Identification inspection: whether the aluminum profile and package are marked with product standard code, production license number, etc.
Surface quality: the surface of aluminum profiles is clean, free of cracks, peeling, corrosion, bubbles and other defects, and free of corrosion spots, electric burns, black spots, oxide film falling off, etc.
Thickness of oxide film: the oxide film of aluminum profile is formed during anodic oxidation, which plays a protective and decorative role and can be detected by eddy current thickness gauge.
Sealing quality: there are many cavities on the surface of aluminum profile after anodizing. If it is not sealed or sealed well, the corrosion resistance of aluminum profiles will be reduced. Commonly used seal quality inspection methods include acid leaching method, admittance method and butyric acid phosphate method. In the field inspection, the acid leaching method is generally used, that is, acetone is used to clean the aluminum profile surface to remove oil and dust. Drop nitric acid with a volume ratio of 50% on the surface and gently scrub it. After one minute, rinse the nitric acid with clean water and dry it. A drop of medical purple medicine drops on the water. After one minute, wipe off the purple liquid, thoroughly clean the surface, carefully observe the traces left, and the aluminum profile with poor sealing will leave obvious traces. The heavier the trace, the worse the sealing quality.
Corrosion resistance: this index mainly affects the service life of aluminum profiles. Corrosion resistance inspection includes copper accelerated acetate spray test and alkali drop test. This paper introduces the alkali dropping test, that is, at 35 ℃± 1 ℃, drop about 10mg and 100g/L sodium hydroxide solution on the surface of aluminum profiles, visually inspect until corrosion bubbles are formed, and calculate the penetration time of the oxide film. This test is easy to make a rough judgment outdoors in summer. In order to ensure the accuracy of the test, it must be carried out under strict conditions in the laboratory.
