According to a paper published in the Journal of Oleo Science, frictional properties are key to designing cosmetic dispersions of solid particles in a liquid. These mechanical properties can affect application, finish, UV protection, etc.
Here, the frictional properties of 33 cosmetic dispersions were evaluated using a sinusoidal motion friction evaluation system applied on artificial skin. All cosmetic dispersions exhibited a stabile pattern and the friction behavior did not change throughout.
See archived: Yield Stress Measurements for Personal Care, Part I; Definitions and Basics
Analyzing friction-based parameters by principal component analysis demonstrated that factors including static friction coefficient, kinetic friction coefficient, delay time and a viscosity coefficient are involved in characterizing friction dynamics. As a result, the dispersions could be classified in three groups in terms of friction dynamics.
The author believe the results obtained by this method could elucidate the characteristics of cosmetics and control their function and utility.
See archived: Skin Friction Coefficient Values