Expanding the application areas for the electromagnetic nano-mills (AVS), GlobeCore engineers conducted tests in dry milling of paint pigments.
Pigments and fillers perform an important function in paints and varnishes. First of all, pigments provide the variations of color and color shades. Second, they form a film layer, making the coating more durable. And third, the pigments improve anticorrosive properties of paints and lacquers.
Paint pigments are divided into two groups: mineral and organic. Mineral pigments, in turn, are natural or artificial. Natural mineral pigments are obtained by crushing and refining of various ores and clays, such as light gray, white chalk, green glauconite, dry yellow ocher. Artificial mineral pigments are produced by chemical processing of mineral raw materials. Organic pigments are materials of organic origin.
Each pigment has certain properties. The most important property is the fineness of grinding, which also influences paint spreading and tinting strength. Paint spreading is calculated in square meters per liter and the tinting strength is the ability of the pigment to change the color of another pigment. Increasing the fineness of grinding automatically increases paint spreading and tinting strength.
To obtain an alkali-resistant paint, GlobeCore performed mixing and regrinding of pigment components: silicon, aluminum, zinc and zirconium.
Initially, the selected degree of grinding was more than 50 microns, and the mixture itself was not homogeneous. To achieve better results, it was decided to try a finer grinding and regrind 500 g of the mixture to less than 10 microns to achieve a homogenous state. The grinding was performed using ferromagnetic steel particles 400 gr each, for 30 minutes, at the temperature of 90 … 100 ° C. The mixture changed color from bright red to pale pink due to the finer grinding of components.
The results of the experiment, its details and conditions can be found in the video report.