Fibers

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16 pages, 6922 KiB

Open AccessArticle

Contacting of Bicomponent TPU-Fibers with a Conductive Core: A Method for Data Acquisition and Analysis of the Electrical Properties

by Jeanette Ortega, Felix Krooß, Yuwei Stefan Li and Thomas Gries

Fibers 2024, 12(5), 41; https://doi.org/10.3390/fib12050041 - 8 May 2024

Viewed by 1351

Abstract

With the megatrend of digitalization, the demand for sensors in previously difficult-to-access scenarios is increasing. Filament-shaped sensors (FSS) are ideal for this demand, especially in applications in which the monitoring of textile structures is the focus. Electrically conductive bicomponent filaments based on thermoplastic [...] Read more.

With the megatrend of digitalization, the demand for sensors in previously difficult-to-access scenarios is increasing. Filament-shaped sensors (FSS) are ideal for this demand, especially in applications in which the monitoring of textile structures is the focus. Electrically conductive bicomponent filaments based on thermoplastic polyurethane (TPU) and doped with carbon nanotubes (CNTs) offer great potential due to their flexible mechanical properties. Through the core-conducting, bicomponent structure, the sensing material is protected from environmental factors such as surrounding conductive materials and external moisture. The insulating material, however, simultaneously complicates the contacting method in order to measure sensing changes in the conductive core. In this work, laser cutting is employed as a technology in order to expose the conductive core of the filaments. The filament is then coated with silver and mechanically crimped, providing both a conductive interface for the data acquisition device as well as a protective layer. Laser parameters (power 20–100 W and speed 5–50 mm/s) are investigated to identify the parameters with the best cutting properties for which the filaments are analyzed visually and electrically. This work provides a robust and reproducible method for contacting core-conducting TPU filaments for strain-sensing applications. This study shows that while the choice of laser parameter influences the morphology of the cut surface, its impact on the resulting linear resistivity is negligible. Full article

(This article belongs to the Special Issue Fibers 10th Anniversary: Past, Present, and Future)

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16 pages, 19373 KiB

Open AccessArticle

Performance of Flax/Epoxy Composites Made from Fabrics of Different Structures

by Abdolmajid Alipour and Krishnan Jayaraman

Fibers 2024, 12(4), 34; https://doi.org/10.3390/fib12040034 - 7 Apr 2024

Cited by 2 | Viewed by 2263

Abstract

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 [...] Read more.

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

(This article belongs to the Special Issue Fibers 10th Anniversary: Past, Present, and Future)

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20 pages, 19429 KiB

Open AccessArticle

Synthesis of Lignin/PAN Fibers from Sawdust

by Meruyert Nazhipkyzy, Anar B. Maltay, Bakhytzhan Lesbayev and Dana D. Assylkhanova

Fibers 2024, 12(3), 27; https://doi.org/10.3390/fib12030027 - 13 Mar 2024

Cited by 1 | Viewed by 2106

Abstract

Carbon nanofibers based on lignin from wood waste have a promising potential for the ability to produce electrodes that can modernize existing energy storage technology. The most important detail is that the low cost, as well as the availability of the initial products [...] Read more.

Carbon nanofibers based on lignin from wood waste have a promising potential for the ability to produce electrodes that can modernize existing energy storage technology. The most important detail is that the low cost, as well as the availability of the initial products for the production of lignin, will reduce the cost of energy storage devices and contribute to improving the environment. In this study, pine sawdust and elm sawdust were used as raw materials for the production of lignin, which accumulate in large quantities in metal workshops in Almaty. Lignin extraction was carried out using an organosolvent method, which is environmentally friendly, low-cost, uses minimal amounts of strong acids and metal catalysts, does not pollute water, and does not emit sulfur dioxide (SO₂). A comprehensive study of the characteristics of the obtained lignins from wood waste was carried out. Infrared spectroscopy (IR) revealed that the obtained lignin contains aromatic, phenolic, hydroxyl, methyl, and methoxyl groups. The results of nuclear magnetic resonance (NMR) spectroscopy showed the presence of a high number of syringyl (S) links compared to guaiacyl (G), which contribute to increased efficiency in the thermal processing of lignin. Also, this study investigated the use of the obtained lignins to produce continuous fibers by electrospinning. The effect of lignin mass on the viscosity of the lignin/polyacrylonitrile (PAN) solution and the effect of the carbonization temperature on the physico-chemical characteristics of the lignin/PAN solution were investigated. The following research methods were used for this purpose: Raman spectroscopy, thermogravimetric analysis (TGA), electron scanning microscopy, energy dispersion analysis, IR, NMR, and optical microscopy. The conditions for the production of lignin-containing carbon fibers at temperatures of 800, 900, and the carbonation heating rate, is an important parameter in the production of carbon fibers as it strongly affects the characteristics of the resulting carbon fibers. The heating rate affects were studied, and it was found that, at a heating rate of 5 °C/min and a carbonation temperature of 800 °C, porous carbon nanofibers with a diameter of 47 nm are formed in a nitrogen medium for 60 min. Full article

(This article belongs to the Special Issue Fibers 10th Anniversary: Past, Present, and Future)

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15 pages, 18908 KiB

Open AccessArticle

Silica Scaling Inhibition in Water Treatment Process Using Fibrous Al₂O₃-Nylon 6 Adsorbents

by Ngan Thi Thu Phan, Minehiko Sato and Takaomi Kobayashi

Fibers 2024, 12(1), 11; https://doi.org/10.3390/fib12010011 - 15 Jan 2024

Cited by 2 | Viewed by 1844

Abstract

This study describes a novel approach using fibrous Al₂O₃-Nylon 6 composites to induce inhibition behavior in silica scaling systems. The composite fibers were fabricated with a wet-spinning process using the coagulation of a methanolic Nylon-CaCl₂ solution with Al [...] Read more.

This study describes a novel approach using fibrous Al₂O₃-Nylon 6 composites to induce inhibition behavior in silica scaling systems. The composite fibers were fabricated with a wet-spinning process using the coagulation of a methanolic Nylon-CaCl₂ solution with Al₂O₃ powder after immersing the thread-like solution in water. The mesoporous nylon fibers composed of Al₂O₃ powders ranging from 10 to 30 wt% loading demonstrated superior adsorption capabilities to silica in water, behaving with the Freundlich model and exhibiting effective multilayer adsorption onto the Al₂O₃ sites embedded in the fiber. Furthermore, the composite fibers inhibited silica scaling, even at high concentrations, due to a substantially efficient reduction in soluble silica when the composite fiber was present in the system. The utilization of 15 g of composite fibers resulted in a rapid drop to approximately 30 mg/L within the initial 10 h, which is a considerable improvement compared to the 300 mg/L observed in the fiber-free control sample. Notably, the presence of an elevated fiber content exceeding 7.5 g demonstrated the complete inhibition of silica precipitation. An analysis of the pore volume using nitrogen adsorption experiments before and after silica adsorption showed that silica adsorption resulted in a significant decrease in mesoporous properties at the alumina sites. This indicated an efficient adsorption of silica onto the alumina site, effectively removing silica from the system. Full article

(This article belongs to the Special Issue Fibers 10th Anniversary: Past, Present, and Future)

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19 pages, 8938 KiB

Open AccessFeature PaperArticle

Methodological Aspects and Mesh Convergence in Numerical Analysis of Athermal Fiber Network Material Deformation

by Nishan Parvez, Syed Nabeel Amjad, Mithun K. Dey and Catalin R. Picu

Fibers 2024, 12(1), 9; https://doi.org/10.3390/fib12010009 - 12 Jan 2024

Cited by 1 | Viewed by 2221

Abstract

A balance between model complexity, accuracy, and computational cost is a central concern in numerical simulations. In particular, for stochastic fiber networks, the non-affine deformation of fibers, related non-linear geometric features due to large global deformation, and size effects can significantly affect the [...] Read more.

A balance between model complexity, accuracy, and computational cost is a central concern in numerical simulations. In particular, for stochastic fiber networks, the non-affine deformation of fibers, related non-linear geometric features due to large global deformation, and size effects can significantly affect the accuracy of the computer experiment outputs and increase the computational cost. In this work, we systematically investigate methodological aspects of fiber network simulations with a focus on the output accuracy and computational cost in models with cellular (Voronoi) and fibrous (Mikado) network architecture. We study both p and h-refinement of the discretizations in finite element solution procedure, with uniform and length-based adaptive h-refinement strategies. The analysis is conducted for linear elastic and viscoelastic constitutive behavior of the fibers, as well as for networks with initially straight and crimped fibers. With relative error as the determining criterion, we provide recommendations for mesh refinement, comment on the necessity of multiple realizations, and give an overview of associated computational cost that will serve as guidance toward minimizing the computational cost while maintaining a desired level of solution accuracy. Full article

(This article belongs to the Special Issue Fibers 10th Anniversary: Past, Present, and Future)

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23 pages, 12635 KiB

Open AccessArticle

Barley Straw Fiber Extraction in the Context of a Circular Economy

by Zorana Kovačević, Sara Strgačić and Sandra Bischof

Fibers 2023, 11(12), 108; https://doi.org/10.3390/fib11120108 - 8 Dec 2023

Cited by 2 | Viewed by 2768

Abstract

The potential for sustainable lignocellulosic agro-waste is immense, owing to the fact that it represents the most abundant organic compound on Earth. It is a valuable and desirable source for material production across numerous industries due to its abundance, renewability, and biodegradability. This [...] Read more.

The potential for sustainable lignocellulosic agro-waste is immense, owing to the fact that it represents the most abundant organic compound on Earth. It is a valuable and desirable source for material production across numerous industries due to its abundance, renewability, and biodegradability. This paper explores the world of barley fibers, which are extracted from the straw of two different cultivars (old Rex or new Barun) and have tremendous potential for use, primarily for technical textiles. The quantity of the extracted fibers depends both on the type of barley used and on climate conditions that influence the plants’ growth, resulting in fiber yields ranging from 14.82% to 19.59%. The chemical composition of isolated fibers revealed an optimal content of cellulose and lignin in barley fibers isolated from the Rex variety. Those results were confirmed with FTIR analysis, which revealed a lower intensity of peaks associated with hemicellulose and lignin and, therefore, indicated their better removal after the chemical maceration process. In terms of fiber density, the quality of the fibers was comparable to that of cotton fibers, but they differed significantly in moisture regain (10.37–11.01%), which was higher. Furthermore, sufficient fiber tenacity (20.31–23.08 cN/tex) was obtained in a case of old-variety Rex, indicating the possibility of spinning those fibers into yarns, followed by their extended usage for apparel. Additionally, our paper reveals the possibility of fulfilling the requirements of the zero waste principle due to the fact that a high percentage of solid waste left after the fiber extraction (26.3–32.3%) was afterwards successfully used for the production of biofuels, enabling the closing of the loop in a circular economy. Full article

(This article belongs to the Special Issue Fibers 10th Anniversary: Past, Present, and Future)

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12 pages, 2826 KiB

Open AccessArticle

Comparative Studies of Changes in Cotton Fabrics and Fibers under the Influence of Disinfection, Sterilization, and DNA Degradation Agents

by Daria Śmigiel-Kamińska, Jolanta Wąs-Gubała and Jolanta Kumirska

Fibers 2023, 11(12), 100; https://doi.org/10.3390/fib11120100 - 22 Nov 2023

Cited by 2 | Viewed by 1794

Abstract

The purpose of this study was to detect changes in the structure and chemical composition of undyed and dyed cotton fabrics under the influence of six popular agents for disinfection, sterilization, and DNA degradation with different chemical compositions. The original and exposed fabrics [...] Read more.

The purpose of this study was to detect changes in the structure and chemical composition of undyed and dyed cotton fabrics under the influence of six popular agents for disinfection, sterilization, and DNA degradation with different chemical compositions. The original and exposed fabrics and their constituent fibers were subjected to comparative analysis using various optical microscopy methods, infrared spectroscopy, and UV–Vis microspectrophotometry in order to differentiate the exanimated material due to the agents applied. Differences in color, from a slight change to complete discoloration, and in the structure of the tested fabrics, which became more rigid, brittle, or, for example, compact, were noticed. With the use of ATR FTIR, it was possible to identify the presence in the exposed fabrics of residues of these agents that contained quaternary ammonium salts. Bright-field microscopy made it possible to show, above all, changes or lack thereof in the fluorescence properties of single exposed fibers in relation to control ones. With the use of UV–Vis microspectrophotometry, changes in colored fibers following the action of a specific agent on the examined fabrics were monitored. A case study was presented as an application aspect of the research, in which the use of concrete disinfectants was recognized based on changes observed in cotton clothing. Full article

(This article belongs to the Special Issue Fibers 10th Anniversary: Past, Present, and Future)

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14 pages, 7979 KiB

Open AccessArticle

Next-Generation Cellulosic Filaments from Hemp Pulp via Dry-Jet Wet Spinning Using HighPerCell^® Technology

by Antje Ota, Marc Philip Vocht, Ronald Beyer, Anne Reboux, Charles Reboux and Frank Hermanutz

Fibers 2023, 11(11), 90; https://doi.org/10.3390/fib11110090 - 26 Oct 2023

Cited by 1 | Viewed by 2568

Abstract

Fiber demand of cellulosic fibers is rapidly increasing; however, these fibers are mainly based on the use of wood pulp (WP), which often have long transport times and, consequently, a high CO₂ footprint. So, alternative pulps based on non-wood, annual fast-growing plants [...] Read more.

Fiber demand of cellulosic fibers is rapidly increasing; however, these fibers are mainly based on the use of wood pulp (WP), which often have long transport times and, consequently, a high CO₂ footprint. So, alternative pulps based on non-wood, annual fast-growing plants are an option to cover the demand for raw materials and resources. Herein, we report on the use of a novel developed hemp pulp (HP) for man-made cellulosic fiber filament spinning. Commercial WP was used as a reference material. While HP could be used and directly spun as received without any further pretreatment, an additional step to adjust the degree of polymerization (DP) was needed to use the wood pulp. Continuous filaments were spun using a novel dry-jet wet spinning (HighPerCell^® process) technique, which is based on the use of 1-ethyl-3-methylimidazolium octanoate ([C₂C₁im][Oc]) as a solvent. Via this approach, several thousand meters (12,000 m–15,000 m) of continuous multifilament filaments were spun. The HP pulps showed excellent spinning performance. The novel approach allows the preparation of cellulosic fibers for either technical—with high tensile strength—or textile—possessing a low fibrillation tendency—applications. Textile hemp-based filaments were used for first weaving trials, resulting in a flawless fabric. Full article

(This article belongs to the Special Issue Fibers 10th Anniversary: Past, Present, and Future)

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31 pages, 4674 KiB

Open AccessArticle

The Production of Ultra-Thin Polyethylene-Based Carbon Fibers out of an “Islands-in-the-Sea” (INS) Precursor

by Flávio A. Marter Diniz, Tim Röding, Mohamed Bouhrara and Thomas Gries

Fibers 2023, 11(9), 75; https://doi.org/10.3390/fib11090075 - 8 Sep 2023

Cited by 1 | Viewed by 2350

Abstract

Carbon fibers (CF) and their composites (CC) are one of the world’s most promising and avant-garde high-performance materials, as they combine excellent mechanical characteristics with high weight reduction potential. Polyethylene (PE) is the perfect alternative precursor for CF as it combines widespread availability, [...] Read more.

Carbon fibers (CF) and their composites (CC) are one of the world’s most promising and avant-garde high-performance materials, as they combine excellent mechanical characteristics with high weight reduction potential. Polyethylene (PE) is the perfect alternative precursor for CF as it combines widespread availability, low cost, high carbon content, and, most importantly, precursor fibers that can be produced via melt-spinning. PE-based CF production involves a challenging and time-consuming diffusion-limited chemical stabilization step. The work presented in this article tackles the challenge of reducing the chemical stabilization process time by converting a bicomponent island-in-the-sea fiber, consisting of PA6 as sea matrix and HDPE as island material, into an ultra-thin PE-precursor fiber. The produced precursor fiber is then successfully converted into an ultra-thin PE-based CF through sulfonation and subsequent carbonization in a continuous set-up. The resulting CF has a smooth surface with no observable surface defects and a filament diameter of around 3 µm. The successful conversion to ultra-thin CF is shown in both batch and continuous processes. Additionally, a reduction in sulfonation reaction time from 4 h to 3 h is achieved. Full article

(This article belongs to the Special Issue Fibers 10th Anniversary: Past, Present, and Future)

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20 pages, 5272 KiB

Open AccessArticle

Controllable Water-Triggered Degradation of PCL Solution-Blown Nanofibrous Webs Made Possible by Lipase Enzyme Entrapment

by Fnu Asaduzzaman and Sonja Salmon

Fibers 2023, 11(6), 49; https://doi.org/10.3390/fib11060049 - 1 Jun 2023

Viewed by 2475

Abstract

Polymers in nanofibrous forms offer new opportunities for achieving triggered polymer degradation, which is important for functional and environmental reasons. The polycaprolactone (PCL) nanofibrous nonwoven polymer webs developed in this work by solution blow spinning with entrapped enzymes were completely, rapidly and controllably [...] Read more.

Polymers in nanofibrous forms offer new opportunities for achieving triggered polymer degradation, which is important for functional and environmental reasons. The polycaprolactone (PCL) nanofibrous nonwoven polymer webs developed in this work by solution blow spinning with entrapped enzymes were completely, rapidly and controllably degraded when triggered by exposure to water. Lipase (CALB) from Candida antarctica was successfully entrapped in the PCL webs via an enzyme-compatible water-in-oil emulsion in the PCL–chloroform spinning solution with added surfactant. Protein (enzyme) in the nanofibrous webs was detected by Fourier Transform Infrared Spectroscopy (FTIR), while time of flight-secondary ion mass spectroscopy (ToF-SIMS) and laser confocal microscopy indicated that enzymes were immobilized within solid fibers as well as within microbead structures distributed throughout the webs. Degradation studies of CALB-enzyme functionalized solution-blown nonwoven (EFSBN)-PCL webs at 40 °C or ambient temperature showed that EFSBN-PCL webs degraded rapidly when exposed to aqueous pH 8 buffer. Scanning electron microscopy (SEM) images of partially degraded webs showed that thinner fibers disappeared first, thus, controlling fiber dimensions could control degradation rates. Rapid degradation was attributed to the combination of nanofibrous web structure and the distribution of enzymes throughout the webs. CALB immobilized in the solid dry webs exhibited long storage stability at room temperature or when refrigerated, with around 60% catalytic activity being retained after 120 days compared to the initial activity. Dry storage stability at ambient conditions and rapid degradation upon exposure to water demonstrated that EFSBN-PCL could be used as fibers or binders in degradable textile or paper products, as components in packaging, for tissue engineering and for controlled-release drug or controlled-release industrial and consumer product applications. Full article

(This article belongs to the Special Issue Fibers 10th Anniversary: Past, Present, and Future)

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10 pages, 3218 KiB

Open AccessArticle

On the Pressure and Rate of Infiltration Made by a Carbon Fiber Yarn with an Aluminum Melt during Ultrasonic Treatment

by Sergei Galyshev, Bulat Atanov and Valery Orlov

Fibers 2023, 11(5), 41; https://doi.org/10.3390/fib11050041 - 6 May 2023

Viewed by 1669

Abstract

The effect of the infiltration time of a carbon fiber yarn in the range of 6 to 13.6 s on the infiltrated volume under the cavitation of an aluminum melt has been studied. When the infiltration time was more than 10 s, the [...] Read more.

The effect of the infiltration time of a carbon fiber yarn in the range of 6 to 13.6 s on the infiltrated volume under the cavitation of an aluminum melt has been studied. When the infiltration time was more than 10 s, the carbon fiber was completely infiltrated with the matrix melt, and a decrease in the infiltration time led to a monotonous decrease in the fraction of the infiltrated volume. Based on the experimental data, the infiltration rate and the pressure necessary to infiltrate a carbon fiber yarn with an aluminum melt were estimated. The infiltration rate was 20.9 cm³/s and was independent of the infiltration depth. The calculated pressure necessary for the complete infiltration of a carbon fiber yarn at this rate was about 270 Pa. A comparison of the pressure values calculated according to Darcy’s and Forchheimer’s laws showed that the difference between them did not exceed 0.01%. This indicates that a simpler Darcy’s law could be used to estimate pressure. Full article

(This article belongs to the Special Issue Fibers 10th Anniversary: Past, Present, and Future)

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19 pages, 3801 KiB

Open AccessArticle

Shear Strength Prediction of Steel-Fiber-Reinforced Concrete Beams Using the M5P Model

by Nadia Moneem Al-Abdaly, Mahdi J. Hussein, Hamza Imran, Sadiq N. Henedy, Luís Filipe Almeida Bernardo and Zainab Al-Khafaji

Fibers 2023, 11(5), 37; https://doi.org/10.3390/fib11050037 - 27 Apr 2023

Cited by 3 | Viewed by 2317

Abstract

This article presents a mathematical model developed using the M5P tree to predict the shear strength of steel-fiber-reinforced concrete (SFRC) for slender beams using soft computing techniques. This method is becoming increasingly popular for addressing complex technical problems. Other approaches, such as semi-empirical [...] Read more.

This article presents a mathematical model developed using the M5P tree to predict the shear strength of steel-fiber-reinforced concrete (SFRC) for slender beams using soft computing techniques. This method is becoming increasingly popular for addressing complex technical problems. Other approaches, such as semi-empirical equations, can show known inaccuracies, and some soft computing methods may not produce predictive equations. The model was trained and tested using 332 samples from an experimental database found in the previous literature, and it takes into account independent variables such as the effective depth d, beam width b_w, longitudinal reinforcement ratio ρ, concrete compressive strength f_c, shear span to effective depth ratio a/d, and steel fiber factor F_sf. The predictive performance of the proposed M5P-based model was also compared with the one of existing models proposed in the previous literature. The evaluation revealed that the M5P-based model provided a more consistent and accurate prediction of the actual strength compared to the existing models, achieving an R² value of 0.969 and an RMSE value of 37.307 for the testing dataset. It was found to be a reliable and also straightforward model. The proposed model is likely to be highly helpful in assessing the shear capacity of SFRC beams during the pre-planning and pre-design stages and could also be useful to help for future revisions of design standards. Full article

(This article belongs to the Special Issue Fibers 10th Anniversary: Past, Present, and Future)

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15 pages, 3449 KiB

Open AccessArticle

Adsorption Studies of Ammonia, Protein, and Phytic Acid Using Chitosan Fiber Coated with Oxidized Cellulose Nanofiber

by Duangkamol Dechojarassri, Kensuke Nishida, Ryousuke Ozakiya, Tetsuya Furuike and Hiroshi Tamura

Fibers 2023, 11(4), 32; https://doi.org/10.3390/fib11040032 - 30 Mar 2023

Cited by 1 | Viewed by 1967

Abstract

Herein, chitosan (CS) fibers coated with TEMPO-oxidized cellulose nanofibers (CS/TOCN fibers) were successfully prepared using a wet spinning technique; CS was dissolved in acetic acid to obtain a CS doping solution. The tensile strength and ammonia adsorption percentages increased with increasing TOCN concentration. [...] Read more.

Herein, chitosan (CS) fibers coated with TEMPO-oxidized cellulose nanofibers (CS/TOCN fibers) were successfully prepared using a wet spinning technique; CS was dissolved in acetic acid to obtain a CS doping solution. The tensile strength and ammonia adsorption percentages increased with increasing TOCN concentration. The maximum ammonia adsorption percentage (41.39%, 8.3 mg/g) was obtained when 2% NaOH and 0.01% TOCN were used as the coagulation solution. Additionally, the adsorption of model proteins, including lysozyme (Lz), cytochrome C (Cyt C), and bovine serum albumin (BSA), were studied. In water, the CS/TOCN fibers with negative charges adsorbed more Lz with positive charges than CS fibers containing positive charges. Contrastingly, CS fibers adsorbed more Cyt C and BSA containing negative charges in phosphate-buffered saline solutions than CS/TOCN fibers. Furthermore, the adsorption percentage of phytic acid using the CS/TOCN fibers reached 64.18% (288 mg/g) within 60 min. Thus, TOCNs improved the tensile properties of CS fibers and preferred positively charged materials contaminated in water, such as ammonia, Lz, and phytic acid. Full article

(This article belongs to the Special Issue Fibers 10th Anniversary: Past, Present, and Future)

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16 pages, 7014 KiB

Open AccessArticle

Damage Investigation on the Carbon Tows during Rewinding and Braiding Processes

by Justine Calba, Damien Soulat, Xavier Legrand and Sébastien Renauld

Fibers 2023, 11(3), 30; https://doi.org/10.3390/fib11030030 - 22 Mar 2023

Cited by 2 | Viewed by 2235

Abstract

During the manufacturing process, the fibrous materials used in composite reinforcements are subjected to many sources of damage that must be managed if the best possible quality is to be reached for the final product. More specifically, carbon fibers are subjected, during reinforcement [...] Read more.

During the manufacturing process, the fibrous materials used in composite reinforcements are subjected to many sources of damage that must be managed if the best possible quality is to be reached for the final product. More specifically, carbon fibers are subjected, during reinforcement manufacturing, to friction with mechanical components and with other tows and to excessive tensile loads due to specific configurations required by textile devices, which results in degradation that affects their mechanical properties and those of final products. While many studies have focused on carbon tow damage during the weaving process, roving quality control during the post-braiding steps, such as the rewinding or braiding processes, is less studied in the literature. In this study, an experimental approach was developed to quantify the damage inflicted on 12 K carbon tows during the rewinding and braiding processes using image analysis software. Based on these images, a damage criterion is defined to quantify the influence of the parameters associated with rewinding and braiding processes on degradation of carbon tows. During the rewinding stage, the influence of the process parameters on the degradation by friction of the tows was significant, but the properties (linear density and tenacity) of these carbon tows were little-modified. On the other hand, the great influence of the tension applied on tows on the inflicted damage was experimentally demonstrated, during both the rewinding and braiding steps, which may have resulted in a loss of tenacity of up to 27%. Full article

(This article belongs to the Special Issue Fibers 10th Anniversary: Past, Present, and Future)

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Review

Jump to: Research

40 pages, 13357 KiB

Open AccessReview

A Review on False-Twist Texturing

by Mathias Ortega, Alexander Saynisch, Bahar-Merve Yurtseven and Thomas Gries

Fibers 2024, 12(4), 36; https://doi.org/10.3390/fib12040036 - 7 Apr 2024

Viewed by 3737

Abstract

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 [...] Read more.

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 article belongs to the Special Issue Fibers 10th Anniversary: Past, Present, and Future)

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26 pages, 2239 KiB

Open AccessReview

Retting of Bast Fiber Crops Like Hemp and Flax—A Review for Classification of Procedures

by Morris Angulu and Hans-Jörg Gusovius

Fibers 2024, 12(3), 28; https://doi.org/10.3390/fib12030028 - 15 Mar 2024

Cited by 5 | Viewed by 2919

Abstract

The interest and thus the number of publications on the supply chains of bast fiber plants has steadily increased in recent years. A number of specific technical terms related to methods and their use for individual areas of the supply chain are often [...] Read more.

The interest and thus the number of publications on the supply chains of bast fiber plants has steadily increased in recent years. A number of specific technical terms related to methods and their use for individual areas of the supply chain are often interpreted and used in very different ways. Therefore, the aim of this publication is to increase the clarity of the description of the operations and to improve the understanding of the sequence and the purpose of the process steps. This is based on a selected review of the relevant literature as well as on suggestions for their classification Full article

(This article belongs to the Special Issue Fibers 10th Anniversary: Past, Present, and Future)

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22 pages, 5728 KiB

Open AccessReview

Targeted Pre-Treatment of Hemp Fibers and the Effect on Mechanical Properties of Polymer Composites

by K. Palanikumar, Elango Natarajan, Kalaimani Markandan, Chun Kit Ang and Gérald Franz

Fibers 2023, 11(5), 43; https://doi.org/10.3390/fib11050043 - 9 May 2023

Cited by 15 | Viewed by 5516

Abstract

Research on plant-fiber-reinforced composites has gained significant research interest since it generates composites with exceptional mechanical properties; however, the potential of hemp fibers can only be fully exploited if the fibers are well separated from the bundle to achieve cellulose-rich fibers. This is [...] Read more.

Research on plant-fiber-reinforced composites has gained significant research interest since it generates composites with exceptional mechanical properties; however, the potential of hemp fibers can only be fully exploited if the fibers are well separated from the bundle to achieve cellulose-rich fibers. This is because well-separated bast fibers that are long and exhibit higher fiber aspect ratio enhance the mechanical properties of the composite by influencing property translations upon loading. A key feature for successful implementation of natural fibers is to selectively remove non-cellulosic components of hemp fiber to yield cellulose-rich fibers with minimal defects. Targeted pre-treatment techniques have been commonly used to address the aforementioned concerns by optimizing properties on the fiber’s surface. This in turn improves interfacial bonding between the fibers and the hydrophobic polymer, enhances the robustness of hemp fibers by improving their thermal stability and increases resistance to microbial degradation. In this study, we comprehensively review the targeted pre-treatment techniques of hemp fiber and the effect of hemp fiber as a reinforcement on the mechanical properties of polymeric composites. Full article

(This article belongs to the Special Issue Fibers 10th Anniversary: Past, Present, and Future)

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