company news about Detailed explanation of the process flow of spraying

Spraying is the use of corona discharge phenomenon to adsorb powder coating on the workpiece. The process goes like this: Powder coating is fed into the spray gun by the powder supply system through compressed air gas, and the high pressure generated by the high voltage electrostatic generator is added to the front end of the spray gun. Due to corona discharge, a dense charge is generated near it. When the powder is sprayed by the gun mouth, charged coating particles are formed, which are sucked into the workpiece with opposite polarity. When a certain thickness is reached, due to the electrostatic repulsion, it does not continue to adsorb, so that the whole workpiece obtains a certain thickness of the powder coating, and then the powder is heated to melt, level, and cure, that is, a hard coating film is formed on the surface of the workpiece. 1. Pre-treatment:
Objective: To remove the oil, dust and rust on the surface of the workpiece, and to generate a layer of anti-corrosion and increase the adhesion of the spray coating "phosphating layer" on the surface of the workpiece.
Main process steps: oil removal, rust removal, phosphating, passivation. Not only is there no oil, rust, and dust on the surface of the workpiece after pre-treatment, but also a uniform and rough gray phosphating film that is not easy to rust is generated on the original silver-white glossy surface, which can both prevent rust and increase the adhesion of the spray layer.
2, electrostatic spraying
Purpose: The powder coating is evenly sprayed on the surface of the workpiece. Special workpiece (including the position that is prone to electrostatic shielding) should be sprayed with a high-performance electrostatic spray molding machine.
Process steps:
Using the principle of electrostatic adsorption, spray a layer of powder coating evenly on the surface of the workpiece;
The fallen powder is recovered through a recovery system and can be reused after being sifted.
3, high temperature curing
Purpose: To heat the powder coating on the surface of the workpiece to the specified temperature and hold the corresponding time, so that it can melt, level and cure, so as to obtain the surface effect of the workpiece we want.
Process steps: Push the sprayed workpiece into the curing furnace, heat it to the predetermined temperature (generally 185 degrees), and hold it for the corresponding time (15 minutes); Open the furnace and take out the cooling to get the finished product. The general workpiece is different, and the heating temperature and holding time are also different.
Tip: Heating and control system (including electric heating, oil, gas, coal and other heating methods) + insulation box = curing furnace.
4. Let cool
Cooling is the process of cooling the result of the spraying process to return it to normal temperature.
5, decorative treatment
Purpose: To make the workpiece after electrostatic spraying to achieve a special appearance effect such as: various wood grain, pattern, lighting and so on.
Process steps: cover light; Transfer and other processing technology.