Science of Comfortable Washing with Foam

Abstract

Rich foam is one of the most important features of a body cleanser. Although there have been many studies on the visual and physical aspects of foam, such as “foamability” and “stability,” the origin of the sensory values that foam provides, such as“ pleasant” and“ mild to the skin”, are not well understood. In this study, we investigated the rheology and dynamic friction properties of foam, focusing on the adhesion to solid surfaces with which it directly contacts. The results suggest that the flow of foam on solid surfaces is highly dependent on the properties of the solid surface, and that the presence of foam felt by our hands when expanding the foam is caused by the resistance forces attributed to the deformation of bubbles and adhesive force to the substrate.