Usually, electrostatic spraying is an excellent choice for medium and small workpieces with standard shapes and sizes that are not too large. Not only can greatly save manpower and improve efficiency, but also fully automated, save worry and trouble.
Of course, it is not impossible for workpieces with complex shapes or large pieces to be sprayed. Due to the electrostatic shielding and the tip effect of the electrostatic field, the amount of paint adsorbed will be larger for the convex parts and edges of the workpiece; the electric field shielding will be generated for the concave parts, resulting in a thinner coating. Therefore, it is recommended to choose electrostatic spraying enterprises and arrange manual spraying stations to make up for the defects of uneven surface coating of special-shaped workpieces.
1. Preconditions
Wood moisture content
Wood is generally considered a poor conductor and cannot be electrostatically sprayed 55when the wood moisture content is too low. According to our company's multi-party testing, it is necessary to ensure that the wood moisture content is above 8% before electrostatic coating can be implemented.
Humidity effect
Under normal circumstances, it is more appropriate to keep the humidity in the construction environment in the range of 30-75%. If the humidity in the air is too high, electricity leakage will easily occur, which will affect the adsorption and wrapping effect of water-based paint.
2. Matters needing attention in operation
Adjust the paint output of the nozzle
When the ejection volume of the nozzle is too large, it is easy to cause insufficient electrostatic charge, resulting in poor atomization of the workpiece surface; however, the paint output of the nozzle is too low, which will affect the production efficiency. Therefore, the ejection volume of the nozzle should be adjusted to the maximum on the premise of ensuring the effect of the electric charge.
Adjust the hanging distance of the workpiece
Note that the distance between the workpiece and the ground should not be less than 1M, and the upper end of the workpiece to the transport chain should not be less than 0.5M.
Adjust the hanging method of the workpiece
Whether the hanging orientation and spacing of the workpiece are reasonable has a great influence on the final surface effect of electrostatic coating. The hanging distance of the workpiece is based on the principle of not colliding with each other during the removal process. For example, a square or rectangle should be hung vertically to avoid sagging due to excessive adsorption of paint on edges and corners caused by inclined hanging.
The effect of workpiece size
Good uniformity of electrostatic spraying effect for general lines or small area workpieces
3. Electrostatic spraying common problems and solutions
When the factory conducts electrostatic spraying, it is most likely to cause leveling and orange stripes. The solutions are as follows:
Increase the speed of the disc to improve the atomization effect. A good atomization effect will bring a better leveling effect.
Use Haisun water-based paint products: special for static electricity to improve leveling.
According to the spray effect, adjust the water-based paint to the appropriate viscosity to achieve the best leveling.
If the workpiece is large, the speed of the hanging wire can be adjusted to a suitable range according to the actual situation on site.
Make sure that the Haisun water-based paint primer is applied evenly and there is no leakage of paint.
Make sure the primer is well sanded and the surface of the workpiece is free of dust.
Avoid cross-contamination with oil-based paints. Including the pollution of putty after the oil-based paint is polished, it will bring hidden dangers to electrostatic painting.