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Fibers, Volume 6, Issue 4 (December 2018)

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Cover Story (view full-size image) Gas-liquid hollow fiber membrane contactors are the example of highly effective separation [...] Read more.
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Open AccessFeature PaperArticle Reinforced Concrete Beams with Carbon-Fiber-Reinforced Polymer Bars—Experimental Study
Fibers 2018, 6(4), 99; https://doi.org/10.3390/fib6040099
Received: 20 November 2018 / Revised: 7 December 2018 / Accepted: 11 December 2018 / Published: 14 December 2018
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Abstract
Innovative reinforcement as fiber-reinforced polymer (FRP) bars has been proposed as alternative for the substitution of the traditional steel bars in reinforced concrete (RC) structures. Although the advantages of this polymer reinforcement have long been recognised, the predominantly elastic response, the reduced bond
[...] Read more.
Innovative reinforcement as fiber-reinforced polymer (FRP) bars has been proposed as alternative for the substitution of the traditional steel bars in reinforced concrete (RC) structures. Although the advantages of this polymer reinforcement have long been recognised, the predominantly elastic response, the reduced bond capacity under repeated load and the low ductility of RC members with FRP bars restricted its wide application in construction so far. In this work, the behavior of seven slender concrete beams reinforced with carbon-FRP bars under increasing static loading is experimentally investigated. Load capacities, deflections, pre-cracking and after-cracking stiffness, sudden local drops of strength, failure modes, and cracking propagation have been presented and commented. Special attention has been given in the bond conditions of the anchorage lengths of the tensile carbon-FRP bars. The application of local confinement conditions along the anchorage lengths of the carbon-FRP bars in some specimens seems to influence their cracking behavior. Nevertheless, more research is required in this direction. Comparisons of experimental results for carbon-FRP beams with beams reinforced with glass-FRP bars extracted from recent literature are also presented and commented. Comparisons of the experimental results with the predictions according to ACI 440.1R-15 and to CSA S806-12 are also included herein. Full article
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Open AccessArticle Physico-Mechanical, Thermal and Biodegradation Performance of Random Flax/Polylactic Acid and Unidirectional Flax/Polylactic Acid Biocomposites
Fibers 2018, 6(4), 98; https://doi.org/10.3390/fib6040098
Received: 11 August 2018 / Revised: 28 November 2018 / Accepted: 30 November 2018 / Published: 10 December 2018
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Abstract
Fully biodegradable flax/polylactic acid (PLA) thermoplastic composites were fabricated by using random (nonwoven mat) and aligned (unidirectional yarn) flax fiber as reinforcements (39% flax by volume) and Polylactic acid (PLA) as matrix. Results revealed that the aligned flax fibers have a greater reinforcing
[...] Read more.
Fully biodegradable flax/polylactic acid (PLA) thermoplastic composites were fabricated by using random (nonwoven mat) and aligned (unidirectional yarn) flax fiber as reinforcements (39% flax by volume) and Polylactic acid (PLA) as matrix. Results revealed that the aligned flax fibers have a greater reinforcing effect due to the uniform distribution of load axially along the fiber length in the composite. The aligned flax/PLA and random flax/PLA showed the tensile strength of (83.0 ± 5.0) and (151.0 ± 7.0) MPa respectively and flexural strength of (130.0 ± 5.0) and (215.0 ± 7.2) MPa respectively. Young’s modulus of (9.3 ± 1.5) and (18.5 ± 2.0) GPa and flexural modulus of (9.9 ± 1.0) and (18.8 ± 1.0) GPa was attained for the random and unidirectional fiber composites, respectively. It was also found that both composite constituents, fiber and matrix, were degradable if buried in compost soil (ready soil after composting process), which is a distinctive advantage of the new composite structures. Remarkably, the biodegradation property of aligned flax fiber composites was significantly lower than random mat composites, possibly due to the less water swelling behavior of the aligned fiber composites. After 120 days burial test, the aligned flax/PLA composite displayed the reduction of 19% mass, residual flexural strength and modulus decreased by 57 and 50% respectively, while the random mat composites exhibited the loss of 27% mass, residual flexural strength and modulus declined by 80% at the same period. Full article
(This article belongs to the Special Issue Natural Fibre Biocomposites)
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Open AccessArticle Chitosan as a Coupling Agent for Phosphate Glass Fibre/Polycaprolactone Composites
Fibers 2018, 6(4), 97; https://doi.org/10.3390/fib6040097
Received: 5 November 2018 / Revised: 28 November 2018 / Accepted: 30 November 2018 / Published: 10 December 2018
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Abstract
This study shows that chitosan (CS) could be highly useful as a coupling agent in phosphate glass fibre/polycaprolactone (PGF/PCL) composites, as it improved the interfacial shear strength by up to 78%. PGFs of the composition 45P2O5–5B2O3
[...] Read more.
This study shows that chitosan (CS) could be highly useful as a coupling agent in phosphate glass fibre/polycaprolactone (PGF/PCL) composites, as it improved the interfacial shear strength by up to 78%. PGFs of the composition 45P2O5–5B2O3–5Na2O–24CaO–10MgO–11Fe2O3 were dip-coated with CS (with a degree of deacetylation >80%) dissolved in acetic acid solution (2% v/v). Different CS concentrations (3–9 g L−1) and coating processes were investigated. Tensile and fragmentation tests were conducted to obtain the mechanical properties of the single fibres and interfacial properties of the PGF/PCL composites, respectively. It was observed that post-cleaning, the treated fibres had their tensile strength reduced by around 20%; however, the CS-coated fibres experienced strength increases of up to 1.1–11.5%. TGA and SEM analyses were used to confirm the presence of CS on the fibre surface. FTIR, Raman, and X-ray photoelectron spectroscopy (XPS) analyses further confirmed the presence of CS and indicated the protonation of CS amine groups. Moreover, the nitrogen spectrum of XPS demonstrated a minimum threshold of CS coating required to provide an improved interface. Full article
(This article belongs to the Special Issue Glass Fibers 2018)
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Open AccessArticle Characterization of a Y-Coupler and Its Impact on the Performance of Plastic Optical Fiber Links
Fibers 2018, 6(4), 96; https://doi.org/10.3390/fib6040096
Received: 18 October 2018 / Revised: 14 November 2018 / Accepted: 28 November 2018 / Published: 10 December 2018
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Abstract
Couplers and splitters are common devices in single-mode and multi-mode glass fibers applications, where they perform a variety of functions. However, when switching to plastic optical fibers (POFs), there is a shortage of commercial devices, which are usually custom-made. The problem with these
[...] Read more.
Couplers and splitters are common devices in single-mode and multi-mode glass fibers applications, where they perform a variety of functions. However, when switching to plastic optical fibers (POFs), there is a shortage of commercial devices, which are usually custom-made. The problem with these devices is that modal power distribution in POFs is easily modified by spatial disturbances that produce a localized strong power transfer between modes, thus changing their transmission properties. In this work, a commercial Y-coupler designed for POFs is experimentally characterized. Measurements of its spectral, spatial and temporal characteristics have been performed, including insertion loss as a function of wavelength, angular power distribution, and frequency response. The obtained results show that this device has an equalizing effect over the power spatial distribution that reduces the fiber bandwidth, demonstrating the importance of considering the impact of this type of devices on the transmission properties of any POF system. Full article
(This article belongs to the Special Issue Plastic Optical Fibers)
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Open AccessArticle Critical Velocity of High-Performance Yarn Transversely Impacted by Razor Blade
Fibers 2018, 6(4), 95; https://doi.org/10.3390/fib6040095
Received: 12 November 2018 / Revised: 2 December 2018 / Accepted: 5 December 2018 / Published: 7 December 2018
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Abstract
A ballistic parameter that influences the ballistic performances of a high-performance yarn is the critical velocity. The critical velocity is defined as the projectile striking velocity that causes instantaneous rupture of the yarn upon impact. In this study, we performed ballistic experiments to
[...] Read more.
A ballistic parameter that influences the ballistic performances of a high-performance yarn is the critical velocity. The critical velocity is defined as the projectile striking velocity that causes instantaneous rupture of the yarn upon impact. In this study, we performed ballistic experiments to determine the critical velocity of a Twaron® yarn transversely impacted by a razor blade. A high-speed camera was integrated into the experimental apparatus to capture the in-situ deformation of the yarn. The experimental critical velocity demonstrated a reduction compared to the critical velocity predicted by the classical theory. The high-speed images revealed the yarn specimen failed from the projectile side toward the free end when impacted by the razor blade. To improve the prediction capability, the Euler–Bernoulli beam and Hertzian contact models were used to predict the critical velocity. For the Euler–Bernoulli beam model, the critical velocity was obtained by assuming the specimen ruptured instantaneously when the maximum flexural strain reached the ultimate tensile strain of the yarn upon impact. On the other hand, for the Hertzian contact model, the yarn was assumed to fail when the indentation depth was equivalent to the diameter of the yarn. The errors between the average critical velocities determined from experiments and the predicted critical velocities were around 19% and 48% for the Euler–Bernoulli beam model and Hertzian contact model, respectively. Full article
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Open AccessArticle Mechanical, Degradation and Water Uptake Properties of Fabric Reinforced Polypropylene Based Composites: Effect of Alkali on Composites
Fibers 2018, 6(4), 94; https://doi.org/10.3390/fib6040094
Received: 16 August 2018 / Revised: 7 November 2018 / Accepted: 12 November 2018 / Published: 6 December 2018
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Abstract
In this study, a fabric was manufactured consisting of 50% pineapple, 25% jute and 25% cotton fibers by weight, to make composites using polypropylene (PP) as a matrix material. We used compression molding technique, which kept 30% of the fabric content by total
[...] Read more.
In this study, a fabric was manufactured consisting of 50% pineapple, 25% jute and 25% cotton fibers by weight, to make composites using polypropylene (PP) as a matrix material. We used compression molding technique, which kept 30% of the fabric content by total weight as the composite. The tensile strength (TS), tensile modulus (TM), elongation break (Eb%), bending strength (BS) and bending modulus (BM) were investigated. From analyzed data, it was found that the composite values of TS, TM, Eb%, BS and BM were 58 MPa, 867 MPa, 22.38%, 42 MPa and 495 MPa, respectively. The TS, TM, Eb%, BS and BM of the neat polypropylene sheet were 28 MPa, 338 MPa, 75%, 20 MPa and 230 MPa, respectively. Due to fabric reinforcement, composite values for TS, TM, BS and BM increased 107%, 156%, 110% and 115%, respectively in comparison with a polypropylene sheet. A water absorption test was performed by dipping the composite samples in deionized water and it was noticed that water absorption was lower for PP-based composites. For investigating the effect of alkali, we sunk the composites in a solution containing 3%, 5% and 7% sodium hydroxide alkali solutions by weight, for 60 min after which their mechanical properties were investigated. A degradation test was carried out by putting the samples in soil for six months and it was noticed that the mechanical properties of fabric/PP composites degraded slowly. Full article
(This article belongs to the Special Issue Natural Fiber-Reinforced Hybrid Composites)
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Open AccessArticle Fasteners in Steel Fiber Reinforced Concrete Subjected to Increased Loading Rates
Fibers 2018, 6(4), 93; https://doi.org/10.3390/fib6040093
Received: 15 November 2018 / Revised: 2 December 2018 / Accepted: 3 December 2018 / Published: 6 December 2018
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Abstract
Increased loading rates on fasteners may be caused by high ground accelerations as a consequence of e.g., nuclear explosions, earthquakes or car collisions. It was concluded by Hoehler et al. (2006) that fasteners under rapid loading rates show an increased ultimate resistance in
[...] Read more.
Increased loading rates on fasteners may be caused by high ground accelerations as a consequence of e.g., nuclear explosions, earthquakes or car collisions. It was concluded by Hoehler et al. (2006) that fasteners under rapid loading rates show an increased ultimate resistance in the concrete dominant failure modes or the ultimate resistance is at least as large as under quasi-static loading. Due to the increased demand on using fasteners in steel fiber reinforced concrete (SFRC), it is intended to show how the ultimate concrete cone capacity of fasteners changes under higher than quasi-static loading rate in normal plain concrete (PC) and in SFRC. This paper presents the results of an extensive experimental program carried out on single fasteners loaded in tension in normal plain concrete and in SFRC. The test series were conducted using a servo-hydraulic loading cylinder. The tests were performed in displacement control with a programmed ramp speed of 1, 100, 1000, and 3500 mm/min. This corresponded to calculated initial loading rates ranging between 0.4 and 1600 kN/s. The results of the tension tests clearly show that the rate-dependent behavior of fasteners in SFRC with 30 and 50 kg/m3 hooked-end-type fibers fits well to the previously reported rate-dependent concrete cone behavior in normal plain concrete. Additionally, a positive influence of the fibers on the concrete cone capacity is clearly visible. Full article
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Open AccessArticle Highly Conductive Carbon Fiber-Reinforced Polymer Composite Electronic Box: Out-Of-Autoclave Manufacturing for Space Applications
Fibers 2018, 6(4), 92; https://doi.org/10.3390/fib6040092
Received: 29 October 2018 / Revised: 16 November 2018 / Accepted: 19 November 2018 / Published: 30 November 2018
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Abstract
One of the main advantages of carbon fiber-reinforced polymer (CFRP) electronic housings, when compared with traditionally used aluminum ones, is the potential for mass savings. In recent years, the power consumption of electronics has been growing, resulting in the need for higher thermal
[...] Read more.
One of the main advantages of carbon fiber-reinforced polymer (CFRP) electronic housings, when compared with traditionally used aluminum ones, is the potential for mass savings. In recent years, the power consumption of electronics has been growing, resulting in the need for higher thermal dissipation of electronic housings, requiring the use of highly thermally conductive materials. In this work, the manufacturing of a highly conductive CFRP electronic housing is reported. With a view to reducing total energy costs on manufacturing, an out-of-the autoclave manufacturing process was followed. Due to the inherent low thermal conductivity of typical raw materials for composite materials, strategies were evaluated to increase its value by changing the components used. The use of pitch-based carbon fibers was found to be a very promising solution. In addition, structural, thermal and manufacturing simulations were produced in the design phase. Improved performance was demonstrated from materials manufacturing to final breadboard testing. The results indicate potential gains of around 23% in mass reduction when compared to conventional aluminum electronic boxes. Moreover, the proposed design and the manufactured breadboard showed good compliance with mechanical and electrical requirements for spacecraft structures. The thermal balance results showed a performance slightly below to what would be expected from the detailed design. Full article
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Open AccessArticle Preparation and Behavior of Bamboo Fiber-Reinforced Polydimethylsiloxane Composite Foams during Compression
Fibers 2018, 6(4), 91; https://doi.org/10.3390/fib6040091
Received: 9 October 2018 / Revised: 4 November 2018 / Accepted: 26 November 2018 / Published: 29 November 2018
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Abstract
This study investigates the mechanical properties of bamboo fiber-reinforced polydimethylsiloxane (BF-PDMS) foams with up to 3.4% (by mass) fiber during compression. Pristine PDMS foams and BF-PDMS composite foams were fabricated using a sugar leaching method. Compression test results of pristine PDMS and BF-PDMS
[...] Read more.
This study investigates the mechanical properties of bamboo fiber-reinforced polydimethylsiloxane (BF-PDMS) foams with up to 3.4% (by mass) fiber during compression. Pristine PDMS foams and BF-PDMS composite foams were fabricated using a sugar leaching method. Compression test results of pristine PDMS and BF-PDMS composite foams display plateau and densification regions. Predictions of a modified phenomenological foam (PF) model based on Maxwell and Kelvin–Voight models are in good agreement with compression test results. Stiffness coefficients were extracted by fitting results of compression tests to the modified PF model. Spring and densification coefficients of BF-PDMS composite foams are 2.5- and 15-fold greater than those of pristine PDMS foams, respectively. Strains corresponding to onset of densification computed using extracted coefficients were 35% and 25% for pristine PDMS foams and BF-PDMS composite foams, respectively. Compressing foams at 6.0 and 0.5 mm/min results in highest and lowest compressive stress, respectively. Insights from this study are useful in many areas such as environmental protection, pressure sensing, and energy where PDMS composite foams will find applications. Full article
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Open AccessArticle Simulation of Convection–Diffusion Transport in a Laminar Flow Past a Row of Parallel Absorbing Fibers
Fibers 2018, 6(4), 90; https://doi.org/10.3390/fib6040090
Received: 1 November 2018 / Revised: 20 November 2018 / Accepted: 22 November 2018 / Published: 25 November 2018
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Abstract
A numerical simulation of the laminar flow field and convection–diffusion mass transfer in a regular system of parallel fully absorbing fibers for the range of Reynolds numbers up to Re = 300 is performed. An isolated row of equidistant circular fibers arranged normally
[...] Read more.
A numerical simulation of the laminar flow field and convection–diffusion mass transfer in a regular system of parallel fully absorbing fibers for the range of Reynolds numbers up to Re = 300 is performed. An isolated row of equidistant circular fibers arranged normally to the external flow is considered as the simplest model for a hollow-fiber membrane contactor. The drag forces acting on the fibers with dependence on Re and on the ratio of the fiber diameter to the distance between the fiber axes, as well as the fiber Sherwood number versus Re and the Schmidt number, Sc, are calculated. A nonlinear regression formula is proposed for calculating the fiber drag force versus Re in a wide range of the interfiber distances. It is shown that the Natanson formula for the fiber Sherwood number as a function of the fiber drag force, Re, and Sc, which was originally derived in the limit of high Peclet numbers, is applicable for small and intermediate Reynolds numbers; intermediate and large Peclet numbers, where Pe = Re × Sc; and for sparse and moderately dense rows of fibers. Full article
(This article belongs to the Special Issue Polymer Hollow Fiber Membrane 2019)
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Open AccessArticle A Method to Process Hollow-Core Anti-Resonant Fibers into Fiber Filters
Fibers 2018, 6(4), 89; https://doi.org/10.3390/fib6040089
Received: 25 July 2018 / Revised: 10 August 2018 / Accepted: 15 August 2018 / Published: 22 November 2018
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Abstract
Hollow-Core Anti-Resonant Fiber (HC-ARF) shows promising applications. Nevertheless, there has been a persistent problem when it comes to all-fiber integration due to a lack of HC-ARF-based fiber components. In response to this remaining challenge, we investigate a reliable, versatile and efficient method to
[...] Read more.
Hollow-Core Anti-Resonant Fiber (HC-ARF) shows promising applications. Nevertheless, there has been a persistent problem when it comes to all-fiber integration due to a lack of HC-ARF-based fiber components. In response to this remaining challenge, we investigate a reliable, versatile and efficient method to convert an HC-ARF into a fiber filter. By locally heating an HC-ARF with a CO2 laser, the fiber structure becomes deformed, and cladding capillaries shrink to produce a thicker wall. This process is analogous to “writing” a new fiber with a thicker wall on the original fiber, resulting in creating new high loss regions in the original transmission bands. Thus, the construction of a fiber filter is realized by “writing” a new fiber on the original fiber. The feasibility of this method is confirmed through experiments, adopting both one- and two-layer HC-ARF. The HC-ARF-based fiber filters are found to have transmission spectra consistent with simulation prediction. Both band pass and band reject fiber filters with more than a 20-dB extinction ratio are obtainable without extra loss. Thus, an in-fiber HC-ARF filter is demonstrated by the CO2 writing process. Its versatile approach promises controlled band selection and would find interesting applications to be discussed. Full article
(This article belongs to the Special Issue Hollow core optical fibers)
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Open AccessArticle In-Situ Vacuum Assisted Gas Stripping Recovery System for Ethanol Removal from a Column Bioreactor
Fibers 2018, 6(4), 88; https://doi.org/10.3390/fib6040088
Received: 28 September 2018 / Revised: 1 November 2018 / Accepted: 6 November 2018 / Published: 9 November 2018
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Abstract
A three-step process consisting of biomass hydrolysis, fermentation and in-situ gas stripping by a vacuum assisted recovery system, was optimized to increase the ethanol production from sugar beet pulp. The process combines the advantages of stripping and vacuum separation and enhances the fermentation
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A three-step process consisting of biomass hydrolysis, fermentation and in-situ gas stripping by a vacuum assisted recovery system, was optimized to increase the ethanol production from sugar beet pulp. The process combines the advantages of stripping and vacuum separation and enhances the fermentation productivity through in-situ ethanol removal. Using the design of experiment and response surface methodology, the effect of major factors in the process, such as pressure, recycling ratio and solids concentration, was tested to efficiently remove ethanol after the combined hydrolysis and fermentation step. Statistical analysis indicates that a decreased pressure rate and an increased liquid phase recycling ratio enhance the productivity and the yield of the strip-vacuum fermentation process. The results also highlight further possibilities of this process to improve integrated bioethanol production processes. According to the statistical analysis, ethanol production is strongly influenced by recycling ratio and vacuum ratio. Mathematical models that were established for description of investigated processes can be used for the optimization of the ethanol production. Full article
(This article belongs to the Special Issue Enzymatic Cellulose Degradation)
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Open AccessArticle Flexural Behavior of Carbon Textile-Reinforced Geopolymer Composite Thin Plate
Fibers 2018, 6(4), 87; https://doi.org/10.3390/fib6040087
Received: 28 September 2018 / Revised: 4 November 2018 / Accepted: 6 November 2018 / Published: 8 November 2018
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Abstract
Textile-reinforced Portland cement-based concrete has been researched and developed over the last few decades. It was widely used in a different range of applications, such as repair and/or strengthening of structural elements, thin walls, lightweight structures, façade elements, and others. Due to its
[...] Read more.
Textile-reinforced Portland cement-based concrete has been researched and developed over the last few decades. It was widely used in a different range of applications, such as repair and/or strengthening of structural elements, thin walls, lightweight structures, façade elements, and others. Due to its varied application, this study aims to develop the carbon textile-reinforced geopolymer composite. Specimens of rectangular form with the dimensions of 400 × 100 × 15 mm3, reinforced with carbon textile, were produced. Four-point bending test was used to evaluate the effect of carbon textile on the mechanical strength of reinforced geopolymer composite based on the three factors: the different mortar compositions corresponding to the addition of the chopped basalt fiber (BF), the number of carbon textile layers, and the different thicknesses of the mortar cover layer. Besides that, a small part of the pull-out test was also considered to assess the adhesion strength at the interface between carbon textile and geopolymer mortar. The experimental results from the four-point bending test showed that the mechanical strength of composite specimens increased when the content of the chopped basalt fiber increased. With the increasing number of the textile layers, the specimens improved the flexural strength significantly. However, the flexural toughness of the specimens reinforced with three textile layers did not improve, as compared to those reinforced with two textile layers. The experimental results for the specimens related to the mortar cover thicknesses indicated that specimens with the mortar cover thickness of 2 mm provide the best strength. The experimental results from the pull-out tests showed that all the specimens have the same failure mode by slipping of the fiber yarn from the matrix. Full article
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Open AccessArticle Utilization of Recycled Material Sources for Wood-Polypropylene Composites: Effect on Internal Composite Structure, Particle Characteristics and Physico-Mechanical Properties
Fibers 2018, 6(4), 86; https://doi.org/10.3390/fib6040086
Received: 9 October 2018 / Revised: 29 October 2018 / Accepted: 1 November 2018 / Published: 7 November 2018
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In this study, various wood material sources were used for the manufacture of wood-polymer composites (WPC). The materials were categorised as virgin wood particles (VWP), reprocessed WPC particles (RWP) and recycled thermoset composite particles (RCP) and derived from two virgin wood sources, three-layer
[...] Read more.
In this study, various wood material sources were used for the manufacture of wood-polymer composites (WPC). The materials were categorised as virgin wood particles (VWP), reprocessed WPC particles (RWP) and recycled thermoset composite particles (RCP) and derived from two virgin wood sources, three-layer particleboards, medium-density fibreboards (MDF) boards, or two different wood/polypropylene composites. All produced wood-polypropylene compounds contained 60% wood material and were manufactured using a co-rotating extruder. Malleated polypropylene was used as a coupling agent. Specimens were injection moulded and subsequently tested for their physico-mechanical properties. To characterize particles before and after processing, dynamic image analysis (DIA) measurement were performed. Additionally, X-ray micro-computed tomography (XµCT) was used to characterize the internal structure of the composites and to verify the obtained particle’s characteristics. It was found that length and aspect ratio of particles were remarkably different before and after processing (loss in length of 15–70% and aspect ratio of 10–40%). Moreover, there were notably differences between the particle sources (RCP retained the highest length and aspect ratio values, followed by VWP and RWP). The results suggest that increased aspect ratios can indeed significantly improve mechanical properties (up to 300% increase in impact bending strength and 75% increase in tensile strength, comparing WPC based either on virgin spruce or MDF material). This phenomenon is suggested to be partially superimposed by improved dispersion of particles, which is expected due to lower variance and increased mechanical properties of RWP composites. However, no notable alterations were observed for composite density. Reprocessed WPC and, particularly, RCP material have proved to be an appealing raw material substitute for the manufacturing of wood–polymer composites. Full article
(This article belongs to the Special Issue Wood Plastic Composites)
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Open AccessArticle Microwave Assisted Preparation of Flame Resistant Cotton Using Economic Inorganic Materials
Fibers 2018, 6(4), 85; https://doi.org/10.3390/fib6040085
Received: 11 September 2018 / Revised: 17 October 2018 / Accepted: 3 November 2018 / Published: 6 November 2018
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Abstract
Innovative approaches for preparing flame retardant cotton fabrics were employed by utilizing a microwave-assisted technique with a minimum amount of co-solvent. Our attempts at flame retardant cotton fabrics treated with low cost inorganic formulations, such as urea and diammonium phosphate, were done successfully.
[...] Read more.
Innovative approaches for preparing flame retardant cotton fabrics were employed by utilizing a microwave-assisted technique with a minimum amount of co-solvent. Our attempts at flame retardant cotton fabrics treated with low cost inorganic formulations, such as urea and diammonium phosphate, were done successfully. The evidence of flame retardant chemical penetrations or surface modification of cotton fabrics was confirmed by scanning electron microscope (SEM) and the treated cotton fabrics were evaluated by flammability tests, such as 45° angle (clothing textiles test), vertical flame (clothing textile test) and limiting oxygen index (LOI). For formulations with urea only, LOI values of treated fabrics were 21.0–22.0% after add-on values for the formulation were 5.16–18.22%. For formulations comprising urea with diammonium phosphate, LOI values were greater than 29.0% after add-on values for the formulation were 1.85–7.73%. With the formulation comprising urea and diammonium phosphate, all treated fabrics passed the vertical flame test for add-on values 5.34–7.73%. Their char lengths were less than half the length of the original fabric and after-flame and after-glow times were less than 3.2 s. Additional thermal properties of desired products will be discussed using thermogravimetric analysis (TGA) and microscale combustion calorimeter (MCC). Full article
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Open AccessArticle Preparation of Chitosan-Coated Poly(L-Lactic Acid) Fibers for Suture Threads
Fibers 2018, 6(4), 84; https://doi.org/10.3390/fib6040084
Received: 26 September 2018 / Revised: 23 October 2018 / Accepted: 24 October 2018 / Published: 25 October 2018
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Abstract
Poly(L-lactic acid) (PLA) is a biodegradable fiber, and a promising material for use in biomedical applications. However, its hydrophobicity, low hydrolyzability, and poor cell adhesion can be problematic in some cases; consequently, the development of improved PLA-based materials is required. In this study,
[...] Read more.
Poly(L-lactic acid) (PLA) is a biodegradable fiber, and a promising material for use in biomedical applications. However, its hydrophobicity, low hydrolyzability, and poor cell adhesion can be problematic in some cases; consequently, the development of improved PLA-based materials is required. In this study, chitosan-coated (CS-coated) PLA was prepared by plasma treatment and the layer-by-layer (LBL) method. Plasma treatment prior to CS coating effectively hydrophilized and activated the PLA surface. The LBL method was used to increase the number of CS and sodium alginate (SA) coating layers by electrostatically superposing alternating anionic and cationic polymers. The prepared fibers were characterized by tensile testing, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), nitrogen analysis and degradation testing, which revealed that the 100 W plasma treatment for 60 s was optimum, and that plasma treatment and the LBL method effectively coated CS onto the PLA fibers. The existence or not of a coating on the PLA fiber did not appear to influence the degradation of the fiber, which is ascribable to the extremely thin coating, as evidenced by nitrogen analysis and SEM. The CS-coated PLA fibers were prepared without damaging the PLA surface and can be used in biomaterial applications such as suture threads. Full article
(This article belongs to the Special Issue Smart Coatings on Fibers and Textiles)
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Open AccessArticle High-Pressure Aging of Asymmetric Torlon® Hollow Fibers for Helium Separation from Natural Gas
Fibers 2018, 6(4), 83; https://doi.org/10.3390/fib6040083
Received: 2 September 2018 / Revised: 20 October 2018 / Accepted: 23 October 2018 / Published: 25 October 2018
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Abstract
Membrane separation for helium extraction from natural gas gained increased interest recently. Several vendors offer membrane elements for helium extraction, although data on their performance and operating experience are unpublished. The aim of this work was to obtain and study the separation performance
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Membrane separation for helium extraction from natural gas gained increased interest recently. Several vendors offer membrane elements for helium extraction, although data on their performance and operating experience are unpublished. The aim of this work was to obtain and study the separation performance of asymmetric hollow-fiber membrane element from commercial polyamide-imide Torlon®, in conditions close to the industrial process of helium extraction from natural gas. A membrane element with an active area of 0.177 m2, a helium permeance of 100 l(STP)/(m2·h·bar), and a selectivity α(He/CH4) = 340 was produced. This corresponds to a selective layer thickness of 82.3 nm, which was confirmed by SEM and resistance model calculations. The obtained membrane element was employed to decrease the concentration of helium in its binary mixture with methane from 0.4% to 0.05%. A relationship of separation characteristics from transmembrane pressure is also presented. At 70 bar and a stage cut of 2.7%, the feed flow rate was 0.16 m3(STP)/h, which yielded a helium permeate concentration of 14.7%. At 80 bar, a decrease in permeance to 60 l(STP)/(m2·h·bar) and in selectivity to 240 was observed. It was shown that the main reason for aging was the increased support resistance, due to a partial compaction of pores with a radius of less than 15 nm. Full article
(This article belongs to the Special Issue Polymer Hollow Fiber Membrane)
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Open AccessArticle Fabrication and Characteristics of Yb-Doped Silica Fibers Produced by the Sol-Gel Based Granulated Silica Method
Fibers 2018, 6(4), 82; https://doi.org/10.3390/fib6040082
Received: 7 September 2018 / Revised: 5 October 2018 / Accepted: 19 October 2018 / Published: 23 October 2018
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Abstract
Combining the sol-gel method for fiber material production with the granulated silica method for preform assembly results in a robust method that offers a high degree of freedom regarding both the composition and the geometry of the produced fiber. Using this method, two
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Combining the sol-gel method for fiber material production with the granulated silica method for preform assembly results in a robust method that offers a high degree of freedom regarding both the composition and the geometry of the produced fiber. Using this method, two types of Yb-doped silica glass composition, that feature an excess in P concentration with respect to Al, have been prepared. The elemental distributions in a fiber core were analyzed by scanning transmission electron microscopy (STEM). The elemental mapping shows a similar localization of Al, P and Yb through the microstructure. In addition, the influence of the variation in the co-dopant concentration, with respect to Yb, on the fiber properties has been investigated. The results show an increase in the refractive index step and in the fiber’s transmission loss as the excess concentration of P increases. A significant contribution to the losses can be assigned to the existence of impurities such as iron, which was detected in our samples by mass spectrometer. Single exponential fluorescence decays with lifetimes of around 0.88 ms were measured for the two compositions. Finally, pumping at 976 nm a laser slope efficiency of 67% at 1031 nm was achieved for one of the fiber compositions. Full article
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Open AccessArticle Effect of Density and Fiber Size on Porosity and Thermal Conductivity of Fiberboard Mats
Fibers 2018, 6(4), 81; https://doi.org/10.3390/fib6040081
Received: 31 August 2018 / Revised: 11 October 2018 / Accepted: 14 October 2018 / Published: 19 October 2018
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Abstract
The thermal conductivity and porosity of fiberboard mats are crucial parameters for efficient energy consumption of the hot-pressing process and for final panel quality. In this work, the effect of fiber size and mat density on porosity and thermal conductivity of the mat
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The thermal conductivity and porosity of fiberboard mats are crucial parameters for efficient energy consumption of the hot-pressing process and for final panel quality. In this work, the effect of fiber size and mat density on porosity and thermal conductivity of the mat were investigated. The fiber size was characterized as fine, medium and coarse. The mat porosity was measured by image analysis using the black and white contrast method. The thermal conductivity was determined at different density levels with a temperature gradient of 1.6 °C mm−1 and 7.6% (s = 0.3) moisture content. The results showed that fiber size was a dominant variable governing heat conduction and mat porosity. The mats made with medium size fibers showed a higher resistance to compression. The thermal conductivity of coarse fiber mats decreased drastically between 700 kg m−3 and 810 kg m−3. This was likely due to a higher fracture frequency observed for coarse fibers in comparison to the other fiber sizes studied. Hence, the fine and medium fibers conducted heat more efficiently. Moreover, fiber bundles and fractured fibers were observed during the mat porosity measurements, principally in mats made with fine fiber size. Full article
(This article belongs to the Special Issue Natural Fibre Biocomposites)
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Open AccessArticle Hollow Core Optical Fibers for Industrial Ultra Short Pulse Laser Beam Delivery Applications
Fibers 2018, 6(4), 80; https://doi.org/10.3390/fib6040080
Received: 14 September 2018 / Revised: 4 October 2018 / Accepted: 10 October 2018 / Published: 16 October 2018
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Abstract
Hollow core fibers were introduced many years ago but are now starting to be used regularly in more demanding applications. While first experiments mainly focused on the characterization and analysis of the fibers themselves, they are now implemented as a tool in the
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Hollow core fibers were introduced many years ago but are now starting to be used regularly in more demanding applications. While first experiments mainly focused on the characterization and analysis of the fibers themselves, they are now implemented as a tool in the laser beam delivery. Owing to their different designs and implementations, different tasks can be achieved, such as flexible beam delivery, wide spectral broadening up to supercontinuum generation or intense gas-laser interaction over long distances. To achieve a constant result in these applications under varying conditions, many parameters of these fibers have to be controlled precisely during fabrication and implementation. A wide variety of hollow core fiber designs have been analyzed and implemented into a high-power industrial beam delivery and their performance has been measured. Full article
(This article belongs to the Special Issue Hollow core optical fibers)
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Open AccessArticle Use of Ginger Nanofibers for the Preparation of Cellulose Nanocomposites and Their Antimicrobial Activities
Fibers 2018, 6(4), 79; https://doi.org/10.3390/fib6040079
Received: 11 September 2018 / Revised: 1 October 2018 / Accepted: 2 October 2018 / Published: 15 October 2018
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Abstract
Ginger residues left after the extraction of active ingredients from ginger rhizomes are considered to be a bio-waste, available in abundance and very rarely used. Extraction and isolation of natural nanofibers from the agro-waste is economical, environmentally benign, and an alternate strategy to
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Ginger residues left after the extraction of active ingredients from ginger rhizomes are considered to be a bio-waste, available in abundance and very rarely used. Extraction and isolation of natural nanofibers from the agro-waste is economical, environmentally benign, and an alternate strategy to replace synthetic fibers. Here, we report, for the first time, the isolation of ginger nanofibers (GNF) from ginger rhizomes spent by acid hydrolysis and followed by high-pressure homogenization. Scanning electron microscopy was utilized to identify the surface morphology of the GNF and the widths ranged between 130 to 200 nm. Structural analysis of GNF was identified by Fourier transform infrared spectroscopy, Differential scanning calorimetry, and X-ray diffraction methods. This GNF was used to make natural nanocomposites by the solvent-casting method reinforcement, using potato starch (PS) and tapioca starch (TS), and was characterized through various methods. These composites were prepared by the addition of 1, 3, 5, and 7 weight % of GNF with PS or TS. Among these, 5% of the GNF composites of these starches showed very high mechanical properties. The antibacterial test showed that the bionanocomposites with 5% GNF exhibited good antibacterial activity against Bacillus cereus, Escherichia coli, Staphylococcus aureus, and Salmonella typhimurium, due to the addition of GNF in the biopolymer matrices. The viable use of GNF from the unexploited ginger agro-waste would create additional profit and it would help to diminish a large amount of waste generation. Thus, the developed bio-composite could also be employed for development of packing materials and be used in medical applications, such as wound healing pads and medical disposables. Full article
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Open AccessArticle Integrity of Carbon-Fibre Epoxy Composites through a Nanomechanical Mapping Protocol towards Quality Assurance
Fibers 2018, 6(4), 78; https://doi.org/10.3390/fib6040078
Received: 3 July 2018 / Revised: 25 September 2018 / Accepted: 2 October 2018 / Published: 11 October 2018
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Abstract
The purpose of this study is to assess the integrity of carbon-fibre reinforced plastics (CFRP) comprising of commercial and surface modified CFs through nanomechanical mapping protocol, towards the feasibility of nanoindentation tool as a quality assurance means in a composite manufacturing process. Carbon
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The purpose of this study is to assess the integrity of carbon-fibre reinforced plastics (CFRP) comprising of commercial and surface modified CFs through nanomechanical mapping protocol, towards the feasibility of nanoindentation tool as a quality assurance means in a composite manufacturing process. Carbon fibre surface modification was selected for enhancement of the wetting properties of carbon fibres in order to improve the adhesion force between the fibre and the polymer matrix. In all cases, epoxy resin was used as a matrix for the manufacturing of composite samples. Plastic deformation/elastic recovery were recorded (together with viscoelasticity and adhesion-discontinuities and fluctuations during measurement), while elastic modulus values are also mapped. Moreover, the resistance to applied load is assessed and compared for all cases. Full article
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Open AccessArticle Combining Hollow Core Photonic Crystal Fibers with Multimode, Solid Core Fiber Couplers through Arc Fusion Splicing for the Miniaturization of Nonlinear Spectroscopy Sensing Devices
Fibers 2018, 6(4), 77; https://doi.org/10.3390/fib6040077
Received: 15 September 2018 / Revised: 4 October 2018 / Accepted: 4 October 2018 / Published: 11 October 2018
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Abstract
The presence of fiber optic devices, such as couplers or wavelength division multiplexers, based on hollow-core fibers (HCFs) is still rather uncommon, while such devices can be imagined to greatly increase the potential of HCFs for different applications, such as sensing, nonlinear optics,
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The presence of fiber optic devices, such as couplers or wavelength division multiplexers, based on hollow-core fibers (HCFs) is still rather uncommon, while such devices can be imagined to greatly increase the potential of HCFs for different applications, such as sensing, nonlinear optics, etc. In this paper, we present a combination of a standard, multimode fiber (MMF) optic coupler with a hollow core photonic bandgap fiber through arc fusion splicing and its application for the purpose of multiphoton spectroscopy. The presented splicing method is of high affordability due to the low cost of arc fusion splicers, and the measured splicing loss (SL) of the HCF-MMF splice is as low as (0.32 ± 0.1) dB, while the splice itself is durable enough to withstand a bending radius (rbend) of 1.8 cm. This resulted in a hybrid between the hollow core photonic bandgap fiber (HCPBF) and MMF coupler, delivering 20 mW of average power and 250-fs short laser pulses to the sample, which was good enough to test the proposed sensor setup in a simple, proof-of-concept multiphoton fluorescence excitation-detection experiment, allowing the successful measurement of the fluorescence emission spectrum of 10−5 M fluorescein solution. In our opinion, the presented results indicate the possibility of creating multi-purpose HCF setups, which would excel in various types of sensing applications. Full article
(This article belongs to the Special Issue Hollow core optical fibers)
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Open AccessReview Gas-Liquid Hollow Fiber Membrane Contactors for Different Applications
Fibers 2018, 6(4), 76; https://doi.org/10.3390/fib6040076
Received: 14 September 2018 / Revised: 1 October 2018 / Accepted: 2 October 2018 / Published: 10 October 2018
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Abstract
Gas-liquid membrane contactors that were based on hollow fiber membranes are the example of highly effective hybrid separation processes in the field of membrane technology. Membranes provide a fixed and well-determined interface for gas/liquid mass transfer without dispensing one phase into another while
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Gas-liquid membrane contactors that were based on hollow fiber membranes are the example of highly effective hybrid separation processes in the field of membrane technology. Membranes provide a fixed and well-determined interface for gas/liquid mass transfer without dispensing one phase into another while their structure (hollow fiber) offers very large surface area per apparatus volume resulted in the compactness and modularity of separation equipment. In many cases, stated benefits are complemented with high separation selectivity typical for absorption technology. Since hollow fiber membrane contactors are agreed to be one of the most perspective methods for CO2 capture technologies, the major reviews are devoted to research activities within this field. This review is focused on the research works carried out so far on the applications of membrane contactors for other gas-liquid separation tasks, such as water deoxygenation/ozonation, air humidity control, ethylene/ethane separation, etc. A wide range of materials, membranes, and liquid solvents for membrane contactor processes are considered. Special attention is given to current studies on the capture of acid gases (H2S, SO2) from different mixtures. The examples of pilot-scale and semi-industrial implementation of membrane contactors are given. Full article
(This article belongs to the Special Issue Polymer Hollow Fiber Membrane)
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Open AccessArticle Modeling of Coupled Heat and Mass Transfers in a Stabilized Earthen Building Envelope with Thatched Fibers
Fibers 2018, 6(4), 75; https://doi.org/10.3390/fib6040075
Received: 10 August 2018 / Revised: 14 September 2018 / Accepted: 29 September 2018 / Published: 2 October 2018
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Abstract
In order to reduce the heat and mass transfers in buildings, which increase energy bills, the development of composites materials such as earth bricks stabilized with thatch fibers is important for their construction. This paper aims to study a one-dimensional model of heat
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In order to reduce the heat and mass transfers in buildings, which increase energy bills, the development of composites materials such as earth bricks stabilized with thatch fibers is important for their construction. This paper aims to study a one-dimensional model of heat and moisture transfer through porous building materials. The coupled phenomena of heat and mass transfer are described by the Luikov model. Equations and boundary conditions are discretized using the finite difference method. The results obtained illustrate the temporal evolutions of the temperature and the moisture content, as well as the distributions of the temperature and moisture content inside the wall. The profile of the temperature and water content that are obtained are compared with the other numerical solutions that are available in the literature. Full article
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Open AccessArticle Geometry of Chalcogenide Negative Curvature Fibers for CO2 Laser Transmission
Fibers 2018, 6(4), 74; https://doi.org/10.3390/fib6040074
Received: 12 July 2018 / Revised: 27 September 2018 / Accepted: 27 September 2018 / Published: 30 September 2018
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Abstract
We study the impact of geometry on leakage loss in negative curvature fibers made with As2Se3 chalcogenide and As2S3 chalcogenide glasses for carbon dioxide (CO2) laser transmission. The minimum leakage loss decreases when the core
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We study the impact of geometry on leakage loss in negative curvature fibers made with As 2 Se 3 chalcogenide and As 2 S 3 chalcogenide glasses for carbon dioxide (CO 2 ) laser transmission. The minimum leakage loss decreases when the core diameter increases both for fibers with six and for fibers with eight cladding tubes. The optimum gap corresponding to the minimum loss increases when the core diameter increases for negative curvature fibers with six cladding tubes. For negative curvature fibers with eight cladding tubes, the optimum gap is always less than 20 μ m when the core diameter ranges from 300 μ m to 500 μ m. The influence of material loss on fiber loss is also studied. When material loss exceeds 10 2 dB/m, it dominates the fiber leakage loss for negative curvature fiber at a wavelength of 10.6 μ m. Full article
(This article belongs to the Special Issue Hollow core optical fibers)
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Open AccessArticle Applying Image Processing to the Textile Grading of Fleece Based on Pilling Assessment
Fibers 2018, 6(4), 73; https://doi.org/10.3390/fib6040073
Received: 3 August 2018 / Revised: 11 September 2018 / Accepted: 26 September 2018 / Published: 28 September 2018
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Abstract
Textile pilling causes an undesirable appearance on the surface of garments, which is a long-standing problem. In this study, textile grading of fleece based on pilling assessment was performed using image processing and machine learning methods. Two image processing methods were used. The
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Textile pilling causes an undesirable appearance on the surface of garments, which is a long-standing problem. In this study, textile grading of fleece based on pilling assessment was performed using image processing and machine learning methods. Two image processing methods were used. The first method involved using the discrete Fourier transform combined with Gaussian filtering, and the second method involved using the Daubechies wavelet. Furthermore, binarization was used to segment the textile pilling from the background. Morphological and topological image processing methods were applied to extract the essential characteristics of textile image information to establish a database for the textile. Finally, machine learning methods, namely the artificial neural network (ANN) and the support vector machine (SVM), were used to objectively solve the textile grading problem. When the Fourier-Gaussian method was used, the classification accuracies of the ANN and SVM were 96.6% and 95.3%, and the overall accuracies of the Daubechies wavelet were 96.3% and 90.9%, respectively. Full article
(This article belongs to the Special Issue Smart Coatings on Fibers and Textiles)
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Open AccessArticle A Time-Efficient Dip Coating Technique for the Deposition of Microgels onto the Optical Fiber Tip
Fibers 2018, 6(4), 72; https://doi.org/10.3390/fib6040072
Received: 1 August 2018 / Revised: 21 September 2018 / Accepted: 23 September 2018 / Published: 28 September 2018
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Abstract
The combination of responsive microgels and Lab-on-Fiber devices represents a valuable technological tool for developing advanced optrodes, especially useful for biomedical applications. Recently, we have reported on a fabrication method, based on the dip coating technique, for creating a microgels monolayer in a
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The combination of responsive microgels and Lab-on-Fiber devices represents a valuable technological tool for developing advanced optrodes, especially useful for biomedical applications. Recently, we have reported on a fabrication method, based on the dip coating technique, for creating a microgels monolayer in a controlled fashion onto the fiber tip. In the wake of these results, with a view towards industrial applications, here we carefully analyze, by means of both morphological and optical characterizations, the effect of each fabrication step (fiber dipping, rinsing, and drying) on the microgels film properties. Interestingly, we demonstrate that it is possible to significantly reduce the duration (from 960 min to 31 min) and the complexity of the fabrication procedure, without compromising the quality of the microgels film at all. Repeatability studies are carried out to confirm the validity of the optimized deposition procedure. Moreover, the new procedure is successfully applied to different kinds of substrates (patterned gold and bare optical fiber glass), demonstrating the generality of our findings. Overall, the results presented in this work offer the possibility to improve of a factor ~30 the fabrication throughput of microgels-assisted optical fiber probes, thus enabling their possible exploitation in industrial applications. Full article
(This article belongs to the Special Issue Smart Coatings on Fibers and Textiles)
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Open AccessArticle Development of Electrophoretic Deposition Prototype for Continuous Production of Carbon Nanotube-Modified Carbon Fiber Fabrics Used in High-Performance Multifunctional Composites
Fibers 2018, 6(4), 71; https://doi.org/10.3390/fib6040071
Received: 3 September 2018 / Revised: 18 September 2018 / Accepted: 27 September 2018 / Published: 28 September 2018
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Abstract
An electrophoretic deposition (EPD) prototype was developed aiming at the continuous production of carbon nanotube (CNT) deposited carbon fiber fabric. Such multi-scale reinforcement was used to manufacture carbon fiber-reinforced polymer (CFRP) composites. The overall objective was to improve the mechanical performance and functionalities
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An electrophoretic deposition (EPD) prototype was developed aiming at the continuous production of carbon nanotube (CNT) deposited carbon fiber fabric. Such multi-scale reinforcement was used to manufacture carbon fiber-reinforced polymer (CFRP) composites. The overall objective was to improve the mechanical performance and functionalities of CFRP composites. In the current study, the design concept and practical limit of the continuous EPD prototype, as well as the flexural strength and interlaminar shear strength, were the focus. Initial mechanical tests showed that the flexural stiffness and strength of composites with the developed reinforcement were significantly reduced with respect to the composites with pristine reinforcement. However, optical microscopy study revealed that geometrical imperfections, such as waviness and misalignment, had been introduced into the reinforcement fibers and/or bundles when being pulled through the EPD bath, collected on a roll, and dried. These defects are likely to partly or completely shadow any enhancement of the mechanical properties due to the CNT deposit. In order to eliminate the effect of the discovered defects, the pristine reinforcement was subjected to the same EPD treatment, but without the addition of CNT in the EPD bath. When compared with such water-treated reinforcement, the CNT-deposited reinforcement clearly showed a positive effect on the flexural properties and interlaminar shear strength of the composites. It was also discovered that CNTs agglomerate with time under the electric field due to the change of ionic density, which is possibly due to the electrolysis of water (for carboxylated CNT aqueous suspension without surfactant) or the deposition of ionic surfactant along with CNT deposition (for non-functionalized CNT aqueous suspension with surfactant). Currently, this sets time limits for the continuous deposition. Full article
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Open AccessReview Review on Fabrication of Structurally Colored Fibers by Electrospinning
Fibers 2018, 6(4), 70; https://doi.org/10.3390/fib6040070
Received: 29 June 2018 / Revised: 19 September 2018 / Accepted: 20 September 2018 / Published: 26 September 2018
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Abstract
Structural color derived from the physical interactions of photons, with the specific chromatic mechanism differing from that of dyes and pigments, has brought considerable attention by the conducive virtue of being dye-free and fadeless. This has recently become a research hot-spot. Assemblies of
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Structural color derived from the physical interactions of photons, with the specific chromatic mechanism differing from that of dyes and pigments, has brought considerable attention by the conducive virtue of being dye-free and fadeless. This has recently become a research hot-spot. Assemblies of colloidal nanoparticles enable the manufacture of periodic photonic nanostructures. In our review, the mechanism of nanoparticle assemblies into structurally colored structures by the electrospinning method was briefly introduced, followed by a comparatively comprehensive review summarizing the research related to photonic crystals with periodically aligned nanostructures constructed by the assembly of colloidal nanoparticles, and the concrete studies concerning the fabrication of well-aligned electrospun nanofibers incorporating with colloidal nanoparticles based on the investigation of relevant factors such as the sizes of colloidal nanoparticles, the weight ratio between colloidal nanoparticles, and the polymer matrix. Electrospinning is expected to be a deserving technique for the fabrication of structurally colored nanofibers while the colloidal nanoparticles can be well confined into aligned arrangement inside nanofibres during the electrospinning process after the achievement of resolving remaining challenges. Full article
(This article belongs to the Special Issue Smart Coatings on Fibers and Textiles)
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