Air spraying method for metal and plastic coating in Dalian:

Air spraying method for metal and plastic coating in Dalian:

Air spraying

Air spraying is the process of using compressed air to spray out from the center hole of an air cap, creating a negative pressure zone in front of the paint nozzle. This causes the paint in the paint container to be sprayed out from the paint nozzle and immediately enter a high-speed compressed air flow. The paint is atomized and flies in the form of paint mist, attaching to the surface of the object being coated. The paint mist particles quickly accumulate into a continuous paint film.

Air spraying for metal and plastic coating in Dalian is a widely used method in electric vehicle coating, which has the advantages of high coating efficiency; Strong adaptability, suitable for various coatings and workpieces of various materials and shapes, without being limited by the site; High painting efficiency; Adequate atomization of paint; Low investment cost; The coating is uniform and aesthetically pleasing. But the utilization rate of coatings is low, generally only 50%~60%, and only 15%~30% for small parts; The scattered paint mist creates a harsh working environment and requires good ventilation equipment; High requirements are placed on the construction environment and construction parameters (spray booth process parameters, paint construction parameters).

Characteristics of air spraying

Advantages: High coating efficiency, capable of spraying 150-200 square meters per hour. The coating thickness is uniform, smooth, and flat, with good decorative appearance and strong adaptability. It is suitable for various coatings and workpieces of various materials and shapes.

◆ Disadvantages

A large amount of diluent is used, and a large amount of solvent evaporates during operation, which can easily cause air pollution. The working environment is harsh and can easily lead to accidents such as combustion and explosion. The work site must have good ventilation facilities. The utilization rate of coatings is low, generally only 50% to 60%, and for small parts it is only 15% to 30%. The scattered paint mist further deteriorates the working environment, and mass production should be carried out in the paint booth.

During spraying construction, the wind speed inside the spraying room must also be controlled, preferably at 0.3-0.5m/s. The direction of air flow should be from top to bottom, that is, fresh and clean airflow should flow through the construction area and be extracted from the bottom along with the paint mist. If the air flow rate is too high, the adhesion of paint mist on the work will decrease, the loss of paint liquid will increase, and the high wind speed will also accelerate the evaporation of solvents in the paint film, resulting in poor leveling of the paint film and easy occurrence of coating defects such as orange peel; If the air flow rate is too low, it cannot provide ventilation and air exchange, which affects solvent evaporation and causes environmental pollution.