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HighlightsFull-fiber auxetic-interlaced yarn sensor was fabricated by a continuous and mass-producible computerized wrapping spinning technology.Auxetic-interlaced yarn sensor shows a Poisson’s ratio of − 1.5, a robust mechanical property (0.6 cN/dtex), and a fast train-resistance responsiveness (0.025 s).A novel sign-language translation glove was developed to recognize the full English alphabet and translate the wearer’s sign language to text.Yarn sensors have shown promising application prospects in wearable electronics owing to their shape adaptability, good flexibility, and weavability. However, it is still a critical challenge to develop simultaneously structure stable, fast response, body conformal, mechanical robust yarn sensor using full microfibers in an industrial-scalable manner. Herein, a full-fiber auxetic-interlaced yarn sensor (AIYS) with negative Poisson’s ratio is designed and fabricated using a continuous, mass-producible, structure-programmable, and low-cost spinning technology. Based on the unique microfiber interlaced architecture, AIYS simultaneously achieves a Poisson’s ratio of−1.5, a robust mechanical property (0.6 cN/dtex), and a fast train-resistance responsiveness (0.025 s), which enhances conformality with the human body and quickly transduce human joint bending and/or stretching into electrical signals. Moreover, AIYS shows good flexibility, washability, weavability, and high repeatability. Furtherly, with the AIYS array, an ultrafast full-letter sign-language translation glove is developed using artificial neural network. The sign-language translation glove achieves an accuracy of 99.8% for all letters of the English alphabet within a short time of 0.25 s. Furthermore, owing to excellent full letter-recognition ability, real-time translation of daily dialogues and complex sentences is also demonstrated. The smart glove exhibits a remarkable potential in eliminating the communication barriers between signers and non-signers.

The technology of warp knitting is one of the more recently developed processes in knitting technology. Complex machine technology and highly productive machines characterize the process. This principle allows obtaining fabrics with various characteristics and for various applications. It is possible to insert straight weft yarns in the textile structure. The weft yarn can be inserted either over the entire width of the textile surface, that is, full wefts, or only over a specific area of the textile, that is, partial wefts. However, weft insertion is the limiting factor in respect of process speed, even if different methods for traversing yarn positioning in the textile industry with the potential to increase the weft insertion speed had been introduced. This paper aims to analyze the inlay yarn condition in respect of yarn tension and yarn speed during the cyclical process of the state-of-the-magazine inlay yarn insertion system and, based on these findings to propose a solution to increase the laying velocity by developing a new method. The approach used is to reduce the vibration induced by the reciprocating movement of the guide bar during inlay operation by using a continuous movement of the mobile elements. This will allow in the future increasing the production velocity, to reduce the stress on the inlay yarn due to acceleration and deceleration.

This paper presents a study of the sensing properties exhibited by textile-based knitted strain sensors. Knitted sensors were manufactured using flat-bed knitting technology, and electro-mechanical tests were subsequently performed on the specimens using a tensile testing machine to apply strain whilst the sensor was incorporated into a Wheatstone bridge arrangement to allow electrical monitoring. The sensing fabrics were manufactured from silver-plated nylon and elastomeric yarns. The component yarns offered similar diameters, bending characteristics and surface friction, but their production parameters differed in respect of the required yarn input tension, the number of conductive courses in the sensing structure and the elastomeric yarn extension characteristics. Experimental results showed that these manufacturing controls significantly affected the sensing properties of the knitted structures such that the gauge factor values, the working range and the linearity of the sensors varied according to the knitted structure. These results confirm that production parameters play a fundamental role in determining the physical behavior and the sensing properties of knitted sensors. It is thus possible to manipulate the sensing properties of knitted sensors and the sensor response may be engineered by varying the production parameters applied to specific designs.

Yarns of fiber assemblies such as ropes would abrade with each other during repeated stretching or bending. The yarn on yarn abrasion failure is a main reason for the final assembly failure as the result of the relative movement to each other. To explore the influencing factors and failure mechanism, this work, taking the Ultra High Molecular Weight Polyethylene Fiber (UHMWPE) as the research object, discussed the influences of abrading frequency and the yarn tension on its abrasion life. Based on the observation and analysis of the rising temperatures from abrasion, the abrasion fragments, and morphology of failed yarns, the heating failure and crack propagation mechanisms were proposed, which provide insights into a variety of UHMWPE product designs and applications.

In recent decades, consumer expectations and behavior have altered, focusing on more comfortable, well-fitting clothes. Wearing a slim-fitting garment helps to move more freely. Different elastomeric polymers are being introduced as a core constituent of the yarn to make denim fabric more comfortable during movement. The use of elastic material ensures that the material is stretchable and recoverable. The performance of several elastomeric hybrid yarns has been investigated in the first section of this study. Here, polyethylene terephthalate/polytrimethylene terephthalate (PET/PTT (T400®)), polytrimethylene terephthalate (PTT (Solotex®)), polybutylene terephthalate (PBT), and Lycra® (elastane) were used as the core component of the core and dual core-spun yarns. After that, 3/1 Z twill denim fabrics were made with these as weft yarns, and the fabric’s performance was assessed. It is found that dual core-spun yarns were shown to have lower strength than core-spun yarns, while it had a higher elongation value. PTT/PBT dual core-spun yarn had less unevenness and hairiness than yarn made solely of elastane. PBT in the core of the weft yarns provided strong strength, dimensional change, and stiffness qualities in the fabric. In contrast, elastane in the core of the weft yarns provided good elastic performance. Yarn and fabric performance for the hybrid yarns were statistically significant at a significance level of 0.05.

Flexible and stretchable strain sensors are an important development for measuring various movements and forces and are increasingly used in a wide range of smart textiles. For example, strain sensors can be used to measure the movements of arms, legs or individual joints. Thereby, most strain sensors are capable of detecting large movements with a high sensitivity. Very few are able to measure small movements, i.e., strains of less than 5%, with a high sensitivity, which is necessary to carry out important health measurements, such as breathing, bending, heartbeat, and vibrations. This research deals with the development of strain sensors capable of detecting strain of 1% with a high sensitivity. For this purpose, a total of six commercially available metallic yarns were coated with a carbon-containing silicone coating. The process is based on a vertical dip-coating technology with a self-printed 3D coating bath. Afterwards, the finished yarns were interlooped and stretched by 1% while electrical resistance measurements were carried out. It was shown that, although the coating reduced the overall conductivity of the yarns, it also improved their sensitivity to stress. Conclusively, highly sensitive strain sensors, designed specially for small loads, were produced by a simple coating set-up and interlooping structure of the sensory yarns, which could easily be embedded in greater textile structures for wearable electronics.

In this study the influence of fabric weave (plain, twill, and panama) and weft type (flax and hemp yarns) on selected mechanical and comfort properties of six fabrics was analyzed. The results showed that tear and abrasion properties were most affected by the weave. The tensile properties of the linen fabrics were not significantly different when weft hemp yarns were used instead of flax. Fabrics with the same weave seemed to be equally resilient to abrasion regardless of the type of weft. By contrast, the hemp weft yarns favorized the physical and comfort properties of the investigated fabrics. For the same weave, the hemp–linen fabrics were slightly lighter and exhibited lower bulk density, significantly larger air permeability, and improved moisture management properties. Although the results of maximum thermal flux (Qmax) suggested a cooler sensation of the linen fabrics with panama and twill, the hemp–linen fabric with a plain weave seemed to be the optimal choice when a cool sensation was desired. Higher thermal conductivity values also suggested slightly better heat transfer properties of the hemp–linen fabrics, and these were significantly influenced by the weave type. The results clearly indicated the advantages of using hemp for improving physical and specific comfort properties of linen fabrics.

As a high-performance fiber, high modulus polyethylene fiber (HMPE) has been widely used in the rope industry. However, due to its low melting point and poor thermal conductivity, it tends to break under the conditions of repeated yarn on yarn abrasion during tension-tension fatigue or tension-bending fatigue. This paper puts forward a method to improve the yarn on yarn abrasion performance of HMPE using a functional graphene/polyurethane composites coating (FG/PU) and discussed the influence of yarn tension, abrasion frequency on the yarn on yarn performance. Based on the yarn morphology and abrasion temperature observation, the failure mechanism was discussed. The experimental results show that the FG/PU coating obtained can improve the yarn on yarn abrasion performance obviously, especially in the case of high-frequency and large tension condition.

This paper presents a study of the electromagnetic shielding characterization of woven fabrics, produced with two different types of conductive yarns, namely silver-containing (Ag/PA/Co) core yarns and silver-containing (Ag/PA-Co) blended yarns. The effect of various yarn and fabric properties, such as yarn count, core filament count, blend ratio, weft density, electrical resistivity, yarn type and wave frequency, on the electromagnetic shielding effectiveness was investigated. The results have shown that the shielding effectiveness can be tailored by changing the yarn and fabric parameters and also there are significant differences between the electromagnetic shielding characteristics and performances of the fabrics produced with different yarn groups. Such fabrics are future promising for both daily and professional uses, since they combine high shielding effectiveness performance and the comfort properties of conventional fabrics.

Flexible, stretchable and sensitive textile-based sensors play important roles in a wide variety of artificial intelligence because of its seamless integration with clothing and good comfort. Herein, MXene sensing layer is deposited on the surface of springlike helical core-sheath polyester yarns thanks to the capillarity effect and its intrinsic hydrophilic ability, and the resultant strain sensor and humidity sensor exhibit wide detection range from 0.3 to 120% strain and 30–100% relative humidity (RH) detection, owing to elastic core-sheath structures. The strain sensor shows excellent reproducibility (over 10000 cycles) and fast response time (120 ms). The core-sheath yarn sensor can detect various human motions such as walking, bending and twisting as well as physiological signal (pulse), which have great potential in real-time precise medicine and health care. The yarn sensor could also be an excellent humidity sensor because of the high specific area structure of yarn and intrinsic hydrophilic properties of MXene sensing layer.