How to deal with the problem of yellowing surface of industrial aluminum profiles
Usually, the surface yellowing of industrial aluminum profiles mainly occurs in the oxidation process, before the oxidation process, because the metal surface removed the oxidation layer, there is no protection of dense oxidation layer, aluminum profile exposed to the air, a variety of metal ions formed between the original battery, and thus cause corrosion, so that industrial aluminum profile looks yellow.
The reasons for the change slate of the surface of industrial aluminum profiles are as follows:
1. Yellow-changing appearance caused by electrophoresis paint itself
2. Yellow-variable appearance caused by poor conduction during oxidation
3. Yellow-changing appearance caused by the incomplete washing before electrophoresis
4. Yellow-change appearance caused by the contamination of oxidation tank fluid by nitric acid
How to avoid this yellowing phenomenon? Add the mixture in the pure sink before the hot washing tank, adjust the PH value 8-9.5, wash for 2-3 minutes, use ammonium root and the sulphate in the oxide membrane hole, and then electrophoresis production, will not present the yellow ingress appearance.
The common yellowing treatment of aluminum profiles is to scrub off directly with pure alkali, and is also suitable for the cleaning and gloss recovery of most metal surfaces, which is different from the time-consuming and laborious cleaning of the surface using wire balls or brushes.