The tinting strength of a final product together with powerdraw of the mill and grinding time are optimized by adjusting the grinding conditions. The following three-step optimization procedure is described in the paper: in order to determine the most significant grinding variables, the first set of experiments was designed and carried out using the Plackett-Burman method. In the second step, a set of experiments with the selected variables was designed using the Box-Behnken method. The models of tinting strength and grinding power were then identified. In the third step, multicriteria optimization was performed. The paper presents and discusses the optimization results. In particular, the sets of Pareto-optimal solutions are provided for different levels of specific energy. The optimization results of tinting strength and grinding time clearly demonstrate that a low rotor speed combined with a low specific energy can sometimes provide better tinting strength compared with the high rotor speed strategy.
- Colorant paste
- Experimental design
- Pigment grinding
- Tinting strength optimization