electrostatic spray gun
electrostatic Definition：
Using corona discharge principle, the coating method of atomized coating under the action of high voltage direct current field and negatively charged on the surface of positive charged substrate is studied.
Applied discipline:
Mechanical Engineering (first level discipline); Surface Engineering (two level discipline); coating and painting (three level discipline)
The contents are examined and approved by the national science and technology terminology examination and Approval Committee
Catalog
brief introduction
The working principle of electrostatic spraying
Editor's Edition
Electrostatic spraying is the use of high voltage electrostatic field to make the negatively charged coating particles move along the opposite direction of the electric field,
A spraying method for coating particles on the surface of workpiece. Electrostatic spraying equipment consists of spray gun, spray cup and electrostatic spraying high voltage power supply.
Edit the work principle of electrostatic spraying in this section
When the work is done, the electrostatic spray gun or the spray plate, the spray cup, the coating particle part meets the negative pole, the work piece connects the positive pole and the ground, under the high voltage power supply high voltage function, the spray gun (or the spray plate, the spray cup) the end and the work piece forms an electrostatic field. The charge voltage and the paint particles coating particles by electric field force and electrostatic field is proportional, and inversely proportional to the distance between the nozzle and workpiece, when the voltage is high enough, the formation of air ionization zone near the lance tip, air ionization and intense heat, the lance tip or extremely sharp edges around the needle a dark red halo, can clearly see in the dark, when the air generated strong corona discharge.
Most of the film forming materials, resins and pigments, are made up of polymer organic compounds, mostly conductive dielectrics, and solvent coatings have organic solvents, solvents, curing agents, electrostatic diluents, and other additives. In addition to benzene, xylene, solvent gasoline, such as solvents, most of them are polar substances, the resistivity is low, there is a certain conductivity, they can improve the electrification of coatings.
The molecular structure of dielectric can be divided into two types: polar molecule and nonpolar molecule. The dielectric composed of polar molecules shows electrical properties when applied to the external electric field; the dielectric composition of nonpolar molecules is good outside.
The paint is sprayed by the nozzle, and the atomized coating particles are charged by contacting the polar needle or the spray plate of the muzzle, and the edge of the jet cup. The surface charge density will be increased again when the gas ionization zone produced by the corona discharge. Under the electrostatic field of these negatively charged coating particles, the polar surface of the workpiece moves and is deposited on the surface of the workpiece to form a uniform coating.
