ABSTRACT

The tensile response of staple yarns is usually determined by the dynamics of spinning process, constituent fiber properties, the radial disposition of fibers along the yarn length commonly known as migration and the packing density of the fibers in the yarn. The packing density of the fibers is seldom uniform and, therefore, it is more appropriate to represent it in terms of fiber distribution in the yarn cross-section. The realistic representation of a position that a fiber occupies in the yarn along its axis, i.e. migration, should be supplemented by the distribution of fibers in the yam cross-section, which is affected by the fiber properties, and dynamics of preparatory and spinning processes. The problem is further aggravated when the yarn is spun from blends of similar or dissimilar fiber types as the method of blending adopted is expected to profoundly influence the position and the shape that fibers will take in the yam matrix. In our previous presentation in this forum it has been shown that the tensile properties of 100% cotton yarns spun from the blends of low and high tenacity cotton fibers are influenced by the blending technique, i.e. draw-frame and intimate. Further work in this study is being performed to evaluate fiber distribution in the yam cross-section and the migration of both low and high tenacity cotton fibers. In this paper the results on fiber distribution in the yarn cross-section are presented. The modeled fiber distribution of such blended yams is found to follow a parabolic function in most cases with some exceptions. The digital image analysis technique to measure fiber migration along the yam axis has been established. The results on fiber migration will be reported in our subsequent publications.