Three types of aluminum profile surface treatment methods principle and its advantages

In order to increase the corrosion resistance and mechanical properties of the aluminum profile surface, the aluminum profile will have various surface treatment methods after the extrusion.

The surface treatment methods of aluminum alloy materials are mainly anodizing treatment, electrophoretic coating and powder coating.

These three processing methods have different principles and have their own advantages.

The following is a simple analysis of their advantages and disadvantages.

Three types of aluminum profile surface treatment methods principle and their advantages

Principles of three surface treatment methods for aluminum profiles

Anodizing:

Anodizing (It is also spelled anodizing in British English) is an electrolytic passivation process used to increase the thickness of the natural oxide layer on the surface of metal parts.

The process is called anodizing because the part to be treated forms the anode electrode of an electrolytic cell.

Anodizing increases resistance to corrosion and wear, and provides better adhesion for paint primers and glues than bare metal does.

Anodic films can also be used for a number of cosmetic effects, either with thick porous coatings that can absorb dyes or with thin transparent coatings that add interference effects to reflected light. From Wiki

The aluminum profile will be placed in the electrolyte solution as an anode.

The formation of oxide layer on the surface of the aluminum profiles by the action of the electrolyte is called anodizing.

Electrophoretic coating:

E-coating is a method of painting that uses electrical current to deposit the paint. The process works on the principle of “Opposites Attract”.

This process is also known as Electro Deposition (ED).

The electrolytic coating is dissolved in water to cause electrolysis to generate charged particles.

Under the action of the external electric field, charged particles move to the surface of the aluminum profile and move to the surface of the aluminum profile to form a dense and uniform layer called electrophoresis coating.

Powder coating:

Powder coating is a type of coating that is applied as a free-flowing, dry powder.

The powder may be a thermoplastic or a thermoset polymer. It is usually used to create a hard finish that is tougher than conventional paint.

Powder coating is mainly used for coating of metals, such as household appliances, aluminum extrusions, hardware and automobile parts.

The dry powder will be placed in the spray gun. Under the action of compressed air, the surface of the aluminum profile is adsorbed by high-voltage static electricity, which is called electrostatic powder coating.

Advantages of three surface treatment methods of aluminum profile

Anodizing:

A porous oxide film can be formed, and the hardness of the film layer can be up to 500 HV;

The oxide film of the porous structure can also adsorb lubricants, pigments, etc. to enhance the corrosion resistance and wear resistance of the profile surface;

It can prevent the breakdown voltage from being greater than 30V/μm;

It has high-temperature resistance and can withstand the high temperature of 1500°C;

It can be oxidized and colored into various decorative colors with good adsorption capacity,

It is widely used in aerospace, electronic appliances, various Construction of aluminum profile frame structures and architectural decoration.

Electrophoretic coating:

Water as the dispersion medium, the amount of cosolvent is very small, reducing the pollution of air and water, no fire hazard;

The paint has good permeability, can cover the edge and gap of aluminum profile, forming a dense uniform oxide film, the overall anti-corrosion ability is very strong;

The appearance quality is high, there will be no running phenomenon, and no solvent condenses on the surface of the profile to form a poor appearance;

Using an advanced RO circulation system, the recovery rate of the coating is more than 98% ;

The wastewater discharge is small, which not only saves chemical paint but also reduces environmental pollution.

Powder coating:

The molecular weight of the resin for powder coating is larger than that of the solution coating, so the surface of the aluminum profile has good chemical resistance.

The coating of 50-300μm can be obtained by powder coating once, which greatly reduces the number of coatings and saves working time.

There are no dripping phenomenon and pinhole defects in the coating type coating, which may result in a better film layer, making powder coated aluminum profiles product sturdy and durable;

The color is rich and varied and the decorative effect is improved;

The quality of the surface and the quality of the Pre-treatment are not as strict as the anodizing and electrophoretic methods.

Honstar Aluminum Products Co., Ltd has been an aluminum industry leader for over 12 years in manufacturing precision aluminum parts, custom aluminum extrusions and standard aluminum extrusions.

We focus exclusively on producing the smallest, most complex, precision aluminum parts, custom aluminum extrusions, standard aluminum extrusions and floor covering aluminum profiles.