Five processes for surface treatment of building aluminum profiles

The production of building aluminum profile aluminum alloy door and window profile can be divided into four processes: ingot preparation, extrusion molding, heat treatment and surface treatment. With the continuous improvement of people's living standards, the requirements for the appearance color of doors and windows are higher and higher, and with the gradual refinement of aluminum processing technology, some complex surface treatments have developed vigorously. We often see aluminum surface treatment processes such as electrophoresis, anodizing, fluorocarbon coating spraying, etc.

1、 Electrophoresis

Electrophoresis is that when the electrophoretic coating is at the Yin and Yang poles, under the action of voltage, the charged coating ions move to the cathode and react with the alkaline generated on the cathode surface to form insoluble substances, which are deposited on the workpiece surface. Aluminum profile electrophoresis 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. The electrophoretic aluminum profile is very bright and has a mirror effect, which also improves the corrosion resistance.

technological process

Electrolysis (decomposition)? Electrophoretic (swimming, migration)? Electrodeposition (precipitation)? Electroosmosis (dehydration)

2、 Anodizing

Anodized aluminum profile refers to the process that aluminum and its alloy form an oxide film on aluminum products (anode) under the action of external current under the corresponding electrolyte and specific process conditions. However, the oxide film formed on the surface of anodic alumina is different from the general oxide film. Anodic alumina can be dyed by electrolytic coloring. In order to overcome the defects of surface hardness and wear resistance of aluminum alloy, expand the scope of application and prolong the service life, surface treatment technology has become an indispensable link in the use of aluminum alloy, and anodic oxidation technology is widely used and successful at present.

technological process

Degreasing? Chemical polishing? Acid corrosion? Peel the black film? Anodizing? Dyeing pretreatment? Dyeing? Hole sealing? dry

The difference between anodic oxidation and electrophoresis: anodic oxidation is oxidation before coloring, and electrophoresis is direct coloring.

3、 Electrostatic powder spraying

The powder coating is sprayed on the surface of the workpiece with electrostatic powder spraying equipment. Under the action of static electricity, the powder will be evenly adsorbed on the surface of the workpiece to form a powder coating. The powder coating will become a coating with different effects after high-temperature baking, leveling and curing. The spraying effect far exceeds the spraying process in terms of mechanical strength, adhesion, corrosion resistance and aging resistance.

technological process

Surface pretreatment? spray? 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, and the aluminum will be suspended during curing. The fluorocarbon coating with excellent quality has metallic luster, bright color and obvious three-dimensional feeling.

technological process

Pretreatment process: degreasing and decontamination of aluminum materials? Water wash? Alkali washing (degreasing)? Water wash? Pickling? Water wash? Chrome? Water wash? Pure water washing

Spraying process: primer spraying? Topcoat? Gloss paint? Baking (180-250 ℃)? quality testing

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, which is called fluorocarbon spraying and curium oil in Hong Kong.

5、 Transfer wood grain

Wood grain transfer profile refers to the rapid transfer and penetration of the wood grain pattern on the transfer paper or transfer film into the sprayed or electrophoretic profile on the basis of powder spraying or electrophoretic painting and according to the principle of high temperature sublimation thermal penetration through heating and pressurization. The wood grain profile produced has clear texture and 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 substrate? Wrapping wood grain printing paper? Cover the plastic bag? Vacuum? bake? Tear off the printing paper? Do surface cleaning