Silver aluminium pigments in production of metallic masterbaches

Most aluminum pigments manufactured today rely on the Hall process, a wet ball milling technique. This process is desirable not only because of its efficiency, but also the elimination of grinding under dry conditions makes it very safe. Wet ball milling process carries out the particle size reduction in the presence of a suitable lubricant and an aliphatic hydrocarbon solvent, producing a safer, far superior aluminum flake pigment. When milled into a pigment, the most striking feature is the geometry of the particle itself. Aluminum pigments are actually aluminum flakes rather than being spherical or granular as are most other pigments. It is this flake-like shape that is responsible for many of aluminum´s characteristics. Aluminum pigments are used in many types of polymers to impart both aesthetic and functional values. Some important functional values are light reflection, Opacity, Gas and vapor barrier and thermal properties of aluminum pigments. Typical grades are sold at 60-90 metal concentration, whereas levels are typically 0.1-5.0 in the final product. Obtaining a reduced metal concentrate requires a compounding step in which the master batch or color concentrate manufacturer reduces the loading to 10-20 in a compatible resin.