Aluminum coils are cleaned using hot water. Hot water cleaning mainly cleans the degreasing agent remaining on the surface of the substrate to ensure that these residues can be dissolved to prevent the degreasing agent from causing secondary pollution to the substrate. The methods of use are mostly dipping and spray brushing. The water quality should not be too hard, otherwise the minerals in the water will form mineral spots on the surface of the substrate. Passivation treatment is to use pressure spraying, dip coating or roller coating to form a conversion film on the surface of the substrate. Aluminum coils generally use pressurized spraying. The sludge generated by the passivation liquid during use often blocks the spray holes, thus affecting the spraying effect. Although the dip coating method solves this problem, the consumption of passivation liquid is large. In actual operation, the above two methods require flushing the excess passivation liquid with water, which will cause wastewater recovery and purification problems. Roller coating is the best passivation construction method, which has the characteristics of uniform coating, economical and practical, and does not require showering. Washing and other advantages.
1. You can use hot water to clean the aluminum coil. Hot water cleaning mainly cleans the degreasing agent remaining on the surface of the substrate to ensure that these residues can be melted to prevent the degreasing agent from causing secondary pollution to the substrate. The methods of use are mostly dipping and spray scrubbing. The water quality should be good and the hardness should not be too high. Otherwise, the minerals in the water will form mineral spots on the surface of the substrate.
2. Passivate it. Passivation treatment is to use pressure spray, dip coating or roller coating to make the passivation agent form a conversion film on the surface of the substrate. When pressurized spraying is used normally, the sludge produced by the passivating liquid during use will often block the spray holes, thereby affecting the spraying effect. Although the dip coating method solves this problem, the consumption of passivation liquid is large.
3. Hot alkali degreasing. Because the pre-coating line speed is fast, the degreasing agent used usually has a high concentration. Typical degreasing agents contain sodium hydroxide (naoh), sodium carbonate (na2co3), water glass (na2sio3), and phosphate. and other components. The hot alkali degreasing process is normally divided into two steps to ensure that the surface of the aluminum coil substrate is clean, and spray scrubbing is often used.
In actual operation, the above methods all need to rinse the excess passivation liquid with water, which will cause wastewater recovery and purification problems. Roller coating is a better passivation construction method, which accounts for the uniform coating, is economical and practical, and does not require showering. Washing and other advantages.
