1. Main features of electrophoretic coating
1. The electrophoretic coating can be completely dissolved and emulsified in water, and the viscosity of the prepared bath is very low, which is similar to that of water. It is easy to penetrate into the bag-shaped structure and gaps of the body (coated object) immersed in the bath liquid.
2. The electrophoresis bath has high conductivity, and the coating particles can swim lively, but the conductivity of the wet coating film deposited on the object to be coated is small, and its resistance increases with the thickness of the wet coating film, and when it reaches a certain resistance value, It is no longer electrodeposited. Based on these two points, electrophoretic coating has good electrophoretic penetration and produces a relatively uniform coating film.
3. The solid content of the tank liquid is low, the viscosity is small, and there is less paint outside the tank taken out by the vehicle body, and it can be recycled by ultrafiltration (UF) devices and reverse osmosis (RO) devices.
4. The adhesion of the coating film is strong, and the rust resistance is high (the salt spray corrosion resistance of the 20 micron thick anodic electrophoretic coating film is more than 300h, and the cathodic electrophoretic coating film is more than 1000h).
5. The solvent (water-soluble solvent) content of the electrophoresis tank is small, and it cannot be burned even if it is ignited with a blowtorch, so there is less worry about on-site fire and explosion.
Second, the limitations of electrophoretic coating
1. It is only suitable for primer coating on conductive objects. Non-conductive objects such as wood, plastic, cloth, etc. cannot use this coating method;
2. The coated object composed of a variety of metals, if the electrophoretic properties are not the same, it is not suitable to use the electrophoretic coating process;
3. Electrophoretic coating process cannot be used for the coated object that cannot withstand high temperature (16-185°C). In recent years, electrophoretic coatings that can be dried at 120°C and 150°C have been successfully developed ;
| project | content |
| The priming process can be fully automated and unmanned | From paint pretreatment to electrophoretic primer drying, it is possible to realize production line, which is suitable for continuous production of large quantities of water |
Uniform film thickness can be obtained | It is easy to obtain a uniform target film thickness by adjusting the electric quantity. By selecting the type of electrophoretic paint and adjusting the parameters of the swimming coating process, the film thickness can be controlled within the range of *& . (0!' The paint film (film thickness and performance) deposited between workpieces and on different days can be reproduced differently from the dipping method. , the coating film between the gaps does not produce "dissolving" phenomenon during drying |
Good penetration (force) performance, improving the corrosion resistance of the inner cavity of the workpiece, especially the corrosion resistance of the cathodic electrophoretic coating film | The parts that cannot be painted by spraying, dipping and other coating methods and the parts where the paint is difficult to enter can also be painted, and the coating film between the gaps will not be washed off by steam during drying, so that the inside of the workpiece The corrosion resistance of cavities, welds, edges, etc. is significantly improved. The salt spray resistance of cathodic electrophoretic paint film is above 500h, up to more than 1000 hours |
| High utilization rate of paint | Compared with other water-soluble paints, the effective utilization rate of the paint can be higher than 95% compared with the solvent content and the spraying method. The paint in the tank is a water dilution with low solid content, and the viscosity is small, so there is less swimming coating out of the tank. The wet paint film is water-insoluble, and after electrophoresis, UF liquid can be used to seal and wash with water to recover the paint liquid brought out of the tank |
Relatively high safety, low-pollution coating (paint), no fire hazard | Compared with other water-soluble paints, the solvent content is less and due to the low concentration, there is no fire hazard. The paint is recycled well, the solvent content is low, and there is less pollution to water quality and air. The electrophoretic paint is a low-pollution paint. UF and RO devices are used to achieve Fully enclosed water washing can greatly reduce the amount of wastewater treatment |
The appearance of the electrophoretic coating film is good, and it has good | The coating film obtained by electrophoretic coating has less water content and less solvent content. During the drying process, it will not produce flow marks, dissolution, paint accumulation and other disadvantages like other coatings. The coating film after electrophoretic washing is dry, even hand It is not sticky to the touch. The drying time can be short, and it can be directly dried at high temperature |
4. Electrophoretic coating should not be used for coatings with limited requirements for color, and the color of the coating film must be coated in separate slots;
5. Electrophoretic coating is not recommended for small-batch production occasions (the update period of the bath solution exceeds 1 month), because the update speed of the bath solution is too slow, the aging of the resin in the bath solution and the change of the solvent composition are large, so that the bath Liquid is unstable.
