Banner
Home > news > Content
Detailed explanation of standards for surface treatment of industrial aluminum profiles
- 2019-10-28-

There are several methods for surface treatment of industrial aluminum profiles, such as anodizing, powder coating, electrophoresis, etc. No matter which method is used, a protective film is formed on the surface of the aluminum profile. To judge whether the surface treatment of the industrial aluminum profile is up to standard, That is, it is judged whether the thickness of the oxide film is up to standard. The following small series will explain to you the thickness standard of oxide film obtained by each white surface treatment method.


One is anodizing.

The surface of the aluminum profile has a thick oxide film and is mainly divided into four grades according to the use requirements: AA10, AA15, AA20, and AA25, that is, the average thickness of the surface film thickness of the aluminum alloy profile is 10 μm, 15 μm, 20 μm, and 25 μm, respectively. 8 μm, 12 μm, 16 μm, 20 μm.

The second is powder coating.

The film thickness of the powder coating surface coating is generally not graded, and the average film thickness is usually not less than 40 μm and the partial thickness is not less than 35 μm.

The third is electrophoretic surface treatment.

Electrophoretic surface film thickness is generally divided into three grades: A, B, and S.

Class A: 12μm oxide film + 9μm electrophoresis film, the composite film thickness is not less than 21μm.

Grade B: 9μm oxide film + 7μm electrophoresis film, the composite film thickness is not less than 16μm.

S grade: 6μm oxide film + 15μm electrophoresis film, the composite film thickness is not less than 21μm.

On several sides of the same aluminum profile, even in the groove, the film is uniform and has a large relationship with the corresponding cathode area. The cathode area is large, so that the current density distributed in each part of the aluminum profile is uniform, and the film thickness is also uniform. In the horizontal line production, the film thickness of the same part of each profile of the hanging material sometimes appears to be low, which is probably because the cathode plate corresponding to the part appears loose or even falls off, which reduces the cathode area. , resulting in a low film thickness.

In the actual production process, there are other reasons that may cause uneven film thickness of the oxide film, such as poor contact between the clamp and the profile, and the contact area is too small, which may make the oxide film incomplete or oxide-free. In addition, the wide range of sulfuric acid concentration will make the oxide film thickness of different tank materials different.   A large range of changes in sulfuric acid concentration makes the k in the empirical formula ( δ = kIt) for calculating the thickness of the oxide film inaccurate, and thus the film thickness of the obtained oxide film is inconsistent. In the production, as long as the above problems are solved one by one, the film thickness of the oxide film can be ensured to be uniform.