Method of controlling free flow of finished powder
1.1 The main component of low temperature pulverized powder coating is resin, and the molecular weight of resin is low, generally only several thousand, the softening point is generally not more than 115℃, the softening point of epoxy resin is only about 90℃.
The glass transition temperature of resin used in powder coating is lower, which is generally about 58℃.
At present, ACM mill is used for grinding and grinding of powder coating, and grinding and powder grading are carried out simultaneously.
In the actual production process of powder coating powder manufacturer, ACM mill works for a long time or in hot summer, the temperature of the powder out of the screen is high. If the powder is packaged immediately, it will soon agglomerate.
Therefore, we installed a freezing device in the air inlet pipe of ACM mill to improve the coating performance of the powder.
In order to improve the fluidity of powder coating, gaseous silica is generally added when the extruded piece is crushed.
Gaseous silica is a very fine amorphous silica obtained by flame hydrolysis of silicon tetrachloride, which is composed of spherical particles with an average particle size of 7-40nm.
The powder coating made by this method is observed under the electron microscope, and the powder particles are not adhered to each other, and the particle sense is strong.
The gas phase silica suitable for powder coating can be divided into hydrophilic type and hydrophobic type from the chemical structure. The hydrophobic type of silica can improve the charged performance of powder coating better than that of the hydrophilic type. Usually, 1‰~2‰ of the total amount of powder is added when pulverizing.