Classification of Aluminum paste
April 12, 2025
Lubricants must be added at all stages of the production process to prevent from clumping, which has a unique effect on the wetting properties of metallic pigments.There are obvious differences in wetting properties between between leafing type and non-leafing type.
Due to their high surface tension leafing pigments are not wetted by the binder and therefore float on the wet film. This effect is achieved by the use of e.g. stearic acid as lubricant .
In paint systems with strongly polar solvents or binders there is always a danger that the leafing pigments will "drown" through wetting and turn into non-leafing pigments. This possibility must betaken into account
when drawing up the formula of paints. If necessary special leafing stabilized pigments should be used.
Non-leafing pigments are created either by the addition of strongly polar substances or wetting agents to leafing pigments or by the use of special lubricants (e.g. oleic acid) directly in the milling process.
Non-leafing pigments are completely wetted and thus spread evenly throughout the entire paint film.
