Textiles

Persistent poor acoustic conditions can imbalance humans’ psychophysical capabilities. A good acoustic project starts with either correct measurements of the existing acoustic parameters or with the correct hypothesis of new sound conditions. International standards define invasive measurement conditions and procedures that can disturb user activities. For this reason, alternative methodologies have been developed by mounting real-time sound-monitoring devices. Most of the research on these aims to decrease their dimensions in order to be placed in the tight service spaces of modern architecture and to reduce their aesthetic impact on interiors design. In this perspective, this article explores the features and potentialities of textile-based sound sensors (TSS) as they can not only fulfill these needs but can also be used as architectural ornaments by partially wrapping interiors. The ubiquitous of e-textiles for wearable applications has led to increasing the performance of TSS. Therefore, a comparison of the sensitivity values, signal-to-noise ratio and noise floor of sound TSS with sound sensors is presented, which is still missing in the literature. The paper demonstrates how these can be exploited for sound monitoring and can provide valid opportunities for new smart acoustic textiles. Full article

In this paper, we describe algorithms that perform loop order analysis of weft-knitted textiles, which build upon the foundational TopoKnit topological data structure and associated query functions. During knitting, loops of yarn may be overlayed on top of each other and then stitched together with another piece of yarn. Loop order analysis aims to determine the front-to-back ordering of these overlapping loops, given a stitch pattern that defines the knitted fabric. Loop order information is crucial for the simulation of electrical current, water, force, and heat flow within functional fabrics. The new algorithms are based on the assumption that stitch instructions are executed row-by-row and for each row the instructions can be executed in any temporal order. To make our algorithms knitting-machine-independent, loop order analysis utilizes precedence rules that capture the order that stitch commands are executed when a row of yarn loops are being knitted by a two-bed flat weft knitting machine. Basing the algorithms on precedence rules allows them to be modified to adapt to the analysis of fabrics manufactured on a variety of knitting machines that may execute stitch commands in different temporal orders. Additionally, we have developed visualization methods for displaying the loop order information within the context of a TopoKnit yarn topology graph. Full article

The electrocardiogram (ECG) is one of the most commonly measured biosignals. In particular, textile electrodes allow for the measuring of long-term ECG without skin irritation or other discomforts for the patient. Such textile electrodes, however, usually suffer from insufficient or unreliable skin contact. Thus, developing textile electrodes is impeded by the often-complicated differentiation between signal artifacts due to moving and breathing and artifacts related to unreliable skin contact. Here, we suggest a simple method of using 50/60 Hz power grid noise to evaluate the skin contact of different textile electrodes in comparison with commercial glued electrodes. We use this method to show the drying of wetted skin under an embroidered electrode as well as sweating of the originally dry skin under a coated electrode with high water vapor resistance. Full article

In the past two decades, a growing body of research regarding the utilization of natural bacterial pigments or dyes for textile dyeing has emerged. Bacterial pigments are bacterial secondary metabolites that usually have bright colors and some special properties (e.g., antimicrobial, antioxidative, UV protective etc.). In addition to their high production yield, these special properties led scientists to research and develop methods for utilizing bacterial pigments in textile dyeing. This study presents the current state this field of research, with a focus on the dyeing potential of bacterial pigments for different types of textile material. The potential future directions of research in this area are also highlighted. In addition to the durable dyeing of textiles, bacterial pigments with special properties, such as antimicrobial activity, can add multifunctionality to dyed materials, thus increasing the value of the final product. This emerging field of research will also have a great impact on sustainability and the environment, contributing to the decreased usage of synthetic dyes in the textile industry. Full article

This review supports an overview of selected high-performance fibers and functional fiber materials. A review of several properties and applications is given. For fiber materials and fabrics, microscopic images taken by scanning electron microscopy (SEM) are presented. As well as this, electron dispersive spectroscopy (EDS) is performed on the fiber materials and an overview of EDS spectra is presented. The features of SEM images and EDS spectra are discussed, especially with the aim of supporting people who are working in the field of fiber analytics. To support a complete view of both analytic methods—SEM and EDS—challenges and typical mistakes for SEM measurements on textiles are also described. Altogether, this review supports a useful overview of interesting high technology fiber materials and their investigation using the analytical methods SEM and EDS. Using these, material properties and their composition are presented and discussed. The composition of industrial fiber materials is investigated and discussed, as well as fiber treatments for the realization of functional fiber properties. Furthermore, it aims to support a helpful tool for fiber and textile analytics and identification. Full article

Geotextiles, a group of high-performance materials, have grown during the last decades into needful auxiliaries when it comes to infrastructure, soil, construction, agriculture and environmental applications. Although geotextiles made of synthetic fibers (geosynthetics) are considered a modern achievement, the basic concept dates back to ancient times when textiles consisting of locally available natural fibers were employed to increase the stability of roads and soils. In recent decades, considering the growing interest in environmental protection and sustainable development based on using renewable resources and the recovery and recycling of waste of various origins, the use of natural fibers-based geotextiles is a viable alternative, despite their limited-life service owing to their biodegradability. In addition to this feature, their low cost, good mechanical properties and large-scale accessibility recommend them for geo-engineering applications, environmental sensitive applications in geotechnical engineering, such as land improvements and soil erosion control. This paper focuses on geotextiles as a versatile tool in environmental applications given their high theoretic and practical relevance as substantiated by recent literature reports. Natural and synthetic geotextiles are presented herein, as well as their features that recommend them for geo-engineering. Insights on the main types of applications of geotextiles are also included, along with a wide variety of materials employed to perform specific functions. Full article

The expansion of clothing and textile industry and the fast fashion trend among consumers have caused a rapid global increase in textile waste in the municipal solid waste (MSW) stream. Worldwide, 75% of textile waste is landfilled, while 25% is recycled or reused. Landfilling of textile waste is a prevalent option that is deemed unsustainable. Promoting an enhanced diversion of textile waste from landfills demands optimized reuse and recycling technologies. Reuse is the more preferred option compared with recycling. Various textile reuse and recycling technologies are available and progressively innovated to favor blended fabrics. This paper aims to establish reuse and recycling technologies (anaerobic digestion, fermentation, composting, fiber regeneration, and thermal recovery) to manage textile waste. Improved collection systems, automation of sorting, and discovering new technologies for textile recycling remains a challenge. Applying extended producer responsibility (EPR) policy and a circular economy system implies a holistic consensus among major stakeholders. Full article

In this research, we focused on testing the physical and mechanical properties of the developed polyacrylonitrile (PAN) composite nanofibers with succinite (Baltic amber) and SiO₂ particles using standard methods of nanofiber testing (physical and mechanical properties). Polyacrylonitrile composite nanofibers (based on the electrospinning method) were coated on an aluminum substrate for structural investigation. SEM was used to determine the average fiber diameter and standard deviation. The mechanical properties of the fibers were determined using a universal testing machine (NANO, MTS). We observed that constant or decreased levels of crystallinity in the ultrafine composite nanofibers led to the preservation of high levels of strain at failure and that the strength of nanofibers increased substantially as their diameter reduced. Improvements in PAN composite nanofibers with succinite and SiO₂ nanopowder are feasible with continuous decreases in diameter. The drastically decreased strain at failure demonstrated a substantial reduction in viscosity (toughness) of the annealed nanofibers. Large stresses at failure in the as-spun nanofibers were a result of their low crystallinity. As a result, decreasing the diameter of PAN nanofibers from approximately 2 micrometers to 139 nanometers (the smallest nanofiber tested) resulted in instantaneous increases in the elastic modulus from 1 to 26 GPa, true strength from 100 to 1750 MPa, and toughness from 20 to 604 MPa. Full article

A new geometrical modeling tool has been developed to predict the elastic stiffness properties of 2D orthogonal and 2.5D woven interlock composites. The model estimates the change in performance due to changes in the ordering weaving parameters of the 2.5D weave architecture. Analysis results were validated compared to other models developed in published articles and the literature. Numerical analysis was performed to evaluate the accuracy of the results from the proposed models. These results demonstrate the effectiveness of the models presented by comparisons with experimental results, showing that the model could replicate the mechanical behaviors of 2D fabric and 2.5D interlock composite laminates for predicting 2D textile structures and 2.5D interlock composites with different types, shapes, and conditions. The model presented in this paper is able to replicate the behavior of woven composites of fiber reinforced with various types. Full article

Nanofiber-based nonwoven mats produced in electrospinning setups are usually very fragile, which often limits their applicability. Yarns have the potential to enable the incorporation of nanofibers into other materials using well-established techniques such as sewing, knitting, weaving and embroidering, thus broadening the application of nanofibers. Here, we review the development of continuous yarn electrospinning processes. Amongst several possible approaches, funnel-based collector systems have been widely adopted. Here, we summarize recent developments in the field and highlight studies providing visions on how to expand that field of research in future studies of continuous yarn electrospinning. Full article

The RTM (Resin Transfer Molding) manufacturing process is largely used for the fabrication of textile composites. During the forming phase, the deformations of composite reinforcements at the mesoscopic scale, such as the positions, orientations, and changes in the sections of deformed yarns, are essential to calculate the permeability of the reinforcement in the injection phase and evaluate the mechanical behaviors of the final products. However, the mesoscopic models of the forming simulation lead to a high computational cost due to the numerous yarns and their complex contacts, especially for thick reinforcements. In this paper, a macro-meso method for predicting the mesoscopic deformations of composite reinforcements with a reasonable calculation time is presented in this paper. The proposed multi-scale method allows for the linkage of the macroscopic simulation of reinforcements with the mesoscopic modelling of an RVE (Representative Volume Element) through a macro-meso embedded approach. Based on macroscopic simulations using a 3D hyperelastic constitutive law, an embedded mesoscopic geometry is first deduced. The macro-meso embedded solution can lead to excessive extensions of yarns. To overcome this inconvenience, a local mesoscopic simulation based on the macro-meso embedded analysis is carried out on a single RVE. Finally, the multi-scale forming simulations are investigated in comparison with the experimental results, illustrating the efficiency of the proposed method. Full article

Flexible textile strain sensors that can be directly integrated into clothing have attracted much attention due to their great potential in wearable human health monitoring systems and human–computer interactions. Fiber- or yarn-based strain sensors are promising candidate materials for flexible and wearable electronics due to their light weights, good stretchability, high intrinsic and structural flexibility, and flexible integrability. This article investigates representative conductive materials, traditional and novel preparation methods and the structural design of fiber- or yarn-based resistive strain sensors as well as the interconnection and encapsulation of sensing fibers or yarns. In addition, this review summarizes the effects of the conductive materials, preparation strategy and structures on the crucial sensing performance. Discussions will be presented regarding the applications of fiber- or yarn-based resistive strain sensors. Finally, this article summarizes the bottleneck of current fiber- or yarn-based resistive strain sensors in terms of conductive materials, fabrication techniques, integration and performance, as well as scientific understanding, and proposes future research directions. Full article

Deciphering how the dielectric properties of textile materials are orchestrated by their internal components has far-reaching implications. For the development of textile-based electronics, which have gained ever-increasing attention for their uniquely combined features of electronics and traditional fabrics, both performance and form factor are critically dependent on the dielectric properties. The knowledge of the dielectric properties of textile materials is thus crucial in successful design and operation of textile-based electronics. While the dielectric properties of textile materials could be estimated to some extent from the compositional profiles, recent studies have identified various additional factors that have also substantial influence. From the viewpoint of materials characterization, such dependence of the dielectric properties of textile materials have given rise to a new possibility—information on various internal components could be, upon successful correlation, extracted by measuring the dielectric properties. In view of these considerable implications, this invited review paper summarizes various fundamental theories and principles related to the dielectric properties of textile materials. In order to provide an imperative basis for uncovering various factors that intricately influence the dielectric properties of textile materials, the foundations of the dielectrics and polarization mechanisms are first recapitulated, followed by an overview on the concept of homogenization and the dielectric mixture theory. The principal advantages, challenges and opportunities in the analytical approximations of the dielectric properties of textile materials are then discussed based on the findings from the recent literature, and finally a variety of characterization methods suitable for measuring the dielectric properties of textile materials are described. It is among the objectives of this paper to build a practical signpost for scientists and engineers in this rapidly evolving, cross-disciplinary field. Full article

Integrative medicine is a rapidly growing specialty field of medical care that emphasizes the amalgamation of complementary therapies and conventional medicine. Aromatherapy, one of the complementary therapies, is a centuries-old tradition, used in many cultures and societies as an alternative to, or in conjunction with, conventional medicine. However, there is very little understanding of its therapeutic benefits in the scientific realm related to the correct dosage of essential oils, their delivery mechanism and their efficacy on human physiology in general. We reviewed studies published between 2011–2021 focused on aromatherapy and textiles, and explore “textile” materials as a possible carrier for essential oils in this paper. Due to their proximity to the biggest organ of the human body, textiles can potentially serve as a good delivery system for the therapeutic benefit of essential oils. After this rigorous review, we found gaps in the field. Therefore, we propose cross-disciplinary synergies for future research to fully understand the therapeutic efficacy of essential oils. Full article

This study performs an analysis of steam penetration through thermal protective fabric materials. Different, multilayered thermal protective fabrics were selected and tested in a laboratory-simulated steam exposure, and their steam protective performance (SPP) was measured in terms of the time required to generate second-degree burns on the bodies of wearers. Additionally, the total transmitted thermal energy (TTTE) through the fabrics during testing was measured. Through statistical analysis, it was established that fabric properties, namely air permeability and thickness, are the key factors that affect the SPP and TTTE; the relationship among the fabric properties, SPP, and TTTE is also summarized. Theoretically, it has been found that heat and mass (steam) transfer occur through fabrics in the course of steam exposure, which mainly affect the SPP and TTTE. This study could help textile/materials engineers to develop high performance thermal protective fabrics for the increased occupational health and safety of firefighters and industrial workers. Full article

The current research is focused on the design and development of auxetic woven structures. Finite element analysis based on computational modeling and prediction of axial strain as well as Poisson’s ratio was carried out. Further, an analytical model was used to calculate the same parameters by a foldable zig-zag geometry. In the analytical model, Poisson’s ratio is based on the crimp percentage, bending modulus, yarn spacing, and coefficient of friction. In this yarn, properties and fabric parameters were also considered. Experimental samples were evaluated for the actual performance of the defined auxetic material. Auxetic fabric was developed with foldable strips created in a zig-zag way in the vertical (warp) direction. It is based on the principle that when the fabric is stretched, the unfolding of the folds takes place, leading to an increase in transverse dimensions. Both the analytical and computational models gave close predictions to the experimental results. The fabric with foldable strips created in a zig-zag way in the vertical (warp) direction produced negative Poisson’s ratio (NPR), up to 8.7% of axial strain, and a maximum Poisson’s ratio of −0.41 produced at an axial strain of around 1%. The error percentage in the analytical model was 37.14% for the experimental results. The computational results also predict the Poisson’s ratio with an error percentage of 22.26%. Such predictions are useful for estimating the performance of auxetic woven structures in composite reinforcement. The auxetic structure exhibits remarkable stress-strain behavior in the longitudinal as well as transverse directions. This performance is useful for energy absorption in composite reinforcement. Full article

A standardized source of light is essential for visual color assessments, which is why lighting booths were developed. For the best results in visual assessment, it is important to consider the right choice of light source, the right viewing conditions, and the variability of the viewer. To date, many light booth technologies have been introduced to meet user demands. Since most of the light sources on the market are characterized by the designer or manufacturer, the resulting variations from booth-to-booth remain. In this study, we compared the performance of two standard light booths to assess the color difference of eleven metameric pairs. In this study, we checked an earlier technology-based light booth that is still used in the textile industry and contains illuminant A (Tungsten lamp) with CCT 2700 K, TL84 (tri-band fluorescent tube) with CCT 4000 K, and simulator D65 (CCT 6500 K) with a different light booth whose original light sources have been replaced by currently available LED retro kits from equivalent CCTs. As an inexperienced customer or industrial user, our question was, how important is this replacement? The results revealed that two different standard lighting technologies with similar CCTs cannot reproduce the same estimates because the light sources produced different SPDs. It is illustrating that caution is necessary when comparing results obtained from two different light booths containing light sources with similar CCTs but different SPDs. This comparative study suggested that the variability of the light sources’ SPDs or the observer or the sample should be modeled considering light booth’s technology to estimate its contribution to the overall variability. The close relationship between perceived and CAM02-UCS suggests that if both booths are used after the light sources have been calibrated, a formula based on color appearance models must be used to predict color appearance. To obtain better agreement between perceived and calculated color difference, one must need to avoid light booths with nominally white light sources. Full article

In the context of wearable technology, several techniques have been used for the fabrication of radio frequency identification (RFID) tags such as 3D printing, inkjet printing, and even embroidery. In contrast to these methods where the tag is attached to the object by using sewing or simple sticking, the E-Thread^® technology is a novel assembling method allowing for the integration of the RFID tag into a textile yarn and thus makes it embeddable into the object at the fabrication stage. The current E-Thread^® yarn uses a RFID tag in which the antenna is a straight half-wave dipole that makes the solution vulnerable to mechanical strains (i.e., elongation). In this paper, we propose an alternative to the current RFID yarn solution with the use of an antenna having a helical geometry that answers to the mechanical issues and keeps quite similar electrical and radiative properties with respect to the present solution. The RFID helical tag was designed and simulated taking into consideration the constraints of the manufacturing process. The helical RFID tag was then fabricated using the E-Thread^® technology and experimental characterization showed that the obtained structure exhibited good performance with $10.6 \mathrm{m}$ of read range in the ultra high frequency (UHF) RFID band and $10\%$ of tolerance in terms of elongation. Full article

The integration of carbon nanotube fabric into textiles is paving its way into smart materials and wearable applications. Potential novel applications of carbon nanotube hybrid (CNTH) materials and fabric composites span across a range of market levels from high-level PPE appropriate for military and industrial applications down to consumer products that can be used in everyday scenarios. The high-level performance properties of CNTH materials and their ability to be customized provide new possibilities for constructing fabrics with properties that are made to order. Furthermore, CNTH in combination with advanced textile compositing and construction methods allows the CNTH material to further leverage material customization aspects to meet specific requirements. The unique synthesis process for nanotube fabric allows for modification of the physical properties of the CNTH itself. The CNTH fabric combined with the customizability of standard textile composite materials and with the use of apparel design features allows for the design of materials with new combinations of physical properties. These unique properties offer high potential for developing families of smart wearable garments that can be scaled for industrial production. This article discusses the synthesis of carbon nanotube hybrid fabric, the process of hybrid fabric and textile integration, properties of the hybrid textile, and potential applications. The paper also provides an outlook towards large scale production of the hybrid textile material. Full article