The quality of aluminum alloy doors and windows can be roughly judged from the selection of raw materials (aluminum profiles), the quality of aluminum surface treatment and internal processing, and the price of aluminum alloy doors and windows.
Take a look at the materials. The thickness, strength and oxide film of aluminum profiles used for high-quality aluminum alloy doors and windows shall comply with the relevant national standards. The wall thickness of the main load-bearing bars of aluminum alloy windows shall be more than 1.4 mm, the wall thickness of the main stress bars of the aluminum alloy doors shall be more than 2.0 mm, the tensile strength shall be 157 n / m2, the yield strength shall be 108 n / m2, and the oxide film thickness shall be It should be up to 10 microns. If not up to the above standards, it is poor quality aluminum alloy doors and windows, can not be used.
Second, look at processing. High quality aluminum alloy doors and windows, fine processing, exquisite installation, good sealing performance, switch freely. Poor quality aluminum alloy doors and windows, blind selection of aluminum profile series and specifications, rough processing, saw cutting instead of milling processing, not according to the requirements of installation, poor sealing performance, switch is not free, not only air and rain leakage and glass burst phenomenon, but also encounter strong wind and external force, it is easy to pull parts or glass scraping or falling, damage and injury.
Third, look at the price. In general, the price of high-quality aluminum alloy doors and windows is about 30% higher than that of inferior aluminum alloy doors and windows due to its high production cost. Some aluminum alloy doors and windows with wall thickness of only 0.6-0.8 mm aluminum profiles have tensile strength and yield strength much lower than the relevant national standards, so they are not safe to use. In addition, the processing of aluminum alloy doors and windows more individual, they do not understand the structural characteristics and performance of aluminum alloy doors and windows. In order to reduce the cost, shoddy, shoddy, product hidden danger is bigger, generally not suitable for use. It is better to choose the products of regular aluminum alloy doors and windows manufacturers. Here is a special note: the national standard profile thickness is 1.4mm. If the supplier chooses the material with wall thickness of 1.2mm or 1.0mm or even thinner, it belongs to substandard products. Please pay attention when purchasing.
4、 Look at the material. There are mainly six aspects to refer to in terms of materials and materials:
1. Thickness: there are 70 series and 90 series aluminum alloy sliding doors and windows, and 70 series can be used for aluminum alloy sliding doors in residential buildings. The number of aluminum alloy series indicates the thickness of door frame and the number of mm of structural dimension. There are four kinds of common aluminum alloy sliding windows: 55 series, 60 series, 70 series and 90 series. The selection should be determined according to the size of the window opening and the local wind pressure value. The aluminum alloy sliding window used for closed balcony should not be less than 70 series.
2. Strength: the tensile strength should reach 157 n / m2 and the yield strength should reach 108 n / m2. When purchasing, the profile can be moderately bent, and it should be able to return to its original state after release.
Color: the color of the same aluminum alloy profile should be consistent. If the color difference is obvious, it is not suitable to purchase.
4. Flatness: check the surface of aluminum alloy profile, and there should be no depression or bulge.
Defects of aluminum alloy, such as blisters, black spots on the surface of doors and windows should be avoided.
⒍ oxidation degree: the thickness of oxide film should reach 10 μ M. When purchasing, mark the profile surface lightly to see whether the oxide film on the surface can be wiped off.