How to judge the quality of aluminum profiles？

1. Label inspection

Whether the aluminum alloy profiles and packaging are marked with the product qualification certificate and production license number, etc.

2. Appearance quality

In addition to cleaning, the surface of aluminum alloy profiles is not allowed to have defects such as cracks, peeling, corrosion, bubbles, etc., and defects such as corrosion spots, electric burns (oxidation electrode points), black spots, and oxide film peeling are not allowed. It also depends on the color and luster of the surface of the aluminum profile, and whether there is a color difference. The darker the color, the more impurities it contains.

3. Look at the seal

Scrub the surface of the aluminum profile with acetone by pickling method, then drop 50% nitric acid on the surface of the aluminum profile and wipe it gently. After 1 minute, rinse with water and let dry. Then, place a drop of purple syrup on the surface of the aluminum profile for one minute. Finally, wipe off the purple potion and rinse off. Aluminum profiles with poor sealing will leave obvious marks. The heavier the trace, the worse the quality.

4. Look at the degree of oxidation of the thickness

By electrifying both ends of the aluminum profile, the oxide film of the anodized aluminum profile is formed in the acid-base solution. It has protective and decorative functions and can be detected by an eddy current thickness gauge. The thickness of the oxide film is generally between 8 and 15 μ. The thicker the oxide film, the stronger the corrosion resistance and the higher the oxidation cost.

5. Look at the chromaticity

The color of the same aluminum alloy profile should be consistent. If the color difference is obvious, it is not suitable for purchase. Generally speaking, the cross-section color of ordinary aluminum alloy profiles is silvery white and the texture is uniform. If the color is darker, it can be concluded that it is recycled aluminum or scrap aluminum was sent back to the furnace for forging.

6. Look at the flatness

Flatness is the plane gap. For industrial aluminum profiles, the smaller the gap value, the better, which is the requirement for its section size. In general, the standard specifies the degree of bending and twisting, which cannot exceed the allowable range.

7. Look at the strength

When choosing, you can moderately bend the profile with your hands. If the profile can be bent without much effort, then it can be determined that the strength of the aluminum profile is not up to standard. In addition, the strength of the profile is not as hard as possible. Aluminum has a certain toughness. Using this function can be forged into different shapes, so car owners need to look for the brand and observe when purchasing.

8. Look at the corrosion resistance

Drop about 10mg, 100g/L NaOH solution onto the surface of the aluminum profile at a temperature of 35°C±1°C, observe the droplet visually until corrosion bubbles appear, and calculate the oxide film penetration time. This test is easy to make a rough judgment outdoors in summer.

9. Look at the gloss

For aluminum alloy doors and windows, you should avoid buying profiles with open-air bubbles and slag inclusions on the surface, as well as profiles with obvious cracks, burrs, peeling, and other defects. If the above phenomenon occurs, it can be concluded that it is secondary processing of recycled aluminum or waste aluminum. This kind of material is easy to crack and oxidize in the later stage due to the uneven texture and disordered alloy ratio.

10. Look at the thickness

The commonly used aluminum window profiles are 70 and 90 series, and their wall thickness should be 1.2-2.0 mm. The national standard for the wall thickness of balcony window aluminum profiles is 1.2 mm, the wall thickness of balcony window profiles is 1.41.6, and the thickest part of the upper and lower beams of frameless windows is 3-4 mm, far exceeding the national standard.