Effects Of Exfoliating Facial Cleanser On The Friction Properties Of Human Skin

In daily life, the human facial skin always exposure to the external environment, which may cause skin some problems such as dry, wrinkling and sunburn, however, the cosmetics can play important roles in the facial skin moisturizing, whitening and sun protecting. Unfortunately the aging skin corneum often impedes the permeation of cosmetics and the roles. Regular removal of the extra aging horny cells can facilitate the infiltration of cosmetics and improve the performance of the skin. Therefore, the study on the effect of exfoliating facial cleanser on friction performance of human skin and exfoliating effect is of great reference value for people to choose the suitable exfoliating cosmetics, and also for cosmetics manufacturing.The reciprocating sliding friction tests on the healthy human skin have been carried out in a flat-on-flat configuration using a reciprocating UMT-Ⅱ series multi-specimen Biomedical Micro-Tribometer under the simulated face washing conditions.The friction media are three kinds of exfoliating facial cleanser with different size, amount and hardness exfoliating particles. The hardness, amount and size of the particles were measured by using Nano-Hardness Tester and Optical Microscope. The skin surface roughness, surface profile, conductance and hydrophilic were examined by using laser confocal scanning imagers, scanning electron microscope, video contact angle measuring instrument and biofeedback equipment respectively. The effects of three kinds of exfoliating facial cleanser on the tribological property of human skin and the ability of removal of the aging horny cells have been analyzed.The main conclusions can be summarized as follows:1. Due to the aging horny cells have been removed by the exfoliating facial cleanser under reciprocating sliding were mode, the skin surface roughness decreased and the skin hydration increased,which resulted in the skin adhesion and friction coefficient increasing, The skin friction coefficient was higher than that of exfoliating facial cleanser before using.2. After the aging horny cells have been removed, the skin conductance and hydration increased, the friction property of the skin also changed, and the penetration and persistence of moisturizer on skin surface were increased.3. Under the condition of the exfoliating facial cleanser medium B with two kinds of size and moderate volume and hardness exfoliating particles existing between the two-body, the skin friction coefficient was higher than those of group A and C. The skin surface roughness decreased largely and more aging horny cells have been removed, which resulted of the skin permeation to the moisturizing cosmetic was better.4. Due to the gender differences on the skin surface structure, the effect of exfoliating facial cleanser on the skin roughness and conductance of males were more significant than those of females, while the comfort sensations of females were more significant than those of males.