16—MEASUREMENTS OF THE INFLUENCE OF FINISHING AGENTS ON THE FRICTION OF FIBRES

ABSTRACT Experiments with continuous yarns, treated with a large variety of finishing agents, in which the coefficient of friction was measured by an inclined-plane method, yielded useful information on the properties of finishing agents on the one hand and also led to the development of a measuring technique for short fibres (30–40 mm). This method permits the determination from a 50 mg sample of fibrous textile material of the static as well as the dynamic coefficient of friction in such a way that reproducible results are obtained, the accuracy of the method being indicated by the very low coefficient of variation of the individual measurements. This method is based upon the formula ; the rubbing surface consists of fibres taken from the sample under test. It can be used by girls accustomed to routine testing work; the time taken for complete determination of coefficients of friction of a sample being about 90 minutes. The results obtained with finishes of various kinds on viscose staple fibre are described as well as a number of observations that bear upon the rheological phenomena of inter-fibre movement in general.