In order to meet the needs of users, aluminum materials for construction are generally put on the market after surface treatment. There are currently three methods for surface protection of building aluminum:

 

(1) Anodizing, Shanghai aluminum alloy extrusions have introduced aluminum alloy doors and windows in the 1950s, and are still commonly used surface treatment measures for aluminum doors and windows;

 

(2) Electrophoretic acrylic resin after anodization has been commercialized in Japan in the 1960s, and has been used in Europe until the 1970s, and is currently mainly used in Asia. The technology has been developed from transparent bright film to matte transparent film and color film, the variety is more diversified, and the industrial control and product quality are relatively stable;

 

(3) Electrostatic spraying after chemical conversion treatment includes electrostatic powder spraying and electrostatic liquid phase spraying. Electrostatic liquid phase spraying fluorocarbon resin has been commercialized in the United States in the 1960s. The electrostatic powder coating thermosetting polyester coating has been commercialized in Europe in the late 1960s, and it is still the dominant surface treatment method in European countries. Today, the single anodized aluminum doors and windows have significantly reduced the domestic and foreign markets. Japan favors electrophoretic coatings. White electrophoretic coatings have developed rapidly and have been applied in Europe. Electrostatic powder coating has become the preferred surface treatment method in Europe and America due to its variety of colors, convenient control, environmental protection, and excellent performance. In recent years, the electrostatic powder coating market is also expanding rapidly in China.