In the coating process line, the electrostatic spray gun is the core equipment of the surface treatment of the main body, it is through the use of low-pressure high atomization device and through the electrostatic generator to generate electrostatic electric field force efficient and rapid coating to the surface of the object to be coated, so that the object to be coated to achieve the perfect surface treatment, so both the coating atomizer and electrostatic electrode generator.
The electrostatic spray gun is a method of electrostatic coating in which the grounded object is the positive electrode, the paint atomization device is the negative electrode, and the paint atomization device is made with high negative voltage to make the electrostatic boundary between the two poles, so that the atomized paint particles are negatively charged and the paint is effectively absorbed on the surface of the object with the opposite electrode. Then why is the coating object used as the positive electrode and the paint atomizer used as the negative electrode? It is because it is more difficult and unsafe to transfer to spark discharge when it is opposite.
In order to implement electrostatic coating, the grounding of the painted object is an important requirement, and the painted object must be a good conductor of electricity. Wood is usually considered as a bad electrical conductor, but when its moisture content is 8% or more. Electrostatic coating can be applied, and it is confirmed by experience.
The current value between positive and negative poles is 20~50 microampere (MICRO-AMPERE), which is very small, so it is possible to apply electrostatic coating to objects with high resistance value, such as wood.
Electrostatic spray guns have different classifications according to their functions and uses.
According to the type of classification: manual electrostatic spray gun and automatic electrostatic spray gun.
Manual electrostatic spray gun: manual spraying using the spraying tool, suitable for spraying large, medium and small workpieces, the appearance of irregular workpieces. Also mostly used for outdoor large workpiece spraying. Can achieve uniform spraying of a wide range of workpieces in a short period of time.
Automatic electrostatic spray gun.
1. Cup type electrostatic spray gun is with the help of its edge linear speed up to 30m / s above the spinning cup, so that the paint atomized under the action of centrifugal force, the paint mist in the centrifugal force and electrostatic gravitational force to fly to the painted object.
2. Disc-type electrostatic spray gun, also known as Ω-shaped electrostatic spray gun, the use of high-speed rotating disc (diameter of 200mm or more, speed 3000 ~ 6000r / min) of the centrifugal force will be thrown out of the paint atomization, charged and fly to the painted object.
3. Ordinary automatic electrostatic spray gun.
China spray gun industry is growing at a multiplier, according to the analysis of the development trend of China's spraying industry, rotary cup electrostatic spray gun will become the mainstream of the painting industry in the past few years, according to the process technology to divide, spraying can be divided into manual spraying and automated spraying, spraying including spraying materials and spraying equipment.
According to the Foresight Industry Research Institute released in 2018 to 2023, the development trend of China's spraying industry, China's spraying market size accounted for nearly half of the Asia-Pacific region, with the use of coating equipment industry: construction, hardware industry, furniture industry, automotive industry, plastic spraying, industrial spraying and so on industry development, then the demand for industrial paint gun is still growing, the number of electrostatic spray gun manufacturers are also increasing. But for this technical requirements of the industry, the survival of the fittest is the trend, and spraying technology in the continuous development of seeking, perhaps in foreign countries spraying equipment, technology and other development is very mature, in the country is still in the blank stage, with the improvement of automated industrial production, the requirements of various industries to improve, then the growth of electrostatic spray gun manufacturers R & D and production technology has become an inevitable trend, because these high-tech equipment to cater to the market for the needs of the industry.