The main aluminum alloy coloring processes are as follows:
Anodized coloring
Adsorption dyeing: using the porous oxide film formed after anodizing, the dye molecules are adsorbed into the pores to achieve coloring. The disadvantage is that dye molecules may fall off due to rubbing, light, etc., resulting in color fading.
Electrolytic coloring: Metal ions are precipitated by electrolysis at the bottom of the oxide film pores to develop color. The advantage is that the color is firm and not easy to fade; The disadvantage is that there are relatively few color types and high process control requirements.
Spray coloring
Electrostatic spraying: The powder unpainted is adsorbed on the surface of the aluminum alloy through high-voltage static electricity to form a flat and smooth coating. The advantages are diverse colors, strong adhesion, and good corrosion resistance; The disadvantages are that bright colors are easy to fade, and improper surface treatment may cause orange peel or powdering.
Fluorocarbon spraying: It is a high-grade spraying process, which forms a thick film coating through multi-layer spraying (primer, topcoat, varnish). The advantages are excellent weather resistance, chemical resistance and mechanical properties; The disadvantage is that the price is high, and if not handled properly, it is easy to produce orange peel.
Electrophoresis coloring
Organic resin particles are deposited on the surface of aluminum alloys by electrochemical methods to form a transparent or colored coating. The advantages are good corrosion resistance, strong bonding and bright color; The disadvantage is that the color options are relatively limited and the surface quality of the substrate is high.
Other processes
Physical treatments such as wire drawing and sandblasting: Mechanical rubbing or sandblasting to form specific textures, which indirectly affect the visual effect, often used in combination with other coloring processes.
Electroplating: Coating the surface of aluminum alloy with metal layers, such as nickel, chromium, etc., which is both decorative and functional, but the cost is high and the process is complex.
The selection of coloring process requires comprehensive consideration of factors such as the use environment, cost, aesthetics and durability. For example, aluminum alloy products used outdoors prefer fluorocarbon spraying or electrophoresis; Interior decoration can be anodized adsorption dyeing or electrostatic spraying.
