Novel composite siro-spinning with forced migrations of filaments

In this study, a novel composite siro-spinning method with cyclically migrating filaments was developed as a simple and safe way to enhance filament-staple-fiber coherence. The novel composite siro-spinning method was theoretically demonstrated to produce a yarn with migrated filaments clasping both internal and external fibers. It was predicted that migrated filaments of the novel composite sirospun yarn were not straight enough to resist yarn tensile drawing as the filament parallelism with the yarn axis decreased. However, migrated filaments could clasp the staple fibers firmly to enhance filament-staple-fiber coherence, contributing an excellent frictional resistance of the novel composite yarn. Experiments were then conducted to validate the demonstration. Experimental results proved that the novel composite sirospun yarn had cyclic filament immersion and exposure appearance, resulting in medium hairiness and yarn imperfection after comparison with corefil sirospun and siro corefil yarns. The novel composite sirospun yarn with severe filament migrations had poor filament straightness, but filament deformations that were effective in clamping staple fibers. Therefore, the novel composite sirospun yarn had less strength, but greater frictional resistance than corefil sirospun and siro corefil yarns.

Effect of Yarn Structure on Mechanical Properties of Twisted Yarn Composites

T wisted yarns are used for bio-composites and nanocomposites as reinforcement . In a twisted yarn, single yarns migrate from surface to inner along the yarn axis. In this research , migration structure is studied by using X-ray CT system . The result is obtained that the orientation angle correlates with layer .

Finite Element Modeling of an Oriented Assembly of Continuous Fibers

A micromechanical model of the large displacement behavior of a sliver of oriented helical fibers has produced algorithms for predicting and updating all five independent mechanical constants. The incorporation of the micromechanics in a finite-element model of a uniform rope of initially untwisted fibrous material is described. The response of the whole model to combined external and torsional stresses such as occur during twist insertion is then described. A detailed analysis of the stresses and strains in the deformed model shows that fiber packing in the yarn is predicted to quickly become non-uniform. The inner regions become most densely packed, and fibers there are subject to the highest stress levels. Fibers further from the center largely avoid being stressed by moving toward the yarn axis.