 ~ 1.5