Coating process of powder electrostatic spraying on screw locomotive shed

As we all know, solvent-based coatings not only pollute the environment during the manufacturing process, but also the spraying of paint and the volatilization of solvents during spraying construction and curing can easily cause air environmental pollution

In order to prevent solvent-based coatings from damaging the ecological environment, many countries have intervened in the development of solvent-based coatings in the form of environmental protection laws and regulations to limit the emission of VOC.

Powder coating is a new type of coating that does not contain organic solvents and appears in the form of powder particles .

It not only has no solvent release in the production and coating process, less pollution, and meets environmental protection requirements; but also the quality of the coating film is good, and the recovery rate of powder sprayed during the coating process can reach 98%, which is conducive to the protection of the ecological environment; The coating is easy to implement assembly line production, the process is simple, the coating efficiency is high, and it is safe and hygienic;

It conforms to the "Four E" principles put forward internationally: Economy, Efficency, Energy, and Ecology, so it can develop rapidly

The company first used polyester powder electrostatic coating on the screw locomotive shed.

Characteristics and application range of polyester powder coatings

Polyester powder coating has excellent gloss, leveling and excellent weather resistance and mechanical properties

Mainly used in home appliances, lighting advertising, vehicles, barriers, transportation facilities, building materials, daily hardware, mechanical and electrical products, construction machinery, screw compressors and other metal surface coating protection

Principle of powder electrostatic spraying

The spray application of powder coatings must be guaranteed by specific coating equipment, and the choice of coating equipment is determined by the coating process
.

At present, there are many coating processes for powder coatings, mainly including fluidized bed coating process, electrostatic fluidized bed coating process, electrostatic spraying coating process, electric field cloud coating process, friction electrostatic spraying UV powder coating process, etc.
The packaging process has its own lengths and shorts, and should be selected reasonably according to the actual product
.

The powder coating of the screw locomotive shed is suitable for the typical powder electrostatic coating process
.
Powder electrostatic spraying mainly uses the principle of high-voltage electrostatic corona electric field: the workpiece should be grounded first when spraying.
Under the action of purified compressed air, the powder coating is sent from the powder supply system to the powder spray gun through the powder pipe
.

The head of the spray gun is equipped with a metal ring as an electrode, and the end of the metal ring has a sharp edge.
When the electrode is connected with high-voltage static electricity, the tip produces a corona discharge, and a dense negative charge is generated near it
.

When the powder is sprayed from the powder spray gun, it forms powder charged particles, which are adsorbed on the oppositely charged surface of the carport under the action of the electrostatic field force and the air flow
.

As the powder sprayed on the surface of the carport increases, the more the charge accumulates.
When it reaches a certain thickness, due to the electrostatic repulsion, the adsorption will not continue, so that the surface of the carport will adsorb a certain thickness of powder coating
.
The powder is heated by the baking furnace to melt, level and solidify, forming a tough and smooth coating film on the surface of the carport
.

Schematic diagram of carport powder electrostatic spraying process

Powder electrostatic coating process parameters

Physical and Chemical Performance Quality Index of Carport Coating Film

Analysis of economic and environmental benefits of powder coatings and solvent-based coatings (take the 941 screw locomotive shed as an example)

Concluding remarks

With the successive promulgation of national regulations on cleaner production in the industry, the strengthening of human environmental awareness and the improvement of the development of powder coatings and coatings in the field of coatings and coatings will be more valued and the application prospects will be broader, and the process of replacing OC-containing coatings will be accelerated.
The effects of energy saving, consumption reduction, pollution reduction, and efficiency increase are more significant
.