1. Thin oxide film. National standards stipulate that the oxide film thickness of architectural aluminum profiles shall not be less than 10 μm (micrometers). If the thickness is insufficient, the surface of the aluminum profile is prone to rust and corrosion. During inspections, some aluminum profiles without trademarks, factory addresses, production licenses, or certificates of conformity were found to have an oxide film thickness of only 2 to 4 μm, and some even had no oxide film. According to expert estimates, for every 1 μm reduction in oxide film thickness, the electricity cost per ton of profiles can be reduced by more than 150 yuan. For example, solar aluminum profiles undergo sandblasting and oxidation treatment on the surface, making them less prone to rust and corrosion, and the oxide film thickness generally needs to be above 15 μm.
2. Unqualified chemical composition. Aluminum profiles mixed with a large amount of impure aluminum or scrap aluminum can significantly reduce costs, but this will lead to unqualified chemical composition in architectural aluminum profiles, seriously endangering the safety of construction projects.
3. Reducing the wall thickness of profiles.
4. Inferior aluminum profiles significantly reduce the sealing time, which decreases the consumption of chemical reagents and lowers costs, but also greatly reduces the corrosion resistance of the profiles.
