Composite Textiles Research Articles

Additive technology of soluble mold tooling for embedded devices in composite structures: A study on manufactured tolerances

Composite textiles have found widespread use and advantages in various industries and applications. The constant demand for high-quality products and services requires companies to minimize their manufacturing costs and delivery time in order to compete with general and niche marketplaces. Creation of molding and tooling options for advanced composites encompasses a large portion of fabrication time, making it a costly process and a restraining factor. This research discusses a preliminary investigation into the use and control of soluble polymer compounds and additive manufacturing to fabricate sacrificial molds. These molds suffer from dimensional errors due to several factors, which have also been characterized. The basic soluble mold of a composite is 3D printed to meet the desired dimensions and geometry of holistic structures or spliced components. The time taken to dissolve the mold depends on the rate of agitation of the solvent. This process is steered towards enabling the implantation of optoelectronic devices within the composite to provide a sensing capability for structural health monitoring. The shape deviation of the 3D printed mold is also studied and compared to its original dimensions to optimize the dimensional quality to produce dimensionally accurate parts of up to 0.02% error.

Effects of three-dimensional reduced graphene oxide coupled with nickel nanoparticles on the microwave absorption of carbon fiber-based composites

Reduced graphene oxide (RGO) has been widely used for improved electrical conductivity, thermal conductivity and mechanical properties, allowing for broad applications in electronics and aerospace industry. In the present work, two-dimensional RGO interfaces were introduced into the one-dimensional carbon fiber (CF) networks for synthesizing a three-dimensional carbon fiber/reduced graphene oxide (CF-RGO) composite textile. Besides, the zero-dimensional nickel nanoparticles were deposited on the surface of CF-RGO to prepare a lightweight and flexible carbon fiber/reduced graphene oxide/nickel (CF-RGO-Ni). Furthermore, the microscopic morphologies, X-ray diffraction (XRD) spectras, saturation magnetization, dielectric parameter and microwave absorption property of the as-prepared samples were characterized. Consequently, The results show that the dielectric parameters and microwave absorption property of the as-prepared composite textiles would substantially influenced by the presence of RGO nanosheets and nickel nanoparticles. Furthermore, both the thickness of the composite textiles and the proportion of the composite in wax-based composites have been studied to explore their effects on the microwave absorption performance. The results present that the qualified bandwidth (<-10 dB) of the CF-RGO and CF-RGO-Ni composite textiles would be tuned by the RGO nanosheets and nickel nanoparticles, and the related mechanisms have been discussed.

Manipulating microstructures and electrical properties of carbon fiber/reduced graphene oxide/nickel composite textiles with electrochemical deposition techniques

Since graphene and their composites play significant roles in the catalysts, energy storage, electronics and other fields, where electron transport is highly critical, here, we introduce reduced graphene oxide (RGO) interfaces in the carbon fiber (CF) networks for preparing a novel lightweight carbon fiber/reduced graphene oxide/nickel (CF-RGO-Ni) composite textile. Upon the charaterizations on the microscopic morphologies, electrical and magnetic properties, and density, the presence of RGO nanosheets and nickel nanoparticles would substantially influence the related physical properties in the resulting composite textiles. Furthermore, the key parameters, including RGO loading, deposition time, current density and annealing temperature of carbon matrices, have been studied to understand their effects on the electrochemical deposition of nickel nanoparticles. Implication of the results suggests that the RGO interface is a unique medium for essentially promoting the electrochemical deposition kinetics and active sites for growing nickel nanoparticles, which indicates a universal approach for preparing advanced lightweight composites with the presence of graphene naonstructures.

Comprehensive approaches to three-dimensional flexible supercapacitor electrodes based on MnO2/carbon nanotube/activated carbon fiber felt

With the fast development of portable and wearable devices, flexible supercapacitor electrodes are widely researched. Here, comprehensive approaches were designed to introduce carbon nanotube (CNT) and/or MnO2 into activated carbon fiber felt (ACFF) using “dipping and drying” method. Differences on micro-morphologies and electrochemical characteristics for prepared textiles were compared. High-performance flexible MnO2/CNT/ACFF composite electrodes were synthesized by introducing CNT and MnO2/CNT fillers successively. Compared with original ACFF textiles, significant improvements in electrochemical performance were achieved. Areal capacitance, energy density and power density of the composite textiles reached as high as 4148 mF cm−2, 141 μWh cm−2 and 4466 μW cm−2, respectively. Furthermore, flexible supercapacitors were fabricated based on the composite textile electrodes and gel electrolytes. When being bent at different angles or suffering deformations such as bending for 100 cycles, the flexible supercapacitors preserve almost all the capacitance, which indicates the excellent flexibility of the composite textile electrode. This work provides various approaches to design composite textiles, and the prepared MnO2/CNT/ACFF composite textile may be a promising electrode material for high-performance flexible supercapacitors.

Construction of three-dimensional graphene interfaces into carbon fiber textiles for increasing deposition of nickel nanoparticles: flexible hierarchical magnetic textile composites for strong electromagnetic shielding

Since manipulating electromagnetic waves with electromagnetic active materials for environmental and electric engineering is a significant task, here a novel prototype is reported by introducing reduced graphene oxide (RGO) interfaces in carbon fiber (CF) networks for a hierarchical carbon fiber/reduced graphene oxide/nickel (CF-RGO-Ni) composite textile. Upon charaterizations of the microscopic morphologies, electrical and magnetic properties, the presence of three-dimensional RGO interfaces and bifunctional nickel nanoparticles substantially influences the related physical properties in the resulting hierarchical composite textiles. Eletromagnetic interference (EMI) shielding performance suggests that the hierarchical composite textiles hold a strong shielding effectiveness greater than 61 dB, showing greater advantages than conventional polymeric and foamy shielding composites. As a polymer-free lightweight structure, flexible CF-RGO-Ni composites of all electromagnetic active components offer unique understanding of the multi-scale and multiple mechanisms in electromagnetic energy consumption. Such a novel prototype of shielding structures along with convenient technology highlight a strategy to achieve high-performance EMI shielding, coupled with a universal approach for preparing advanced lightweight composites with graphene interfaces.

Simultaneous Production of High-Performance Flexible Textile Electrodes and Fiber Electrodes for Wearable Energy Storage

Flexible supercapacitors are important energy storage devices used for wearable and smart electronics. Various flexible supercapacitors have been prepared, including fiber supercapacitors, paper-like supercapacitors, three-dimensional aerogel materials based supercapacitors and textile supercapacitors. During them, fiber supercapacitors can be utilized in micro-devices, while textile supercapacitors are suitable for large-sized energy storage. To fabricate the flexible supercapacitors, the key lies in the acquirement of flexible electrodes, e.g., flexible fiber electrodes and textile electrodes. In this text, an effective strategy was proposed for the simultaneous productions of high-performance flexible textile electrodes and fiber electrodes. The prepared textile electrodes are textile/CNTs and textile/MnO2/CNTs composite textiles. During them, textile/MnO2/CNTs textile electrode/supercapacitor displays outstanding areal capacitances up to 3 F cm-2 and energy densities, and highly conductive textile is suitable for fabricating thicker electrode for supercapacitors with the high power. Scalable preparation of fiber electrodes was easily realized by dismantling textiles. In addition, the textile electrodes and fiber electrodes possess a long operation life and outstanding flexibility. Electrochemical properties of the electrodes may be further improved by optimization of MnO2, CNTs and polymers on the textiles. Despite of this, the present work is promising to promote the development of flexible electrodes and flexible energy storage devices.ercapacitors.[1-4] Reference [1] L. Dong, C. Xu*, et al. Adv Mater, 2016, 28, 1675. [2] L. Dong, C. Xu*, et al. J Mater Chem A, 2015, 3, 4729. [3] L. Dong, C. Xu*, et al. J Mater Chem A, 2016, 4, 4659. [4] L. Dong, C. Xu*, et al. Carbon, 2015, 90, 164 Acknowledgements: We thank the financial surppots from NSFC, 973, and Shenzhen Technical Plan Projects.

Nanofiber-enhanced lightweight composite textiles for acoustic applications

This paper proposes lightweight textile acoustic structure, wherein electrospun polyacrylonitrile-based nanofibers enhance sound absorption properties with no weight and thickness penalty. Polyacrylonitrile nanofibers with diameter of 110 ± 7 nm were electrospun on spacer-knitted fabrics by varying deposition amount and surface coating arrangement. Proposed novel approach eliminated additional processing steps such as handling and post-lamination and provided easy scalability of nanofibers at macro-scale. The results showed that the sound absorption of nano-enhanced specimens was improved drastically when deposited amount of nanofibers or its effective surface area increased. Sound propagation paths in different configurations were interpreted from sound absorption and air permeability measurements. The sound absorption coefficient values up to 0.7 are achieved in the low and medium frequency ranges with no weight and thickness penalty by tuning deposition amount and surface coating arrangement.

The Effect of Surface Treatments of Textile Reinforcement on Mechanical Parameters of HPC Facade Elements

Development of extremely thin concrete structures and demand for extremely thin elements are the reason of using composite non-traditional materials as reinforcement. Steel reinforcement is not very chemically resistant and it limits the thickness because of the required concrete cover as protection. This is the reason why textile reinforced concrete (TRC) going to be very famous and modern material. TRC in combination with fine grain high performance concrete (HPC) allows a significant saving of concrete. Due to its non-corrosive properties of composite technical textiles it is possible to design very subtle structures and elements. TRC and HPC in general are developed at the Faculty of Civil Engineering and the Klokner Institute, CTU in Prague. This present paper investigates the cohesion influence of textile reinforcement on four point bending test. All small experimental panels were reinforced with the same 3D technical textile from AR-glass roving with different type of cover layer. Different conditions of interaction between technical textiles and HPC were ensured by modified surface using silica sand and silica flour.

High-performance compressible supercapacitors based on functionally synergic multiscale carbon composite textiles

The functional synergy between body material and carbon nano-fillers leads to the outstanding electrochemical performances of composite textiles.

F041005 平織炭素繊維強化熱可塑性プラスチック複合材料における樹脂含浸挙動

Fiber reinforced thermoplastic composites has poorer matrix resin impregnation to fiber reinforcement, because of extreme high viscosity of molten thermoplastics. Intermediate materials using Micro-Braiding technique have been developed to overcome these difficulties. In this study, composite textiles plates were fabricated under various fabrication conditions, and their impregnation were investigated experimentally and predicted by theoretical formulae. As a result, impregnation increased with molding pressure and time, and impregnation of single-ply textiles is improved compared with that of multi-ply textiles because they have more collapsed fiber bundles, hence closer impregnation distance. On another front, the analytical predictions were in disagreement with the experimental results.

Experimental and Numerical Analysis of Crack Propagation in Light Composite Materials under Dynamic Fracturing

Research and analysis of mechanical properties including crack propagation in a light composite material is currently very important because composite structures are gradually becoming an alternative material that allows a significant reduction in the weight of car parts. This leads to an increase in efficiency in transport vehicles. This article describes experimental as well as model analysis of damage to composite textiles during dynamic fracturing. The obtained information provides an approach to the complex problem of crack propagation in composite textiles intended for use in car seats. This is especially important from the point of view of safety, because during an accident a significant overload of the human body occurs and its kinetic energy can cause deformation of a breach in the composite textile. Therefore, identifying the direction of crack propagation is very important for the safety of passengers. Experimental studies have demonstrated that a dynamic breach is caused by the significant deformation of the tested sample. The distribution and direction of crack propagation in the sample was studied using a FEM model, based on the Griffith-Irwin criterion with nonlinear orthotropic properties of the composite textile.

Out-of-plane behaviour of infill masonry panels strengthened with composite materials

The performance of various composite materials applied to strengthen hollow masonry panels under out-of-plane actions is compared here. The strengthening solutions belong to three reinforcement Externally Bonded (EB) wet lay-up systems: (i) bidirectional composite meshes applied with inorganic matrices, i.e., Textile Reinforced Mortars (TRM); unidirectional composite textiles applied with (ii) inorganic matrices, i.e., Steel Reinforced Grouts (SRG), or (iii) organic (epoxy) matrices, i.e., Fibre Reinforced Polymers (FRP), Steel Reinforced Polymers (SRP) and Natural FRPs. Carbon FRP, flax and hemp NFRP, and basalt and glass-based TRM were examined. As inorganic matrix, a cement-based mortar was used for TRMs; in the case of SRGs, comparisons with a magnesia-based matrix were also carried out. Twenty-seven specimens were subjected to simplified four-point monotonic bending tests, aimed at reproducing in the laboratory the failure condition of infill masonry walls under out-of-plane actions. The results are compared in terms of failure mode and mechanical improvement, and provide an analytical evaluation of moment–curvature behaviour according to bilinear laws.

Chemical, mechanical and antibacterial properties of silver nanocluster/silica composite coated textiles for safety systems and aerospace applications

This work describes the chemical, mechanical and antibacterial properties of a novel silver nanocluster/silica composite coating, obtained by sputtering, on textiles for use in nuclear bacteriological and chemical (NBC) protection suites and for aerospace applications.The properties of the coated textiles were analyzed in terms of surface morphology, silver concentration and silver release in artificial sweat and synthetic tap water, respectively. No release of silver nanoparticles was observed at given conditions.The water repellency, permeability, flammability and mechanical resistance of the textiles before and after sputtering demonstrated that the textile properties were not negatively affected by the coating.The antibacterial effect was evaluated at different experimental conditions using a standard bacterial strain of Staphylococcus aureus and compared with the behavior of uncoated textiles.The coating process conferred all textiles a good antibacterial activity. Optimal deposition conditions were elaborated to obtain sufficient antibacterial action without altering the aesthetical appearance of the textiles.The antibacterial coating retained its antibacterial activity after one cycle in a washing machine only for the Nylon based textile.

Conductive Fabric Responding to Extremely Small Temperature Changes

This paper presents a conductive fabric with temperature sensing capability. A polycarbonate film covered with the thin layer of the molecular semiconductor α’-(BEDT-TTF)2IxBr3-x was used as a sensing component; the resistance of α’-(BEDT-TTF)2IxBr3-x-based layer changes as 250-300Ω/cm2 per degree; BEDT-TTF=bis(ethylendithio)- tetrathiafulvalene. Due to the low mass of the layer of organic molecular semiconductor and its good thermal conductivity, such temperature sensor reacts quickly towards thermal changes. The film was successfully embedded on the surface of a polyester textile obtaining a conductive fabric that responds fast and in a reversible manner to extremely small temperature changes. Such composite textiles can be easily prepared at low cost and they are compatible with printing techniques. This work strongly contributes on the ongoing research of developing smart textiles for their biomedical applications.

OS1401 テキスタイルCFRP複合材料における樹脂含浸挙動

Fiber reinforced thermoplastic composites has poorer matrix resin impregnation to fiber reinforcement, because of extreme high viscosity of molten thermoplastics. Intermediate materials using Micro-Braiding technique have been developed to overcome these difficulties. In this study, composite textiles plates were fabricated under various fabrication conditions, and their impregnation were investigated experimentally and predicted by theoretical formulae. As a result, impregnation increased with molding pressure and time, and impregnation of single-ply textiles is improved compared with that of multi-ply textiles because they have more collapsed fiber bundles, hence closer impregnation distance. On another front, the analytical predictions were in disagreement with the experimental results.

Effects of architecture on ballistic resistance of textile fabrics: Numerical study

Composite textiles composed of materials such as Kevlar, Dyneema and Zylon are extensively used in many force/impact protection applications, such as body armor, and automobile and airplane engine fragment resistant containment. Significant effort has been devoted to ballistic testing of composite fabrics made from various manufacturing processes and designs. Performing comprehensive ballistic and impact tests for these composite textiles is a very time-consuming and costly task. Numerical models are presented in this research, thereby providing predictive capability for the manufacturer and designer to minimize field testing, as well as shedding light on to the damage mechanisms of composite fabrics subjected to ballistic impact. Several representative composite fabric architectures (such as plain weave, basket weave and knitted fabrics) are generated for finite element analysis. Numerical investigation is conducted on these fabric structures of the same mass per unit area subjected to projectile impacts. Failure patterns of woven and knitted fabrics obtained from numerical simulations are compared with those observed experimentally. Performances of the representative textile structures are evaluated based on the resultant velocity of the projectile, as well as various energy components. The influences of yarn–yarn and yarn–projectile friction properties on the ballistic performance of various textile structures are presented. To highlight the effects of projectile geometry and angular rotation on the fracture of woven and knitted fabrics, a series of simulations are also performed with three distinctive projectiles of the same mass and impact energy.

Improving Electrical Performances of Wool Textiles: Synthesis of Conducting Polypyrrole on the Fiber Surface

Antistatic treatments lower the electrical resistivity of textiles and facilitate charge dissipation avoiding high potential electrical discharges. Moreover, low surface resistivity gives textiles electro-conducting, soil release, thermal and electromagnetic shielding properties. A new way of producing electrically conducting textiles consists of treatments with organic conducting polymers. Unfortunately, conducting polymers have a low level of processability because of their poor mechanical and physical properties. These problems have been overcome by simple in situ depositions of conducting polymers on different substrates in order to produce composite materials with good mechanical properties. Polypyrrole (PPy) is one of the most promising candidates because it exhibits high conductivity and good environmental stability. In situ PPy synthesis on wool and on other animal fibers is presented in this work. A preliminary oxidative treatment (e.g. shrink-proofing, bleaching or depigmentation) improves the electrical properties of the resulting conductive composite textiles significantly.

Vapour phase polymerisation of pyrrole on cellulose-based textile substrates

Conducting textiles were prepared embedding polypyrrole in natural and man made cellulose-based fibres, such as cotton, viscose, cupro and lyocell, by means of in situ polymerisation. Chemical vapour phase deposition of polypyrrole is a suitable process for producing electro-conductive composites in two steps: (a) fabric impregnation with an aqueous solution of oxidant and dopant and subsequent drying; (b) exposition to pyrrole vapour and polymerisation. Comparative morphological and structural analysis was carried out on the conducting viscose prepared with both vapour and liquid phases processes and some significant differences in the structural, calorimetric and electrical properties were highlighted, due to the different methods of preparation. Vapour phase prepared fabrics show a high uniform polypyrrole coating on the fibre surface and its partial penetration inside the amorphous zones of the fibre bulk. WAXD analysis shows that the conducting fabrics preserve the crystalline structure of the cellulose matrix, while SAXS results evidence the presence of a nanoparticle dispersion of polypyrrole in the cellulose matrix. Polypyrrole–cellulose conducting composite textiles show good performances to light exposure and washing fastness tests.

Evolution of electrical properties of some conductive polymer composite textiles with organic solvent vapours diffusion

The sensitivity of several conductive polymer composites (CPC) to solvent vapours has been studied. Electrical properties of three CPC poly(amide12-b-tetramethylene oxide)-carbon black (PEBAX-CB), poly(propylene)-carbon black (PP-CB) and poly(ethylene-co-ethyl acrylate)-carbon black (EEA-CB) were investigated in the presence of four organic solvent vapours, chloroform, toluene, methanol and ethanol. The experiments show that it is possible to use extruded CPC textiles to combine acceptable conductivity for heating and satisfying response for vapour detection. Moreover, the investigation of the mechanisms involved during the solvent vapours diffusion into the CPC, shows that not only the response of the systems Δ R/ R 0 can be used for vapour detection but also the shape of the curves, i.e., the diffusion mode characterised by Δ R/ R max versus t curves slope and onset. The diffusion curve shape analysis together with the use of CPC of different chemical nature and structure (comonomer content and crystallinity) is expected to decrease the number of CPC necessary for vapour detection.

Porosity and air permeability of composite clean room textiles

It is well‐known that clean room textiles are acting as a barrier protecting humans against the surrounding atmosphere or vice versa. These textiles are produced in the limited range of porosity and the air permeability. The porosity calculated from fabric geometry and the air permeability of two typical clean room textiles of Czech production are measured. The variation of air permeability is described by the analysis based on the coefficient of variation and spatial autocorrelation. The air permeability of composite textiles of multiple layers is predicted from a simple model. This model is based on the idea of a combination of air pressure drop in individual layers. The predicted air permeability is compared with experimental measurements.