Classification and Characteristics of Spray Paint in Powder Dust-free Coating Production Line

Spraying paint is a method of spraying paint on workpiece surface after spraying paint atomization to form a uniform and dense coating. The common spraying methods are air spraying and high pressure air-free spraying.

Air spray paint is sprayed on the surface of workpiece by high-speed airflow generated when compressed air with pressure of 0.3-0.4 MPa is ejected from nozzle to form paint film.

Air spraying paint has the advantages of simple equipment, compact coatings, not limited by coatings and workpiece shape. The disadvantage of air spraying paint is that there is a large amount of paint mist in the process of spraying paint, which pollutes the air and causes a large loss of paint. The water and other impurities in compressed air are easily mixed into the paint flow, and the treatment is not clean, which will affect the quality of the coating.

Coating Line for Driving Shaft

Air spraying paint is widely used in hand spraying paint with large area and complex workpiece shape. In order to limit the pollution of paint mist to the environment, air spraying should be carried out in the spraying room.

High-pressure air-free spraying is to use high-pressure pump to pressurize paint to 12.0-21.6 MPa from the spray gun, because of the sudden drop in pressure, it immediately expands and atomizes, spraying to the surface of the workpiece to form a paint film.

High-pressure air-free spraying has the advantages of high productivity, less paint mist, low air pollution, good working conditions and strong adhesion of paint film. And because there is no water, oil and other impurities in the flow of plastic painting line, the protective performance of the coating is also good. The disadvantage of high-pressure air-free spraying is that the structure of the equipment is complex, the coating is less uniform than that of air-spraying, and the decoration is poor.

High-pressure air-free spraying is suitable for large-scale products such as ships, locomotives and vehicles, bridges, heavy machinery and so on. In order to improve the sanitary condition, the high-pressure air-free spraying operation of the spraying line of the steam drive shaft should be carried out in the spraying room.

According to the operation mode, spraying can be divided into manual spraying and automatic spraying.

Manual spraying is a kind of spraying gun which is used by workers to spray the workpiece according to the shape of the workpiece. Its advantages are flexible and convenient operation, suitable for workpieces of different environments, shapes and sizes, less one-time investment and low energy consumption. The disadvantages are low production efficiency, unstable spraying quality, high labor intensity, vulnerable to paint mist pollution and poor working conditions.

Automatic spraying is to use automatic mechanical control spraying gun to spray the workpiece. The advantages of automatic spraying are high productivity, stable spraying quality and good working conditions for workers. The disadvantages are large one-time investment, complex equipment structure and large maintenance and management workload.