Off-axis tensile properties of multistitched plain woven E-glass/polyester composites

The aim of this study was to understand the ±45 ° directional off-axis tensile properties of the developed two dimensional (2D) multistitched multilayer E-glass/polyester woven composites. It was found that the off-axis tensile strength of the unstitched structure was slightly higher than those of the multistitched structures. The reason was that the multistitching process caused the filament breakages. It was also found that when the stitching direction and stitching density in structures increased, their off-axis tensile modulus decreased. Therefore, stitching directions, stitching density and stitching yarn on the composite structures were considered as important parameters. All structures under the off-axis tensile load had normal deformation, or angular deformation or shrinkage in width. In addition, both the normal deformation and the shrinkages in width occurred in most of the two and four directional stitched structures. On the other hand, four directional Kevlar^® 129 yarn dense stitched E-glass/polyester structure showed only shrinkage in width after angular deformation. This could be considered as a new failure mode because of the multistitching. These results indicated that the stitching directions and density generally influenced the off-axis tensile properties of the multistitched E-glass/polyester woven composites.     

Predicting the air permeability of polyester/cotton blended woven fabrics

The aim of this study was to model the air permeability of polyester cotton blended woven fabrics. Fabrics of varying construction parameters i.e. yarn linear densities and thread densities were selected and tested for air permeability, fabric areal density and fabric thickness. A total of 135 different fabric constructions were tested among which 117 were allocated for development of prediction model while the remaining were utilized for its validation. Four variables were selected as input parameters on basis of statistical analysis i.e. warp yarn linear density, weft yarn linear density, ends per 25 mm and picks per 25 mm. Response surface regression was applied on the collected data set in order to develop the prediction model of the selected variables. The model showed satisfactory predictability when applied on unseen data and yielded an absolute average error of 5.1 %. The developed model can be effectively used for prediction of air permeability of the woven fabrics.     

Mechanical properties of rice straw fiber-reinforced polymer composites

Rice straw fibers have been used as reinforcing fillers in different polymers, tow composites were prepared by using polyvinyl alcohol and polystyrene polymers with different ratio of polymers. The pressed samples were subjected to various electron beam irradiation dose. The results indicated that, flexural strength, impact strength and modulus of elasticity increase with increasing the polymer ratio in the mix composition. It was found that the water absorption and thickness swelling percentages of rice straw fiber polystyrene composites decrease with increasing the polystyrene content in the same composition, while its values for rice straw polyvinyl alcohol composites improve. These are attributed to hydrophobic and hydrophilic characteristics of the tow composites. The improvement of physico-mechanical properties of both composites with the increase of electron beam irradiation dose are probably attributed to randomly initiated chain reactions, which started by the reactive centers created by electron beam. These observations were confirmed by IR spectrometer and SEM studies.     

Warp and weft directional tensile properties of multistitched woven fabric E-glass/polyester nano composites

The aim of this study was to understand the warp and weft directional tensile properties of the developed two dimensional (2D) multistitched multilayer E-glass/polyester woven nano composites. It was found that the warp and weft directional specific tensile strength and modulus of unstitched structure were higher than those of the machine stitched and machine stitched/nano structures due to stitching caused filament breakages. When the nano silica material in the unstitched E-glass/polyester composite structure increased, the warp and weft directional specific tensile strength and the modulus of the unstitched/nano structures increased. The failure of warp and weft directional 2D unstitched and unstitched/nano woven E-glass/polyester composite structures had a complete delamination in their cross-sections. But, the failure of warp and weft directional 2D stitched and stitched/nano woven E-glass/polyester composite structures had a local delamination in their cross-sections and the failure was confined at a narrow area. The warp and weft directional specific damaged areas of unstitched structure were higher than those of the stitched and stitched/nano structures. Also, the warp and weft directional specific damaged areas of machine stitched structure were slightly higher than those of the machine stitched/nano structure. It could be concluded that the addition of nano silica to the stitched structures improved to their damage resistance.     

Analysis and tensile characterization of air-entangled textured polyester woven fabrics depending on interlacement and yarn sets

The aim of this study was to understand the failure mechanism of two dimensional dry fabric structure considering yarn sets and interlacements. For this purpose, data generated on air-entangled textured polyester woven fabric under the simple tensile load and analyzed by developed regression model. The regression model showed that warp and weft directional tensile strengths of satin fabric were higher than those of plain and rib fabrics in unravel sample. This might be related to the number of interlacements of the fabrics. There was not a considerable difference between warp directional tensile strength of ravel and unravel satin fabrics, whereas weft directional tensile strength of ravel satin fabric decreased rapidly with respect to its unravel form. The satin fabric showed the highest warp directional tensile strength among the others. The lowest weft directional tensile strength was received from ribs fabric. In semi-ravel sample, all fabrics showed low warp and weft directional tensile strength values except in plain fabric. Warp directional tensile elongation of plain fabric was the highest in unravel sample. Satin fabric showed the highest warp directional tensile elongation in the ravel sample. Warp directional tensile elongations of all the fabrics in the semi-ravel sample became low. Weft directional tensile elongation of satin fabric was the highest in unravel sample. In addition, satin and plain fabrics showed the highest weft directional tensile elongations in the ravel sample. Weft directional tensile elongations of all the fabrics in the semi-ravel sample became low except in ribs fabric.     

Characterizations of stick-slip stage of yarn pull-out in dry and softening treated polyester plain woven fabric

The aim of this study was to understand the stick-slip properties of polyester plain woven fabric. For this reason, pull-out test was conducted on dry and softening treated polyester woven fabrics. It was found that stick-slip force and accumulative retraction force depend on the number of pulled ends in the fabric, fabric sample dimensions and softening treatments. Stick-slip forces of polyester fabric in the multiple yarn pull-out test were higher than those of the single yarn pull-out test. Stick-slip force in single and multiple yarn pull-out tests in the dry polyester plain fabric were generally higher than those of the softening treated polyester plain fabric. On the other hand, the amount of stick-slip force was related to the number of interlacement points in the fabric whereas the amount of accumulative retraction force was related to fabric structural response.     

Study on mechanical and thermal properties of fiber-reinforced Epoxy/Hybrid-silica composite

Recently, carbon fiber composites have been widely used as structural reinforcement materials of buildings, replacing reinforcing bars or concrete. And the increase in use of super fibers such as aramid and high strength PE, which is aimed at improving the reinforcement properties, has resulted in a demand for a resin system with excellent mechanical and thermal properties. In this research, a fiber-reinforced composite has been produced by using the super fibers such as carbon fiber or aramid fiber, reinforcement resin and the silica hybrid compound containing epoxy group. This study was carried out to confirm the effect of the silica hybrid on mechanical properties, heat resistance and adhesion strength of a fiber-reinforced epoxy composite, which was produced by blending silica or introducing silica hybrid through covalent bonds. And the silica hybrid containing epoxy group, which may be introduced to the structure of fiber-reinforced epoxy composite through covalent bonds caused by reaction with a hardener, has been used, so that the heat resistance and adhesion strength could be improved.     

Basalt nanoparticle reinforced hybrid woven composites: Mechanical and thermo-mechanical performance

Nanoparticles are gaining wider importance and increasing utility in many areas of engineering and technology. This investigative work is conducted to study the effect of incorporating basalt nano particles in composites with basalt/basalt and basalt/jute woven structures as reinforcement. The nanoparticles were developed from basalt, they were characterized and used for reinforcing composites of basalt and jute hybrid fabrics. The mechanical and thermo-mechanical properties of hybrid woven basalt reinforced epoxy composites were evaluated. Microscopic examination was carried out in order to analyze the internal structure and fractured surfaces. Interfacial characteristics, material morphology and failure was studied by use of Scanning Electron Microscope (SEM) and optical microscopy. Thermal stability was characterized by TGA. The results elaborated that the incorporation of basalt nanoparticles exhibited superior properties compared to the pure epoxy resin impregnated basalt fabric reinforced composites in terms of mechanical and thermal stability.     

Mechanical and water absorption properties of woven jute/banana hybrid composites

This work aims to predict the mechanical properties of woven jute/banana hybrid composite. Woven fabrics are arranged in three layers of different sequence. Resin used in this work is Epoxy LY556 with hardener HY951. Composite specimen are prepared by hand-layup techniques. The effect of layering sequence on the mechanical properties namely tensile, flexural and impact was analysed. It is found that the tensile and flexural strength of hybrid composite (Banana/Jute/Banana) is higher than that of individual composites. Similarly, the impact strength of Jute/Banana/Jute hybrid composite is better than other types of composite. It is found that the moisture absorption of woven banana fiber composite is lesser than the hybrid composite. Fractography study of the fractured specimen is carried out using scanning electron microscope to analyse the fracture behaviour of the hybrid composite.     

Mechanical properties of fragrant screwpine fiber reinforced unsaturated polyester composite: Effect of fiber length,fiber treatment and water absorption

Fragrant screwpine fiber reinforced unsaturated polyester composites (FSFRUPC) were subjected to water immersion tests in order to examine the effect of water absorption on the mechanical properties. FSFRUP composite specimen containing 30 % fiber volume fraction with fiber length of 3 mm and 9 mm was considered in this study. Water absorption test was performed by immersing specimen in sea, distilled and well water at room temperature under different time durations (24, 48, 72, 96, 120, 144, 168, 192, 216, 240 hours). The tensile, flexural and impact properties of the water absorption specimen were appraised and compared with those of the dry composite specimen as per the ASTM standard. The tensile, flexural and impact properties of FSFRUPC specimen were found to decrease with the increase in the percentage of moisture uptake. The percentage of moisture uptake of composite was reduced after alkali treatment with 3 % NaoH for 3 hours. In moisture absorption test, the lowest diffusion coefficient, D (6.62513×10^-13 m²/s) and swelling rate parameter, K _sr (6.341×10^-3 h^-1) were obtained through the specimen immersed in sea water. The chemical composition, elemental composition of fiber and surface morphology of the FSFRUPC were analysed by using Fourier transform infrared spectroscopy (FTIR), Energy dispersive spectroscopy (EDS) and scanning electron microscopy (SEM) respectively.     

Analysis and off-axis tensile characterization of air-entangled textured polyester woven fabrics depending on unit cell interlacing frequency

The aim of this study is to analyze and determine the off-axis tensile properties of air-entangled textured polyester fabrics based on unit cell interlacing frequency. For this purpose, continuous filament polyester air-entangled textured yarn was used to produce plain, ribs and satin woven fabrics. The fabrics were cut from the warp direction (0°) to weft direction (90°) at every 15° increment, and tensile tests were applied to those of the off-axis samples. The strength and elongation results were introduced to the statistical model developed, and regression analyses were carried out. Hence, the effects of off-axis loading and interlacement on the directional tensile properties of the fabric were investigated. The regression model showed that off-axis loading influences fabric tensile strength. On the other hand, interlacement frequency is the most important factor for fabric tensile elongation. The results from the regression model were compared with the measured values. This study confirmed that the method used in this study as can be a viable and reliable tool. Future research will concentrate on multiaxially directional fabric and the probability that it will result in homogeneous in-plane fabric properties.     

Mechanical properties and hand evaluation of hemp woven fabrics treated with liquid ammonia

The effects of liquid ammonia (L/A) treatment on the mechanical properties and hand of 100 % hemp woven fabrics were investigated by the KES-FB (Kawabata Evaluation System for Fabric). Tensile energy and tensile resilience were increased by the L/A treatment. Bending and shearing values such as bending rigidity, bending moment, shear stiffness, shear hysteresis of the L/A treated fabrics were lower than those of the untreated ones. Compressional linearity and compressional energy were decreased while the compressional resilience was increased by the L/A treatment. From the hand evaluation, the primary hand values as well as total hand value of the hemp fabric were markedly increased by the L/A treatment, especially when yarn number was fine. Therefore, L/A treatment was found to be an effective method of improving the flexibility and softness of hemp woven fabrics.     

Effect of coir fiber content and compatibilizer on the properties of unidirectional coir fiber/polypropylene composites

The main objective of this research was to study the effect of fiber content variation and stearic acid (SA) treatment on the fundamental properties of unidirectional coir fiber (CF) reinforced polypropylene (PP) composites. Several percentages of filler contents were used (10–40 wt %) in order to gain insights into the effect of filler content on the properties of the composites. Coir/PP composites were fabricated by compression molding, and the properties of composites were studied by physico-mechanical and thermal properties. The results from mechanical properties such as tensile strength (TS), tensile modulus (TM) and impact strength (IS) of the CF/PP composites were found to be increased with increasing fiber content, reached an optimum and thereafter decreased with further increase in fiber content. Treatment of the coir with SA as the coupling agent enhanced the mechanical properties, crystallization temperature and crystallinity of virgin PP and water desorption of the resulting composites, resulting from the improved adhesion between the CF and PP matrix. Scanning electron micrographs (SEM) of the tensile fractured samples showed improved adhesion between fiber and matrix upon treatment with SA. Interfacial shear strength (IFSS) of the composites was measured by single fiber fragmentation test (SFFT).     

Evaluation of bamboo charcoal/stainless steel/TPU composite woven fabrics

Composite woven fabric satisfies what people require. Bamboo charcoal (BC) has been identified as a multifunctional material that has far-infrared ray, anions, deodorization and etc. BC fibers and yarns were made of bamboo charcoal powders and have further become a pervasive materials used in textile industry. In this study, cotton yarns, stainless steel/cotton (SS/C) complex yarn, bamboo charcoal/cotton (BC/C) complex yarns were woven into the plain, twill and Dobby composite woven fabrics. The warp yarn was composed of cotton yarns, and the weft yarn was made up of BC/C and SS/C complex yarns with a picking ratio of 1:1 and 3:1. Thermoplastic polyurethanes (TPU) film was then attached to the composite woven fabrics, forming the BC/SS/TPU composite woven fabrics. Tests of electromagnetic shielding effectiveness (EMSE), far-infrared emissivity, anions, water resistance, and water vapor permeability measured the single-layer, two-layer and four-layer composite woven fabrics, obtaining a far-infrared emissivity of 0.95 by 39.8 counts per minute, an anion count of 149 amount/cc, an EMSE of −11.87 dB under frequency of 900 MHz, a surface resistivity of 8×10⁻⁶ Ω/square, a water resistance of −8219 mmH₂O, and water vapor permeability of 989 g/m²·h and 319 g/m²·24 h in accordance with JIS L 1099 A1 and ASTM E96 BW.     

Mechanical,thermal and interfacial properties of green composites from basalt and hybrid woven fabrics

Composites based on pure Basalt and Basalt/Jute fabrics were fabricated. The mechanical properties of the composites such as flexural modulus, tensile modulus and impact strength were measured depending upon weave, fiber contents and resin. Dynamic mechanical analysis of all composites were done. From the results it is found that pure basalt fiber combination maintains higher values in all mechanical tests. Thermo-gravimetric (TG/DTG) composites showed that thermal degradation temperatures of composites shifted to higher temperature regions compared to pure jute fabrics. Addition of basalt fiber improved the thermal stability of the composite considerably. Scanning electron microscopic images of tensile fractured composite samples illustrated that better fiber-matrix interfacial interaction occurred in hybrid composites. The thermal conductivity of composites are also investigated and thermal model is used to check their correlation.     

Microstructure and properties of Ni-Fe3O4 composite plated polyester fabric

In this study, electroless Ni-Fe₃O₄ composite plating on polyester fabric modified with 3-aminopropyltrimethoxysilane (APTMS) was investigated under ultrasonic irradiation. Effects of deposit weight on microstructure and properties of Ni-Fe₃O₄ composite coating were studied. Surface morphology, chemical composition and state, crystal structure of the electroless Ni-Fe₃O₄ composite plated polyester fabric were characterized by SEM, EDX, XPS and XRD. Magnetic properties, electrical resistivity and electromagnetic interference (EMI) shielding effectiveness (SE) of Ni-Fe₃O₄ plated polyester fabric were also evaluated. The presence of co-deposition of Fe₃O₄ in Ni coating on the polyester fabric is demonstrated by an XPS analysis. At a higher deposit weight, there is an increase in particle size and saturation magnetization, and a decrease in electrical resistivity with respect to the rise of deposit weight, respectively. As the Ni-Fe₃O₄ weight on the treated fabric is 32.90 g/m², the EMI SE of the Ni-Fe₃O₄ plated polyester fabric arrives 15–20 dB at frequencies that range from 8 to 18 GHz. The results indicate the Ni-Fe₃O₄ plated polyester fabrics are used as super-paramagnetic, conductive and EMI shielding materials.     

Mechanical properties and water purification characteristics of natural jute fiber-reinforced non-cement alkali-activated porous vegetation blocks

This study reports the effects of the volume fraction of natural jute fiber and the content of the alkali activator on the physical and mechanical properties, sulfate ion resistance, and water purification characteristics of non-cement porous vegetation blocks. The volume fractions of the natural jute fiber were 0.0, 0.1, and 0.2 %, and the alkali activator was applied by replacing 5, 6, 7, 8, 9, and 10 % by weight of the blast-furnace slag. Void ratio, compressive strength, sulfate resistance, and water purification characteristics were characterized. The results indicate that increasing natural jute fiber and the alkali activator content increased the void ratio and improved compressive strength and sulfate resistance. pH was not affected by natural jute fiber content but increased with alkali activator content. At alkali activator contents of 9–10 %, the observed compressive strength was similar to that of cement blocks, whereas mixes with alkali activator contents of 8–10 % showed similar or greater void ratios than those of cement blocks. The compressive strength of the cement blocks decreased following immersion in sulfate solutions; however, the compressive strength of the mixes with the alkali activator and blast-furnace slag increased following exposure to sulfates. Water purification characteristics were examined by allowing water to filter through the blocks; the non-cement porous vegetation blocks reduced the suspended solids, 5-day biological oxygen demand, chemical oxygen demand, total nitrogen, and total phosphorous in the water by >40 %.     

Predicting the tensile strength of polyester/cotton blended woven fabrics using feed forward back propagation artificial neural networks

Tensile strength plays a vital role in determining the mechanical behavior of woven fabrics. In this study, two artificial neural networks have been designed to predict the warp and weft wise tensile strength of polyester cotton blended fabrics. Various process and material related parameters have been considered for selection of vital few input parameters that significantly affect fabric tensile strength. A total of 270 fabric samples are woven with varying constructions. Application of nonlinear modeling technique and appreciable volume of data sets for training, testing and validating both prediction models resulted in best fitting of data and minimization of prediction error. Sensitivity analysis has been carried out for both models to determine the contribution percentage of input parameters and evaluating the most impacting variable on fabric strength.     

Mechanical properties and water absorption of short snake grass fiber reinforced isophthallic polyester composites

Natural fiber composite replaces the conventional and synthetic materials in many fields especially in light weight applications. The randomly oriented short snake grass fiber reinforced isophthallic polyester composites are prepared by hand lay-up technique and finally compression molded. The various length and weight fraction of fiber are used in composite fabrication. The mechanical properties and water absorption under various climatic conditions are examined according to the prescribed standard. SEM image revealing the fiber pullout and breakage of the tensile and impact fractured composite specimens has been analysed and compared with control through scanning electron microscope. The result shows that the mechanical properties increase with increase in fiber length and weight fraction of the composites. The rate of water absorption increases with increase in temperature and time. Obtained experimental tensile strength of the composite is compared with various theoretical models such as Series, Hirsch’s, Halpin-Tsai, Modified Halpin-Tsai and Modified Bowyer & Brader’s and the obtained inferences are discussed.