What is Powder Coating?

The conveying system of a coating production line is generally composed of conveyors, conveying tracks (including tensioning devices), conveying chains, workpiece carriers and other equipment. In some heavy or super-large workpiece production lines, from the loading area, pre-treatment, drying tunnel, spraying room, to the unloading area, the conveying system often runs through the entire coating production line to maintain the operation of the entire line. In the early stage of coating line plan design and formulation, different conveying systems should be designed in combination with factors such as the size and structure of the plant and the structural form, size, and weight of the workpiece.

Powder spray coating:

In addition to thermosetting epoxy, polyester, and acrylic, a large number of thermoplastic grease-resistant materials can also be used as powder coatings, such as polyethylene, polypropylene, polystyrene, fluorinated polyether, nylon, polycarbonate, and various fluorine-containing resins. With the development of science and technology and industry, powder coatings are currently widely used in the automotive industry, electrical insulation, corrosion-resistant chemical pumps, valves, cylinders, pipelines, outdoor steel components, steel furniture, castings and other surface coatings.

Powder electrostatic spraying equipment:

Powder electrostatic spraying equipment mainly includes: powder spraying room, high-voltage electrostatic generator, electrostatic spray gun, powder feeder, powder recovery device, etc. Powder spraying room is one of the main equipment for powder electrostatic coating. During operation, the dust content in the spraying room should be controlled to be lower than the explosion limit (generally set at 10g/m³). The powder spraying room should be easy to clean so that the powder is not easily deposited in the room, so as to change the color of the powder. There should be enough light in the room to facilitate the coating work.

Electrostatic spray gun:

Classification: Spray guns can be divided into portable powder spray guns, fixed automatic powder spray guns, disc spray guns, etc. according to their uses; they can be divided into internally charged guns and externally charged guns according to the form of charge; they can be divided into conflict guns, rebound guns, secondary air inlet guns, centrifugal cup guns, etc. according to the form of diffusion mechanism. Spraying efficiency: The charging mechanism of the powder spray gun is a key factor in improving the spraying efficiency. Generally speaking, the core of the powder spraying equipment is the spray gun and the charging system. As far as the current market is concerned, the proportion of corona spray guns is extremely large. This is because the biggest advantage of using high-voltage corona discharge to charge powder is that it can spray all types of thermosetting powder coatings today and can obtain very good results. Its advantages are mainly reflected in excellent stability, high powder application rate and fast powder application speed.

Powder supply system:

The powder supply system is used to continuously and evenly transport the powder material to be coated from the powder container to the powder spray gun for spraying. The powder supply system consists of an air compressor, an oil-water separator, an air dryer, a regulating valve, a compressed air pipeline, an electromagnetic control valve, a powder feeder, a powder delivery pipeline, etc.

Powder feeder form:

In the powder electrostatic spraying powder supply system, there are many types of powder feeders used, which can usually be divided into: pressure vessel type, mechanical conveying type with screw or turntable, and Venturi air suction type.

Powder recovery device:

Powder recovery can be divided into wet and dry methods. The wet method is to filter the airflow with powder through a liquid container to achieve purification, and the powder with liquid is dried and reused. Dry powder recovery is to collect powder particles in the powder airflow discharged from the powder spraying room. There are many types of dry powder recovery, such as gravity settling, inertial separation, cyclone separation, sintering plate separation, etc. In actual production, multi-stage recovery devices are often used to achieve better separation effects.