Fibers, Volume 12, Issue 4 (April 2024) – 8 articles

Asbestos is a widely used name for natural silicate minerals with fibrous properties. Asbestos minerals were one of the most popular and cheapest raw materials used in the construction industry in the past when they was used in the form of cement–asbestos composite material. Nowadays, we know that asbestos possesses carcinogenic properties. Due to this fact, asbestos was banned in many countries including Lithuania. All asbestos-containing materials are considered waste and stored in special landfills, which causes significant environmental pollution. One of the methods proposed to solve the asbestos problem may be thermal treatment. In the present study, asbestos-containing wastes in the form of cement–asbestos materials were examined. These asbestos-containing materials were characterised via chemical analysis (XRF) connected with mineralogical phase analysis with powder X-ray diffraction (XRD) as well as scanning electron microscopy (SEM). The thermal decomposition of samples was studied via differential thermal analysis (DTA) and thermogravimetric measurements with evolved gas analysis (TG–EGA). It was found that thermal treatment is a possible way to destroy asbestos contained in cement–asbestos wastes and convert it into new mineral phases. The work also compared the obtained characteristics of asbestos waste with the characteristics of waste produced in other countries. Full article

The annual demand for fibres continues to rise worldwide. Consequently, more and more fibres must be produced to meet this demand, most of which are melt-spun polymeric man-made fibres. Smooth filaments made of polymers are mainly used for technical applications in industry. For use in clothing or home textiles, for example, a texturing process is used to give the filaments a crimp and thus a feel like that of natural fibres. In this state, they can be processed together with natural fibres and used in textiles. Partially oriented yarns (POY) are of great importance in texturing. The yarns are mainly crimped with the help of the so-called false-twist texturing process (FTTP). Since POY accounts for about 60% of the melt-spun filament yarn produced worldwide, the FTTP is the most important texturing process in the textile industry. In this paper, the main components of false-twist texturing (FTT) machines are explained, along with the state of the art and research for each component and its influence on the process. Relevant patents are discussed, as well as process optimisation techniques, innovative polymers, and yarn types recently used in FTT, followed by a conclusion and an outlook for the process. Full article

This paper presents a detailed exploration of the development and characterization of multifunctional dual-purpose woven fabrics for thermal protective clothing. Through this research, 69 woven fabric prototypes have been carefully designed and produced, integrating various raw materials, yarn, and woven fabric construction parameters, with the aim of optimizing thermal protection properties while ensuring comfort and durability. The analysis led to the identification of two optimal woven fabric samples, which, upon further testing, exhibited exceptional dimensional stability, crease recovery, tear resistance, as well as abrasion and water resistance. Furthermore, the thermal properties were evaluated, demonstrating exceptional flame resistance, limited heat transmission, and high thermal insulation. Additionally, the study evaluated dynamic thermal properties, contact conductive heat transfer, air permeability, water vapour resistance, and thermal resistance of two clothing systems constructed from selected woven fabrics. Statistical analysis confirms significant differences between clothing systems, highlighting the influence of yarn composition and fabric structure on thermal performance and comfort, where one system exhibits better thermal insulation characteristics suitable for colder environments while the other excels in breathability for warmer climates. The developed woven fabrics meet high standards for protective clothing against heat and flame, surpassing currently available comparable woven fabrics on the market in terms of efficacy and performance. This research provides insights into the intricate balance between protection, comfort, and durability of woven fabrics, contributing to advancements in protective textile technology. Full article

Flax fibers have been shown to have comparable mechanical properties to some conventional synthetic fibers. Flax fabrics with different textile structures show differences in resistance against mechanical loads mainly rooted in fabric orientation and the resultant resin impregnation. Thus, in this study, flax fabrics with three different textile structures, fine twill weave, coarse twill weave and unidirectional, were used as reinforcements in an epoxy matrix. The surfaces of the fabrics were chemically treated using an alkaline treatment, and the alterations in fabric crystallinity index (CrI) were determined using X-ray diffraction (XRD). Experimental results confirmed that textile structures and CrI had significant effects on the mechanical properties of composites. Although an increment in CrI, resulting from chemical treatment, always enhanced tensile and flexural properties, it adversely affected damage development once composites were exposed to impact load. In terms of textile structures, unidirectional fabric outperformed woven fabrics in tensile and flexural properties while in impact properties, the latter had a better performance inducing less damage development. Finally, the mechanism of damage development in different composites was discussed in detail using Scanning Electron Microscopy (SEM) images. It is envisaged that the results of this study will provide an insight that will lead to the proper choice of the optimal kind of flax fabric for different applications. Full article

In the present work, the fabrication of a membrane composed of polylactic acid (PLA), polyvinyl alcohol (PVA), and Biological Hydroxyapatite (BIO-HA) is reported using the coaxial electrospinning technique. The membrane fabrication process involved mixing a solution of PLA and trichloromethane (TCM) with a second solution of PVA, isopropyl alcohol (IPA), distilled water, and BIO-HA at 110 °C. Subsequently, the electrospinning process was carried out using a voltage of 25 kV for 30 min on a rotating drum collector at 1000 rpm. The membrane was characterized through Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray spectroscopy (EDS), Fourier-Transform Infrared spectroscopy (FTIR), Thermogravimetric Analysis (TGA), and Differential Scanning Calorimetry (DSC). The morphological results revealed the presence of randomly arranged fibers with an average diameter of 290 ± 9 nm and interfiber spacing ranging from 200 to 700 nm, which are characteristics conducive to cell proliferation. Additionally, FTIR studies confirmed the presence of BIO-HA and the constituent elements of the polymers in the composite membrane. The polymeric membrane in contact with human mesenchymal stem cells was characterized as showing significant differences in its behavior at 6, 24, and 72 h post-contact. These studies indicate that the membrane provides physical support as a scaffold due to its suitable morphology for cell adhesion and proliferation, attributable to the electrospinning conditions as well as the polymers contained in BIO-HA. Membrane toxicity was confirmed through a cytotoxicity study using fluorescence microscopy, which showed that the membrane provided a favorable environment for cell proliferation. These results suggest that exposure to BIO-HA enhances its potential application in bone and joint tissue regeneration. Full article

While most of the influences on the mechanical properties of particleboard appear to have been investigated, there is a lack of knowledge about the influence of particle size or particle dimensions due to the absence of a suitable particle measuring technique. The introduction of laser-based 3D scanning technology makes it possible to automatically determine the dimensions, surface area, and volume of particles. In this study, the influence of particle size on the mechanical properties of particleboards was investigated. To isolate potentially overlapping influences, single-layer particleboards with a uniform density profile were produced and analyzed. The amount of adhesive specific to the surface of the (fine) face layer particles and (coarse) core layer particles was adjusted utilizing 3D scanning of the surface areas to ensure comparability despite changes in particle size. It was found that with increasing particle size, the modulus of rupture (MOR) and modulus of elasticity (MOE) increase, while the internal bond strength (IB) decreases. It is considered whether these effects result from a particle-size-dependent orientation of the particles in the board. Furthermore, it is shown that all the aforementioned properties increase with increasing surface-specific adhesive amounts. Examples are provided to demonstrate how such fundamental relationships can be utilized to enhance the particleboard production process. Full article

In the first half of the twentieth century, scientific communities worldwide endeavored to diminish dependence on expensive and scarce animal fibers like wool and silk. Their efforts focused on developing regenerated protein fibers, including soy, zein, and casein, to provide comparable benefits to natural protein fibers, such as lustrous appearance, warmth, and a soft feel. The popularity and cost-effectiveness of mass-produced petroleum-based synthetic polymer fibers during World War II diminished interest in developing soy protein fiber. Realizing the ecological degradation caused by fossil fuels and their derived products, a renewed drive exists to explore bio-based waste materials like soy protein. As a fast-growing crop, soy provides abundant byproducts with opportunities for waste valorization. The soybean oil extraction process produces soy protein as a byproduct, which is a highly tunable biopolymer. Various functional groups within the soy protein structure enable it to acquire different valuable properties. This review critically examines scholarly publications addressing soy protein fiber developmental history, soy protein microstructure modification methods, and soy protein fiber spinning technologies. Additionally, we provide our scientific-based views relevant to overcoming the limitations of previous work and share prospects to make soy protein byproducts viable textile fibers. Full article

Woven fabrics generally have high strength but only limited stretch. This lack of stretch can be overcome by incorporating elastane fibers into the fabric structure. These stretch woven fabrics offer an interesting potential for tight-fitting garments. However, the presence of the elastane fibers may lower the strength of the fabrics. To expand the knowledge on the mechanical behavior of stretch woven fabrics, this study investigated eight commercial fabrics with elastane fiber content between 5 and 51%. Four fabrics were polyester-based and the other four were polyamide-based. The effect of the fabric weight and elastane fiber content on the grab strength, tear strength, and unrecovered stretch was analyzed. It was observed that, at very high elastane fiber content, the load–extension curve was typical to that of an elastane fiber, while the traditional load–extension behavior of woven fabrics with low to average stretch was obtained at lower elastane fiber contents. For the polyester-based fabrics, the grab strength and tear strength generally increased with fabric weight and decreased with elastane fiber content. For the polyamide-based fabrics, a higher elastane fiber content led to a decrease in grab strength, tear strength, and unrecovered stretch. A reduction in tear strength was observed at higher fabric weight. Full article