Dynamic properties of air-jet yarns compared to rotor spinning

In yarn production, the mechanism of twist insertion is a major factor that affects the structure and ultimately the properties and characteristics of the produced yarn. Moreover, the differences within the same spinning technique may have a similar effect where, for instance, the properties of yarns produced using Murata Vortex Spinning (MVS) and Reiter air-jet spinning (J20) will differ, although both technologies are just varieties of the same twist insertion principle of using a stream of air. In this work, the structure and properties of Murata vortex, Reiter, and rotor-spun yarns are compared with more emphasis on their mechanical behavior under dynamic stresses. Unlike the dynamic mechanical analysis of materials that presumes linear viscoelastic behavior and is only valid under small strains, this work suggests a cyclic loading with larger strains as a means of the dynamic evaluation of the yarns. Results show no significant difference between the technologies in terms of their initial modulus and maximum elongation, while a significant difference between the technologies is observed in the maximum loading and, to some extent, the work of rupture. The dynamic sonic modulus is compared to the results of the standard mechanical and the suggested cyclic loading tests, and a high correlation between the values was observed.