Core Yarn Research Articles

Evaluation of the UV Protection Properties of Para-Aramid Woven Fabrics with Various Specialty Core Yarns.

Para-aramid fibers, known for their remarkable strength and thermal stability, are frequently employed in protective textiles for military and aerospace applications. However, continuous exposure to ultraviolet (UV) radiation can damage their protective characteristics. This study analyzes the ultraviolet protection factor (UPF) and UV transmittance of woven fabrics produced from 30/2 Ne spun para-aramid yarns in the warp and 10 Ne core-spun yarns in the weft. The weft yarns consisted of three sheath fibers-para-aramid, meta-aramid, and polyester-in combination with different specialty core materials. The results show significant differences in UPF before and after UV exposure, with para-aramid sheaths giving the highest improvement. UV exposure caused structural changes in the fibers, resulting in increased UV protection, particularly in fabrics with para-aramid sheaths. This study concludes that the combination of para-aramid fibers with specific core materials significantly enhances UV protection, making them well-suited for applications in high UV exposure environments.

One-Dimensional Flexible Capacitive Sensor with Large Strain and High Stability for Human Motion Monitoring.

Flexible capacitive sensors have attracted the attention of researchers owing to their simple structure, ease of realization, and wearability. Currently, flexible capacitive sensors mainly have three-dimensional and two-dimensional structures, which are subject to several limitations in their applications. A low-cost, high-efficiency, and continuously processable process was used to wrap nylon DTY (PA) filaments on the surface of silver-coated nylon (SCN) core yarns and impregnate them with waterborne polyurethane (WPU) to obtain SCN/PA/WPU composite yarns, which were then utilized in the design of SCN/PA/WPU for the preparation of one-dimensionally structured flexible capacitive sensors. The morphology and mechanical properties of the SCN core yarn, SCN/PA wrapped yarn, and SCN/PA/WPU composite yarn were characterized. The strain-sensing performance of the sensor was analyzed, and the sensor was used to monitor human physiological activities. The sensor exhibited excellent strain capacitance sensing performance with a strain range of up to 140%. With a gauge factor of 0.66 at 10% tensile strain, it can detect strains as low as 1% and has good repeatability, withstanding more than 3200 tensile-unload cycles at 80% strain. The one-dimensional structure sensor can be used to monitor the large-scale movements of joints and muscles in various parts of the human body and the physiological signals of tiny human movements, such as breathing, coughing, and facial expressions, which have potential applications in the fields of sports monitoring and smart wearable.

Electric field simulation, structure and properties of nanofiber- coated yarn prepared by multi-needle water bath electrospinning.

To address the issue of low yield in the preparation of nanofiber materials using single-needle electrospinning technology, multi-needle electrospinning technology has emerged as a crucial solution for mass production. However, the mutual interference of multiple electric fields between the needles can cause significant randomness in the morphology of the produced nanofibers. To better predict the influence of electric field distribution on nanofiber morphology, simulation analysis of the multi-needle arrangement was conducted using finite element analysis software. Nanofiber-coated yarn was produced continuously with the core yarn rotating. The water bath was utilized as the receiver of nanofibers on self-made water bath electrospinning equipment. The electric field distribution and mutual interference under seven different needle arrangements was simulated and analyzed by finite element analysis software ANSYS Maxwell. The results indicated that when the needles were arranged diagonally in a staggered pattern and directly above the core yarn, the simulated electric field distribution was relatively uniform, with less mutual interference. The produced nanofibers exhibited a finer diameter and the diameter distribution was more concentrated. In addition, the nanofiber coating showed higher crystallinity and better mechanical properties.&#xD.

Effect of filament positions on the properties of core yarns produced by embeddable and locatable spinning

To investigate the impact of positional changes of the strand and filament on the performance of embeddable and locatable spun (ELS) core yarns, various parameters were set for ELS systems to produce different yarns. The experiment involved controlling the distance between the strand and filament, as well as the distance between strands. The yarns were then subjected to systematic testing and analysis to evaluate their hairiness, dryness, strength, and abrasion resistance. The experimental results revealed some significant findings. Firstly, increasing the strand spacing from 1 mm to 5 mm led to a consecutive reduction (most by 33.3%) in hairiness for 3 mm distance. Secondly, when the strand spacing was set at 3 mm, the yarn strength increased by 6.8%. Furthermore, by maintaining a fixed strand spacing, increasing the distance between the filament and strand resulted in further reduction of yarn hairiness and improved overall yarn strength. Regarding abrasion resistance, the best performance was observed at a strand spacing of 2 mm. Additionally, the overall abrasion resistance of yarns with increasing strand spacing was superior to that of yarns with varying filament positions. Understanding the relationship between filament positions and yarn properties holds practical significance for the advancement of high-performance composite yarns.

Pumpless microfluidic sweat sensing yarn

Textile sweat sensors possess immense potential for non-invasive health monitoring. Rapid in-situ sweat capture and prevention of its evaporation are crucial for accurate and stable real-time monitoring. Herein, we introduce a unidirectional, pump-free microfluidic sweat management system to tackle this challenge. A nanofiber sheath layer on micrometer-scale sensing filaments enables this pumpless microfluidic design. Utilizing the capillary effect of the nanofibers allows for the swift capture of sweat, while the differential configuration of the hydrophilic and hydrophobic properties of the sheath and core yarns prevents sweat evaporation. The Laplace pressure difference between the cross-scale fibers facilitates the management system to ultimately expulse sweat. This results in microfluidic control of sweat without the need for external forces, resulting in rapid (<5 s), sensitive (19.8 nA μM−1), and stable (with signal noise and drift suppression) sweat detection. This yarn sensor can be easily integrated into various fabrics, enabling the creation of health monitoring smart garments. The garments maintain good monitoring performance even after 20 washes. This work provides a solution for designing smart yarns for high-precision, stable, and non-invasive health monitoring.

Research on twists in core and sheath layers of staple core-spun yarn produced by coaxial roller with different diameters

Research on twists in core and sheath layers of staple core-spun yarn produced by coaxial roller with different diameters

New feeding mechanism to enhance the properties of wrapped elastic composite yarn and denim fabrics thereof

In light of the recent technological advancements in composite yarns with multicomponent cores, also known as dual core spun yarns, their utilisation in the textile industry has become widespread. A V-grooved roller is employed to enhance the feeding of multicomponent cores. In this context, diverse composite yarn designs with varying feeding mechanisms can be employed to optimise yarn performance. This study presents an alternative feeding mechanism utilising a W-grooved roller for commercial use in composite yarn production. To achieve this, dual core yarns and wound elastic composite yarns (filament feeding varies with the sheath cotton fibre with elastane in the centre wrapped on the right and left side) were produced using a modified ring spinning system with different parameters. Denim fabrics were then produced using these composite yarns as weft yarns. The results demonstrated that the wrapped elastic composite yarns with left and right filament core positioning exhibited superior yarn properties in terms of strength, elongation at break, evenness and hairiness. Furthermore, denim fabrics made with wrapped elastic composite yarns exhibited superior breaking load and tearing force results on weft basis. These fabrics also exhibited lower growth, defined as the percentage of the fabric returning to its original length after tensile stress removal.

Continuous fabrication of braided composite nanofibrous surgical yarns using advanced AC electrospinning and braiding technology

Composite nanofibrous yarns (CNY), featuring a submicron electrospun sheath coated on a micro-scale core yarn have gained attention within the academic and industrial communities due to their unique structure. When braided, these CNYs hold great promise as next-generation surgical yarns. However, large-scale production of CNYs using conventional electrospinning techniques remains technologically challenging, and maintaining the integrity of the fibrous sheath during braiding presents further difficulties. Here, we propose a novel approach for continuously fabricating functional braided CNYs using collectorless alternating current (AC) electrospinning and braiding technology. Our approach utilized polycaprolactone-polylactic acid (PCL-PLA) blends and PCL-PLA with chlorhexidine (CHX) or triclosan (TRC) electrospun fibers for the sheath layer, while PLA micro-yarns acted as the core layer. Morphological analyses confirmed the successful fabrication of braided CNYs. Additionally, infrared spectroscopy validated the presence of CHX or TRC in the resulting yarns. The resulting braided CNYs exhibited excellent breaking force (29 N) and thermal stability (270 °C). Cytotoxicity and antibacterial assessments demonstrated that CHX-loaded braided CNYs could serve as biocompatible antibacterial surgical sutures. The proposed method offers a versatile approach for producing various functional braided CNYs applicable in tissue engineering scaffolds, filters, wearable electronics, and sensors.

Statistical study and investigation of the cut-resistant and thermo-physiological performance of protective gloves: a new prospective

Objectives. This research investigated the performance properties of protective gloves alongside improvement in thermo-physiological comfort properties. Methods. Knitted gloves prepared from filament stainless steel, filament Kevlar, staple spun Kevlar and filament glass were used in the core, while 100% viscose rayon and 50/50% polyester/viscose rayon were used in the sheath. Gloves were tested for cut resistance, tear resistance, puncture resistance and abrasion resistance as the prime focus, and thermo-physiological comfort properties were also tested. In this research, a multi-response optimization technique, i.e., principal component analysis, was applied to identify the best yarn combination for gloves based on the aforementioned properties. Thermal images were also taken in constant ambient conditions for temperature distribution maps across the hand’s surface. Results. All of the results were evaluated statistically with analysis of variance, and concluded that the effects of the core yarn on thermo-physiological properties were less significant. Conclusion. The results revealed that samples having dual-core yarn exhibited better in terms of overall properties. The sample having dual-core filament Kevlar and staple spun Kevlar ranked the best. In addition, developed samples exhibited better comfort properties than the control sample.

Investigation of the Basic Dimensional Properties and Biomechanical Performance of Artificial ACL Grafts Produced by 3-D Braiding Method

In the current study, an investigation of basic dimensional properties and biomechanical performance of artificial ACL grafts produced by the 3-D braiding method was carried out. Artificial ACL grafts were produced using the 3-D braiding process. All 3-D braiding grafts were produced using various technical yarns for raw and bio-finishing grafts. Ethylene oxide (EtO) sterilization was applied to all grafts. The effects of yarn types, yarn counts, and 3-D braiding constructions on EtO sterilized raw and bio-finished artificial ACL grafts were examined. In conclusion; the tensile strength and thickness values of all 3-D braiding structured ACL grafts were suitable for artificial ligament grafts. Additionally, its grammage values were extremely light. The yarn type, yarn count, and 3-D braiding construction were the most effective process parameters on thickness, grammage, and tensile strength values. They can be improved by using x2-layered 3-D braiding structures, thicker yarn counts, and more than 1 core yarn in similar studies to be conducted in the future.

The Interconnecting Process and Sensing Performance of Stretchable Hybrid Electronic Yarn for Body Temperature Monitoring.

Flexible and stretchable electronic yarn containing electronic components (i.e., hybrid electronic yarn) are essential for manufacturing smart textile garments or fabrics. Due to their low stretchability and easy interconnection fracture, previously reported hybrid electronic sensing yarns have poor mechanical durability and washability. In order to address this issue, a stretchable hybrid electronic yarn for body temperature monitoring was designed and prepared using a spandex filament as the core yarn and a thin enameled copper wire connected with a thermal resistor as the wrapping fiber. The temperature sensing performance of different hybrid electronic yarn samples was evaluated using the following three types of interconnection methods: conductive adhesive bonding, melt soldering, and hot pressure bonding. The optimal interconnection method with good sensing performance was determined. Furthermore, in order to improve the mechanical durability of the hybrid electronic yarn made using the optimal interconnection method, the interconnection area was encapsulated with polymers, and the effect of polymer materials and structures on the temperature-sensing properties was evaluated. The results show that traditional wrapping combined with hot pressing interconnection followed by tube encapsulating technology is beneficial for achieving high stretchability and good temperature-sensing performance of hybrid electronic yarn.

An airflow-driven system for scalable production of nano-microfiber wrapped triboelectric yarns for wearable applications

Nanofibers, with their large aspect ratio, high specific surface area, and high porosity, hold great promise for applications in textile materials, biomedicine, and smart wearables. Currently, the primary method for producing nanofibers is electrospinning. However, this method carries operational risks due to the use of high-voltage electrostatic fields, and it is not suitable for large-scale production due to low efficiency. To address these challenges, we propose an air-driven spinning system that combines solution blow spinning and vortex tubes for the scalable production of polyvinylidene fluoride-trifluoroethylene (PVDF-TrFE) nano-microfiber wrapped conductive yarn. The airbrushing machine allows for high-speed production of PVDF-TrFE nano-microfibers through solution blow spinning, with a maximum production rate of approximately 36 ml/h. The vortex tubes apply rotation and twist to the core yarn using high-speed airflow to bond the nano-microfibers to core yarn. By optimizing the process, we achieve a tight integration between the outer layer of nano-microfibers and the inner layer of conductive core yarn, imparting water repellency, flexibility, washability, air permeability, and a certain level of abrasion resistance to the resulting yarn. We demonstrate the applications of this yarn as triboelectric nanogenerators, including energy harvesting and self-powered sensing. Furthermore, we employ this method to prepare stretchable self-generating triboelectric yarn. This air-driven spinning system overcomes the limitations of electrospinning, providing a scalable and efficient method for the production of nano-microfiber-wrapped yarns with various functional properties.

Moisture‐Insensitive Force Sensor Yarns and Fabrics to Monitor Biological Motion

AbstractTextile sensors are crucial unobtrusive devices attached to arbitrarily curved surfaces owing to their high flexibility and ease of processing in large areas with complex contours. However, issues regarding the reliability and stability of the output of textile sensors and their practical implementation persist. This study proposes sensor yarns comprising carbon‐coated multifibers covering metallic core yarns to detect pressure and strain. Two electrically independent metallic core fibers are twisted in close proximity in a core‐sheath structure with a sheath yarn of carbon‐coated fibers. When an external force is applied, the covering yarns deform elastically, causing a change in resistance. The proposed sensor yarns can be used to develop customized textile sensors, as they can be woven or knitted at the target positions owing to their flexibility. Fabrics and knits with embedded sensor yarns can detect external forces and biological motions, e.g., respiratory monitoring and finger movements. The proposed sensors can be made sensitive or insensitive to moisture depending on the choice of the covering yarn. Thus, the proposed yarns and textile sensors have potential applications in wearable devices and biological sensors that require high conformability to the human body and curved surfaces.

Electric field simulation of multi-needle water bath electrospinning and the structural properties of SCN/PAN micro/nanofiber composite yarns

Multi-needle water bath electrospinning is one of the most efficient methods used to prepare micro/nanofiber composite yarns. The nanofiber structure can be targeted and regulated to obtain high-performance composite yarns. To explore the effect of the receiving distance on the structure and properties of micro/nanofiber composite yarns, polyacrylonitrile nanofibers were uniformly coated on silver-coated nylon yarn via a four-needle continuous water bath electrospinning method. The electric field distribution at different receiving distances was simulated by ANSYS finite element analysis software, and the effects of electric field distribution on the structure and properties of the micro/nanofiber composite yarns were studied. The results indicated that the peak electric field intensity appeared at the tip of the needles and decreased with the increase in the receiving distance. The receiving distance was constant, and the field intensity was lower when the direction of the centerline of the needle tip was farther away from the tip; however, the field intensity at the conductive core yarn was higher than that in the surrounding area (small spikes). The average field intensity of the small spikes at 180 mm was only 1/4 of that at 80 mm. When the receiving distance increased within a certain range (100∼140 mm), the nanofibers had a smooth surface and good separation, their diameters decreased continuously and the porosity changed inversely. With a further increase in the receiving distance, the nanofibers gradually bonded, their diameter increased and the porosity showed the opposite trend. The coating rate of the nanofibers showed a decreasing trend, and the mechanical properties of the micro/nano composite yarns were improved. When the receiving distance was 100 mm, the porosity reached 38.94%, and the breaking force, breaking elongation and breaking strength were 13.71 ± 1.36 cN, 22.76 ± 6.62% and 0.15 ± 0.02 cN·dtex−1, respectively. Upon consideration of all the above factors, the receiving distance of 100 mm is appropriate.

Preparation of biodegradable polypropylene carbonate-polylactic acid core yarn by electrospinning and its antibacterial finishing

With the improvement of living standards, people’s awareness of health and environmental protection continues to strengthen. The production of textiles with antibacterial functions is one of the effective ways to protect people from or reduce bacterial invasion. Therefore, textiles with antibacterial functions are increasingly favored by people. At the same time, due to the impact of global warming, people are committed to reducing carbon emissions in all aspects of life. The biodegradable material polypropylidene carbonate (PPC) that can consume carbon dioxide (CO2) in the production process fully conforms to people’s environmental protection concept. However, polypropylidene carbonate itself has poor thermal stability and narrow application range. Polypropylidene carbonate thermoplastic polyurethane (PPC-TPU) is obtained by chain extension modification, which can broaden the application range of polypropylidene carbonate. To develop a yarn with excellent antibacterial and mechanical properties, which can be woven into fabrics for medical applications while taking into account environmental protection and degradability, the antibacterial yarn in this article was prepared by electrospinning using PPC-TPU and polylactic acid (PLA) yarn as raw materials. The preparation process was optimized by adjusting the supply speed, winding collection speed and horn barrel speed, and the optimal concentration of antimicrobial agent was explored by adding different concentrations of benzalkonium bromide antimicrobial. Through the characterization of the properties of the materials, we believe that PPC-PLA yarn with the addition of 5% benzalkonium bromide has broad development prospects in the medical field due to its excellent mechanical and antibacterial properties.

Large-scalable fabrication of zirconium carbide-based core-sheath yarn for wearable applications

As advances in science and technology highlight the applications of electronic textiles, their reliance on natural resources becomes apparent. To promote sustainability, yarns with strain-sensing and photothermal conversion functions are needed, utilizing recyclable resources effectively. However, current-sensing yarns with photothermal-conversion functions have low photothermal-conversion capabilities. Herein, we report a simple and feasible strategy for fabricating core-sheath-structured yarns with photothermal and sensing capabilities for photothermal conversion and strain-sensing applications. The spinning speed employed in the friction spinning approach exceeded 600 m/h, paving the way for a new method that combines sensing and photothermal properties. The multi-layer yarn included spandex as the core yarn, carbon nanotube-coated cotton as the middle layer, and a zirconium carbide@polyurethane film as the sheath. The obtained spandex/carbon nanotube @cotton/zirconium carbide@polyurethane yarn had good strain sensing ability, and the yarn temperature could be increased to 103.5 °C after 1 min of infrared-light irradiation, being stabilized at 121.7 °C after 5 min. The durability tests demonstrated that the sensing and photothermal capabilities of the yarns were maintained well after cyclic performance test, cyclic friction test and cyclic twist test. The obtained core sheath yarn may provide a feasible way for industrial-scale manufacture wearable electronic devices and smart sensing yarn with excellent sensing and photothermal performance.

Mn-doped ZnO/SnO2-based yarn sensor for ammonia detection

Metal oxide semiconductor (MOS) gas sensing materials have high operating temperatures and often use rigid materials as substrates, making them difficult to be widely applied in the field of wearable electronic devices. In this work, the sheath-core structure electrospun nanofiber core-spun yarn (ES-PY) was prepared using the coaxial electrospun yarn technology, and then the poly (dopamine) was polymerized on its surface to obtain the poly (dopamine) nanofiber core-spun yarn (PDA-PY). ZnO/SnO2/Mn metal oxide semiconductor nanoparticles (ZS/Mn-NPs) were synthesized via a two-step hydrothermal process by doping Mn into ZnO/SnO2. These were subsequently loaded onto the surface of PDA-PY to produce the yarn sensor (ZS/Mn-PY).The combination of the nano-size effect of the nanofibers and the doping-promoting effect of the Mn-doped metal oxide semiconductor further increases the adsorption sites of the gas molecules so that the sensor exhibits excellent gas sensitivity to ammonia (NH3), with a response up to 13.13 (Ra/Rg) in an ammonia atmosphere at a concentration of 100 ppm, and still up to 2.61 when exposed to an ammonia atmosphere at a concentration as low as 10 ppm at room temperature. In addition, it retains the excellent flexibility and strength of the core yarn. And provides a simple and effective method for preparing flexible textile gas sensor.

Effect of Core Yarn on Linear Actuation of Electroactive Polymer Coated Yarn Actuators

AbstractSmart textiles combine the features of conventional textiles with promising properties of smart materials such as electromechanically active polymers, resulting in textile actuators. Textile actuators comprise of individual yarn actuators, so understanding their electro‐chemo‐mechanical behavior is of great importance. Herein, this study investigates the effect of inherent structural and mechanical properties of commercial yarns, that form the core of the yarn actuators, on the linear actuation of the conducting‐polymer‐based yarn actuators. Commercial yarns were coated with poly(3,4‐ethylenedioxythiophene)‐poly(styrenesulfonate) (PEDOT:PSS) to make them conductive. Then polypyrrole (PPy) that provides the electromechanical actuation is electropolymerized on the yarn surface under controlled conditions. The linear actuation of the yarn actuators is investigated in aqueous electrolyte under isotonic and isometric conditions. The yarn actuators generated an isotonic strain up to 0.99% and isometric force of 95 mN. The isometric strain achieved in this work is more than tenfold and threefold greater than the previously reported yarn actuators. The isometric actuation force shows an increase of nearly 11‐fold over our previous results. Finally, a qualitative mechanical model is introduced to describe the actuation behavior of yarn actuators. The strain and force created by the yarn actuators make them promising candidates for wearable actuator technologies.

Enhancement Reinforcing Concrete Beams Using Polypropylene Cord-Knitted Bars

Currently, technical fabrics play a major role in many industries due to their multiple characteristics. The aim of this research was to utilize composite knitted bars to reinforce concrete beams. Six cord-knitted samples with two different polypropylene yarn counts (outer layer) and three different core materials were manufactured and immersed in a local epoxy material (Kemapoxy 150). Composite knitted bars were prepared in this way. Several tests were conducted for fabrics and knitted bar samples. All data were collected and analysed using two different tools: ANOVA test and radar chart area. Finally, three concrete beams with a varying number of cord-knitted bars (one bar, two bars and three bars) were produced. The results indicated that the differences in outer and core yarns for cord-knitted samples have a significant effect on several fabric and bar characteristics. The knitted bars with PP core yarn can be more beneficial for concrete that do does not require high stress, while the knitted bars using glass fibres and polypropylene (50% and 50% PE) as core materials are not appropriate for applications that require more flexibility and extensibility. Reinforced concrete beams were improved significantly with cord-knitted bars, taking into account the number of bars per area, which may cause the minimizing of flexure force through an increase in that number of bars per area.

Research on a novel sheath core-wrap staple yarn based on the ring spinning frame with special-shaped roller

This work explored a novel method for producing sheath core-wrap staple yarn on a modified ring spinning machine. The sheath core-wrap staple yarn is a new composite yarn whose core layer and sheath layer are both composed of staple fibers. In this paper, the conventional front roller on the ring spinning machine was replaced by a special-shaped roller, named a coaxial front roller of different diameters. In the spinning process, two colored cotton rovings were fed into the back roller. Then they are conveyed to the coaxial front roller of different diameters and output at different speeds. Finally, they were spun in a sheath core-wrap staple yarn under the twist effect. The covering effect and properties of sheath core-wrap staple yarn are the critical concerns in this article. Mathematical equations have been derived to calculate the ideal twist multiplier. It is most favorable for the core fiber to be covered at the ideal twist multiplier 408. The effects of the twist multiplier and core proportion on core exposure ratio and yarn properties (tensile properties, abrasion resistance, evenness, and hairiness) were investigated. The results showed that the core exposure ratio of all sheath core-wrap staple yarns were less than 2%, and the minimum core exposure ratio was obtained at the twist multiplier 400. The results also demonstrated that the tensile property, abrasion resistance, evenness, and hairiness improved with the increase of the twist multiplier and the core proportion. The proposed method provides new insight for researchers to fully understand the production process of sheath core-warp staple yarn and improve the yarn quality.