As we all know, industrial aluminum profiles are alloy extrusion materials. In the production process, it is easy to cause material damage and surface defects due to improper operation of one step. Under normal circumstances, the surface color of industrial aluminum profiles should be silver-white. In addition to the rough surface, it sometimes appears yellowing. The following content summarizes the reasons for the yellowing of the surface of industrial aluminum profiles.
There are two reasons why the surface of industrial aluminum profiles turns yellow. One is that the profile is extruded in an improper way, and the other is that the profile surface treatment process is improper. For a specific analysis, please refer to the following:
The profile needs to be cooled after being extruded by the die in order to improve the mechanical and physical properties of the material. Coolant is used in the cooling process, and the effects of coolants used on different materials are different. Common coolants are generally water or oily coolants. If water is used for cooling or when the copper content in the coolant is relatively high, it will cause the surface of the profile to turn yellow. The reason for this is that the nature of aluminum is relatively active, and it is easy to react chemically with materials in the air or water.
The surface of industrial aluminum profiles is usually covered with an oxide film, which not only increases the corrosion resistance of the profiles but also increases the aesthetics of the profiles. However, before the surface treatment of the profiles, the surface of the extruded profiles needs to be cleaned to fully remove the oil stains on the surface. If the cleaning work in this step is not in place, the oxide film will not be easy to color or the coloring will not be uniform during the subsequent oxidation process, resulting in yellowing.
