Powder spraying process on the surface of aluminum alloy

Powder spraying of aluminum alloy

Powder spraying is used to spray powder coating on the surface of the workpiece by spraying powder equipment (electrostatic spray plastic machine). In electrostatic action, the powder will be evenly adsorbed on the surface of the workpiece to form a powdery coating; the powder coating is solidified by high temperature baking and becomes the final coating of different effect (different kinds of powder coating effect) The powder spraying effect is superior to the spray painting process in terms of mechanical strength, adhesion, corrosion resistance and aging resistance, and the cost is also under the same effect of spray painting.

A set of electrostatic powder spraying system mainly consists of a set of powder feeding devices, one or several sets of electrostatic spray guns and control devices, an electrostatic generator (usually arranged in an electrostatic spray gun) and a set of powder recovery devices.

Powder feeding device

In a powder feeding device, the powder is in a state of fluidization, which is realized by the effect of compressed air, and then the powder is carried by high speed flow through the siphon, forming a mixture of powder and gas through a Venturi powder pump, a powder conveying pipe, and finally to the spray gun.

The powder conveyed to the spray gun is controllable. In particular, it can adjust the parameters of the powder and air separately, change the powder quantity and the atomization state of the powder, thus the different coating thickness can be realized to meet the needs of different products. The powder feeding device has sufficient capacity, even if the powder conveying tube of the spray gun is 50 feet long, it can also provide enough pressure and flow.

By the high voltage produced by the electrostatic generator, the low current causes the electrode needle in the front of the spray gun to discharge in the air. When the powder is sprayed through the nozzle of the gun head, the powder particles are charged with the powder, and it reaches the surface of the ground which has been grounded by the double action of electrostatic adsorption and air flow.

The spray gun can produce enough voltage to ensure maximum coating effect. The maximum voltage can reach 100kV. When spraying the inner angle or deep cavity, the spray gun can effectively overcome the Faraday cage effect and ensure that the surface of each piece of the workpiece is required to cover a good cover and uniform film thickness.

Spray gun

The structural design of the spray gun must meet the charging requirements of the powder, and the functional design must meet the spraying requirements of various forms of spraying work and various shapes of workpieces.

Powder coating is a new technology of surface coating technology. It is a coating process with powder form and coating. It can replace traditional paint technology on many occasions. It has been widely used at home and abroad.

Working principle

Using the principle of electrostatic spraying powder spray, the dry powder is adsorbed on the metal aluminum profile of the spraying site and solidified into a layer of about 60 microns thick and bright after 200 centigrade high temperature barbecue. The smooth and smooth color of the product has strong acid resistance, alkali resistance, crashworthiness, abrasion resistance, and corrosion resistance, and acid rain corrosion for a long time without the phenomenon of coating powder, fading and falling off. The service life of powder sprayed aluminum profiles under normal conditions is 30 years. Its surface coating will ensure that it does not fade, do not change color or crack in 5-10 years. Its weatherability and corrosion resistance are better than that of common aluminum.


Post time: May-02-2018