Application of newly developed fibre orientation measurement techniques for needle-punched nonwoven

New structural characteristics based on tracer fibre and Lindsley’s techniques to measure the fibre orientation in X, Yand Z directions of needle-punched nonwoven have been investigated. The results are verified with variable cylinder speed,punch density and needle depth penetration. It is evident that measured structural characteristics and fabric tensile strengthshow very good correlation in machine direction but poor correlation in cross-direction

Effect of fibre orientation on mechanical and functional properties of needle-punched nonwoven

An attempt has been made to study the effect of fibre orientation, measured by the structural characteristics, onmechanical and functional properties of needle-punched nonwoven by varying the carding machine and punchingparameters. It is observed that all measured physical, mechanical and functional properties of nonwovens have strongcorrelation with the proposed structural characteristics. Cylinder speed, punch density and needle depth penetration havesignificant effect on fabric thickness, air permeability, pore diameter, filtration efficiency and pressure drop

Fabric comfort by modifying yarn structure: Part II—Low-stress mechanical, thermal and transmission characteristics of fabrics

19-25The present study aims at investigating the influence of yarn structure, modified through process parameters of ring frame (spindle speed, twist multiplier and ring frame draft), on low-stress mechanical, thermal properties and transmission properties of fabric. It is observed that the structural changes influence thermal, transmission and low-stress mechanical characteristics of fabrics due to change in fabric porosity and thickness. In general, the bending and compression properties increase but shear and surface properties of the fabrics decrease with the increase in spindle speed, twist multiplier and draft. The study further reveals that air permeability, thermal absorptivity, thermal diffusivity, heat conductivity and moisture transmission properties increase but thermal resistance decreases with the increase in spinning process parameters

Tensile failure of blended spun yarns under dynamic condition: Part I –Yarn failure during warping

The failure behaviour of polyester/viscose blended ring, rotor and air-jet spun yarns has been studied on the basis of fibre failure coefficient, yarn broken end configuration and failure zone length. The failure behaviour of spun yarns under warping process is simulated in the dynamic tensile tester. The tensile failure behaviour of ring, rotor and air-jet yarns are found to be different owing to their difference in fibre consolidation mechanism. The yarn failure is observed to be more and more dominated by fibre slippage once moving from ring to rotor and finally to air-jet yarns. The study also reports mathematical modeling of spun yarn failure behaviour during warping process. The mathematical model indicates that the spun yarn failure is non-linearly related to yarn structural parameters

Fabric comfort by modifying yarn structure: Part II—Low-stress mechanical, thermal and transmission characteristics of fabrics

The present study aims at investigating the influence of yarn structure, modified through process parameters of ringframe (spindle speed, twist multiplier and ring frame draft), on low-stress mechanical, thermal properties and transmissionproperties of fabric. It is observed that the structural changes influence thermal, transmission and low-stress mechanicalcharacteristics of fabrics due to change in fabric porosity and thickness. In general, the bending and compression propertiesincrease but shear and surface properties of the fabrics decrease with the increase in spindle speed, twist multiplier and draft.The study further reveals that air permeability, thermal absorptivity, thermal diffusivity, heat conductivity and moisturetransmission properties increase but thermal resistance decreases with the increase in spinning process parameters

Fabric comfort by modifying yarn structure: Part I – Study on structural changes by cross-sectional microtomy of yarn

A study has been carried out to engineer the fabric comfort by modifying the internal yarn structure through spinningprocess parameters. The yarn packing density is found to be one of most influential factors of yarn structure, which governsthe comfort aspect of the textile material. The work reported here mainly deals with the influence of ring frame processparameters, i.e. spindle speed, twist and draft, on mechanics of yarn structure. It is evident that an increase in spindle speed,twist multiplier and draft decreases the yarn diameter and accordingly increases the packing density. The reduction in yarndiameter is found to be maximum with the increase of draft followed by twist multiplier and spindle speed. The yarnpacking density also follows the similar trend. The radial packing density of considered yarns is neither uniform across theyarn cross-section nor maximum near the yarn axis. The maximum packing density is noticed at some distance from theyarn axis and it decreases further towards yarn surface. In general, yarns do not possess maximum packing density near yarnaxis. It is observed that considered process parameters significantly influence the packing in core, intermediate and surfacezone of the yarns

Fabric comfort by modifying yarn structure: Part I – Study on structural changes by cross-sectional microtomy of yarn

424-430A study has been carried out to engineer the fabric comfort by modifying the internal yarn structure through spinning process parameters. The yarn packing density is found to be one of most influential factors of yarn structure, which governs the comfort aspect of the textile material. The work reported here mainly deals with the influence of ring frame process parameters, i.e. spindle speed, twist and draft, on mechanics of yarn structure. It is evident that an increase in spindle speed, twist multiplier and draft decreases the yarn diameter and accordingly increases the packing density. The reduction in yarn diameter is found to be maximum with the increase of draft followed by twist multiplier and spindle speed. The yarn packing density also follows the similar trend. The radial packing density of considered yarns is neither uniform across the yarn cross-section nor maximum near the yarn axis. The maximum packing density is noticed at some distance from the yarn axis and it decreases further towards yarn surface. In general, yarns do not possess maximum packing density near yarn axis. It is observed that considered process parameters significantly influence the packing in core, intermediate and surface zone of the yarns

Modulation of cross-sectional structure of air-vortex yarn through process variables

127-136Influence of process parameters on structural mechanics of air-vortex polyester cotton (65/35) blended yarn has been studied. Box-Behnken three variables design is used to optimize the spindle diameter, nozzle pressure and yarn delivery speed to achieve the required packing density of air vortex yarn. Image processing technique is used to measure the fibre area in different concentric zones. The study confirms that the yarn packing density and radial packing density of yarns are influenced by individual as well as interaction effect of process parameters. The packing density is not found to be maximum near the yarn axis. It is depicted that packing density of core, intermediate and surface zones of the yarn shows an increase with the increase in nozzle pressure, and decrease with the increase in spindle diameter and yarn delivery speed. The packing density of ring-spun yarn is found to be higher than vortex yarns with distinctly higher packing in the core- zone of the yarn