Characterization of Powder Cosmetics Based on Friction Dynamics.

Frictional properties are one of the most important physical factors in the design of powder cosmetics. In this study, 21 powder cosmetics were applied to artificial skin, and their friction characteristics were evaluated using a sinusoidal motion friction evaluation system. Three friction profiles were observed that depended on the sliding velocity. Principal component analysis showed that the principal component (Z), which characterized the friction dynamics of powder cosmetics, included the static friction coefficient (μ ), the kinetic friction coefficient (μ ), the delay time (δ), and the viscosity coefficient (C). Furthermore, a cluster analysis on Z suggested that powder cosmetics can be classified into three groups according to their friction dynamics. These results may be helpful to understand the phenomena that occur during the application of powder cosmetics.