Paint spray gun -- just as the name suggests, "Spray" means the way it works, "paint" means the material for spraying. As a tool for spraying paint, it is a kind of coating equipment, used for surface treatment of products. The paint is atomized by compressed air into small paint drops, which is sprayed to the surface of the coated object under the driving of air flow. It is mainly composed of spray, nozzle, needle valve and gun shell, and meanwhile, connected to external air pressure device, such as pressure tank, pressure barrel, pump, etc. Compared with the traditional manual painting, the spray gun is more time-effective, more beautiful, 5-10 times higher in efficiency, with the coating being fine, smooth and even.
In the selection of spray gun, in addition to the working conditions, the size and weight of the spray gun itself, the way of coating supply and the diameter of the coating nozzle should be considered.
(1) The size and weight of the gun itself. In consideration of reducing the labor intensity of the operator, small size is better, but the spray gun with small gun body also has adverse factors, such as small spraying amount and air amount, which slows down the operation speed of the spray gun, increases the spraying times, and reduces the operation efficiency, so it is not suitable for large-scale coating. However, when using large spray gun to spray small parts or tubular coating, the coating loss increases. Therefore, the large spray gun can be used for the flat large-scale coating, and the small spray gun is suitable for the coating with very different unevenness
(2) Coating dosage and supply mode. When spraying flat coating, due to small amount of paint and frequent color change, small gravity spray gun is recommended. However, it is not suitable for back-surface coating, since the amount of coating is a little larger, and color change is more frequent, especially when spraying the sides, it is better to use a suction type spray gun with a can less than 1 liter. However, when spraying the flat coating, the suction spray gun is not applicable. If it is a continuous operation with a large amount of paint and rare color change, the pressure feed type can be used with a paint booster tank with a capacity of 10-100 L, or when the amount of paint is larger, the pump and paint circulation pipeline are used to press the paint. The pressure spray gun, light in weight, does not have a cup or tank, and it is convenient to spray up and down, left and right. The disadvantage is that the cleaning work is more complex than the gravity type and suction type. The balance between the paint pressure and air pressure should have certain technology, but it is easy to master after being proficient.
(3) Nozzle diameter. The larger the nozzle diameter is, the larger the spraying amount of coating will be, and the higher the viscosity of coating will be, the less the spraying amount of coating will be. Therefore, the spray gun with large nozzle diameter should be selected for the coating with high viscosity. The spraying amount of the pressure spray gun will increase with the increase of the pressure, so the pressure spray gun with small nozzle diameter can also be selected. When the appearance requirements of spraying primer are not high, and the coating film is required to be thick, the spray gun with large nozzle diameter can be selected; when there is a high requirement for atomization in spraying the finish paint, the smaller nozzle can be selected. When spraying the primer, if the low viscosity coating is used, the nozzle with smaller diameter can be selected.