Before forming the aluminum coil, some pre-treatment sections are required to ensure the cleanliness of the surface of the aluminum coil. To prevent residual oil and lubricants on its surface from affecting painting and application. So, aluminum coils need to undergo the following pre-treatment before forming.
Firstly, it is advisable to use hot water to wash the aluminum coil. If the hot water scrubbing agent is used to clean the residual degreasing agent on the surface of the substrate, it should be ensured that these residues can dissolve to prevent the degreasing agent from causing secondary pollution to the substrate. The application methods are mostly immersion washing and spray brushing. The hardness of the water used should not be too high, otherwise the minerals in the water will form mineral spots on the surface of the substrate.
Secondly, due to the fast line speed of pre coating, the degreasing agent used for hot alkali degreasing usually has a high concentration. Typical degreasing agents contain sodium hydroxide (NaOH), sodium carbonate (Na2CO3), sodium silicate (Na2SiO3), phosphate and other components. The hot alkali degreasing process is usually divided into two steps to ensure that the surface of the aluminum coil substrate is washed clean, and spray scrubbing is often used.
Again, passivate it. Passivation treatment is the process of forming a conversion film on the surface of a substrate using passivating agents through methods such as pressure spraying, immersion coating, or roll coating. Usually, the method of pressurized spraying is used, and the sludge generated during the use of passivation solution often clogs the spray hole, thereby affecting the effectiveness of spraying. Although the immersion coating method addresses this issue, the amount of passivation solution sent is relatively large. Both of the above methods require cleaning the excess passivation solution with water in essential manipulation, which can lead to issues with wastewater recovery and purification. Roller coating is a good passivation construction method, with advantages such as average coating, economic applicability, and no need for rinsing. Aluminum plates are usually treated with chromate/oxide type treatment agents, which contain chromate, chromic acid, phosphoric acid, and promoting agents fluoride and molybdate. This type of treatment agent must be added with phosphoric acid, otherwise it cannot be used to treat aluminum plates for food and beverages.
From the overall market situation, people's demand for high-end products is still increasing, and they are quite resistant to counterfeit and inferior products. Aluminum coils will also become a part of the products we need, making our products more beautiful and high-end. Aluminum coils have been widely used in electronics, packaging, construction, machinery, and other fields. In the future development, aluminum coils can still occupy a part of the market, and the number of aluminum coil manufacturers will gradually increase. The competition for products will be reduced to skill competition and brand competition.
