5—FRICTIONAL FORCES IN COTTON AND REGENERATED CELLULOSIC FIBRES

Inter-fibre frictional forces, F, corresponding to normal loads, R, of up to 300 g, experimentally determined for a large number of fibres, mostly cottons, rayons, and polynosic rayons, conform to a general expression of the form F = αRn . The parameters α and n are, however, shown to be interdependent, correlations as high as −0·991 and −0·962 being obtained for cottons and regenerated cellulosic fibres, respectively. An explanation is sought for this phenomenon in the fine structure of the fibre, which influences the surface characteristics through changes in visco-elastic properties. Supporting evidence is adduced from the results of experiments on mercerized cottons, which behave in a similar manner to rayons and polynosic rayons, all of which are known to reveal cellulose II structures by X-ray methods. A simple physical approach on considerations of surface area shows that fibre characteristics, namely, length, fineness, and maturity, have a decreasing influence on the frictional behaviour as the ap...