| 1. |
- Nouri, Mustapha, et al.
(författare)
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Enhanced Modeling of Water Diffusion in Natural Fibers : Application to Diss Fibers
- 2022
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Ingår i: Journal of Natural Fibers. - : Taylor and Francis Ltd.. - 1544-0478 .- 1544-046X. ; 19:14, s. 9259-
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Tidskriftsartikel (refereegranskat)abstract
- Water diffusion through natural fibers represents an important aspect with regard to the integrity of biocomposites. Usually, diffusion model is defined assuming circular fiber cross-sections, while microscopic analysis findings revealed other geometries. This was found to affect the modeling of water transport through fibers and provide a gap versus experimental data. This work aims to present a numerical approach using finite element method to overcome the limits of use of analytical approaches relating to the morphological shape of vegetal fibers. The cross-section of the Diss fibers was observed by an optical microscope and simulated at an ellipsoidal shape after processing the images. Then, the average morphological parameters were determined. A numerical finite element model was implemented based on the observed geometry in order to determine the diffusion coefficient by an inverse approach compared to experimental results. The results showed that the numerical approach made it possible to raise the effect of fiber morphology, often assumed to be circular for plant fibers in analytical approaches, on the diffusion coefficient value, which was defined by a unique diffusion coefficient.
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| 2. |
- Peterson, Joel, 1959-, et al.
(författare)
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Mechanical-Property-Based Comparison of Paper Yarn with Cotton, Viscose, and Polyester Yarns
- 2021
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Ingår i: Journal of Natural Fibers. - : Taylor & Francis Group. - 1544-0478 .- 1544-046X. ; 18:4, s. 492-501
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Tidskriftsartikel (refereegranskat)abstract
- Cotton and oil-based fibre consumption is highly problematic because the growth of these materials often requires fertilisers and toxic pesticides. Less environmentally damaging alternative fibres are urgently required. This study investigates Manila-hemp paper-yarn textile fabrics. Manila-hemp (abacá) is a species of banana grown as a commercial crop in the Philippines, Ecuador, and Costa Rica. Knitted structures of paper, cotton, viscose, and polyester yarns are tested and compared. Tensile strength tests are also performed. Paper yarn shows low shrinkage and no pilling, which are excellent characteristics for use in the textile and clothing industries. However, its poor handleability/knittability, high stiffness, and hard grip must be resolved for the widespread application of paper yarn in the textile industry in the future.
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| 3. |
- Seo, Youngjae, et al.
(författare)
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Highly Reliable Yarn-Type Supercapacitor Using Conductive Silk Yarns with Multilayered Active Materials
- 2022
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Ingår i: Journal of Natural Fibers. - : Informa UK Limited. - 1544-0478 .- 1544-046X. ; 19:3, s. 835-846
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Tidskriftsartikel (refereegranskat)abstract
- The fibrous supercapacitor is a promising candidate for wearable energy-storage systems due to excellent mechanical reliability under deformation. In this study, a mechanically reliable fibrous supercapacitor with high volumetric power density and energy density was developed using fiber electrodes composed of multilayered active materials coated on silk yarns. The conductive silk yarn electrodes are fabricated via a sequential dip-coating process of silver nanowires, multi-walled carbon nanotubes (MWCNT, three to seven walls), and poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS). The composite-coated silk yarn electrodes were stable under cyclic bending as well as under washing in water. Due to the synergetic effect of the three conducting materials, an excellent electrochemical performance was obtained resulting in high volumetric energy and power densities of 8–13 mWh cm−3 and 8–19 W cm−3, respectively. A yarn-type supercapacitor was demonstrated by integrating composite-coated silk yarn electrodes with a hydrogel electrolyte, showing a promising stability as evidenced by the retention of over 94% and 93% of the specific capacitance after 90-degree bending and stretching.
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| 4. |
- Svennerstedt, Bengt
(författare)
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Hemp Fiber Strength and Thickness: A Study of Plant Development of Swedish-Grown Industrial Hemp
- 2009
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Ingår i: Journal of Natural Fibers. - : Informa UK Limited. - 1544-0478 .- 1544-046X. ; 6, s. 295-302
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents results from fiber hemp experiments in southern Sweden carried out during 2004-2006. Field trials were performed, testing two monoecious varieties (Beniko and Futura 75) at a seed rate of 30 kg/ha. The trials were harvested at one to three stages in the autumn each year. Mean fiber strength varied between 304 and 353 MPa for Beniko and between 257 and 496 MPa for Futura 75, based on results from 2004 to 2006. Mean fiber thickness varied between 111 and 133 mm for Beniko and between 109 and 134 mm for Futura 75, based on results from 2005 to 2006.
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| 5. |
- Tarrés, Q., et al.
(författare)
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Micromechanics of Tensile Strength of Thermo-mechanical Pulp Reinforced Poly(lactic) Acid Biodegradable Composites
- 2022
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Ingår i: Journal of Natural Fibers. - : Taylor and Francis Ltd.. - 1544-0478 .- 1544-046X. ; 19:15, s. 9931-9144
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Tidskriftsartikel (refereegranskat)abstract
- Development of materials that are biobased and environmental sound is one of the goals within the current bioeconomy. This goal comes from an increasing conscientious society that pushes manufacturers and regulators toward a sustainable development. However, to be a feasible alternative, biobased materials should also match or outperform the mechanical performance of fossil-based materials. In this study, wood pulp fiber-reinforced polylactic acid (PLA) biocomposites were prepared, tested, and compared with glass fiber reinforced polypropylene. Pre-extrusion with a kinetic mixer and subsequent injection processing ensured correct dispersion of the reinforcement. The biocomposites showed mechanical properties in line with commercial materials, comparable to composites reinforced with 20% w/w of glass fiber. Micromechanics of PLA-based biocomposites showed the existence of strong interphase between the matrix and the pulp fibers. The interfacial shear strength was around 29 MPa and with a intrinsic tensile strength of the fibers 729 MPa. These materials offer a reliable alternative to oil-based matrices reinforced with mineral fibers.
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| 6. |
- Zimna, Katarzyna, et al.
(författare)
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Design Potential of Technical Hemp and PLA Nonwovens
- 2024
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Ingår i: Journal of Natural Fibers. - 1544-0478 .- 1544-046X. ; 21:1
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Tidskriftsartikel (refereegranskat)abstract
- The main purpose of the article is to present the potential use of hemp fibers as reinforcement in composites, but from a design perspective. The authors ask whether sustainable nonwovens, produced based on natural fibers, have the potential as a material for designers and artists and not only as a technical textile. Technical production of nonwovens like carding, punching and laser cutting was used to achieve not just functional, but also aesthetic quality of the samples. The possibilities of utilizing natural materials for design endeavors were presented. The production process of these items was described, along with the main design concept. Research was carried out through a series of interdisciplinary activities, using the knowledge and tools typical for textile and materials engineering, as well as the methodology and strategies derived from the fields of visual art and design. It has been shown that during the development of a new sustainable material significant attention should be paid to design aspects, so it shows its full potential, as not just being eco-friendly, but also functional and aesthetic. While technical hemp and PLA composites have been produced and studied before, the design aspect is unique in the current study.
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| 7. |
- Akin, Danny E., et al.
(författare)
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Progress in enzyme-retting of flax
- 2004
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Ingår i: Journal of Natural Fibers. - 1544-0478. ; 1:1, s. 21-47
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Tidskriftsartikel (refereegranskat)abstract
- New methods for retting flax are sought to overcome problems in the current method of dew-retting of flax. Published data are reviewed and new data presented on the development and testing of a method to ret flax using pectinase-rich enzyme mixtures plus chelators based on cost and fiber yield and properties. In spray enzyme retting (SER), flax stems are crimped to physically disrupt the plant's protective barrier and then sprayed until soaked with, or briefly immersed in, an enzyme/ chelator formulation. Flax is then incubated at temperatures optimal for enzyme activity, washed, and dried. Pilot scale tests, conducted with 10 kg samples of flax retted with a series of formulations, showed that this method effectively retted flax stems from a variety of sources, including fiber flax, mature fiber flax, and linseed straw. Fiber yield, strength, and fineness were significantly influenced by variations in enzyme-chelator amounts. Cellulases in pectinase mixtures appeared to preferentially attack dislocations in fibers and fiber bundles resulting in loss of fiber strength. Polygalacturonases alone effectively separated fiber from non-fiber components. The SER method proved to be an effective framework for further tests on enzyme-chelator formulations that now must be integrated with physical processing to optimize the extraction of flax fibers based on cost and fiber yield and properties.
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