Aluminum flakes are produced by grinding aluminum powder as a raw material. Aluminum flakes can be used in aluminum products and are generally found in liquid paints. A range of mechanical properties and chemical compositions are available. Besides, aluminum flakes are usually treated with organic compounds to improve their brightness and storage stability.
Aluminum flakes have three distinct particle sizes. These include small, large, and irregular shaped particles. The size of the particle determines its luminance and texture. Smaller aluminum flakes are more diffuse. Larger aluminum particles are more compact and more uniform. Also, the shape of the flakes impacts their texture.
Aluminum flakes can be ground to produce extra fine particles. They are typically sifted using a nylon sifter. Once formed, they are stored in a sealed container. If the flakes are treated with an organic compound with a polar group, they will retain their dispersion ability and improve their storage stability.
Fatty acids are often used as grinding aids. They impart parallel alignment of the aluminum flakes and inhibit aggregation. Other conventionally known grinding aids can also be used.
Aluminum flakes can be treated with polar or nonpolar solvents. Using an excessive amount of organic solvent weakens the impact of the grinding media. This can cause a decreased flaking efficiency. Nonpolar solvents also avoid corrosion of aluminum flakes.
Aluminum flakes can be stored in sealed containers. However, they can also be exposed to air, water, and other contaminants. This can result in the deterioration of their brightness. In order to maintain their storage stability, aluminum flakes are usually treated with organic compound with a polar group.