Braided Fiber Research Articles

UV/thermal dual-cured MWCNTs composites for pipeline rehabilitation: Mechanical properties and damage analysis

Deformation and damage in underground pipelines remain challenging to monitor over the long term due to sensor degradation caused by corrosive substances present in the pipelines. This study investigates the potential of incorporating multi-walled carbon nanotubes (MWCNTs) into ultraviolet-cured-in-place pipe (UV-CIPP) material, a widely adopted trenchless repair technique, to enhance performance and enable deformation monitoring. A UV/thermal dual-curing strategy is introduced to mitigate the significant reduction in light transmittance caused by the inclusion of MWCNTs in the composite material. The addition of MWCNTs led to a 94.86 % reduction in light transmittance through glass fibers. However, this issue was effectively resolved through the incorporation of thermal curing, allowing for the production of ultra-high-strength composites using only three layers of fibers within a short curing time. Under optimal conditions (0.2 wt% MWCNTs with the impregnation layer on top), the flexural strength and modulus reached 442.75 MPa and 15.58 GPa, respectively, marking improvements of 14.01 % and 45.2 % over the base material. Additionally, the hardness on the composite's backside increased by 10.95 % compared to the front, indicating enhanced reinforcement. The tensile strength of braided glass fibers improved by 42.31 % and 197.54 % with the addition of 0.2 wt% and 1.0 wt% MWCNTs, respectively. Failure modes varied based on the location of the sensing layer, but all specimens eventually failed due to resin cracking, delamination of the MWCNTs-impregnated layer, and fiber fractures. The UV/thermal dual-cured composite material developed for pipeline rehabilitation in this study exhibits ultra-high strength and shows significant potential for multifunctional sensing applications.

Fabrication of flame-retardant PA6/three-dimensional braided glass fiber composites via in situ polymerization

Reaction injection molding method is employed to improve flame retardancy and mechanical properties of three-dimensional braided glass fiber (3D-braided-GF) reinforced in situ polymerized polyamide 6 (PA6) composites. The kernel lies in adding flame retardants, hexaphenoxycyclotriphosphazene (HPCTP), to the reactive monomers to allow it to be in situ filled into composites during preparing PA6 through anionic polymerization, which enables flame retardants to achieve better dispersion. In addition, extremely low-viscosity reactive monomers are easier to immerse in 3D-braided-GF, ameliorating interfacial adhesion between GF and PA6. The preliminary research indicates that samples with 10 wt.% HPCTP concentration can achieve the best mechanical properties and a satisfied flame-retardant grade (UL 94 HB). However, with the incorporation of 15 wt.% HPCTP into samples, the optimum flame-retardant grade (UL 94 V2) and the reduced mechanical performance are obtained. Furthermore, a dual flame retardancy mechanism in both gaseous and condensed phases of samples is further elucidated. This study can provide a reference for scenarios with high requirements for the flame-retardant and mechanical properties, such as high-speed rail and aircraft.

Study on the Effect of "3D-rGO" Buffer Layer on the Microstructure and Properties of SiO2f/SiO2 and TC4 Brazed Joint.

Brazing a SiO2f/SiO2 composite with metals is often faced with two problems: poor wettability with the brazing alloy and high residual stress in the joint. To overcome these problems, we report a combined method of selective etching and depositing reduced graphene oxide (rGO) on the surface of a SiO2f/SiO2 composite (3D-rGO-SiO2f/SiO2) to assist brazing with TC4. After the combined treatment, a "3D-rGO" buffer layer formed on the surface layer of the SiO2f/SiO2, and the contact angle was reduced from 130° to 38°, which meant the wettability of active brazing alloy on the surface of SiO2f/SiO2 was obviously improved. In addition, the "3D-rGO" buffer layer contributed to fully integrating the brazing alloy and SiO2f/SiO2; then, the infiltration of the brazing alloy into the surface layer of the SiO2f/SiO2 was enhanced and formed the reduced graphene oxide with a pinning structure in the three dimensional ("3D-pinning-rGO") structure. Moreover, the joining area of the brazing alloy and SiO2f/SiO2 was expanded and the mismatch degree between the SiO2f/SiO2 and TC4 was reduced, which was achieved by the "3D-pinning-rGO" structure. Furthermore, the concentration of the residual stress in the SiO2f/SiO2-TC4 joints transferred from the SiO2f/SiO2 to the braided quartz fibers, and the residual stress reduced from 142 MPa to 85 MPa. Furthermore, the 3D-pinning-rGO layer facilitated the transfer of heat between the substrates during the brazing process. Finally, the shear strength of the SiO2f/SiO2-TC4 joints increased from 12.5 MPa to 43.7 MPa by the selective etching and depositing rGO method.

Flexural performance enhancement of modified gypsum-based composite boards using basalt fiber braids

In conventional fiber-reinforced gypsum boards, while the integration of fibers curtails crack propagation and moderately increases the flexural strength, the phenomenon of strain-softening is inevitably induced, which restricts the wider application of gypsum boards. The present study primarily focuses on evaluating the influence of basalt fiber (BF) braids on the flexural performance of fiber-reinforced modified gypsum matrix composite boards. The investigation considers factors such as the types of modified gypsum-based matrix, the number of BF braid layers, and the placement of fibers. During the experiments, the failure modes of various structural gypsum boards were observed, and comparisons were made regarding the changes in flexural stress-strain behavior, flexural strength, and displacement. Moreover, a reasonable explanation of the entire flexural stress process was provided based on the internal forces of the gypsum boards. Furthermore, a comparative analysis is conducted to examine the variations in ductility indices among different structural configurations of gypsum boards. The research results indicate that the combined action of fibers and BF braids effectively restricts the development of cracks, preventing a sudden decrease in stress during the growth stage. Additionally, BF braids fulfill their role, ensuring stress strengthening occurs within the gypsum board. Furthermore, the configuration of modified gypsum with fibers and two layers of BF braids (MG-BF-B-L2) exhibits the most significant improvement in flexural performance. Compared to modified gypsum group (MG), the flexural strength, entire ductility, and post-peak ductility have increased to 3.39 times, 7.66 times, and 1.58 times, respectively.

Influence of fabric structures and temperature on the mechanical properties of quartz braids

Herein, quartz fiber braids with different structures (plain, twill, satin, broken twill) were woven to explore the influence of structures on the performance of fabrics. The influences of high temperature and structure on the mechanical properties of quartz fiber braids were investigated in detail. As the temperature increased to 1000°C, the mechanical properties of quartz fiber decreased by around 90% due to its crystallization. Among the different fabric structures tested, quartz fabrics with satin and broken twill structures possessed good tensile properties (400 MPa) at room temperature. However, as the temperature and duration of heat treatment increased, the tensile performance of broken twill weave fabrics decreased by 50 MPa. In summary, the study demonstrates that quartz fibers and their fabrics possess significant potential for applications in high temperature environments, with the ability to withstand elevated temperatures for short durations, thereby enhancing their performance and extending their range of applications.

Thermoregulatory elasticity braided fibers designed with core–sheath structure for wearable personal thermal management

The thermoregulatory elasticity fiber was designed and fabricated using coaxial wet spinning, which combines solar-thermal and phase-change energy. This exploration presents a strategy to develop smart fabrics for personal thermal management.

Flexible furniture structure based on braiding technology and fiber jamming

Inspired by the fields of composites and soft robotics, this paper designs a textile-based structure which could realize variable stiffness and variable configurations, and they thus make it present high adaptability as a flexible furniture structure. The mechanisms of the variable properties realized by the braiding and jamming, together with the fabrication considerations and analytical methods are introduced in detail. Down-scale beam elements with different profiles were physically and numerically established, based on which the distinct foldability, variable stiffness and reconfigurability are quantitated and analyzed. This study brings a new idea for the development of the indoor furniture structure.

Technique Variation in the Surgical Treatment of Lateral Ankle Instability.

Lateral ankle sprains are the most common type of injury to the ankle and can lead to ankle instability. There are many described techniques for the surgical treatment of lateral ankle instability. The purpose of this study is to quantify the variation in surgeon technique for lateral ankle instability treatment. Surveys were sent to 62 orthopaedic foot and ankle surgeons regarding surgical technique for the treatment of lateral ankle instability. Clinical agreement was defined as greater than 80% agreement to assess the cohesiveness of surgical methods as described by Marx et al. Results. Response rate was 49/62 (79%). There was clinical agreement for not using bone tunnels and not using metal anchors. All other factors lacked clinical agreement. A greater average number of throws and knots (4.2 for each, range 1-6 throws, range 2-12 knots) were used by surgeons that do not believe knots cause pain compared to an average of 3.9 (range, 1-6) throws and 4.0 (range, 2-15) knots by surgeons who do believe knots cause pain. The association that surgeon who believed knots do cause pain and thus used fewer knots and throws was not statistically significant (P > .05). The preferred material by surgeons in our study are as follows: nonabsorbable braided suture (26/49, 53%), suture tape (15/49, 31%), and fiber tape (4/49, 8%). Among surgeons who use absorbable suture (34/49, 69%), there was no significant difference (P > .05) between surgeons who believe knots cause pain (23/34, 68%) and those who do not (11/34, 32%). Among this small sample of orthopaedic foot and ankle surgeons, there is wide variation in surgical technique for lateral ankle instability treatment and little agreement on the clinical standard of care. This disagreement highlights the need for comparative outcome studies in the treatment of ankle instability. Level III: Retrospective cohort study.

Design of efficient thermal conductive epoxy resin composites via highspeed transport pathways of heterogeneous compatible carbon framework

Thermal interface materials are crucial for addressing the hot issues of a rapid increase in thermal density in narrow and limited service spaces. Flexible and designable epoxy resin (EP) based composites are competitive choice yet lacks desirable thermal conductivity (∼0.2 W m−1 K−1) and mechanical properties (tensile strength: ∼19.6 MPa). Herein, EP-based composites with a reinforced three-dimensional (3D) interconnected carbon material architecture were prepared by in-situ growing 1D carbon nanotubes (CNTs) on the surface of 2D carbon fiber braid (CFB) and infiltrating matrix EP. CNTs not only promote the wettability between carbon fibers inside CFB and EP but also observably bridge the adjacent carbon fibers. The analysis of numerical models reveals the prominent contribution of 3D CFB/CNTs network to a significant increase in thermal conductivity. Non-equilibrium molecular dynamics (NEMD) indicates the high intrinsic thermal conductivity of CNTs in both systems: single CNT model and CNT/Ni model. The coupling behavior of high-frequency phonons at the interface contributes to the in-plane thermal transport. The in-plane thermal conductivity of 7.86 W m−1 K−1 and the through-plane thermal conductivity of 5.85 W m−1 K−1 are obtained in the composites with 23.2 wt% hybrid fillers, increased by 3830 % compared to neat EP. The tensile (58.93 MPa) and compressive strength (138.83 MPa) are also enhanced, meeting practical demands. These properties even perform no obvious changes after 100 cycles of bending. The stable and reliable EP-based composites with outstanding comprehensive performance designed by this work have enormous application potential in the advanced heat dissipation system.

Conductive, water-retaining and knittable hydrogel fiber from xanthan gum and aniline tetramer modified-polysaccharide for strain and pressure sensors

Herein, we explored strategies for defoaming and controllable adjustment of spinnable and mechanical properties of polyanion polysaccharide-based hydrogels to fabricate conductive, water-retaining, and knittable hydrogel fibers for next-generation flexible electronics. Xanthan gum (XG) and aniline tetramer modified-polysaccharide (TMAT38) were crosslinked with sodium trimetaphosphate (STMP) and subsequently by Fe3+/Fe2+ ions coordination to prepare conductive and spinnable hydrogels. Polypropylene glycol was introduced as chemical antifoam, and solvent displacement method was adopted to improve mechanical and water-retaining properties. The glycerol-immersed XG5-TMAT38-STMP-Fe3+/CA-PPG hydrogel exhibited conductivity of 3.55×10−3–27.30×10−3 S/cm, storage modulus at linear viscoelastic region of 573 Pa–1717 Pa and self-healing percentage of 100 %–108 %. The 2 h glycerol-immersed hydrogel fibers with good flexibility, moisture retention and freezing tolerance were ready to bend and knit into fabrics. The hydrogel fiber braid possessed better conductivity, reliability and durability than the single hydrogel fiber as strain sensors. The hydrogel fiber fabric perceived tiny vibration triggered by swallowing, speaking and writing with good sensitivity and reproducibility. Furthermore, a three-component model was developed to evaluate response sensitivity and recoverability of the hydrogel fiber fabric-based pressure sensors, which facilitated understanding transient response of polymer-based hydrogel strain and pressure sensors.

Synergetic surface modification of 3D braided carbon fiber-reinforced composites for enhancing mechanical strength

Excellent interfacial bonding contributes to the reduction of internal defects in composites for enhancing the mechanical properties of the 3D braided carbon fiber reinforced composites. In this paper, the effects of plasma and strong acid treatment on the surface morphology, chemical composition, and surface free energy of original carbon fiber braid (CFB) were investigated in detail to reveal the mechanism of synergetic enhancement of surface wettability of carbon fiber by plasma and strong acid. The results showed that the synergetic effect of plasma and strong acid produced significantly improved the resin/fiber interfacial bonding. The interfacial shear strength (IFSS) of the carbon fiber braided reinforced composites (CFBC) treated with the synergetic treatment was 64.6% higher than that of the untreated fiber reinforced composites. The improved interfacial properties increase the polar functional groups on the fiber surface to promote the formation of mechanical interlocking caused by Cassie-Baxter(CB) and Wenzel(WZ) leaps of liquid resin on the fiber surface, and this was verified by molecular dynamics(MD) simulations of carbon fiber-resin interfacial wetting. The simple and effective synergetic reinforcement strategy proposed in this paper can effectively regulate the interfacial bonding and is applicable to the optimal design of original carbon fiber braided reinforced composites.

A matrix computing method for visualizing switchless controlled 3D hexagonal‐annular rotary braiding process architecture

AbstractNumerous process architectures for fabric molding are investigated because fiber braided structure is closely related to the performance of fiber‐reinforced composites. However, existing methods for calculating process architectures have to deal with the coordinates of each fiber when modeling the three‐dimensional braiding method without individually controlled switches. The amount of data grows geometrically as the number of fibers and braiding steps increases. A methodology that enables simple and efficient computation of a model of the relationship between braiding parameters and fiber structure is urgently needed. This paper proposes a novel algorithm to trace the yarn carrier trajectories through machine simulation with Euler rotation‐matrix operations. To predict the real fabric architecture, a contraction factor is introduced to optimize the yarn trajectory while considering the volume of the yarn. The optimized fabric architecture is explored and the braiding process architecture with different braiding parameters is simulated according to the algorithm. Based on the exploration of the relationship between the braiding parameters and the process structure, a hexagonal‐annular braiding machine was established, which can fabricate fabrics with different cross‐sectional shapes. The simulation results were verified by the braiding experiments.

Comparison study on bending properties and failure of 3D5d and 3D6d carbon/phenolic braided composites at room and elevated temperatures

Three-dimensional five-directional and six-directional braided composites (3D5dBCs and 3D6dBCs) are widely used in aerospace industry for their excellent axial and transverse properties. This work successfully fabricated 3D5dBCs and 3D6dBCs with carbon/phenolic, and compared their bending properties and failure mechanisms at room and high temperatures (RT and HT). The influences of braiding structure and temperature on bending properties and failure mechanisms of 3D5dBCs and 3D6dBCs were analyzed. The load/deflection curves are linear elastic at RT, showing prominent plastic characteristics at HT. From RT to HT, the bending properties decrease, but 3D5dBCs always have higher bending properties than 3D6dBCs. The 3D5dBCs and 3D6dBCs are primarily damaged near the surface at RT; fiber shearing fracture feature becomes apparent and the interior damage worsens at HT. 3D5dBCs exhibit obvious shear failure mode, where the fracture is bent and rough, and the damage patterns are braiding and axial fibers shearing fracture, matrix softening, and interface debonding. 3D6dBCs show transverse sawtooth fracture cracks, and the damage mechanisms are braiding fiber shearing fracture, fifth fiber tearing, sixth fiber shedding and pulling-off, matrix plasticization, and interface debonding.

Braided Fiber Current Collectors for High‐Energy‐Density Fiber Lithium‐Ion Batteries

AbstractFiber lithium‐ion batteries represent a promising power strategy for the rising wearable electronics. However, most fiber current collectors are solid with vastly increased weights of inactive materials and sluggish charge transport, thus resulting in low energy densities which have hindered the development of fiber lithium‐ion batteries in the past decade. Here, a braided fiber current collector with multiple channels was prepared by multi‐axial winding method to not only increase the mass fraction of active materials, but also to promote ion transport along fiber electrodes. In comparison to typical solid copper wires, the braided fiber current collector hosted 139 % graphite with only 1/3 mass. The fiber graphite anode with braided current collector delivered high specific capacity of 170 mAh g−1 based on the overall electrode weight, which was 2 times higher than that of its counterpart solid copper wire. The resulting fiber battery showed high energy density of 62 Wh kg−1.

Braided Fiber Current Collectors for High-Energy-Density Fiber Lithium-Ion Batteries.

Fiber lithium-ion batteries represent a promising power strategy for the rising wearable electronics. However, most fiber current collectors are solid with vastly increased weights of inactive materials and sluggish charge transport, thus resulting in low energy densities which have hindered the development of fiber lithium-ion batteries in the past decade. Here, a braided fiber current collector with multiple channels was prepared by multi-axial winding method to not only increase the mass fraction of active materials, but also to promote ion transport along fiber electrodes. In comparison to typical solid copper wires, the braided fiber current collector hosted 139% graphite with only 1/3 mass. The fiber graphite anode with braided current collector delivered high specific capacity of 170 mAh‧g-1 based on the overall electrode weight, which was 2 times higher than that of its counterpart solid copper wire. The resulting fiber battery showed high energy density of 62 Wh‧kg-1.

Effect of Suture Material in History-Indicated Cerclage on Spontaneous Preterm Delivery Risk [ID: 1370506

INTRODUCTION: This study aimed to determine whether suture material in history-indicated cerclage is associated with spontaneous preterm delivery (sPTD). METHODS: We conducted a retrospective cohort study of patients with singleton pregnancies who underwent history-indicated transvaginal cerclage at a tertiary care center from June 2015 to January 2022. The primary outcome was sPTD before 24 weeks of gestation. Secondary outcomes included sPTD at less than 26, 28, 32, and 34 weeks of gestation, chorioamnionitis, days in neonatal intensive care unit, and various adverse neonatal outcomes. Baseline characteristics and outcomes were compared using chi-square and Fisher’s exact tests according to type of suture material: 5-mm braided polyester fiber (Mersilene tape) versus monofilament suture (Prolene). Odds ratios (ORs) for sPTD were estimated using multivariable logistic regression. RESULTS: A total of 64 patients were included in the study, with 50 (78%) patients receiving Mersilene and 14 (22%) receiving Prolene. Mersilene, compared to Prolene, was associated with significantly lower rates of sPTD at less than 24 weeks (6% versus 29%, P=.02) and less than 26 weeks (8% versus 29%, P=.04). At more advanced gestational ages, Mersilene still resulted in lower rates of sPTD compared to Prolene, but statistical significance was lost. After adjusting for race and ethnicity, body mass index, use of postoperative progesterone, and gestational age at cerclage placement, patients with Prolene had increased odds of delivery less than 24 weeks (OR 7.69, 95% CI 1.04–56.6). Secondary outcomes were similar between the two groups. CONCLUSION: In patients undergoing history-indicated cerclage, Mersilene compared to Prolene was associated with a significantly lower risk of previable pregnancy loss.

Interlaminar, free vibration, HDT and water absorption properties of braided flax woven fabric PLA biocomposites

The presented research investigates the influence of braided flax woven-fabric filled with polylactic acid (PLA) polymer on interlaminar shear strength (ILSS), free vibration, heat deflection temperature (HDT) and water absorption. For this purpose, flax fibre-braided yarn and its fabric are prepared using solid braiding and plain weaving techniques. Then, PLA biocomposites are developed by solution casting and hot-press moulding processes. Shear test results showed, the addition of braided flax fibre increased the ILSS of composites compared to unreinforced PLA. Natural frequencies of the composite beams are improved with the braided flax reinforcement. Composites filled with three fabric layers showed higher frequency due to higher structural strength and stiffness associated with these composites. Bio-composites HDT is enhanced with the addition of braided flax fibre from 61.78% to 132.97%. The results of a water absorption test in distilled and seawater revealed that the composites have a relatively high water uptake in distilled water.

A fiber-packed needle-type extraction device with ionic liquid-based molecularly imprinted polymer as coating for extraction of chlorobenzenes in water samples

A needle-type extraction device (NTED) packed with ionic liquid-based molecularly imprinted polymers (MIP) coated copper fiber was produced for extraction of chlorobenzenes (CBs) in the aqueous environment followed by detection with GC-FID. Precipitation polymerization was performed to synthesize CBs imprinted polymers (CBs-MIP) with CBs as a mixed template, and 1-vinyl-3-aminoformylmethyl imidazolium chloride ionic liquid ([VAFMIM]Cl) as a functional monomer. Then CBs-MIP was coated on the braided copper fiber surface by sol–gel technology, which was served as a coated fiber to extract five trace CBs in drinking water, river water and industrial wastewater. The effects of several experimental conditions on extraction, including extraction time and temperature, pump flow rate, stirring speed, desorption time and temperature were studied by the single factor and experimental design method. A Plackett-Burman design (PBD) was used to screen the significant factors and a Box-Behnken design (BBD) was applied to optimize the significant variables to obtain the optimum extraction conditions. The limits of detection (0.0073–0.0130 μg L−1) and enrichment factors (2158–4087) for studied CBs were obtained after optimization. Moreover, the recoveries of CBs spiked in real water samples were 80.01–97.10% with RSD less than 7.70%. The experimental results confirmed that the NTED packed with CBs-MIP coated fiber is a promising device for extracting trace CBs from the water matrix.

Robust superhydrophobic ceramic fiber braid for oil water separation

Oil-water separation by gravity has been introduced as an effective water purification technique. However, traditional materials such as metal mesh and polymer braid are challenging to utilize in harsh water environments. In this work, ceramic fiber braids with excellent chemical and thermal stability were fabricated and used for oil-water separation. Needle-like mullite whiskers with length of ∼100 nm was in-situ grown on the surface of the fibers using gas phase reaction which could significantly increase the surface roughness of ceramic fibers. The ceramic fiber was successfully converted to hydrophobic structure with water contact angle of 159.4° ± 1.9° and sliding angle of 8.8° ± 2.0°. The excellent structural stability and oil water separation performance confirm the wide range applications of the hydrophobic ceramic fiber braids in harsh water environments.

Numerical modelling of braided ceramic fiber seals by using element differential method

• A multi-physical coupled model is proposed for the braided ceramic fiber seals. • The coupled fields contain the process of heat conduction, seepage and deformation. • Element differential method (EDM) is used to solve the multi-physical problems. • The material-dependent parameters in model are obtained by an inverse procedure. • Compared to FEM, EDM is more easy and efficient dealing with the coupled model. A new kind of dynamic seal with braided ceramic fibers has been designed to seal the movable panels in the scramjet engines, which are used for the propulsion of hypersonic vehicle. The braided ceramic fiber structure can provide buffer forces when the seals are subjected to the external dynamical preloads. However, it also makes the seals difficult to analyze. Up to now, the analysis of the seals still uses 1D models so that one cannot implement the coupled analysis of seals and their surrounding structures and flows. In this paper, a novel 2D and 3D mechanics-thermal-seepage coupled model is proposed to describe these seals, which provides a possibility for the aforementioned coupled analysis. Meanwhile, a strong-form numerical method, element differential method (EDM) is employed to discretize the governing equations of the coupled model due to its efficiency and robustness. Three examples are given. The first one is to invert the material-dependent parameters of three kinds of seal strips from the experimental data by Levenberg-Marquardt (LM) algorithm. Other two implement the analyses of 3D square and circular cross-section seals, respectively, which verify that EDM is more efficient than FEM in seal analysis when using the same mesh sizes.