Yuan Lei's Little Knowledge | The Role of Barium Sulfate in Powder Rate of Powder Coatings
1. control the powder particle size distribution, the narrower the better: reasonable control of powder particle size (more difficult), in our actual production only adjust the ACM main and auxiliary mill speed. Powder particle size is important 40-50UM is appropriate, the distribution of about narrow the better.
2. increase resin content: increase resin content, reduce filler content, select resin with good charging performance, epoxy is better to powder, polyester is not powdered by some manufacturers, polyester is more difficult to powder by some manufacturers (epoxy and polyester are ground into powder spray board separately), the leveling sprayed by friction spray gun is obviously better than that of electrostatic spray gun, and friction spray gun can spray thicker coating, and the coating does not have the disadvantages of high pressure gun, such as large orange peel.
3. and reasonable selection of fillers: filler fineness and dispersion are closely related to the powder. Precipitation on the powder is higher than the general ultrafine heavy barium, barium sulfate is better than calcium carbonate.
4. increase the charge aid: add the appropriate amount of conductive aid in the formula (mechanism of action: can make the powder particles carry more charge. There is a strong electric field in the area from the high-voltage electrostatic spray gun to the workpiece, and the air is ionized to produce hundreds of millions of ions. When the powder particles of the electric booster pass through this area, they are polarized, which can trap more negative ions and carry more charge. For the groove dead angle and other parts due to the weak power line of the Faraday effect, the powder particles with more charge can reach the surface of the workpiece by their own strength, thus improving the powder on these parts.
Barium sulfate, powder, resin, polyester, filler, more, charge, particle, improve, better
Kaolin is a non-metallic mineral, which is a kind of clay and clay rock mainly composed of kaolinite clay minerals. Because it is white and delicate, also known as white earth. It is named after Gaoling Village, Jingdezhen, Jiangxi Province.
Barium sulfate is based on barite as the main raw material, through beneficiation, ore washing, crushing and other processes. Barium sulfate has a hardness of 3~3.5 (Mohs) and a specific gravity of 4.3~4.7. It has the characteristics of high specific gravity, low hardness and brittleness. Barite is almost insoluble in water, ethanol and acid, soluble in hot concentrated sulfuric acid. With the development of some high-performance barium sulfate products, the application field of barium sulfate is constantly expanding.