Brush model to predict the friction of hairy textile fabrics from indentation measurements

Many textile surfaces are characterised by emergent fibres, i.e. superficial hairiness. It is well known that hairiness plays an important role for the frictional and tactile properties of fabrics. In the present paper, we describe a brush model to predict the friction of hairy fabrics. The new model is based on the assumption that the deformation of superficial hairs during friction is equivalent to the deformation of the hairy textile structure during surface indentation or compression. The force required to compress a given number of hairs per surface unit can be measured by indentation experiments and used to predict the force required to lay down hairs during dynamic friction. Three cases of hairiness deformation are analysed: purely plastic, purely elastic and visco-elastic. For four different textile fabrics, the theoretical calculations based on visco-elastic material behaviour showed fairly good agreement with the experimental results.