Covering ability of aluminum pigments prepared by milling processes

This paper deals with the influence of milling regimes on the development of a lamellar structure of aluminum pigment particles. A group of parameters describing the degree of fineness and morphology of the pigment particles were monitored simultaneously. The experiments were carried out using a semi-pilot milling plant with a vibrating mill and a ball mill. Based on the experiments, a criterial non-dimensional relationship was outlined. The relationship generalizes the influence of milling process conditions on the lamellar structure of pigment particles. At the same time, an equation which limits milling time used for the milling process was outlined. This equation solves the problem posed by the risk of destroying the lamellar structure of the particles over time. The theory of metal working was applied as an analogical base for establishing the efficiency of the milling process with respect to energy demand. In addition to basic process parameters, the significant influence of surface active agents on pigment lamellar structure was studied.