Textiles, Volume 1, Issue 2 (September 2021) – 14 articles

Alkali-resistant (AR) glass textiles are used as the main reinforcement in several composite applications due to their good performance-to-cost ratio. A huge variety of textiles are already present in the market; they differ on various parameters, such as, for example, the filaments’ diameters, the geometry, the type of weaving, or the nature of the impregnation coating. To orient manufacturers towards the production of efficient textiles, the most important aspect is the balance between cost and performance. In this paper, a series of different fabrics designed for textile-reinforced cementitious composites were considered. Performance was assessed by means of uniaxial tensile tests and the results are presented in terms of load vs. displacement. Then, the selected AR-glass textiles were compared in terms of fabric efficiency, targeting the effect of each parameter on the textile capacity. The research here presented is part of a comprehensive campaign aimed at the optimization of glass-fabric-reinforced cementitious composites for structural retrofitting. To better discuss the different solutions tested, at the end, only considering a small number of the investigated textiles, an efficiency evaluation was carried out at the cementitious composite level. Full article

The purpose of this research was to evaluate the differences and similarities of organic cotton clothing (OCC) purchase behaviors of the consumers who lie at the top and the bottom of the apparel supply chain. The influences of consumers’ sustainability knowledge and social norms on consumers’ attitudes and purchase intentions were examined to understand within the framework of the Theory of Reasoned Action (TRA). Sample data were collected from the United States and Bangladesh and, finally, 136 useable responses were used for the data analysis. Among the useable responses, 85 samples were from the US (containing 91.76% female participants and 4.71% male participants) and 51 responses were from the Bangladesh sample (containing 7.84% female participants and 88.24% male participants). A structural equation model was conducted to test the proposed hypotheses. Findings showed that for US consumers, sustainability knowledge was a powerful predictor of positive attitudes towards OCC, while for Bangladeshi consumers, it was not. In the context of social norms, Bangladeshi consumers demonstrated a strong positive attitudes formation whereas American consumers were found to display less strong relationships. OCC marketers and retailers should concentrate on educating consumers about the real benefits of organic cotton consumption by disseminating proper information about organic cotton fiber and its processing. Full article

Disposal of reactive dye contaminants in surface waters causes serious health risks to the aquatic living bodies and populations adjacent to the polluted water sources. This study investigated the applicability of banana peels to remediate water contamination with reactive dyes used in the textile industry. A set of batch experiments was conducted using a standard dye solution to determine optimum adsorption parameters, and these parameters were used for the removal of dyes from actual wastewater. Fitting experimental data into the isotherm and kinetic models suggested monolayer dye adsorption with chemisorption rate-limiting step. The maximum adsorption found from modeling results was 28.8 mg/g. Fourier transformed infrared (FTIR) spectra revealed the existence of hydroxyl, amine and carboxylic groups, contributing to high adsorption of dye molecules onto the adsorbent surface. About 93% of the dyes from the standard solution were removed at optimum conditions (pH—7.0, initial dye concentration—100 mg/L, contact time—60 min, and adsorbent dose—0.5 g) while this value was 84.2% for industrial textile wastewater. This difference was mainly attributed to the composition difference between the solutions. However, the removal efficiency for actual wastewater is still significant, indicating the high potentiality of banana peel removing dyes from textile effluent. Furthermore, desorption studies showed about 95% of banana peel can be recovered with simple acid-base treatment. Full article

An overview of the most important methods for producing side-emitting polymer optical fibers is given. Based on a systematic literature and patent search, the methods that are applied in practice and explored in research are identified. The fabrication methods are classified into four groups according to the physical phenomenon that hinders total internal reflection: bulk scattering, bending, surface perforations and luminescence. Subdivisions are made regarding the actual processing steps. The production methods are described in detail and discussed with respect to their customizability and applications. Full article

In many textiles and fiber structures, the behavior of the material is determined by the structural arrangements of the fibers, their thickness and cross-section, as well as their material properties. Textiles are thin plates made of thin long yarns in frictional contact with each other that are connected via a rule defined by a looping diagram. The yarns themselves are stretchable or non-stretchable. All these structural parameters of a textile define its macroscopic behavior. Its folding is determined by all these parameters and the kind of the boundary fixation or loading direction. The next influencing characteristic is the value of the loading. The same textile can behave similar to a shell and work just for bending, or behave as a membrane with large tension deformations under different magnitudes of the loading forces. In our research, bounds on the loading and frictional parameters for both types of behavior are found. Additionally, algorithms for the computation of effective textile properties based on the structural information are proposed. Further focus of our research is the nature of folding, induced by pre-strain in yarns and some in-plane restriction of the textile movements, or by the local knitting or weaving pattern and the yarn’s cross-sections. Further investigations concern different applications with spacer fabrics. Structural parameters influencing the macroscopic fabric behavior are investigated and a way for optimization is proposed. An overview of our published mathematical and numerical papers with developed algorithms is given and our numerical tools based on these theoretical results are demonstrated. Full article

The booming wearable market and recent advances in material science has led to the rapid development of the various wearable sensors, actuators, and devices that can be worn, embedded in fabric, accessorized, or tattooed directly onto the skin. Wearable actuators, a subcategory of wearable technology, have attracted enormous interest from researchers in various disciplines and many wearable actuators and devices have been developed in the past few decades to assist and improve people’s everyday lives. In this paper, we review the actuation mechanisms, structures, applications, and limitations of recently developed wearable actuators including pneumatic and hydraulic actuators, shape memory alloys and polymers, thermal and hygroscopic materials, dielectric elastomers, ionic and conducting polymers, piezoelectric actuators, electromagnetic actuators, liquid crystal elastomers, etc. Examples of recent applications such as wearable soft robots, haptic devices, and personal thermal regulation textiles are highlighted. Finally, we point out the current bottleneck and suggest the prospective future research directions for wearable actuators. Full article

The presented research aims to characterize hydrolytic resistance of highly crystalline and oriented polylactide (PLA) as a prerequisite for exploiting this bio-based material in durable applications. Industrially melt-spun PLA monofilaments and nonwovens have been subjected to environmental aging in a temperature range of 50–70 °C at a wide range of relative humidity (RH) in order to identify the onset of the material degradation under application conditions. Along with the measurements of mechanical and thermal behavior of the aged samples, the suitability of FTIR spectroscopy to probe the initial changes in the crystalline structure and in chemical composition of the fibers, caused by hydrolytic degradation, has been evaluated. The diagrams of stability and hydrolytic degradation under employed environmental aging for 7–14 days are presented for both types of PLA materials. Assessment of filtration performance of the artificially aged fibrous PLA media indicated a good agreement with the established stability diagram and confirmed the application potential of PLA nonwoven media, spun from currently available PLA grades, in air filtration under moderate climatic conditions up to max 50 °C and 50% RH. The presented results advance the knowledge on hydrolytic resistance of bio-based industry-relevant fibers and therefore open new application areas for sustainable materials with biodegradable components. Full article

Lignocellulosic fibers are widely applied as reinforcement in polymer composites due to their properties. The thermal degradation behavior governs the maximum temperature at which the fiber can be applied without significant mass loss. It is possible to determine this temperature using Thermogravimetric Analysis (TG). In particular, when curves are obtained at different heating rates, kinetic parameters can be determined by using Arrhenius-based equations, and more detailed characteristics of the material are obtained. However, every curve obtained at a distinct heating rate demands material, cost and time. Methods to predict thermogravimetric curves can be very useful in the materials science field, and in this sense, mathematical approaches are powerful tools, if well employed. For this reason, in the present study, thermogravimetric curves from curaua fiber were obtained at four different heating rates (5, 10, 20 and 40 °C·min⁻¹) and Vyazovkin kinetic parameters were obtained using free available software. After, the experimental curves were fitted using an artificial neural network (ANN) approach followed by a Surface Response Methodology (SRM) aiming to obtain curves at any heating rate between the minimum and maximum experimental heating rates. Finally, Vyazovkin kinetic parameters were tested again, with the new predicted curves at the heating rates of 7, 15, 30 and 50 °C·min⁻¹. Similar values of the kinetic parameters were obtained compared to the experimental ones. In conclusion, due to the capability to learn from the own data, ANN combined with SRM seems to be an excellent alternative to predict TG curves that do not test experimentally, opening the range of applications. Full article

This paper reviews some prominent applications and approaches to developing smart fabrics for wearable technology. The importance of flexible and electrically conductive textiles in the emerging body-centric sensing and wireless communication systems is highlighted. Examples of applications are discussed with a focus on a range of textile-based sensors and antennas. Developments in alternative materials and structures for producing flexible and conductive textiles are reviewed, including inherently conductive polymers, carbon-based materials, and nano-enhanced composite fibers and fibrous structures. Full article

Magnetically responsive, mechanically stable and highly flexible iron (III) oxide-polyvinylidene fluoride (Fe₃O₄-PVDF) piezoelectric composite fiber mats were fabricated via one step electrospinning method for magnetic sensing at cryogenic temperature. The properties of Fe₃O₄-PVDF composite fiber mats were characterized using scanning electron microscopy (SEM), differential scanning calorimetry (DSC), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, d₃₃ and magnetization test. The fiber diameter decreased as the concentration of Fe₃O₄ increased. The DSC results suggested a decrease in the crystallinity of the composite fiber mats after adding Fe₃O₄, and the XRD curves identified that the decrease in crystallinity took place in the β crystalline phases of the fibers. FT-IR results further confirmed the reduction of β phases of the composite fiber mats which dropped the piezoelectric response of the fiber mats by 38% for 5% Fe₃O₄-PVDF than PVDF fiber but still 400% higher than PVDF pellets. The magnetization test advocated a superparamagnetic state of the fiber at room temperature but a ferromagnetic behavior at a lower temperature. The coercivity values of the mats suggested a homogeneous dispersion of the Fe₃O₄ nanoparticles into the PVDF matrix. Young’s modulus (E) of the fibers remained the same before and after the magnetization test, indicating the mechanical stability of the fiber in the range of 5 K to 300 K. Its mechanical stability, superparamagnetic behavior at room temperature and ferromagnetic at low temperature could open up its application in spintronic devices at cryogenic temperature and cryogenic power electronic devices. Full article

Electrospun nano-fibers exhibit two significant properties: a high surface-to-volume ratio and a relatively defect-free molecular structure. Due to the high surface-to-volume ratio, electro-spun materials are well suited for activities requiring increased physical contact, such as providing a site for a chemical reaction or filtration of small-sized physical materials. However, electrospinning has many shortcomings, including difficulties in producing inorganic nanofibers and a limited number or variety of polymers used in the process. The fabrication of nanofiber bundles via electrospinning is explored in this analytical study and the relationship between all effective electrospinning parameters and the relative abundance of various fiber morphologies. Numerous variables could impact the fabrication of nanofibers, resulting in a variety of morphologies such as uniform, entangled, individual beads, beads-on-string, etc. Therefore, adequate ambient conditions and selecting the appropriate polymer and solvent for achieving a homogenous polymer solution and uniform with desired nanofiber properties for different applications of electro-spun materials are examined. Finally, the promising applications of nano-fine fibers in various fields achieved via electrospinning are studied in this paper. Full article

Braids are generally divided into 2D braids and 3D braids. Two-dimensional braids include flat braids and circular braids. Circular braids represent three-dimensional textiles, as they enclose a volume, but consist of a two-dimensional yarn architecture. Three-dimensional braids are defined by a three-dimensional yarn architecture. Historically, 3D braids were produced on row and column braiding machines with Cartesian or radial machine beds, by bobbin movements around inlay yarns. Three-dimensional rotary braiding machines allow a more flexible braiding process, as the bobbins are moved via individually controlled horn gears and switches. Both braiding machines at the Institut für Textiltechnik (ITA) of RWTH Aachen University, Germany, are based on the principal of 3D rotary machines. The fully digitized 3D braiding machine with an Industry 4.0 standard enables the near-net-shape production of three-dimensionally braided textile preforms for lightweight applications. The preforms can be specifically reinforced in all three spatial directions according to the application. Complex 3D structures can be produced in just one process step due to the high degree of design freedom. The 3D hexagonal braiding technology is used in the field of medical textiles. The special shape of the horn gears and their hexagonal arrangement provides the densest packing of the bobbins on the machine bed. In addition, the lace braiding mechanism allows two bobbins to occupy the position between two horn gears, maximizing the number of bobbins. One of the main applications is the near-net-shape production of tubular structures, such as complex stent structures. Three-dimensional braiding offers many advantages compared to 2D braiding, e.g., production of complex three-dimensional geometries in one process step, connection of braided layers, production of cross-section changes and ramifications, and local reinforcement of technical textiles without additional process steps. In the following review, the latest developments in 3D braiding, the machine development of 3D braiding machines, as well as software and simulation developments are presented. In addition, various applications in the fields of lightweight construction and medical textiles are introduced. Full article

The performance of bulletproof vests is mainly based on the energy absorption capacity of the flexible fibrous reinforcements. To understand the in situ behaviour of these textile structures during a ballistic impact, we find the use of sensor yarns integrated into these fibrous reinforcements to be a non-invasive and reliable solution. Measurements of the dynamic deformation of the sensor yarns will provide a new and useful source of information. The design and manufacturing stages of a sensor yarn, made with the same structural yarns of the fabric, are detailed successively. Then, different batches of sensor yarns were designed, and electromechanical tensile tests were performed in quasi-static mode. These experiments provide encouraging results for the measurement of the deformation of a textile structure subject to a dynamic impact. Full article

Recent developments in electrospinning technology have enabled the commercial-scale production of nonwoven fabrics from synthetic and natural polymers. Since the early 2000s, polysaccharides and their derivatives have been recognized as promising raw materials for electrospinning, and their electrospun textiles have attracted increasing attention for their diverse potential applications. In particular, their biomedical applications have been spotlighted thanks to their “green” aspects, e.g., abundance in nature, biocompatibility, and biodegradability. This review focuses on three main research topics in the biomedical applications of electrospun polysaccharidic textiles: (i) delivery of therapeutic molecules, (ii) tissue engineering, and (iii) wound healing, and discusses recent progress and prospects. Full article