Surface treatment process of aluminum coil

The surface treatment processes of aluminum products we often see include electrophoresis, anodizing, fluorocarbon coating spraying, etc.
1、 Electrophoresis
Electrophoresis refers to that the charged coating ions move to the cathode under the action of voltage at the anode and cathode of the electrophoretic coating, and form insoluble substances with the alkaline action generated on the cathode surface, which are deposited on the surface of the workpiece. Electrophoresis of aluminum plate, aluminum coil, aluminum disc and other profiles refers to the process of placing extruded aluminum alloy in the electrophoresis tank and forming a dense resin film on the surface after direct current is applied. After electrophoresis, the surface of aluminum plate, aluminum coil, aluminum disc and other profiles is bright and has mirror effect, and the corrosion resistance is also improved.
technological process
Electrolysis (decomposition) ➤ electrophoretic movement (swimming and migration) ➤ electrodeposition (precipitation) ➤ electroosmosis (dehydration)
2、 Anodizing
Anodized aluminum profile refers to the process of forming an oxide film on aluminum plate, aluminum coil, aluminum disc and other profiles (anodes) under the action of external current under the corresponding electrolyte and specific process conditions. However, the oxide film formed on the surface of anodized aluminum is different from the general oxide film. Anodized aluminum can be dyed by electrolytic coloring. In order to overcome the defects in the surface hardness and wear resistance of aluminum alloy, expand the application range and prolong the service life, the surface treatment technology has become an indispensable link in the use of aluminum alloy, and the anodizing technology is widely used and successful.
technological process
Degreasing ➤ chemical polishing ➤ acid corrosion ➤ stripping black film ➤ anodizing ➤ pretreatment before dyeing ➤ dyeing ➤ sealing holes ➤ drying
The difference between anodic oxidation and electrophoresis: anodic oxidation is oxidation before coloring, and electrophoresis is direct coloring.
3、 Electrostatic powder spraying
Electrostatic powder spraying equipment is used to spray the powder coating on the surface of aluminum plate, aluminum coil, aluminum wafer and other profiles. Under the action of static electricity, the powder will be evenly adsorbed on the surface of the workpiece to form a powdery coating. The powdery coating will be leveled and solidified by high-temperature baking to become a Z final coating with different effects. The spraying effect far exceeds the spraying process in mechanical strength, adhesion, corrosion resistance and aging resistance.
technological process
Surface pretreatment ➤ spraying ➤ baking curing
4、 Fluorocarbon spraying
Fluorocarbon spraying is a kind of electrostatic spraying and liquid spraying. The fluorocarbon spray coating used is a coating made of polyvinylidene fluoride resin baking as the base material or metal aluminum powder as the color material. There are suspension type and semi suspension type. The suspension type refers to the pretreatment and spraying of aluminum materials, and the aluminum materials are suspended in the curing process. The fluorocarbon coating with good quality has metallic luster, bright color and obvious three-dimensional feeling.
technological process
Pretreatment process: degreasing and decontamination of aluminum ➤ water washing ➤ alkali washing (degreasing) ➤ water washing ➤ acid washing ➤ water washing ➤ chromizing ➤ water washing ➤ pure water washing
Spraying process: spraying primer ➤ finishing coat ➤ finishing coat ➤ baking (180-250 ℃) ➤ quality inspection
The difference between electrostatic powder spraying and fluorocarbon spraying: powder spraying is to spray powder coating on the surface of the workpiece with powder spraying equipment (electrostatic plastic spraying machine). Under the action of static electricity, the powder will be evenly adsorbed on the surface of the workpiece to form a powdery coating. Fluorocarbon spraying is a kind of electrostatic spraying and liquid spraying. It is called fluorocarbon spraying and curium oil in Hong Kong.
5、 Transfer wood grain
Wood grain transfer aluminum plate, aluminum roll, aluminum wafer and other profiles refer to the rapid transfer and penetration of wood grain patterns on transfer paper or transfer film onto the sprayed or electrophoretic profiles by heating and pressurization based on the principle of high-temperature sublimation and thermal penetration on the basis of powder coating or electrophoretic coating. The produced wood grain profile has clear texture, strong three-dimensional sense, and can better reflect the natural feeling of wood grain. It is an ideal energy-saving and environmental protection material to replace traditional wood.
technological process
Select the base material ➤ wrap the wood grain printing paper ➤ cover the plastic bag ➤ vacuum ➤ bake ➤ tear off the printing paper ➤ clean the surface