Composite Yarns Research Articles

Electro–Centrifugal Spinning of Core–Sheath Composite Yarns with Micro/Nano Structures for Self–Powered Sensing

In recent years, triboelectric nanogenerators (TENGs) have garnered extensive attention in the realm of self-powered sensors due to their capability to harness low-frequency mechanical energy. Among these, textile-based triboelectric nanogenerator stands out as a pivotal platform for wearable sensing. Nevertheless, conventional approaches, such as directly coating triboelectric materials on fabrics, often compromise the inherent properties. In this study, we utilized our self-developed electro-centrifugal spinning equipment to continuously fabricate core-sheath yarns with micro/nano structures, resulting in the development of pocket-shaped fabric-based (PF) TENGs. This innovative design preserves the original softness and breathability of the fabric while delivering substantial electrical output owing to its layered structure and extensive specific surface area. PF–TENGs can accurately detect electrical output signals from various motion states. This electro–centrifugal spinning technology offers new research directions and sensing application prospects for self-powered smart textile development.

Conductive Graphene–Polyethylene Terephthalate Composite Yarns with Synergistic Multiwalled Carbon Nanotube Additives by Melt‐Spinning

Conductive graphene yarns are pivotal for embedding electronic and intelligent capabilities into fabrics. The study presents successful fabrication of conductive graphene–polyethylene terephthalate (PET) composite yarns with synergistic multiwalled carbon nanotube (MWCNT) additives through the melt‐spinning process, a widely used industrial method for polymer yarn manufacturing. The integration of MWCNTs significantly improves yarns’ electrical conductivity, achieving nearly a 100‐fold increase compared to MWCNT–PET composite yarns. The electrical performance of these yarns is primarily determined by interfacial contacts between conducting nanomaterials, which can be conceptualized as quantum tunneling barriers with multiple molecular energy levels at their extremities. Employing the Simmons model, the current–voltage characteristics is analyzed through a segmented fitting approach to extract critical barrier parameters. The equivalent barrier height and width remain constant across variations in applied voltage, nanomaterial concentration, and temperature. However, the effective total contact area increases significantly with higher nanomaterial contents, thereby substantially boosting the yarns’ electrical conductivity. The larger graphene size (≈200 nm) in comparison with the MWCNT diameter (≈5 nm) results in a substantially greater interfacial area at graphene–MWCNT contacts compared to MWCNT–MWCNT contacts. This disparity in contact area is the primary factor contributing to synergistic enhancement of electrical conductivity in graphene–PET composite yarns.

Comparison of mechanical and flammability properties of thermoplastic and thermoset matrix glass fibre woven fabric composites

This study aims to examine the mechanical and burning properties of composites made from twill (0°/0° and 0°/90° orientations) and plain fabrics using hybrid yarns produced by combining glass and polypropylene yarns with interwoven and intermingled methods. The properties of interwoven and intermingled hybrid fabric composites were compared with thermoset composites. Each composite (56% glass fibre content) plate is produced by combining eight fabrics with the same parameters using the press moulding technique. The effects of yarn and fabric weaving types on the results were examined in detail. When the results are examined, the breakage of glass fibres in intermingled hybrid yarns negatively affects the strength results. Therefore, composites made with intermingled hybrid yarn types and plain weave types of fabric had the lowest tensile strength value (132 MPa). The composite of twill woven fabrics produced with interwoven yarns arranged in 0°/0° orientation had the highest tensile strength of 315 MPa, and these results were very close to those of thermoset composites. Although the 0°/90° oriented twill composite showed a 2.3 times lower tensile strength value than the 0°/0° oriented twill composite, it had a 7.7 times higher value when bending strength values were taken into account. The main reason for this is that glass fibres contribute to the warp and weft directions. It has been observed that the composite consisting of plain fabrics woven with commingled hybrid yarns had the highest impact resistance. Additionally, when the combustion results were examined, it was concluded that the type of yarn and fabric weaving affected the burning rate. The slower combustion of hybrid commingled yarn composites resulted from fibreglass breakage during yarn production. These findings provide valuable insights into optimizing composite materials for specific applications, considering factors such as weaving pattern, fibre orientation, and mechanical performance.

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.

Excellent thermal, moisture-permeable weft-knitted fabric with core-sheath yarn structure for foot protection in cold environments

In extremely cold environments, maintaining body temperature and reducing heat dissipation is essential for maintaining human health and life safety, but the field of thermal insulation shoe upper fabric has not been deeply studied. In this paper, based on the dual-scale structure of the yarn and shoe upper fabric, a composite yarn with a core-sheath structure is designed, and a using plating stitch pattern weft-knitted whole garment thermal insulation shoe upper fabric with double-layer structure is proposed. By testing the mechanical properties and thermal and moisture performance of the shoe upper fabric and the thermal insulation performance of the whole shoe, the thermal insulation mechanism of the weft-knitted whole garment shoe upper fabric with a double-layer structure and dual-scale structure design was systematically studied. The results show that the shoes made of polyimide/hollow polyester composite yarn with core-sheath structure yarn have good thermal insulation performance. The use of core-sheath yarns can improve the thermal insulation performance of the shoe, and, with the increase of the ratio of core-sheath yarn, the thermal insulation performance of the shoe is better. Starting from the dual-scale shoe fabric structure, this article proposes a novel method for the industrial production of thermal insulation shoe upper fabrics, which is expected to provide guidance for the further development of thermal insulation shoe upper fabric in the future.

Enhanced thermal conductivity of UHMWPE by coating boron nitride and polyurethane composites

The development of textile wearable electronics has increased demands and requirements for thermal management materials due to integrated and miniaturized soft equipment. In this work, the surface of ultrahigh molecular weight polyethylene (UHMWPE) fibers was first decorated by polydopamine (PDA) to improve the surface activity and construct a steady interface layer. Then the boron nitride/polyurethane coating surface modified UHMWPE composite yarns with good thermal conductivity were produced using a coaxial wet forming process. The thermally conductive composite yarns demonstrated great mechanical properties (5.09 % strain, 0.79 N/tex strength) and thermal conductivity (0.54 ± 0.02 W·mK−1) with the BN/PU weight ratio of 1. Furthermore, the resistance to failure cycles was taken place, and the composite yarns kept good thermal conductivity after multiple cycles twisting, bending, washing, cooling and heating cycles. By the coaxial wet fabrication, the thermally conductive composite yarns were constructed, offering a viable and trustworthy method for creating polymer-based thermal interface materials with high thermal conductivity.

Design and Strain Sensing Performance of Spiral-Wrapped Composite Conductive Yarn Based on Graphene/Carbon Nanotubes

Design and Strain Sensing Performance of Spiral-Wrapped Composite Conductive Yarn Based on Graphene/Carbon Nanotubes

Non-invasive identification of historical textiles and leather by means of external reflection FTIR spectroscopy

Identifying the fibres in historical textiles presents a complex challenge due to the wide variety of plant, animal and early synthetic materials that have been used. Traditionally, this identification process involves sampling followed by either microscopic examination or ATR-FTIR spectroscopy. However, there are instances when sampling is restricted due to the good condition or significant value of the object under analysis. Additionally, the presence of leather components alongside textiles can further complicate the identification. This paper proposes a novel non-invasive method for fibre identification based on External Reflection (ER) FTIR spectroscopy, which has been rarely applied to textiles or leather. The current research demonstrates that ER-FTIR spectrum is a viable tool for fibre identification on both recent and historical textiles. The non-invasiveness of the analytical approach enables a comprehensive investigation without compromising the number or position of samples. Respect to ATR-FTIR spectra, the ER-FTIR spectra frequently exhibit an amplification of certain diagnostic bands, facilitating the identification of the various fibres examined in this study (cotton, hemp, viscose, silk, wool, leather, polyamide, acrylic, polyester). The extended spectral range (7500–375 cm−1) which is provided by ER-FTIR spectrometry also contains extra bands in the near infrared region, which can provide key information for the discrimination due to the lack of distortion phenomena. The technique was applied to the characterisation of textile materials coming from a collection of 10 traditional Japanese samurai armours spanning from the 16th to the 20th century (Museo delle Culture, Lugano, Switzerland). For the first time, the results provided a comprehensive overview of the textiles utilized in Japanese armours across various historical periods. Overall, the appearance of materials in samurai armours reflects the evolution of armour-making techniques and the influence of socio-cultural factors throughout Japanese history. Synthetic and semi-synthetic materials were easily detected, revealing the occurrence of a past conservation treatment or the early adoption of modern man-made materials in the manufacturing of traditional armours. The approach outlined in this case study can be applied to textile collections of various kinds, offering a reliable mean to discern the yarn composition and detect non-original components. The method also appears as a valuable prescreening tool for designing a less intrusive yet more informative sampling strategy, should additional details about fibre type and dyeing be necessary.

Development of PCM-Loaded Composite Yarns for Enhanced Thermoregulation in Medical Textiles

Development of PCM-Loaded Composite Yarns for Enhanced Thermoregulation in Medical Textiles

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.

Highly conductive copper-coated polyamide yarn for wearable sensing and Joule heating applications

A highly conductive yarn was developed by electroless deposition of copper metal particles on the polyamide 6 yarn. The successful incorporation of Cu particles into the substrate was revealed by surface and elemental characterizations. The Cu/PA 6 yarn exhibited superior electrical conductivity (2.3 Ω/cm) with improved mechanical properties. The excellent electromechanical properties demonstrated by the Cu/PA 6 composite revealed its sensing capacity for a wide range of strains. Therefore, the composite yarn was affixed to the different regions of the human body and was capable of successfully monitoring various human motions, including finger bending, wrist bending, knee bending, drinking, and writing. In addition, rapid heat generation with high and uniform surface temperature (66.3 °C at 4.0 V in 45 s) validated the potential of the Cu/PA 6 yarn for wearable thermal heating devices. Moreover, rapid heating at a lower voltage, when attached to a wristband, revealed the capability of the composite yarn for localized heating or region-specific temperature regulation for personalized healthcare or comfort. This study informs a facile and effective strategy for developing robust yarn-shaped e-textiles for advanced wearable sensing and thermal heating.

Thermal Protection Performance Evaluation Based on Structural Composition Changes of the Intermediate-Layer Fabric in Thermal Protective Clothing

This study is a follow-up to ‘Research on the Development of Fabrics for Industrial and Firefighting Protective Clothing and Comparison of Flame Retardant Performance,’ focusing on the thermal protection performance of clothing designed to protect the human body from high temperatures and heat in industrial settings and fire scenarios. In this study, additional thermal protection performance tests were conducted to provide a more comprehensive analysis. Aside from the flame-retardant performance evaluation conducted according to ISO 15025 on 12 base fabrics with different yarn compositions, the following thermal performance studies were carried out: radiant heat protection (ISO 9151), convective heat protection (ISO 6942), and combined radiant and convective heat protection (ISO 17492). The heat-transfer index of the intermediate layer, which plays a crucial role in the thermal protection performance of thermal clothing, was also assessed. The results indicated that although most of the 12 base fabrics offered a certain level of thermal protection, some of them melted and failed to provide adequate thermal protection.

Fabrication and properties of photothermal conversion and thermochromic cotton yarn

Purpose This paper aims to demonstrate that, in line with the emerging trend of multifunctional yarn development, cotton yarn can effectively harness renewable solar energy to achieve photothermal conversion and thermochromism. This innovation not only maintains the comfort associated with natural fiber cotton yarn but also enhances its ultraviolet (UV) light resistance. Design/methodology/approach In this work, 4% zirconium carbide (ZrC) and thermochromic powder were adhered to cotton yarn through polyurethane (PU) by sizing coating method. After sizing, the two cotton yarns are twisted by ring spinning to obtain composite yarns with photothermal conversion and thermochromic functions. Findings The yarn obtained by cotton/6%PU/8% thermochromic dye single yarn and cotton/6%PU/4% ZrC single yarn composite is the best match. After 5 min of infrared light, the temperature of the composite yarn rose to the maximum, increasing by 36.1°C. The ΔE* value before and after irradiation of infrared lamp is 26.565, which proves that the thermochromic function is good. The yarn dryness unevenness was significantly reduced by 27.2%. The composite yarn has a UPF value of up to 89.22, and its performance characteristics remain stable after 100 minutes of washing. Originality/value The composite yarn’s photothermal conversion and thermochromism functions are mutually reinforcing. Using sunlight can simultaneously achieve heating and discoloration effects without consuming additional energy. The cotton yarn used in this application is versatile, and suitable for a wide range of uses including clothing, temperature visualization detection and other scenarios.

Versatile fabrication of carbon nanotube yarn composites by in-situ interfacial polymerization of polyetherimide

Manufacturing of high-performance carbon nanotube (CNT)-based polymer composites has long been complicated by the difficulty of infiltrating the nanoporous network presented by continuous CNT materials; this can yield composites with heterogeneities that drastically worsen their mechanical properties. We show the synthesis of CNT-polyetherimide (PEI) composite yarns via in-situ interfacial polymerization (ISIP), which side-steps slow, viscous polymer transport by infiltrating and reacting monomer species in-situ via a rapid and scalable process. We demonstrate the ISIP technique on two distinct, industrially-produced CNT yarns, and identify processing parameters that achieve conformal polymer coatings, yielding statistically-significant increases to linear density-specific tensile properties. Using ISIP on pre-densified yarns results in composites with specific stiffness and tenacity of 142 N/tex and 2.2 N/tex, respectively. When ISIP is applied to lightly-processed, porous CNT yarn, the specific stiffness and tenacity reach up to 66 N/tex and 0.7 N/tex. The role of interfacial effects, particularly from amorphous carbon, on the composite properties is also explored. Finally, we demonstrate a prototype roll-to-roll ISIP apparatus which can process arbitrary lengths of yarn for continuous composite production.

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.

Tree-inspired fabric-based of carbon fiber photothermal evaporator for highly efficient water-evaporation desalination

Recently, researchers have increasingly focused on interfacial solar evaporation technology due to its potential in addressing freshwater scarcity through its cleanliness, efficiency, cost-effectiveness, and environmental friendliness. However, developing salt-resistant evaporation devices with high performance using simple processing methods remains challenging. This study presents a novel core-spun composite yarn, utilizing Tencel as the core for its water absorption properties and wrapping it with carbon fiber bundles known for their excellent light absorption capabilities. A photothermal composite yarn fabric evaporation device with a bridge-like structure, utilizing carbon fiber and crafted through three-dimensional braiding technology, was developed. The inclusion of polystyrene foam ensures stable floating and excellent thermal insulation, enhancing thermal management efficiency of the evaporator. Results indicate a stable evaporation rate of 1.71 kg·m−2·h−1 under 1 sun illumination and effectively prevents salt crystallization during prolonged simulated seawater evaporation, specifically with a 10 wt% NaCl solution. This research lays a valuable foundation for designing uncomplicated, efficient, and scalable solar water evaporation devices.

A super-elastic wearable strain sensor based on PU/CNTs yarns for human-motion detection

Yarn-based strain sensors increasingly garner attention for their potential applications in intelligent wearable electronic devices. Developing highly elastic conductive composite yarns and integrating them into fabrics poses a significant challenge in manufacturing flexible electronic devices. In this study, a polyurethane (PU)/carbon nanotubes (CNTs) composite nanofiber yarn was successfully and continuously prepared using a simple conjugate spinning technique. The resulting yarn exhibited excellent mechanical properties, with a high tensile strength of up to 56.7 MPa and an elongation at break of 504 %. A yarn with a dual conductive network was created using CNTs ink dip-coating. It demonstrated excellent conductivity (8.77 S/cm), exceptional linear variation, and reusability. The sensor remained stable after 1000 cycles of testing, exhibiting a relative electrical resistance change of up to 594 % under a strain of 350 %. Additionally, taking advantage of the inherent knittability of one-dimensional yarn structures, a susceptible wearable textile-type strain sensor was successfully developed using textile knitting technology. This sensor can be directly attached to the surface of the human body for real-time monitoring of human body dynamics. This sensor showcases significant promise for use in flexible, intelligent, wearable electronic devices.

The effect of gamma-ray irradiation on polymer-graphene nanocomposite interfaces

CNT yarns are used in ultra-high strength composites for use in manned deep-space vehicles. It has been previously demonstrated through experiments that gamma-ray irradiation substantially improves the mechanical performance of these composites. It is unclear how the irradiation affects the mechanical response of the CNT yarn/polymer interface that ultimately leads to these panel-level performance improvements. Physical insight into this process could enable further improvements in the CNT yarn/polymer interface design in the future. The objective of this research is to use molecular dynamics simulation to provide physical insight into the effect of gamma-ray irradiation on the mechanical behavior (interfacial interaction energy, shear resistance, adhesive strength) of the CNT yarn/polymer interface for a range of high-performance polymer systems. The simulation results indicate that gamma-ray irradiation (simulated via inclusion of defects on the CNT surface) has a most significant effect on the shear deformation resistance of CNT yarn/polymer interfaces, which likely leads to the experimentally-observed improvements in panel-level CNT yarn composites irradiated with gamma rays. The results of this study also demonstrate the importance of computational modeling in providing physical insight into observed bulk-scale material behavior. Although the predictions cannot be validated directly via experiment, such insight can ultimately lead to efficient improvements in material design (e.g. mechanical performance) that lead to further increases in panel-level composite performance.

All-cellulose composite yarn via welding engineering

Due to the wide range of available raw materials and excellent biocompatibility, all-cellulose composites (ACCs) have received significant attention as a kind of renewable and biodegradable candidate to replace petroleum-based synthetic polymers. However, most current research of ACCs is limited to film and bulk materials. Herein, we present a simple, efficient, and scalable welding method for obtaining green, self-reinforced, high performance all-cellulose composite yarns by partially dissolving and regenerating cellulose yarns with phosphoric acid. The in-situ core-shell structure of the welded yarn results in improved strength (134.6 MPa), friction resistance (8000 cycles), moisture regain (11.89 %), and dyeing properties. Moreover, the regeneration and drying procedure can be optimized to further enhance the strength (190.5 MPa) of the welded yarn. This straightforward welding approach provides a promising and convenient route for manufacturing high-performance bio-based yarn.

Lamellar structure of high-strength direct-spun CNT yarns: Implications for interface failure

A previously unreported nanoscale lamella structure in a direct spun high strength carbon nanotube (CNT) yarn was identified and characterized. The thickness of the lamellae is in the order of 100 nm. The lamella structure is present in the entire cross-section. It is hypothesized that the lamella structure originates from a single thin sheet (felt) during the manufacturing process, between steps of CNT aerogel and CNT roving. The existence of this lamella structure has direct implications on the yarn-resin interface behavior of derived composites and, subsequently, the mechanical performance of CNT yarn composites. Peridynamic simulations of four distinct yarn pullout experiments captured the observed failure behavior influenced by microstructure.