Unqualified aluminum alloy doors and windows can be affected by sunlight, air, rain, and other factors during use, leading to deformation of aluminum profiles and even causing glass breakage, detachment, and other phenomena. Poor quality aluminum profiles have the following four characteristics:

　　△ The thickness of the oxide film is thin. The national standard stipulates that the thickness of the oxide film on building aluminum profiles should not be less than 10um (micrometers). Insufficient thickness makes the surface of aluminum profiles prone to rusting and corrosion. During the sampling inspection, some aluminum profiles without production name, factory address, production license, and qualification certificate had an oxide film thickness of only 2 to 4um, and some even had no oxide film. According to experts' estimates, for every 1um reduction in oxide film thickness, each ton of profile can reduce electricity consumption costs by more than 150 yuan.

　　△ The chemical composition is not qualified. Adding a large amount of miscellaneous aluminum and scrap aluminum to aluminum profiles can greatly reduce costs, but it can lead to substandard chemical composition of building aluminum profiles, seriously endangering the safety of construction projects.

　　△ Reduce the wall thickness of the profile. The 90 series sliding window type has a minimum aluminum profile wall thickness of not less than 1.4mm according to national standards, while some Guangdong products have a wall thickness of only 0.6 to 0.7mm. The 46 series floor spring door type has a minimum aluminum profile wall thickness of not less than 1.62mm according to national standards, and during spot checks, some Guangdong products have a wall thickness of only 0.97 to 1.18mm.

　　△ Poor quality aluminum profiles significantly reduce the sealing time, minimize the loss of chemical reagents, and lower costs, but the corrosion resistance of the profiles is also greatly reduced.