Aluminum and aluminum alloy sheets are pure aluminum or aluminum-manganese and aluminum-magnesium metal materials with metallic luster, light weight, and certain corrosion resistance made by casting, rolling, and annealing in a certain proportion. Because aluminum has good ductility, it is widely used in the manufacture of two-piece cans, especially for the manufacture of small flushing cans and easy-opening cans. For the container made of aluminum, the inner wall of the tank needs to be painted before it can be used.