Fibers

14 pages, 4080 KiB

Open AccessArticle

The Coloristic Properties of Biodegradable Fibers

by Mária Petková, Viera Jančovičová, Anna Ujhelyiová and Marcela Hricová

Fibers 2024, 12(7), 59; https://doi.org/10.3390/fib12070059 - 15 Jul 2024

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This work aims to present the results of evaluating the coloristic properties of polylactic acid (PLA) fibers. PLA is common nowadays in much research, as it is a biodegradable plastic from renewable sources. However, little research is devoted to PLA fibers, and even [...] Read more.

This work aims to present the results of evaluating the coloristic properties of polylactic acid (PLA) fibers. PLA is common nowadays in much research, as it is a biodegradable plastic from renewable sources. However, little research is devoted to PLA fibers, and even less to applied research of colored fibers. The prepared color masterbatches, created using inorganic pigments, such as titanium dioxide and carbon black, were subsequently used to prepare dyed PLA fibers in mass. The fibers were drawn to the maximum drawn ratio. The properties of the pure and dyed fibers were investigated before and after accelerated light aging using Q-SUN equipment. The changes were recorded by Fourier Transform Infrared (FTIR) spectroscopy and colorimetric properties were recorded using a device spectrometer from TECHKON SpectroDens. We also evaluated thermal properties from the first heating via differential scanning calorimetry (DSC). The measurements were taken before and after the aging of the PLA fibers, in order to see the effect of aging on the supermolecular structure, excluding the influence of the preparation process and the influence of the kind of PLA. Using inorganic pigments showed sufficient color stability even after accelerated light aging, which is beneficial for using colored fibers in practice. Full article

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22 pages, 9018 KiB

Open AccessArticle

Hydrothermal Aging and Humidity Exposure of Carbon and Basalt Fibers and Life Time Prediction

by John Sunny, Jorge Palacios Moreno, Hadi Nazaripoor and Pierre Mertiny

Fibers 2024, 12(7), 58; https://doi.org/10.3390/fib12070058 - 12 Jul 2024

Viewed by 920

Abstract

Fibers as a reinforcement in polymer-based composite materials play an essential role in the composites’ mechanical performance. It is, therefore, crucial to understand how fibers are affected by different environmental conditions, such as water exposure at elevated temperatures. Even when embedded in a [...] Read more.

Fibers as a reinforcement in polymer-based composite materials play an essential role in the composites’ mechanical performance. It is, therefore, crucial to understand how fibers are affected by different environmental conditions, such as water exposure at elevated temperatures. Even when embedded in a matrix material, i.e., a thermoset or thermosetting polymer, exposure to moisture may occur. Therefore, in many structural applications of fiber-reinforced polymer composites, moisture may have a significant impact on the reinforcing elements and the rate of degradation. The present work focuses on the effects of hydrothermal aging on the mechanical durability of long carbon and basalt fibers by immersion in tap water at 60 °C, 71 °C, and 82 °C. A service life prediction model based on the Arrhenius technique was explored. Using this model, it is possible to forecast the amount of time that it takes to attain a given degradation level over a specified range of temperatures. The present study also investigated changes in tensile strength in response to exposure to 90% humidity at 90 °C. In addition, the chemical elements released during aging in water were determined. Fourier-transform infrared spectroscopy and mass dissolution studies were conducted to elucidate the mechanism causing strength losses. Scanning electron microscopy was employed to evaluate changes of the fiber surface morphologies due to hydrothermal exposure. Full article

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29 pages, 5536 KiB

Open AccessReview

Natural Fiber-Reinforced Mycelium Composite for Innovative and Sustainable Construction Materials

by Maristella E. Voutetaki and Anastasios C. Mpalaskas

Fibers 2024, 12(7), 57; https://doi.org/10.3390/fib12070057 - 9 Jul 2024

Cited by 3 | Viewed by 3618

Abstract

Fiber-reinforced mycelium (FRM) composites offer an innovative and sustainable approach to construction materials for architectural structures. Mycelium, the root structure of fungi, can be combined with various natural fibers (NF) to create a strong and lightweight material with environmental benefits. Incorporating NF like [...] Read more.

Fiber-reinforced mycelium (FRM) composites offer an innovative and sustainable approach to construction materials for architectural structures. Mycelium, the root structure of fungi, can be combined with various natural fibers (NF) to create a strong and lightweight material with environmental benefits. Incorporating NF like hemp, jute, or bamboo into the mycelium matrix enhances mechanical properties. This combination results in a composite that boasts enhanced strength, flexibility, and durability. Natural FRM composites offer sustainability through the utilization of agricultural waste, reducing the carbon footprint compared to conventional construction materials. Additionally, the lightweight yet strong nature of the resulting material makes it versatile for various construction applications, while its inherent insulation properties contribute to improved energy efficiency in buildings. Developing and adopting natural FRM composites showcases a promising step towards sustainable and eco-friendly construction materials. Ongoing research and collaboration between scientists, engineers, and the construction industry will likely lead to further improvements and expanded applications. This article provides a comprehensive analysis of the current research and applications of natural FRM composites for innovative and sustainable construction materials. Additionally, the paper reviews the mechanical properties and potential impacts of these natural FRM composites in the context of sustainable architectural construction practices. Recently, the applicability of mycelium-based materials has extended beyond their original domains of biology and mycology to architecture. Full article

(This article belongs to the Special Issue Fracture Behavior of Fiber-Reinforced Building Materials)

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12 pages, 3186 KiB

Open AccessArticle

Anisotropy and Fiber Orientation: A Key Player in the Lateral Imbibition of Cellulose Paper

by Pierre-Yves Bloch, Jean-Francis Bloch, Konrad Olejnik and Daniel Brissaud

Fibers 2024, 12(7), 56; https://doi.org/10.3390/fib12070056 - 3 Jul 2024

Viewed by 938

Abstract

In this article, we delve into the influence of fiber orientation (structural anisotropy) on paper imbibition, with a particular focus on in-plane imbibition. Utilizing the XLPA experimental method, we analyze several papers with different anisotropies, employing a constant volume of ethanol as the [...] Read more.

In this article, we delve into the influence of fiber orientation (structural anisotropy) on paper imbibition, with a particular focus on in-plane imbibition. Utilizing the XLPA experimental method, we analyze several papers with different anisotropies, employing a constant volume of ethanol as the imbibing fluid. Our findings contribute novel insights into the anisotropic behavior of imbibition, a topic not extensively covered in the literature. We analyze how the orientation of fibers significantly influences lateral imbibition, providing a deeper understanding of the microfluidic properties of paper. The anisotropies found for imbibition fit perfectly with the existing data found in the literature, indicating the influence of fiber orientation. Furthermore, the kinetics are shown to be linked directly with the porosity. Full article

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Graphical abstract

14 pages, 1191 KiB

Open AccessArticle

Carbon Fibers Based on Cellulose–Lignin Hybrid Filaments: Role of Dehydration Catalyst, Temperature, and Tension during Continuous Stabilization and Carbonization

by Christoph Unterweger, Inge Schlapp-Hackl, Christian Fürst, Daria Robertson, MiJung Cho and Michael Hummel

Fibers 2024, 12(7), 55; https://doi.org/10.3390/fib12070055 - 30 Jun 2024

Viewed by 958

Abstract

Lignocellulose has served as precursor material for carbon fibers (CFs) before fossil-based polymers were discovered as superior feedstock. To date, CFs made from polyacrylonitrile have dominated the market. In search of low-cost carbon fibers for applications with medium strength requirements, cellulose and lignin, [...] Read more.

Lignocellulose has served as precursor material for carbon fibers (CFs) before fossil-based polymers were discovered as superior feedstock. To date, CFs made from polyacrylonitrile have dominated the market. In search of low-cost carbon fibers for applications with medium strength requirements, cellulose and lignin, either as individual macromolecule or in combination, have re-gained interest as renewable raw material. In this study, cellulose with 30 wt% lignin was dry-jet wet-spun into a precursor filament for bio-based carbon fibers. The stabilization and carbonization conditions were first tested offline, using stationary ovens. Diammonium sulfate (DAS) and diammonium hydrogen phosphate were tested as catalysts to enhance the stabilization process. Stabilization is critical as the filaments’ strength properties drop in this phase before they rise again at higher temperatures. DAS was identified as a better option and used for subsequent trials on a continuous carbonization line. Carbon fibers with ca. 700 MPa tensile strength and 60–70 GPa tensile modulus were obtained at 1500 °C. Upon further carbonization at 1950 °C, moduli of >100 GPa were achieved. Full article

(This article belongs to the Special Issue Carbon Fibers from Sustainable Precursors II)

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15 pages, 3241 KiB

Open AccessArticle

Influence of Nanoparticles and PVA Fibers on Concrete and Mortar on Microstructural and Durability Properties

by Radhika Sridhar, Pakjira Aosai, Thanongsak Imjai, Monthian Setkit, Anoop Shirkol and Irwanda Laory

Fibers 2024, 12(7), 54; https://doi.org/10.3390/fib12070054 - 26 Jun 2024

Cited by 2 | Viewed by 1775

Abstract

Nanoparticles are one of the effective methodologies implemented in concrete technology. The main objective of this research is to study the influence of nano alumina with different percentage variations ranging from 1% to 3% along with the incorporation of PVA fibers. From the [...] Read more.

Nanoparticles are one of the effective methodologies implemented in concrete technology. The main objective of this research is to study the influence of nano alumina with different percentage variations ranging from 1% to 3% along with the incorporation of PVA fibers. From the mechanical properties test, the optimum dosage was determined to further study the durability behavior. This research work also investigates the hybridization of two nanoparticles such as nano silica (NS) and nano alumina (NA). The results show that the increasing quantity of NA reduces the compressive strength of the mortar due to agglomeration (cluster of particles), which results in a greater molecular attraction force. From the test results, it is concluded that the optimum dosage has been attained with an addition of 2% NA with 0.3% PVA. The compression strength test results at 14 days and 28 days reveal that the addition of NA tends the mineral admixture to react at early ages in the hydration process, which produces a new chemical compound to fill the pores. The rapid chloride penetration (RCPT) test results at 28 days significantly improved with the incorporation of nanoparticles due to their effective size and chemical reaction towards the other compounds. The test results from the hybridization of nanoparticles showed that the compressive strength was significantly enhanced compared to that of the control mortar and mortar with NA. They are effective up to certain limits beyond that addition, and the workability was reduced. Amongst all mixtures, the maximum compression strength has been attained for the mix with the addition of NA 0.5% and NS 2.5% comparatively. The microstructural properties of mortar were also studied through scanning electron microscope (SEM) analysis. The results showed that the incorporation of nanoparticles in the mortar matrix turns homogeneous with fewer pores and greater amount of hydration compounds; thereby, pore refinement has improved the hydration compounds remarkably. Full article

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18 pages, 6263 KiB

Open AccessArticle

Thermal and Moisture Management in the Microclimate of Socks for Diabetic Foot Care: The Role of Mohair-Wool Content

by Adine Gericke and Mohanapriya Venkataraman

Fibers 2024, 12(7), 53; https://doi.org/10.3390/fib12070053 - 25 Jun 2024

Viewed by 751

Abstract

In diabetic patients, optimised plantar health necessitates meticulously designed hosiery. These specialised socks facilitate a healthy microclimate at the skin–textile interface. This requires that stable conditions of temperature and humidity are maintained during wear. This study investigated the thermal resistance and moisture management [...] Read more.

In diabetic patients, optimised plantar health necessitates meticulously designed hosiery. These specialised socks facilitate a healthy microclimate at the skin–textile interface. This requires that stable conditions of temperature and humidity are maintained during wear. This study investigated the thermal resistance and moisture management properties of socks for diabetics. Fabrics and socks were evaluated on the Alambeta and thermal foot manikin instruments and in wear trials. A novel in vitro method, mimicking in-use conditions, was employed to validate findings and assess sock performance during wear. Fabric structure, especially thickness, had a greater impact on thermal resistance than fibre composition, suggesting that socks with different levels of thermal resistance can be customised according to individual preferences. In terms of moisture management, mohair–wool socks outperformed polyester socks, maintaining significantly lower humidity between the skin and the sock, and meeting the requirement to prevent the drying out of the microclimate significantly better. The enhanced moisture vapour sorption exhibited by the mohair–wool fabric contributes to this effect. Overall, the findings suggest that mohair–wool is an excellent fibre choice for diabetic socks, due to its unique moisture management properties and the possibility to tailor thermal properties through fabric structural design. Full article

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22 pages, 7351 KiB

Open AccessArticle

Influence of Basalt Fiber on the Rheological and Mechanical Properties and Durability Behavior of Self-Compacting Concrete (SCC)

by Ahmed Ashteyat, Ala’ Taleb Obaidat, Rahaf Qerba’a and Mu’tasim Abdel-Jaber

Fibers 2024, 12(7), 52; https://doi.org/10.3390/fib12070052 - 24 Jun 2024

Cited by 1 | Viewed by 1010

Abstract

This experimental study presents the influence of basalt fiber on the rheological and mechanical properties and the durability behavior of self-compacting concrete (SCC). In this study, a total of five self-compacting concrete mixtures were prepared: one as a control mix and the other [...] Read more.

This experimental study presents the influence of basalt fiber on the rheological and mechanical properties and the durability behavior of self-compacting concrete (SCC). In this study, a total of five self-compacting concrete mixtures were prepared: one as a control mix and the other mixes with 0.05%, 0.1%, 0.15%, and 0.2% basalt fibers. Slump flow and V-funnel flow tests were employed to assess the influence of basalt fibers on the rheological properties of fresh self-compacting concrete (SCC). Additionally, mechanical properties, including compressive strength, splitting tensile strength, and flexural strength, were analyzed. Furthermore, the mechanical properties were assessed following exposure to elevated temperatures (400 °C and 600 °C) as well as 100 and 200 freeze-thaw (F/T) cycles. Additionally, water absorption and ultrasonic pulse velocity tests were conducted on the SCC mixes after 28 days of curing. The results revealed that the addition of fiber has a significant effect on the rheological properties of fresh SCC mixtures. As the volume of fibers increases, the reduction in rheological properties increases. Basalt fiber had no effect on the compressive strength, while the splitting and flexural strength were significantly enhanced by 33% using basalt fiber. As temperatures and freezing-thawing cycles escalated, the mechanical properties of SCC exhibited a decline. Experimental findings indicated that elevating the temperature to 600 °C resulted in a decrease of over 20% in both the tensile and compressive strengths of SCC. Moreover, the results demonstrated that the incorporation of basalt fibers substantially enhanced the mechanical properties of SCC when subjected to high temperatures and freezing-thawing cycles. In addition, water absorption increased slightly by the incorporation of basalt fiber. Full article

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11 pages, 5732 KiB

Open AccessCommunication

Microplastics and Fibrous Fragments Generated during the Production and Maintenance of Textiles

by Jiří Militký, Jana Novotná, Jakub Wiener, Dana Křemenáková and Mohanapriya Venkataraman

Fibers 2024, 12(7), 51; https://doi.org/10.3390/fib12070051 - 21 Jun 2024

Viewed by 902

Abstract

More than a third of microplastics in surface waters are formed by microplastics released from textile products containing textile fibers (fibrous microplastics). A large amount of fibrous microplastics enters the environment during textile production and the first few washing cycles. Mechanical, thermal, chemical, [...] Read more.

More than a third of microplastics in surface waters are formed by microplastics released from textile products containing textile fibers (fibrous microplastics). A large amount of fibrous microplastics enters the environment during textile production and the first few washing cycles. Mechanical, thermal, chemical, and biological damage to textiles causes the generation of fibrous microplastics. Textile manufacturers, dyers and finishers, garment producers, distributors, or consumers contribute to this process. During the construction of textiles, multiple issues need to be addressed simultaneously. They are related to the optimization of technological processes and the construction and functionalization of fiber structures, considering ecological requirements, including suppressing the formation of fibrous microplastics. This research is focused on the specification of reasons for the generation of fibrous microplastics during textile production. The influence of the structure of fibers, abrasive deformations, and surface structure of fabrics on the generation of fibrous microplastics is discussed. The release of fibrous microplastics during washing is mentioned as well. Full article

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Fibers, Volume 12, Issue 7 (July 2024) – 9 articles

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