Analysis of the advantages and disadvantages of self-swimming paint
1. Advantages of self-coating paint
The water-based colloidal particles react with metal ions on the surface of the workpiece, without organic solvents, heavy metal ions and VOC emissions, and are environmentally friendly production. No flash time is required during baking, less pollution and less explosive.
①The self-coating process is a chemical process, not electrodeposition. Therefore, the coating film has good consistency and uniformity, does not produce edge effects and shielding effects that often occur in cathodic electrophoresis, and does not have the problem of throwing power. Therefore, the advantages of autophoretic coating for workpieces with complex shapes are particularly prominent.
②The coating is insoluble in acid and alkali, and has excellent water resistance. A typical anodic electrophoretic paint will be dissolved in o.lmo1/L NaOH solution for a few minutes, but self-coating paint has no obvious erosion effect after soaking for a week.
③ There is no need to clean the hanger during painting; after curing, the coating is resistant to acid and alkali, so it is not necessary to remove the coating film on the hanger, reducing the cleaning workload.
④The automatic deposition device is far simpler than the traditional industrial coating equipment, its equipment cost is only 30%~70% of the latter, the land area is saved by 20%~50%, the floor area is small, and the equipment input and operation costs are low.
⑤The self-swimming process is directly applicable to the clean metal surface, the process is simple, and no transfer layer, such as phosphating layer, etc. is required during coating, which can save the steel surface treatment process; only four stations are required except for water washing, and the control parameters Less, bath management and process control are simple and easy.
⑥ No external power supply is needed, no electricity is needed, the baking temperature of the workpiece is low, and the bad liquid does not need to be cooled, so the energy consumption is small, which is only half of the electrophoretic coating.
⑦Autophoretic deposition time is generally 1~2min, which has the same coating efficiency as electrophoretic coating; the solid content of the bath solution is 5%~10%, and the wet film still has high permeability and high permeability after the paint piece is taken out of the bath solution. Reactivity, the bath solution adhered to the surface can continue to undergo chemical action and deposit, and only a small part is washed away by water. The utilization rate of paint is better than that of electrophoretic paint, and no ultrafiltration recovery equipment is required.
2. Disadvantages of self-coating paint
① The color is monotonous. So far, only black matt paint, the appearance is not satisfactory, and there is a certain selectivity for repainting. Generally used as a primer only.
②The limitations of the base material. It can only be painted on steel surface, not suitable for galvanized sheet, aluminum sheet and other materials.
③ low electrolyte utilization. Because a certain concentration is required to achieve the corresponding coating thickness in the process of autophoresis, the concentration of the electrolyte solution needs to be kept stable.
In addition, strong acids and strong oxidants are used in the system. During the coating process, the bath parameters are unstable and need to be constantly tracked and adjusted in time.
Since the advent of swimming paint, it is mainly used in the coating of some black metal products that do not require high appearance quality. It can form a uniform and dense black paint film on the steel surface. It has high hardness, bonding force and ductility. Well, at present, it has achieved considerable development with its unique advantages, and has good applications in auto parts, household appliances, instruments, mechanical and electrical products, metal furniture structural parts, etc. As an organic supplement of cathodic electrophoresis, self-coating paint has broad development and application prospects.
