Knitted Structures Research Articles

Properties of graphene composite fiber seamless knitted fabric and its application in boxing training

In boxing, the wrong training methods can easily cause physical injury, so many sports protective clothing will use new materials to reduce the impact of boxing training. The aim of this paper is to design a boxing suit based on graphene composite fiber seamless knitted fabric, so as to reduce the injury of boxers during training. In this paper, the head yarn, inner yarn and knitting structure of graphene composite fiber seamless knitted fabrics are discussed, and nine kinds of fabrics are determined by orthogonal matrix method; then, a comprehensive evaluation of the wear resistance of fabrics was proposed based on sequence entropy weight technology, and the ideal solution similarity (TOPSIS) method was used to calculate the wear resistance; finally, this paper designed the boxing protective suit according to the best combination of performance. The experimental results in this paper showed that the veil of sample No. 7 is 70D/48F graphene nylon, the inner yarn is 30D graphene spandex/70D graphene nylon covered yarn, and the fabric with the knitted structure of 1 + 3 false rib has the best comprehensive performance and the highest relative proximity, reaching 0.862. The actual wearing test proves that the comfort of anti-impact boxing suit is slightly better than that of ordinary boxing suit. The clothing designed in this paper has good anti-impact effect. Therefore, on the whole, the boxing suit with graphene composite fiber seamless knitted fabric has good protective effect and can be used for boxing training.

Development of a new yarn supply for weft knitting machines to produce innovative knitwear

The increasing demand for technical textiles makes innovations and acceleration of processes necessary. This research paper presents an innovative knitting technology. The technology, which was funded by the European Regional Development Fund as an R&D-project (EFRE-0400310), reduces production time and creates completely novel innovative knitting structures. This paper introduces the validation process of the innovative technology and therefore brings the theoretical considerations into a practical application. The yarn supply technology enables the production of an innovative double-layered fabric on flat and circular knitting machines. This double-faced fabric consists of two single-faced fabric sides which are knitted by a first yarn in the front needle bed and a second yarn in the rear needle bed. These two fabrics are joined by a third yarn knitting in both needle beds in the same carriage stroke. The method ensures that up to three yarns knit in one system pass. Furthermore, a fourth yarn can be implemented to insert a weft yarn. Additionally, the two single-faced fabrics can be produced simultaneously in the same carriage stroke in the front and rear needle beds. In this case, fewer carriage strokes are required for knitting standard structures such as Milano Rib. This structure can be produced one third faster than with conventional methods. The results show that the technology on the circular knitting machine produces good quality knitted fabrics. On the flat knitting machine, however, further research and development are needed to validate the technology.

Shape Memory Alloys in Textile Platform: Smart Textile-Composite Actuator and Its Application to Soft Grippers.

In recent years, many researchers have aimed to construct robotic soft grippers that can handle fragile or unusually shaped objects without causing damage. This study proposes a smart textile-composite actuator and its application to a soft robotic gripper. An active fiber and an inactive fiber are combined together using knitting techniques to manufacture a textile actuator. The active fiber is a shape memory alloy (SMA) that is wire-wrapped with conventional fibers, and the inactive fiber is a knitting yarn. A knitted textile structure is flexible, with an excellent structure retention ability and high compliance, which is suitable for developing soft grippers. A driving source of the actuator is the SMA wire, which deforms under heating due to the shape memory effect. Through experiments, the course-to-wale ratio, the number of bundling SMA wires, and the driving current value needed to achieve the maximum deformation of the actuator were investigated. Three actuators were stitched together to make up each finger of the gripper, and layer placement research was completed to find the fingers' suitable bending angle for object grasping. Finally, the gripping performance was evaluated through a test of grasping various object shapes, which demonstrated that the gripper could successfully lift flat/spherical/uniquely shaped objects.

Design and Fabrication of Embroidered Textile Strain Sensors: An Alternative to Stitch-Based Strain Sensors.

Smart textile sensors have been gaining popularity as alternative methods for the continuous monitoring of human motion. Multiple methods of fabrication for these textile sensors have been proposed, but the simpler ones include stitching or embroidering the conductive thread onto an elastic fabric to create a strain sensor. Although multiple studies have demonstrated the efficacy of textile sensors using the stitching technique, there is almost little to no information regarding the fabrication of textile strain sensors using the embroidery method. In this paper, a design guide for the fabrication of an embroidered resistive textile strain sensor is presented. All of the required design steps are explained, as well as the different embroidery design parameters and their optimal values. Finally, three embroidered textile strain sensors were created using these design steps. These sensors are based on the principle of superposition and were fabricated using a stainless-steel conductive thread embroidered onto a polyester-rubber elastic knit structure. The three sensors demonstrated an average gauge factor of 1.88±0.51 over a 26% working range, low hysteresis (8.54±2.66%), and good repeatability after being pre-stretched over a certain number of stretching cycles.

Development of a Systematic Research Method Towards the Evaluation of the Efficacy of Cosmetic Textiles

This study aims to develop a systematic research method consisting of subjective and objective measurement methods to determine the effectiveness of cosmetic textiles on human skin. For this purpose, first of all, the expected properties of the cosmetic textile product were considered and the methods to be used for testing these properties were determined, and finally, a research method was created. Leggings, a cosmetic textile product, was selected to validate the method and a 28-day wear trial was carried out with female subjects to observe the effects of the product on human skin. During the wear trial, the subjects were provided to wear leggings that were designed from different knitting structures and applied cosmetic microcapsules to ensure the optimal slimming, moisturizing, and anti-cellulite properties. Dermatological and anthropometric measurements were carried out at specified periods of the study and the obtained data were statistically analyzed. According to the results, it was determined that the cosmetic textile product developed is skin-friendly and helps to increase skin moisture. Additionally, it was observed to provide a slimming effect to the wearer after a period of regular usage, however, it was suggested as a supportive product for women only with early-stage cellulite. A survey was also conducted to evaluate the cosmetic textiles by using subjective user opinions. The output of the survey has shown a high rate of satisfaction with the comfort, visual and sensory properties of the cosmetic textile product. By introducing the research method developed, it will be possible to accurately determine the effectiveness of cosmetic textiles on human skin and to design, develop and produce new cosmetic textile products with high cosmetic efficacy.

Effect of Tuck Loops on Fabric Properties of Cardigan Derivative Structures

Exploring the effect of tuck loops on fabric properties of some knitted structures was aimed in this study. Samples were produced on a Stoll V-bed knitting loom with 100% acrylic yarn. Five types of knit structures (1x1 rib, half cardigan, double half cardigan, cardigan and double cardigan) were knitted with identical machine settings. Test results revealed that double cardigan fabric has the highest fabric thickness, thermal resistance and coefficient of friction. Double half cardigan provides the highest air permeability, whereas 1x1 rib structure has the highest relative water vapor permeability, mass per unit area and loop length. Half cardigan has the highest bending rigidity. Half cardigan and double half cardigan both have the best pilling results. It was observed that test results of half cardigan-double half cardigan and cardigan-double cardigan are generally similar as pairs. However, dimensional, mechanical and comfort characteristics of 1x1 rib fabric seem quite different.

Influence of the Fabric Topology on the Performance of a Textile-Based Triboelectric Nanogenerator for Self-Powered Monitoring

The fibrous surface of textiles offers a larger contact area and continuous contact with the skin, which makes them a prominent candidate for biomechanical energy harvesting using the triboelectric nanogenerator principle. Herein, a lightweight, comfortable, and robust wearable triboelectric nanogenerator (W-TENG) device is fabricated for its application in self-powered technologies. The TENG output is enhanced via a three-way process: using a textured yarn and modifying the textile material and its structural variation in fabric. The triboelectric performance is correlated to the surface morphology, roughness, and dielectric properties. The current research compares woven and knitted fabric triboelectric nanogenerators using nylon, cotton, polypropylene (PP), and polyester. The surface roughness of the different textile materials and the irregular surface morphology of woven and knitted structures are studied using a three-dimensional (3D) optical profilometer. It is observed that the convolutions on the PP and nylon yarn and the 3D configuration of knitted fabric impart higher roughness than their woven counterpart providing a larger contact area. The higher contact area between the nylon/PP pair of knitted fabric has shown 240.55, 64.96, and 460% increments in voltage, current, and power density, respectively, compared to the woven W-TENG. The knitted fabric-based TENG has additionally demonstrated improved breathability and suitability to generate electrical energy from various human motions.

Multifunctional and Washable Carbon Nanotube-Wrapped Textile Yarns for Wearable E-Textiles.

Carbon nanotube (CNT) yarns are promising for wearable electronic applications due to their excellent electromechanical and thermal properties and structural flexibility. A spinning system was customized to produce CNT-wrapped textile yarns for wearable applications. By adjusting the spinning parameters and core yarn, a highly tailored hybrid CNT yarn could be produced for textile processing, e.g., knitting and weaving. The electrical resistance and mechanical properties of the yarn are influenced by the core yarn. The high flexibility of the yarn enabled state-of-the-art three-dimensional (3D) knitting of the CNT-wrapped yarn for the first time. Using the 3D knitted technology, CNT-wrapped textile yarns were seamlessly integrated into a wrist band and the index finger of a glove. The knitted structure exhibited a large resistance change under strain and precisely recorded the signal under the different movements of the finger and wrist. When the knitted fabric was connected to a power source, rapid heating above skin temperature was observed at a low voltage. This work presents a novel hybrid yarn for the first time, which sustained 30 washing cycles without performance degradation. By changing the core yarn, a highly stretchable and multimodal sensing system could be developed for wearable applications.

Study on thermal comfort of aloe viscose seamless knits

Aloe viscose fiber is rich in a variety of active ingredients, with excellent moisturizing and antibacterial properties, and gradually widely used in clothing production. Therefore, this paper focuses on the thermal comfort of aloe viscose seamless knitted clothing, 15 sets of seam knitting sets with different yarn blending ratios and knitted structures were designed. thermal manikin was used in artificial climate to test the thermal resistance and the voting rate of whole body thermal sensation. SPSS two-factor variance analysis and Duncan multiple comparison method were used to analyze the experimental data. The results show that the difference of veil material and knitted structure has an impact on clothing thermal comfort. In all the samples, the veil is made of 100:0 aloe viscose/viscose fiber, and the thermal comfort of the seam knitting garment w Abstract: In order to study the thermal comfort performance of aloe viscose fiber seamless knitted clothing, 15 sets of seam knitting sets with different yarn blending ratios and knitted structures were designed. Thermal manikin was used in artificial climate to test the thermal resistance and the voting rate of whole body thermal sensation. SPSS two-factor variance analysis and Duncan multiple comparison method were used to analyze the experimental data. The results show that the difference of veil material and knitted structure has an impact on clothing thermal comfort. In all the samples, the veil is made of 100:0 aloe viscose/viscose fiber, and the thermal comfort of the seam knitting garment with the knitted structure of 1 + 3 false rib fabric is the best, with the sets thermal resistance of 0.289 m2 K/W and the sets PMV value of −1.75. It provides theoretical basis and guiding significance for the future production of aloe seamless knitted clothing with excellent thermal resistance.

Role of knitted techniques in recent developments of biomedical applications: A review

All the surgical bandages, extracorporeal devices, and prosthetic implants that we use today are the product of textiles. Because they conform well to the body and feel good against the skin. Woven, non-woven, and knitted are only textile fabric construction methods. Among all, the knitted structures are more breathable and simpler to produce. In the previous two decades, knitting technology has advanced, now it is simple to create customized flexible and cost-effective biomedical devices. Knitted structures are increasingly used in implantable textiles like hernia and heart patches etc. due to their comfort, optimal strength, and ability to ravel from the last loop. The porous structure of knitted fabrics is particularly well suited for the transport of drugs. Since the knitted pattern, yarn effect, and dimensional parameters of fabric are all displayed in the 3D simulation software like Apex-lll and M-1, there is no longer any need to use actual fabric for quality control purposes, which greatly aids in reducing fabric waste. This article offers recent research on knitted fabrics including their advantages, disadvantages and future solutions that could be achieved by using advanced knitting manufacturing technologies. In addition, it calls attention to the significance of knitted structure in biomedical applications which may motivate further research into materials of this kind in the future.

SURFACE ROUGHNESS OF POLYAMIDE KNITTED FABRICS

Fabrics are never ideally smooth. Their texture varies between fine and coarse, quantified through the surface’s vertical deviation. Fabric roughness, or its opposite smoothness, is employed as measure of the surface texture of fabrics. In general, texture depends upon fiber properties, yarn count, yarn twist, and fabric structure and fabric design). This research aims to determine the limitations in visual perception of surface roughness in comparison to objective surface roughness measurements of low weight polyamide fabrics. Subjective evaluation is used for the visual assessment, while instrumental measurement of the properties was conducted using a noncontact laser profilometer. Subjective evaluation was conducted by a panel of forty untrained evaluators on a sample of seven polyamide knitted fabrics with different yarn count and composition. The roughness profile parameters were measured using Talysurf CLI 500 according to ISO 4827. Although the surface roughness measured as arithmetic mean deviation (Ra) and roughness through visual inspection of the fabric are correlated, instrumental measurements of roughness are more precise. Differences in the surface roughness arising from significantly different yarn structures will be observed, while those due to the knitted fabric structure are negligible in visual inspection.

PATTERN RELATED ISSUES IN THE MODELLING OF DEFORMED OVER SURFACE WARP KNITTED STRUCTURES WITH LONGER UNDERLAPS

The yarn level modelling of warp knitted structures is a complex process. For structures placed on the plane, it is well investigated and there are a few software solutions and papers reported. This paper considers the simulation of warp knitted structure, deformed in the 3D space. Especially the modelling of the areas of high curvature are detailed observed. Underlaps with longer lengths makes an unreal visualization for simulation results. Different pattern with different length of the underlaps are modelled with original algorithm developed by the authors. Modelling and visualization problems in the areas with long underlaps are discussed and possible solutions are proposed.

Evaluating width-wise contraction of different cotton single knit structures due to the positioning of tuck and miss loops at different locations in the structural repeats

The contraction rates of weft knitted plain jersey fabric and some patterned single jersey fabrics with respect to machine gauge were determined. Fabric samples were knitted using cotton yarn at various stitch length values on a positive feed based multi feeder circular weft knitting machine. Widthwise contraction rates of the resulting fabric samples were then calculated using the values of wales per inch and needles per inch. It was discovered that when stitch length increased, the value of the contraction rate decreased. Additionally, it was found that the knitted stitches (knit, tuck and miss) greatly impacted how much the fabric contracts. Fabric with miss stitches showed higher contraction than fabrics knitted with tuck stitches. However, knit-miss based single jersey fabrics showed less contraction than plain single jersey fabrics while all courses are knitted at the same course length value. It was also observed that contraction rates also change due to different positioning of tuck and miss loops in the patterned structures.

INVESTIGATION OF TRIBOELECTRICITY ON TEXTILE STRUCTURES THROUGH A TEG WHICH COMBINES SLIDING AND VERTICAL MODE

The use of textile materials and structures to build textile-based TEGs is of particular interest as they can also offer unique textile properties. In this work, the initial goal is to present a prototype TEG measuring device and its experimental results for comparing the open circuit voltages coming from various pairs of knitted samples which may constitute part of a textile TEG. We focus on representing realistic testing conditions as on a wearable garment, by introducing a friction stage between the contact and separation stages which is applied under a lightweight load. Α second goal is to explore the possibilities of some environmentally friendly textile materials to provide electric energy, again under realistic conditions. From the carried tests, it was seen that even conventional natural knitted textiles structures like single jersey, without expensive and complex nano-treatments, can provide considerable voltages if they are part of a wearable garment. Moreover, it was found that even low friction under a weight load of 20grf is adequate to give the above results. The hereby presented measuring TEG device can be used in the comparison or improvement of textile or even non-textile based TEGs, in order to find optimal combinations of materials and designs to be used on clothing TEGs.

C2C12 HÜCRELERİ KULLANILARAK MİYOKARDİYAL DOKU MÜHENDİSLİĞİ İÇİN ÖRME HAVLU KUMAŞ İSKELENİN IN VITRO DEĞERLENDİRİLMESİ

Pile loop knitted scaffold has attracted attention for being used as a three dimensional (3D) biocompatible material particularly for the application of myocardial tissue engineering. In this research, nonintermingled, textured polyethylene terephthalate (PET) multifilament yarn with a filament count of 48 was used for producing a pile loop knit structure to investigate if structure could provide an appropriate microenvironment for the seeded murine C2C12 myoblasts in case of increasing in filament diameter (20.7 micron versus 9.1 micron from the previous study). The resulting structure had a pore network mainly consisting of macropores of 100-200 µm that were well interconnected with micropores (<90 µm). Furthermore, the mean values of the Young’s modulus of the structures at 20% strain were 240.67 kPa in the warp direction, and 85.73 kPa in the weft direction, which can be claimed not to be far from those declared in the literature for the human heart muscle. In addition, the cyclic loading-unloading test revealed no creep in the fabric after 100 cycles. According to the results of the WST-1 assay, the 48 filament-based scaffold was non-cytotoxic for C2C12 cells that were able to proliferate properly on the scaffold, which was visualized by SEM and confocal images. In this respect, pile loop knit structures keep promising results for being used as a cardiac patch.

Textile Knitted Stretch Sensors for Wearable Health Monitoring: Design and Performance Evaluation

The advancement of smart textiles has led to significant interest in developing wearable textile sensors (WTS) and offering new modalities to sense vital signs and activity monitoring in daily life settings. For this, textile fabrication methods such as knitting, weaving, embroidery, and braiding offer promising pathways toward unobtrusive and seamless sensing for WTS applications. Specifically, the knitted sensor has a unique intermeshing loop structure which is currently used to monitor repetitive body movements such as breathing (microscale motion) and walking (macroscale motion). However, the practical sensing application of knit structure demands a comprehensive study of knit structures as a sensor. In this work, we present a detailed performance evaluation of six knitted sensors and sensing variation caused by design, sensor size, stretching percentages % (10, 15, 20, 25), cyclic stretching (1000), and external factors such as sweat (salt-fog test). We also present regulated respiration (inhale-exhale) testing data from 15 healthy human participants; the testing protocol includes three respiration rates; slow (10 breaths/min), normal (15 breaths/min), and fast (30 breaths/min). The test carried out with statistical analysis includes the breathing time and breathing rate variability. These testing results offer an empirically derived guideline for future WTS research, present aggregated information to understand the sensor behavior when it experiences a different range of motion, and highlight the constraints of the silver-based conductive yarn when exposed to the real environment.

Architectural Knitted Windbreaks for Improved Wind Comfort in the City: A Wind Tunnel Study of Custom-Designed Porous Textile Screens

There is a need to shield from the wind to improve pedestrian comfort in urban environments. Perforated windbreaks, such as fences, vegetation or textile nets, have proven to be an efficient solution, whereas knitted textiles have not yet been explored. The purpose of this study was to evaluate the capacity of knitted textile windbreaks to reduce wind velocities, to inform further research and promote wider architectural applications. Five custom-knitted textile prototypes, representing fragments of textile windbreaks, were tested in a wind tunnel and compared against a perforated and a nonperforated solid board. Forces on the models, as well as upstream and downstream velocities, were measured. The results indicate that the optimal optical porosity of knitted windbreaks should be around 10%, which differs from the porosity for perforated windbreaks recommended by prior studies. Moreover, it was observed that a textile windbreak knitted using the drop-stitch technique efficiently reduces the wind, while not generating a large drag force. Furthermore, the drag coefficient for the knitted windbreak is reduced with increased windspeed. With this, the presented study demonstrates that knitted structures exposed to wind influence have the functional potential of becoming efficient windbreaks, thus improving wind comfort and aesthetic user experience in the urban space.

Rheological model for studying fatigue of knitted fabric

The plain knitted structure (cotton) generally utilized in the clothing domain has been studied with cyclic loading at diverse fatigue number cycles. Fatigue test induces delayed-elastic and permanent deformation that increase according to cyclic elongation. The delayed-elastic and permanent deformation of tested knit has been discussed based on Burger’s rheological model. This model is suitable to describe the deformation behavior during relaxation of a plain knitted structure. The proposed rheological model permits us to estimate the elastic, viscoelastic and plastic components of the different tested fabrics after fatigue test.

Washability and abrasion resistance of illuminative knitted e-textiles with POFs and silver-coated conductive yarns

For the integration of conductive yarns in e-textiles, knitting offers structural versatility and malleability for wider product applications in the contexts of wearables and interiors. To enable mass adoption of conductive materials, it is imperative for users to be able to launder these materials as part of product maintenance. Interactive textiles knitted from polymeric optical fibres (POFs) and silver-coated conductive yarns are able to illuminate and change colours via integrated touch sensor systems. Current research only focuses on the washability and abrasion resistance of conductive yarns solely and not both POF and conductive yarn within the same fabric structure. This study is novel as it investigates the washability and abrasion resistance of POF and silver-coated conductive yarn integrated knitted textiles with different loop structures and the impact to their illuminative function. POFs were knitted within the same fabric structure by the inlay method using a 7-gauge industrial hand-operated flatbed knitting machine. This study examined how washing and abrasion affect POFs and silver-coated conductive yarn in five different knit structures, and the illuminative function of the knitted textiles. Washing and abrasion affected the resistance of conductive yarns. Scratches and bent POFs were observed after 20 gentle washing cycles. However, washing had minimal impact on the illuminative function of the knitted e-textiles examined in this study. The experiments provide evidence that e-textiles knitted with POFs and conductive yarns in the same fabric structure withstand washing and abrasion and thus have the potential for mass market adoption in fashion and interior applications.

Analysis of driving forces of 3D knitted shape memory textile actuators using scale-up finite element method

The shape memory textile actuator uses a shape memory alloy that changes its crystal structure according to temperature and then returns to its initial shape, which is suitable for wearable applications that value wearing and portability. The shape memory effect of returning to the initial shape and the complex fabric structure influence each other, and accordingly, various drives have been measured in many studies. Therefore, in this study, the driving force, which is the most important physical property of the shape memory textile actuator, was analyzed through a scale-up finite element analysis. In the wire scale, a shape memory alloy wire was obtained for an analysis of the mechanical and thermal properties through tensile tests and DSC, and in the unit cell scale, a 3D knit structure was modeled using the Texgen and Weftknit programs. Finally, a supercell of size 5 × 5 was subjected to external deformation by displacement and heating conditions using disposition through the ANSYS program. The driving force was measured through microanalysis. Subsequently, the driving force of the manufactured shape memory textile actuator was compared and analyzed to determine the suitability of this method. Furthermore, the direction of subsequent studies was mapped based on the analysis presented on the differences in the maximum driving force and error rate.