Vortex Spinning Research Articles

Comparative analysis on yarn mechanism and yarn properties of different jet vortex spinning systems

Changing the process of jet vortex spun yarn will result in the change of its structure, and further changing its properties. In this article a comparative study is carried out about three aspects, namely the internal structure of the nozzle, the internal flow field distribution of the nozzle, and the yarn properties of MVS861 and MVS870. The correlation between the yarn formation process and yarn properties will be discussed theoretically, which will be validated by designed experiments. There is significant meaning for researching the correlation between yarn formation process and yarn structure because, on the one hand, it can optimize the process of yarn formation and improve the structure of key components used to form yarn, and on the other hand, it can guide theoretically the design of the yarn structure.

Comparative analysis of traditional jet vortex spinning and self-twist jet vortex spinning on yarn mechanism and yarn properties

Because of the friction between the hollow spindle surface and the fiber end increasing, the fiber end rolls on the hollow spindle surface under the high-speed rotating airflow during the twisting process. The fiber gets self-twist, which will be wound into the yarn body. The self-twist of the fiber will increase the friction and the cohesion between the fibers in the yarn, which will improve the strength of the yarn. This article analyzes traditional jet vortex spinning and self-twist jet vortex spinning comparatively from the three aspects of the hollow spindle structure, the airflow distribution inside the nozzle, and the yarn performance. It is beneficial for exploring the yarn mechanism, the yarn performance, and the development of self-twist jet vortex spinning.

Comparative analysis of different jet vortex spinning hollow spindle groove structures on yarn mechanism and yarn properties

According to the self-twist jet vortex spinning process, the free fiber end lays flat and rolls rotationally on the surface of the stationary hollow spindle under the high-speed rotating airflow and the tangential friction torque, which results in the self-twist of the fiber. The self-twist will be wound into the yarn body and increases the friction and the cohesion between the fibers in the yarn, which will improve the strength of the yarn. Based on mechanical analysis and numerical simulation, this article obtains the motion trajectory of the free fiber end and designed six different hollow spindle groove micro-feature structures. Combined with experiments, this article analyzes comparatively the influence of different hollow spindle groove micro-feature structures on the free fiber end and the yarn performance, which lays the foundation for the research and the development of jet vortex spinning.

Effect of Ply Twist Factor on Hairiness and Unevenness of Two Plied Cotton Yarns Made of Different Spinning Technologies

Hairiness and unevenness of cotton plied yarns made of singles spun on Murata Vortex Spinning (MVS) and other spinning systems viz. ring, compact and rotor in relation to ply twist factor have been evaluated. It has been observed that both the type of singles and ply twist has remarkable influence on these parameters. Plied yarn hairiness for ring and compact yarns is less than their respective single counterparts. However, for vortex and rotor yarns, it is found to be higher and decreases with ply twist to be at the same level or even less that of their parent single yarns at high ply twist factor. There is always an increase of short hairs (1, 2 mm) after plying as compared to their respective singles at low ply twist factors, the effect being more prominent for vortex and rotor yarns. The improvement in yarn evenness after plying has also been found to be higher for these yarns but insensitive to ply twist. Further, the percentage decrease in imperfections after plying is observed to be the highest for MVS yarns in majority of the cases.

Optimization of spinning parameters influencing the hairiness properties of polyester/cotton vortex yarn

The influence of vortex spinning parameters on the hairiness properties of polyester/cotton vortex yarn has been studied. Polyester/cotton yarn of 50:50 blend ratio has been produced in two different counts (Ne 20s and Ne 40s) each with four different spinning parameters (delivery speed, spindle size, feed ratio and nozzle pressure). Experiments are designed with the aid of response surface method. Accordingly, different samples are produced with three levels of each parameter. The hairiness index H and zweigle hairiness have been evaluated from the samples produced with these combinations. It is found that the hairiness index H of both coarser and medium count vortex yarns are influenced by all the spinning parameters considered for this study. Also, zweigle S3 values of both coarser and medium count vortex yarns are influenced by all the four parameters. The interactions of some of the spinning parameters have significant influence on the hairiness index, H of both coarser and medium count vortex yarn. Also, few of the interactions have significant influence on zweigle S3 values of both coarser and medium count vortex yarns.

고감성 PTT/Tencel/Cotton MVS 혼방사 패션소재의 물성에 관한 연구 (I) - 사 구조에 따른 혼방사 물성 -

The evolution of spinning technology was focused on improving productivity with good quality of yarns. More detail spinning technology according to mixing of various kinds of fibre materials on the air vortex spinning system is required for obtaining good quality yarns. This paper investigated the physical properties of air vortex yarns compared with ring and compact yarns using PTT/tencel/cotton fibres. It was observed that unevenness of air vortex yarns was higher than those of ring and compact yarns, which resulted in low tenacity and breaking strain of air vortex yarns. Initial modulus of air vortex yarns was higher than those of ring and compact yarns. Yarn imperfections of air vortex yarns such as thin, thick and nep were much more than those of ring and compact yarns. These poor yarn qualities of air vortex yarn were attributed to the fasciated yarn structure with parallel fibres in the core part of the air vortex yarn. However, yarn hairiness of air vortex yarns was less and shorter than those of ring and compact yarns. Thermal shrinkage of air vortex yarns were higher than that of ring yarns, which was caused by sensible thermal shrinkage of PTT fibres on the bulky yarn surface and core part of air vortex yarns.

고감성 의류용 PTT/울/모달 에어 볼텍스 복합사의 물성

Polytrimethylene Terephthalate (PTT) is an eco-fiber with good elastic properties; however, it requires more detailed studies related to spinnability according to blending of various kinds of fibers. The evolution of spinning technology was focused on improved productivity with good quality; in addition, air vortex spinning was recently invented and applied on the spinning factory as the facility with good productivity and quality. More detail spinning technology according to the blending of various kinds of fibers on the air vortex spinning system is required to obtain good quality yarns for high emotional fabrics. In this paper, the physical properties of air vortex, compact and ring staple yarns using PTT/wool/modal blend fibers were investigated with yarn structure to promote high functional PTT that includes fabrics for high emotional garments. Unevenness of air vortex yarns was higher than those of compact and ring yarns; in addition, imperfections were greater than those of compact and ring yarns, which was attributed to a fascinated vortex yarn structure. Tenacity and breaking strain of air vortex yarns were lower than those of compact and ring yarns, caused by higher unevenness and more imperfections of air vortex yarns compared to compact and ring yarns. Vortex yarns showed the highest initial modulus and ring yarns showed the lowest ones which results in a stiff tactile feeling of air vortex yarns in regards to the initial modulus of yarns. Dry and wet thermal shrinkages of air vortex yarns were lower than ring yarns. Good shape retention of vortex yarns was estimated due to low thermal shrinkage.

Moisture Management Behaviour of Knitted Fabric from Structurally Modified Ring and Vortex Spun Yarn

The acceptability of a new product is decided by its performance, level of improvement in quality and economy of production. The basic aim of generating micro pores in a textile structure is to provide better thermo-physiological comfort by enhancing the breathability and hence improving moisture management behaviour. In the present study, an attempt has been made to create a relatively more open structure through removal of a component. A comparative assessment with a homogeneous and parent yarn was also made. Yarns of two linear densities, each from ring and vortex spinning systems were produced using 100 % polyester and 80:20 polyester/cotton blend. The modified yarn was produced by removing a component, viz; cotton, by treatment with sulphuric acid from the blended yarn. The knitted fabric from modified yarn was found to show significant improvement in air permeability, water vapour permeability and total absorbency while the wicking characteristic was found to decline.

Effects of structural parameters on the tangentially injected swirling flow in concentric tubes with different lengths as a model of the vortex spinning nozzle

The tangentially injected swirling tube flow has broad applications in various engineering fields. In the textile industry, the vortex spinning technology, which produces short-staple yarns by means of a tangentially injected swirling airflow, is of great prospect in view of its spinning speed and yarn structure. In this paper, the vortex spinning nozzle is abstracted into a model of concentric tubes of different lengths with tangential injectors. A computational fluid dynamics model is presented to study the effects of some structural parameters on the swirling flow generated in this tube system. The particle image velocimetry (PIV) technique is adopted to measure the flow field. Due to the difficulty in duplicating the Mach number, Reynolds numbers are matched between the tube model and prototype in the PIV experiment. Despite the discrepancy between the velocity values provided by the numerical simulation and experiment due to the compressibility effects not being reproduced in the PIV measurement, a comparative analysis concludes that qualitatively matched results on the flow pattern and effects of the structural parameters are obtained by the numerical simulation and PIV measurement.

Theoretical analysis on the yarn twist mechanism of self-twist jet vortex spinning

In this paper, the hollow spindle receives self-twist modifying treatment, which makes the surface friction coefficient of the hollow spindle increase. When the sliding friction torque is enough to overcome the torsional stiffness of the fiber, under the force of the high-speed airflow, the fiber scrolls on the surface of hollow spindle, resulting in fiber twist, which increases the cohesion between the fibers, improving yarn strength. Based on the flow field simulation of the self-twist jet vortex spinning, it establishes the mechanical system of the free-end self-twist motion of the fiber in the flow field, and analyzes the fracture mechanism of the self-twist jet vortex spinning yarn. It provides more comprehensive support for the design and processing of the key components of the self-twist jet vortex spinning system.

PET, Tencel, Cotton MVS 혼방사의 섬도와 혼용률에 따른 물성 특성

This study investigates the physical properties of Murata Vortex Spinning (MVS) blended yarn with yarn count(20's, 30's, 40's) and blend ratio(Polyester 100, Polyester70:Cotton30, Polyester50:Cotton50, Polyester30:Cotton70, and Polyester50:Tencel40:Cotton10). This study evaluated tenacity, elongation, bending rigidity, bending hysteresis, hairiness coefficient, irregularity and twist number. The structure of MVS blended yarn influenced stress, strain, bending rigidity, bending hysteresis and the hairiness coefficient of MVS blended yarn decreased as the yarn count increased. MVS blended yarn consists of core and sheath. The core of MVS blended yarn is composed of a parallel fiber with a wrapping fiber that covers thecore fiber. This special structure of the MVS blended yarn effects the physical properties of the yarn; in addition, the mechanical properties of the component fibers influenced the stress, strain, bending rigidity, bending hysteresis and hairiness coefficient of MVS blended yarn with the blend ratio. Polyester decreases and cotton increases resulted in decreased physical properties. A similar polyester content increased the tencel and physical properties. Appropriate physical properties and a variety of touch expression can be realized through a correct blend ratio.

Two-dimensional structures in the quintic Ginzburg–Landau equation

By using ZEUS cluster at Embry-Riddle Aeronautical University we perform extensive numerical simulations based on a two-dimensional Fourier spectral method Fourier spatial discretization and an explicit scheme for time differencing) to find the range of existence of the spatiotemporal solitons of the two-dimensional complex Ginzburg-Landau equation with cubic and quintic nonlinearities. We start from the parameters used by Akhmediev {\it et. al.} and slowly vary them one by one to determine the regimes where solitons exist as stable/unstable structures. We present eight classes of dissipative solitons from which six are known (stationary, pulsating, vortex spinning, filament, exploding, creeping) and two are novel (creeping-vortex propellers and spinning "bean-shaped" solitons). By running lengthy simulations for the different parameters of the equation, we find ranges of existence of stable structures (stationary, pulsating, circular vortex spinning, organized exploding), and unstable structures (elliptic vortex spinning that leads to filament, disorganized exploding, creeping). Moreover, by varying even the two initial conditions together with vorticity, we find a richer behavior in the form of creeping-vortex propellers, and spinning "bean-shaped" solitons. Each class differentiates from the other by distinctive features of their energy evolution, shape of initial conditions, as well as domain of existence of parameters.

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.

Optimization of nozzle structure parameters of vortex spinning

In order to optimize the nozzle structure of vortex spinning, the structure of the nozzle components, such as guided body, vortex tube and cone body, were combined to conduct spinning experiments, which provides a certain reference for the setting of nozzle structure parameters. Viscose fiber was used in this study; the weight of the used viscose sliver is 3.2 g/m, with fiber length × fineness of 39 mm × 1.23 dtex. The results showed that the optimum structure parameters of the nozzle are as follows: spiral angle of guided body: 35°; guided needle length: 1 mm; orifice angle of the vortex tube: 50°; orifice diameter: 0.4 mm; orifice number: 5; the tip conical degree of the cone body: 10°; the front inner diameter: 1.3 mm for approximate 20 tex viscose yarn.

Effect of the Distance between Guided Needle and Cone Body on Properties of Vortex Spun Yarn

Effects of the distance between guided needle and cone body on properties of MVS yarns were investigated by numerical simulation. 5 groups of the distance are designed (0.5mm, 1mm, 1.5mm, 2mm and 2.5mm). The 3D computational fluid dynamics models are established to conduct the numerical simulation of the airflow in the nozzle. Through analysis of the characteristics of air flow inside the different nozzles, such as pressure distribution and velocity vectors, the motion of drafted fibers and performances of yarns are discussed. Simulation results show that when the distance is 1.5mm, the airflow state within the nozzle is beneficial to form more open-ends and twist, and the yarn quality would be better.

Investigation of Moisture Transportation Properties of Knitted Fabrics Made from Viscose Vortex Spun Yarns

Moisture transportation through fabrics is one of the important parameters which affect clothing comfort. The combination of different factors which include fiber, yarn and fabric structure will yield varying degrees of clothing comfort. This research work concentrated on the use of viscose fibers spun on the vortex spinning system. Six knitted fabric samples were produced and tested for moisture transportation characteristics, which included air and water moisture permeability. The results indicate that all structures had high wicking levels in the wale than in the course direction. Similarly, all fabrics had poor drying abilities, but good water vapor permeability. There was a good correlation between air permeability and water vapor permeability of the fabrics. This was attributed to the fiber in the yarn not the fabric structure.

Self-induced Marangoni flow in evaporating alcoholic solutions

Abstract The self-induced Marangoni convection in alcoholic solutions is the subject of the present experimental investigation. Pure ethanol and its mixtures with 5%, 10% and 20% in weight of water are presented and discussed. In particular, Marangoni flow in horizontal pipes from 100 to 1000 μm inner diameter is studied. Vortex spinning frequency, average particle tracers velocity and evaporation rate are measured and discussed. The evaporation rate increases and the evaporation flux decreases at bigger tube sizes in line with previous investigations; pure ethanol has higher evaporation rate and flux than ethanol/water mixtures. The spinning frequency and the average tracer particles velocity decrease for increasing water content in the mixtures. All of these findings are due to evaporative cooling effect which is higher at the meniscus wedge (where the triple-line region is found) than at the meniscus center; this causes a difference in temperature between the wedge and the center that generates a gradient of surface tension driving vigorous Marangoni convection, that has been reported and analyzed. The experimental results are explained on the basis of a numerical model including evaporation, vapor diffusion, heat and mass transfer from the liquid to the surrounding ambient and the Marangoni effects.

Effect of vortex tube structure on yarn quality in vortex spinning machine

In order to study the effect of the structure of vortex tube on the yarn performance in jet vortex spinning, 8 groups of vortex tube structure were designed, and the corresponding 3D computational fluid dynamic models were established to numerically simulate the airflow in the nozzle. Through analysis of the characteristics of air flow inside the different nozzles, such as pressure distribution and velocity vectors, the motion of drafted fibers and performances of yarns were discussed. Simulation results show that when the structure of vortex tube has a transition region between the cylindrical and conical cavity (CCT) and the outlet of jet orifice is located at the junction of cylindrical and transition cavity, the airflow state within the nozzle has a large negative pressure with appropriate axial and tangential velocity, which is conducive to the formation of the open-ends of fibers and twisting, and the yarn quality turns out to be better. Spinning experiment results prove that the yarn strength reaches the maximum value, while the unevenness of breaking strength meets the minimum, and the other yarn properties are superior, which shows a good agreement with the simulation results. Thus, the numerical simulation can provide the theoretical as well as quantitative reference for the vortex tube design in the coming future.

Designing the Spindle Parameters of Vortex Spinning by Modeling the Fiber/Air Two-Phase Flow

Vortex spinning is a novel technology which produces short-staple yarns by utilizing high-speed swirling airflow. The structure of the spindle plays an important role in vortex spinning in terms of its effect on the resulting yarn properties. In this paper, a two-dimensional fluid-structure interaction (FSI) model for the fiber/air two-phase flow is presented to design the two spindle parameters—the spindle cone angle and spindle diameter by evaluating their effects on the fiber dynamics in the flow field inside the twisting system and the resulting yarn tenacity. The coupling between the fiber and airflow is solved and the motional characteristics of the fiber are obtained. It is found that the fiber moves downstream in a varying wavy shape and its spreaded trailing portion is then in a helical motion to form the yarn. The results also show that the increase of the spindle cone angle has a negative effect on the tenacity of the produced vortex yarn. The increased spindle diameter gives rise to the decreased vortex yarn tenacity. The numerical results can provide an explanation for the experimental results reported by previous studies.

A numerical and experimental study on the effect of the orifice angle of vortex tube in vortex spinning machine

In order to study the effect of orifice angle of vortex tube on yarn forming in jet vortex spinning, eight levels of nozzle angle are designed, from 40° to 65°, and the corresponding three-dimensional computational fluid dynamics (CFD) models are established to conduct the numerical simulation of the airflow in the nozzle. Through the analysis of numerical simulation, the pressure and velocity distribution are made clear which provides reference for the future design of the vortex tube. Simulation results show that when the orifice angle is around 50°, the airflow state within the nozzle has a large negative pressure with appropriate axial and tangential velocity, which is conducive to the formation of the open ends of fibers and twisting, and the yarn quality is better. Spinning experiment results prove that single yarn strength is the maximum, the irregularity of single yarn strength is the minimum, and other yarn properties are superior with the orifice angle at 50°, which shows a good agreement with the simulation results.