Textural characteristics and friction properties of facial tissues

Abstract

In the current study, we conducted sensory tests for facial tissues that are commercially available in Japan, and we also tested the friction generated by the rubbing of these tissues on an artificial skin model. Using these results, we investigated the factors affecting the textural characteristics of the facial tissues. The tissue sample which contained a moisturizing agent had the highest evaluation score among the samples. Mean friction coefficient decreased as the sliding velocity decreased for low normal loads. The tissue samples which contained moisturizing agents had the low friction coefficients. From the multiple regression analysis to obtain the highest value of the adjusted coefficient of determination, the mean friction coefficient for a normal load of 0.49 N and a sliding velocity of 1 mm/s was the only parameter surprisingly that could be used to predict the evaluation scores; specifically, there was a negative correlation between the mean friction coefficient and the scores. In order to reduce the friction, one should seek to increase the moisture content of a facial tissue or decrease the tensile strength perpendicular to the fiber direction in dry facial tissues. Increasing the elastic modulus and surface roughness and decreasing the fiber diameter were effective methods for reducing the friction coefficient of facial tissues that did not contain moisturizing agents.