Abstract
This study is related to the development of a new continuous manufacturing system for the solid powder cosmetics. This system is combined the wet powder dispersion process by an annular type medium stirring mill and the successive drying process by a flash type dryer.
The impact energy of beads was calculated from a distinct element method （DEM） simulation. The impact energy increases with an increase in rotational speed of the stirring mill. In addition, this tendency is quite similar to the concentration of ferrous ion generated by wear in ion-exchange water. The other optimal operating conditions were determined by experiment. A fluorescent observation revealed that the medium stirring mill was efficient for achieving the homogeneous dispersion of powder and oil. We also investigated various drying systems, and finally found that the dry powders obtained by the flash type dryer could keep the constant particle size distribution in slurry before drying.
