Reasons For Yellowing On The Surface Of Industrial Aluminum Profiles

As is well known, industrial aluminum profiles belong to alloy extrusion materials. Improper operation in one step during the production and processing process can easily lead to material damage and surface defects in the profiles. Under normal circumstances, the surface color of industrial aluminum profiles should be silver white. In addition to rough and unsmooth surfaces, there may also be yellowing. The following content summarizes the reasons for the yellowing phenomenon on the surface of industrial aluminum profiles:
The reasons for the yellowing on the surface of industrial aluminum profiles can be roughly summarized into two types: one is the improper method used during the extrusion process, and the other is the improper surface treatment process of the profiles. Specific analysis can refer to the following content:
1. The profile needs to be cooled after being extruded by the mold to improve the mechanical and physical properties of the material. During its cooling process, coolant will be used, and the effectiveness of coolant used varies for different materials. The common coolant is usually water or oil-based coolant. If water is used for cooling or when the copper content in the coolant is relatively high, it will cause yellowing on the surface of the profile. The reason for this is that aluminum, as a metal, has relatively active properties and is prone to chemical reactions when in contact with materials in air or water.
2. The surface of industrial aluminum profiles is usually covered with an oxide film, which not only increases the corrosion resistance of the profile but also enhances its aesthetic appeal. However, before surface treatment of the profiles, it is necessary to clean the surface of the extruded profiles to fully remove any oil stains on their surfaces. If the cleaning work in this step is not done properly, it will lead to difficulty coloring the oxide film or uneven coloring in the subsequent oxidation process, resulting in yellowing.