Disadvantages of three aluminum coil surface treatment methods

In order to improve the corrosion resistance of the surface of the aluminum coil sheet, the aluminum coil sheets should be subjected to various surface treatment methods after extrusion. Commonly used surface treatment methods for aluminum coils include anodizing, electrophoretic coating, and powder spraying. These three methods have different rationales, and they have both advantages and disadvantages. The following is a brief analysis of three aluminum coil sheet surface treatment methods.

1. Electrophoretic coating: If the electrophoretic coating does not strictly meet the requirements of various technological processes, such as long baking time, tank liquid pollution, unqualified tank liquid composition, etc. The surface of the aluminum coil sheets is rough, foaming, pinholes or shrinkage, varnish stains, low gloss, uneven paint film, and there are surface defects such as cracks on the surface of the profile.

2. Anodizing: The oxide film is easy to mix with impurities and turn yellow; the materials are easy to stick together, making the oxidation color of the profile uneven, forming a rainbow color, resulting in poor product appearance; the profile and cooling bed are easy to form black. K point or white point; the electrolyte temperature is too high or the electrolysis time is too long, resulting in white opaque powder on the surface of the aluminum coil sheet; in the oxidation process, if the profile drops, it is easy to cause a short circuit; if the concentration of sulfuric acid is not well controlled during alkali corrosion, Then the corrosion resistance of the cross-sectional surface will be reduced; the oxide film surface is also prone to occur. Other problems include ashes, blackening or cosmetic quality issues.

3. Powder coating: If the quality of the raw materials is not good, and dust or impurities are mixed in, particles will be generated on the surface of the aluminum coil sheets; the compressed air is not clean, and mixing with oil or water will also cause shrinkage defects on the surface of the aluminum profile; unreasonable matching affects the physical properties and chemical resistance of aluminum products, such as hardness, impact resistance and bending resistance; it also results in poor surface appearance without powder and yellowing.

So this is the disadvantages of three aluminum coil surface treatment methods. If you are interested in knowing more about this topic or if you are interested in buying aluminum coil sheets from Haomei, please send us an email!