Core Yarn Research Articles

Fabrication of a coaxial high performance fiber lithium-ion battery supported by a cotton yarn electrolyte reservoir

Our report describes a coaxial fiber-type lithium-ion battery consisting of cotton core yarn wrapped with carbon nanotube (CNT) films and a nano-web separator. The CNT film was used as a current collector because of its high conductivity, flexibility, and network structure. The cotton yarn served as an electrolyte reservoir and a skeleton for the fiber shape. The cotton yarn even absorbed electrolyte as much as 9 times its own weight and its diameter swelled up to a 20%, which resulted in robust interfacial contact between components of the battery. Also, the swelling behavior of cotton yarn due to electrolyte up-take was simulated to clarify the function of cotton yarn. The nano-web separator was beneficial in accommodating the in-plane deformation occurred during the bending of the battery. This coaxial fiber battery exhibited stable performance even under bent or knotted states and delivered 144.82 mWhcm−3 of volumetric energy density with high coloumbic efficiency of about 95%. Successful demonstration of the flexible fiber battery bespeaks a promising future for wearable electronic devices.

A Research on the Use of Copper Core Yarns in Electromagnetic Shielding Application

In this work, possibilities for producing textile materials with copper core cotton yarns for the purpose of electromagnetic shielding were studied. Cu/Co core yarns were produced by using copper filaments as core material with two different diameters (0.05 and 0.07mm) and cotton as sheath material. All core yarns are produced in Ne 8 yarn count. Conductive Cu/Co yarns were integrated in to 3/1 twill woven fabric structure in the weft direction with 5 different weft densities (8, 13, 18, 23 and 28 per cm). According to the TS EN 50147-1 standard, the shielding effectiveness of these fabrics was measured in the frequency range 1 GHz - 6 GHz. The results have shown that EMSE of fabrics can be tailored by changing the weft density, core filament fineness and wave frequency parameters.

Comparative study of cut and abrasion resistance performance of gloves made from high performance composite yarns

Cut resistant gloves are generally made from different types of high performance composite yarns. To achieve a certain level of cut resistance, material type, material composition and yarn linear density are changed which however make it sometimes difficult to decide the most suitable combination of the materials. In this work, eighteen seamless gloves were made by using core and sheath friction-spun yarns of various linear densities and core types, and their cut resistance performances were compared.For this purpose, eighteen composite yarns with three linear densities i.e. 118 tex (Ne 5), 98 tex (Ne 6) and 84 tex (Ne 7) were made on a friction spinning machine by using 5.55tex (50 denier), 11.11 tex (100 denier), 16.66 tex (150 denier), 33.33 tex (300 denier) multifilament glass yarns, and 89 denier (40 micron) and 139 denier (50 micron) monofilament steel yarn as core and Kevlar®29 staple fiber as sheath. Mechanical tests of the yarns showed that the tensile strength and tenacity of yarns increased as the linear density of glass yarns increased, whereas elongation at break and time to break increased with an increase of linear density of steel monofilament yarn. Coefficient of friction of all the yarns did not show any significant trend. Abrasion and cut resistance of the gloves made from 118 tex (Ne 5) composite yarn with 5.55tex (50 denier) glass yarn as core showed the best results, whereas no significant difference was seen in the dexterity of all the gloves.

The effects of core material parameters on the mechanical properties of double core and single core spun yarns

Comfort and aesthetic appearance are the basic features that consumers expect from their clothes. For improving body movement comfort in apparel, elastic core-spun yarns can be used to produce elasticity of the woven and knitted fabrics. In this study, the effects of elastane linear density on the mechanical properties of double core and single core yarns, spun with different core materials, were investigated. According to statistical evaluations, significant differences were found between yarn properties.

Auxetic Yarn Made with Circular Braiding Technology

This paper reports a new type of auxetic yarn made with circular braiding technology to overcome the yarn slippage problem in the conventional helical auxetic yarn structure. Various auxetic yarn structures are firstly produced on a vertical circular braiding machine with 16 yarn carries by changing the number and arrangement of stiff yarn as well as diameter of elastic yarn and core yarn, and then tested under single and repeating tensile conditions. The results show that not only yarn slippage problem could be overcome in the newly developed auxetic yarn structure, but also an early activation and a higher magnitude of negative Poisson's ratio could be achieved. The results also show that all structural parameters including stiff yarn number and arrangement, core yarn, and elastic yarn diameter have an influence on the auxetic effect of the novel yarn structure. Since the new auxetic yarn is produced by using standard braiding manufacturing technique and conventional non‐auxetic yarns, there are few technological barriers for its large‐scale manufacture for practical application.

A comparative study on properties of dual-core yarns

Core-spun yarns containing Spandex have been widely used for the production of elastic textile materials. However, it has been encountered various problems not only during the usage but also during textile processes due to its high recovery property. In order to solve these problems, multicomponent core-spun yarns called as dual-core (DC) yarns, have been developed. DC yarns can be produced on the modified ring spinning machine in two different ways. In the first method, previously combined two core yarns are fed simultaneously, whereas in the second method, two core yarns are given separately into the centre of sheath fibre bundle. In present study, it was aimed to research the effect of these production methods on yarn features. Polyester and Spandex core components and cotton wrapping fibres were brought together in both two ways and the properties of multicomponent core-spun yarns were compared with cotton ring counterparts for three different yarn counts.

Characterization of flame-retardant performance of polyester/flame-retardant viscose blended yarn

In this paper, a flame-retardant blend yarn was designed with flame-retardant viscose fiber and polyester. Flame-retardant viscose fiber was blended with polyester by core-spun method. Polyester was set as a core and the flame-retardant viscose fiber was set as a sheath to change the flame retardancy and disadvantage of moisture permeability. After the flame-retardant viscose fiber was spun into roving, polyester was added in spun yarn. The core yarn samples with different ratios were prepared by adjusting the amount of flame-retardant viscose fiber. The flame retardancy of core-spun yarn was evaluated by limiting oxygen index, scanning electron microscope, thermogravimetric analysis, and thermogravimetric/Fourier transform infrared techniques. Limiting oxygen index of the yarn with 50% flame-retardant viscose fiber and 50% polyester was 27.6% and just decreased slightly to 27.1% after 30 washing cycles. Polyester begins to melt from inside core-spun yarn after heating and the molten polyester flows to outer layer of yarns by the diversion effect of higher temperature. Then it was carbonized by the polymetaphosphate which was generated by the flame-retardant viscose fiber. In thermal processes, the major product of thermal decomposition was CO2.

High-performance flexible yarn for wearable piezoelectric nanogenerators

The development and popularity of wearable electronics increase demand for wearable energy harvesters that can scavenge energy from environment or human body movements. In this paper, we present a novel yarn as a wearable piezoelectric nanogenerator (PNG) consisting of a layer of electrospun poly(vinylidene fluoride) (PVDF) nanofibers integrated with PVDF film around a silver deposited nylon filament acting as an inner electrode. Electrospun PVDF nanofiber was wrapped around core yarn using a customized electrospinning device followed by coating of PVDF solution. The mesh of PVDF electrospun layer ensured uniform coating of PVDF solution, and the after coated PVDF film improved interfacial properties with inner electrode as well as strengthened the abrasion resistance of the piezoelectric polymer layer. The resultant unique yarn produced an average peak voltage of 0.52 V, peak current of 18.76 nA, and power density of 5.54 μW cm−3 under a cyclic compression of 0.02 MPa at 1.85 Hz, which is significantly higher than the energy output of a yarn with only a PVDF electrospun nanofibrous layer. More importantly, the high-performance was retained after 50 000 cycles of compression. The flexible yarn-based PNG device with good energy output and durability demonstrated its great promise to be used as a wearable energy harvester.

The Microstructure and Shear Properties of SiC/SiC Composite Pins with Designed SiC Fiber Preform

In order to obtain the near net shaped SiC/SiC composite pins without the processing cost, four kinds of SiC fiber pin preforms including the knitting yarn and core yarn with two dimension braided structure were designed. The SiC/SiC composite pins were fabricated by precursor infiltration pyrolysis (PIP) process used a liquid SiC ceramic precursor. The results showed that, the near net shaped SiC/SiC composite pins could be obtained by using the designed SiC fiber preform and the graphite mould with curved groove. The macrostructure and microstructure of the SiC/SiC composite pins were observed by scanning electron microscope. Both the single shear stress-displacement curves and the double shear stress-displacement curves of the different kinds of SiC/SiC composite pins showed the saddle-shaped, which indicated the fracture model of the SiC/SiC composites pins was non-catastrophic, and the SiC/SiC composite pins in this paper possessed the secondary bearing capacity. This paper may provide some new ideas for fiber reinforced SiC ceramic matrix composites components designers.

Dref-3 yarn structure with plied staple fibrous core

PurposeDref-3 friction spun core yarns produced using staple fibre yarn as the core, e.g. Jute core yarn wrapped with cotton fibre, have poorer mechanical properties compared to the core yarn itself. The purpose of this study was to understand the structure of such yarns, that will lead to the optimization of fibre, machine and process variables for production of better quality yarn from the Dref-3/3000 machines.Design/methodology/approachThe Dref spinning trials were conducted following a full factorial design with six variables, all with two operative levels. The Dref-3 friction spun yarn, in which the core is a plied, twisted ring yarn composed of cotton singles and the sheath, formed from the same cotton fibres making the singles, has been examined. The structures have also been studied by using the tracer fibre technique.FindingsIt was observed that rather than depending on the plied core yarn, the tensile properties of the Dref-3 yarn are significantly determined by the parameters those affect the constituent single yarn tensile properties, i.e. the amount of twist and its twist direction, yarn linear density and the sheath fibre proportion used during the Dref spinning in making the final yarn. Further, when the twist direction of single yarn, double yarn and the Dref spinning false twisting are in the same direction, the produced core-sheath yarn exhibits better tensile properties.Practical implicationsThe understanding of the yarn structure will lead to optimized production of all staple fibre core Dref spun yarns.Social implicationsThe research work may lead to utilization of coarse and harsh untapped natural fibres to the production of value-added textile products.Originality/valueThough an earlier research has reported the effects of sheath fibre fineness and length on the tensile and bending properties of Dref-3 friction yarn, the present study is the first documented attempt using the tracer fibre technique to understand Dref-3 yarn structure with plied staple fibrous core.

Investigating the Effects of Core Spun Yarns on the Quick-Dry Property of Towels

The purpose of this study was to investigate the effects of core-spun yarn on the quick-dry property of towels. This study focused on five different raw materials (modal, cotton, polyester, bamboo, viscose) which are the most frequently used in towel production. Seven different core yarns and five different conventional yarns were produced with these fibres on a ring spinning machine. These yarns were used in the weft direction of the towels. Samples produced with the same ground and pile warp yarns were subjected to constant dyeing conditions. All samples were tested for strength, softness, hydrophilicity and quick drying. As a result, polyester core yarn on the towels did not negatively affect basic properties such as water absorbency, softness and strength. However, the usage of polyester core yarns provided better quick dry properties than that of conventional yarns.

Investigating the effect of pattern and core yarn on the mechanical properties of braids and braided composites

There are various parameters that affect the mechanical properties of tubular braids. The purpose of the current study is to investigate the effect of weaving pattern and core yarn type on the mechanical properties of reinforced and unreinforced braids. For this aim, three different patterns for the polyester sheath were considered namely; 1/1 (Diamond), 2/2 (Regular) and 3/3 (Hercules). In addition, polyester and polypropylene yarns with different counts were used as the core part. To investigate the effect of resin on the braid properties, the Vacuum Infusion Process (VIP) method was used by applying polyester resin. The mechanical properties of the products were investigated and analyzed statistically. After that, the properties of the braid and braided composites were modeled using regression methods and the obtained results indicated that the considered models are not appropriate predictors.

Structure–property of DREF-3 friction spun yarn made using twisted staple fibrous core

ABSTRACTThis article discusses the structure–property relationship of DREF-3 friction spun cotton yarn in which the core is a single twisted cotton ring yarn and the sheath is made of the same cotton fibers. The structural changes in the single staple fiber yarn when subjected to DREF spinning have been studied by using tracer fibers. The single yarn physical properties, namely its count, twist multiplier and twist direction, and the proportion of the sheath fibers used during the spinning trials, were found to correlate with the final Dref yarn mechanical properties. It was observed that the direction of single yarn twist has the most significant effect; besides, the amount of twist multiplier in the single yarn and the proportion of sheath wrapping fibers largely determine the tensile properties of such core yarns. Since breaking tenacity and elongation of the DREF yarn are inversely related, it will be appropriate to compare them in terms of specific work of rupture.

Three-dimensional ordered macroporous NiFe2O4 coated carbon yarn for knittable fibriform supercapacitor

Binary metal oxides are considered as promising electrode materials due to the higher electrochemical activity than mono metal oxides. However, the poor conductivity and aggregation of binary metal oxides impede ion and electron transport kinetics, which deteriorates their electrochemical performances. Herein, we design and fabricate three-dimensional ordered macroporous NiFe2O4 on carbon yarn, in which a core of carbon yarn is covered with the sheath of three-dimensional ordered macroporous NiFe2O4. The three-dimensional ordered macroporous structure is feature with abundant transportation shortcuts for electrolyte ions and excellent structural stability, thus offering great advantages for efficient fibriform supercapacitor. The fibriform supercapacitor is further assembled using two intertwined three-dimensional ordered macroporous NiFe2O4-carbon yarn electrodes, both of which are solidified in the KOH-polyvinyl alcohol gel electrolyte. The assembled fibriform supercapacitor exhibits high specific capacitance (247 μF cm-1 at scan rate of 10 mV s−1) and robust cycling stability (96% capacitance retention after 8000 cycles). Furthermore, the fibriform supercapacitor shows substantial mechanical flexibility with minor capacitance decrease upon continuous bending cycles, and the knitted fibriform supercapacitor exhibits the excellent wearability and integration. Thus, the as-prepared fibriform supercapacitor shows great promise as the energy storage unit for wearable electronics.

Electromagnetic absorption behaviour of carbon helical/coiled yarn woven and knitted fabrics and their composites

In this study, a novel carbon helical/coiled yarn was prepared for developing an electromagnetic (EM) absorbing structure in C-band region (4–8 GHz). The carbon helical yarn was fabricated in a direct twisting machine in which a stainless steel (SS) filament was used as the core and carbon yarn was used as the wrapping thread. The woven and plain knit structures were prepared using the carbon helical yarns. Subsequently, composites were prepared by film stacking method by sandwiching a helical yarn fabric between the polypropylene films. The shielding behaviour of fabrics and the composites was tested using the waveguide method. It was observed that 1/1 plain knit fabric having an optimum number of core SS filaments and helical yarn density of 50–150 turns/m showed a higher absorption coefficient of 0.91 than other fabrics. Hence, a particular proportion of helical carbon and SS content in a fabric maximizes its absorption coefficient. In the composite form, the absorption level was reduced and behaved like a metal. In addition, increase in fineness of core SS filaments also decreased the absorption behaviour of fabrics and composites. However, the overall shielding effectiveness of fabric and composite was increased for increasing the wrapping density. Compared to fabric form, composites showed larger reflective and total loss. In addition, three-point flexural strength and impact energy absorption of helical yarn composites were also investigated. The developed fabrics can be used as EM absorbing structures in domestic and military applications, whereas the composite can be used as shielding panels to the replacement of metal shield.

Effect of interface on composites made from DREF spun hybrid yarn with low twisted core flax yarn

In the present work, the influence of interface and hybrid yarn structure on flax-PP based unidirectional composite properties have been studied thoroughly. Flax-PP based core-sheath structured DREF spun hybrid yarns are manufactured after varying the core yarn twist and sheath percentage at three different levels and using MAgPP treated and untreated flax yarn as core. These hybrid yarns are consolidated to manufacture unidirectional composite samples and the resultant composites are tested accordingly. It is observed that MAgPP treatment of the core flax yarn improves the tensile and flexural properties of the hybrid yarn reinforced unidirectional composites while impact strength decreases after the treatment. A negative impact on the tensile and flexural properties of the unidirectional composite samples is observed with increasing core twist and sheath content of the reinforcing hybrid yarn. The impact strength of the composite samples increases for similar changes in hybrid yarn parameters.

Characterization based on the thermal capabilities of metallized fabrics equipped with hybrid conductive yarns for protective clothing

Electronic textiles are recognized for their conductive characteristics in various fields of research including medicine, communications, power and for the development of protective clothing. Out of the several types of conductive textile available, multi-component yarns and fabrics, produced from continuous copper filament as spiral covering on hybrid cover yarns, have never been investigated for their thermal capabilities. In this study, characterization based on the thermal properties for conventional copper core yarn’s fabric and newly developed copper cover yarn’s fabrics was carried out. The results demonstrate better conductivity of copper cover yarn’s fabrics as compared to the copper core conventional fabrics, which is attributed to its better conduction due to greater percentage of copper and direct contact between the heat flux transducers. With the higher porosity values for the newly developed fabric, the liquid water, water vapour and air transport capabilities, which are key aspects of thermal comfort, significantly improved.

Comparison the performance properties of conventional and polyester core yarns produced using different raw materials

Comparison the performance properties of conventional and polyester core yarns produced using different raw materials

Fabrication of hollow nanofibrous structures using a triple layering method for vascular scaffold applications

This study aims to develop a new approach for fabricating hollow nanofibrous yarns by engineering a triple-layer structure (polyvinyl alcohol (PVA) multifilament core surrounded by a layer of PVA nanofibers and a polylactic acid (PLA) nanofiber outer layer). After fabrication of this 3-layer structure, the core portion was extracted, leaving the outer layer intact after dissolving the PVA nanofibers in water. To determine the optimum thickness of the outer layer, hollow nanofiber yarns with five different thicknesses were produced. A hollow nanofiber yarn was also produced using a common method to enable comparison of the methods. In the common method, a core sheath yarn consisting of a PVA multifilament core and a PLA nanofiber outer layer was fabricated, and a hollow yarn was produced by placing the core yarn in hot water. The results revealed facilitation of core extraction from the yarn body of the new 3-layer structure, which occurred due to rapid dissolution of the middle layer. The wicking behavior in the hollow yarn fabricated using the novel method followed the Locus Washburn equation and that of the hollow yarn produced from the core sheath yarn deviated from it. The results demonstrated that tensile properties of hollow nanofiber yarns were improved by increasing the thickness. Furthermore, hemolysis and cytotoxicity assays indicated that the fabricated hollow nanofibrous structure is non-toxic and blood compatible, indicating its potential for use in biomedical applications such as vascular scaffolds.

Analysis of thermal comfort properties of fabrics for protective applications

Protective clothing protects the body from external influence like heat, chemicals, mechanical hazards, bad weather, etc. by shielding the human body from harsh environmental effects. The maintenance of thermal balance is one of the most important aspects of protective clothing. The study aims to investigate the thermal comfort properties of woven hybrid fabrics produced with high performance core spun yarns. For this purpose, meta-aramid, e-glass, Technora® and Dyneema® fibres were combined using core yarn spinning method in order to enhance the protective performance characteristics. The effects of the core/sheath ratio and type of core materials on the thermal comfort characteristics were investigated and evaluated statistically. The results revealed that, core/sheath ratio, types of core materials have significant effects on thermal comfort characteristics of the fabrics. As the core ratio increases from 19 to 56%, the air permeability of the fabrics increases whereas their thermal conductivity and thermal absorptivity properties decrease. Meta-aramid/E-glass core fabrics can be preferable for protective clothing due to high air permeability and thermal conductivity values.