51—THE RADIAL DISTRIBUTION OF FIBRES IN BLENDED YARNS PART II—FACTORS AFFECTING THE PREFERENTIAL MIGRATION OF COMPONENTS IN BLENDS

Abstract

Fifteen selected binary blends, nominally 50/50 by weight, have been specially spun on the cotton system and the radial distribution of blend components has been characterized by a previously described “Migration Index”1. It has been established that significant migration of components can occur in these blends, and that the direction and extent of migration is determined mainly by the relative staple lengths and deniers of the components. Relative shortness and coarseness of fibre are cumulative factors tending to induce outward migration towards the surface of the yarn. Although individual yarn cross-sections exhibit considerable variations in the radial distribution of components, the mean distribution for each yarn as a whole has been shown to depend on a general form common to all fifteen yarns and, for each individual yarn, on a quantitative factor shown to be proportional to its migration index. Mean rnigration indices determined range from zero, corresponding to uniform distribution, to 33%. The standard error of the mean percentage migration index based on a sample of fifty cross-sections is approximately 2.