Disadvantages and prevention of water-based electrostatic spraying!

The utilization rate of electrostatic coating paint can reach 85%~90%, and the coating effect is good.
The comprehensive economic benefits of electrostatic coating of frame structure wood products, such as tables, chairs, doors, photo frames, etc.
, are particularly obvious.
The following lists several common defects in the electrostatic coating construction process, such as surface chalking, wet sagging, dry film sagging, dry film thick edges, dry film orange peel, uneven adsorption, etc.
, and preventive methods are given.
For reference.

Surface chalking

cause

Surface chalking, wire drawing, whitening, and nozzle plugging are all because the coating is drying too fast com" href="">.

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The drying speed is too fast, on the one hand, because the coating itself has a fast surface drying speed, and on the other hand, because the coating is in a high-energy state after being charged with static electricity, which speeds up the drying speed.

Preventive measures

One is to use electrostatic spraying special paint before painting; the other is to increase the dilution ratio to adjust the viscosity of the paint during construction; the third is to humidify the circulating air during the construction process, and the spray room without circulating air can improve the construction environment by spraying heat dissipation water Humidity.

Wet sag

cause

Wet sagging, dripping, and stacking are all caused by the low-viscosity flow of the paint, that is, the viscosity does not match the coating amount.

Preventive measures

The first is to adjust the paint viscosity before construction; the second is to control the coating amount during construction, that is, the discharge volume of the equipment; the third is to prevent wet sagging by adjusting the walking trajectory of the electrostatic nozzle.

Dry film sagging

cause

There are two main reasons for dry film sagging: one is related to the rheological properties of the paint itself.

Electrostatic spraying is a facade coating, which has high requirements for low viscosity and high resistance to sagging.
Second, it is related to temperature.
Too low temperature will slow down the surface drying speed of the paint film, and the probability of sagging will be greater.

Preventive measures

Adjust and control the coating amount during construction, and set a proper leveling and drying temperature according to the temperature and humidity of the construction environment, which can effectively reduce the chance of dry film sagging.

Thick edge of dry film

cause

Thick edges of dry film, also called falling edges or oil accumulation on edges, are caused by excessive local spraying.

Preventive measures

Adjust the traveling track of the electrostatic spray head to ensure that the spray width of the spray gun exceeds the edge of the workpiece.

Dry film orange peel

cause

If the viscosity of the paint is too high, or the paint dries without flowing and leveling after being adsorbed on the workpiece, it will cause a dry film of orange peel.

Preventive measures

One is to appropriately increase the dilution ratio and reduce the construction viscosity; the second is to extend the drying time after the coating is sprayed, and the coating can be heated to dry or solidify after it has flowed and leveled.

Uneven adsorption

cause

The wet adsorption is not uniform, mostly related to the conductivity and moisture content of the substrate.

For example, slender pieces are good for electrostatic adsorption, while "wide" pieces are not good for electrostatic adsorption; solid wood is good for electrostatic adsorption, and MDF is not good for electrostatic adsorption.

Preventive measures

The first is to increase the environmental humidity; the second is to adjust the walking trajectory of the electrostatic nozzle; the third is to adjust the electrostatic voltage (generally lower); the fourth is to increase the rotating air pressure of the nozzle.

In electrostatic coating, humidity is the core.

When the humidity is between 50% and 65%, the effect of electrostatic coating is best.
Excessive humidity will cause water on the surface of the equipment, leading to risks such as electric leakage.

The above content hopes to help the majority of furniture companies to deepen their understanding of the disadvantages of electrostatic coating, take targeted prevention in the actual production process, and improve production efficiency under the premise of ensuring safety.