Use Of Natural Fibers Research Articles

Editor's Corner: Green Materials - The Advancements and Applications of Natural Fibers

After the industrial revolution, our world started shifting its focus towards sustainability and eco-friendly green materials to replace their synthetic counterparts. Cellulose fibers have played a significant role in human history, providing clothing and various products for many centuries. However, as technology advanced, the use of natural fibers became limited and minimized by synthetic materials. Growing environmental awareness has compelled industries to rethink their strategies, directing their attention toward sustainable and eco-friendly alternatives. In this context, natural cellulose fibers have gained a significant interest due to their eco-friendliness. These fibers can be derived from various sources, including trees, plants, and grasses. Cellulose fibers obtained from plants possess remarkable properties such as low density, wide availability, considerable mechanical strength, good thermal insulation, affordability, ease of processing, and non-toxicity

The effect of recycled date palm tree fibers on the impact fatigue and residual static strength of adhesively bonded joints

The role of natural fibers on the impact fatigue strength of bonded single lap joints (SLJs) has been experimentally investigated. The use of natural fiber offers several advantages, including the potential to recycle natural resources and the utilization of sustainable materials. Four types of natural date palm tree fibers (DPTFs) including Rachis, Petiole, Bunch, and Mesh were used to improve the impact fatigue life and the residual static strength of joints after enduring repetitive low energy impacts. The fibers were treated by 6 wt% of NaOH solution and cut manually to short size (0.5–2 mm) and were used by weight ratios of 2 and 5 %. The results show that the addition of DPTFs to the adhesive layer significantly improves the impact fatigue strength of the reinforced joints compared to neat adhesive SLJs. The joints reinforced by 5 wt% and 2 wt% of Mesh improved the impact fatigue life of the joints by 197 % and 87 %, respectively. The impact fatigue life of the joints modified by 5 wt% of fibers was more than the joints reinforced by 2 wt%. Fractography analysis also showed that DPTFs make the crack propagation more stable and increase the strength of the tested joints on different conditions.

Transforming non-wood feedstocks into dissolving pulp via organosolv pulping: An alternative strategy to boost the share of natural fibers in the textile industry.

This work evaluates wheat straw, switchgrass, and hemp hurd as potential alternatives for producing dissolving pulp using sulfur dioxide (SO2)-ethanol-water (SEW) pulping. The SEW process is described in detail for wheat straw, and the best pulping conditions for this feedstock were 130 °C, 4 h, and 10% SO2 concentration, comprised in a sulfur-ethanol-water ratio of 10-45-45. This resulted in a viscose-grade pulp with 93% α-cellulose, 2.0% hemicelluloses, <0.1% lignin, 0.2% ash content, and a viscosity of 4.7 cP. The best pulping conditions for wheat straw were applied to switchgrass and hemp hurd. Wheat straw and switchgrass had similar pulp quality, while hemp hurd pulp had a higher hemicellulose content and lower viscosity. This work suggests that non-wood feedstocks such as wheat straw and switchgrass can be promising alternatives for dissolving pulp production, which can help reduce the pressure on the textile industry to increase the use of natural fibers and mitigate the environmental impact of non-biodegradable synthetic fibers.

Chemical, thermal and morphological properties of polybutylene succinate-waste pineapple leaf fibres composites

The use of natural fibres for polymer composite applications has been widely researched due to the biodegradable and lightweight nature of natural fibres. To achieve good adhesion and compatibility between the matrix and the fibre filler, prior modification of the fibre surface via the use of various methods has been found to be effective. The natural fibres have been modified using chemical, physical, radiation, grafting and biological methods. The current study aims to evaluate the effect of sodium hydroxide-treated waste pineapple leaf fibres (PALF) content on the chemical, thermal, and morphological properties of polybutylene succinate (PBS) composites. PBS-PALF composites with fibre content ranging from 0 to 20 wt% were prepared using an internal mixer and their properties were studied using Fourier transform infrared (FTIR), X-ray diffraction (XRD), Differential scanning calorimetry (DSC), Thermogravimetric analysis (TGA) and Scanning electron microscope (SEM). The FTIR results showed no noticeable functionality differences among the composites, however, carbonyl groups from PBS polymer at ∼1700 cm−1 and hydroxyl groups from PALF at ∼3000 cm−1 were observed in the composites. The water absorption uptake of the composites increased with fibre content due to the hydrophilic nature of the PALF fibres and the highest water absorption percentage achieved was ∼30 %. The incorporation of the fibres into the PBS matrix decreased the crystallinity of the composites as shown by the XRD peaks at 2ϴ = 22 and 30°. SEM images of the composites with 20 wt% exhibited morphologies where the fibres protruded out from the polymer matrix, and this was ascribed to the agglomerated fibres which were poorly mixed with the matrix at the higher fibre content. Overall, the incorporation of high PALF content in the composites disrupted the crystallinity and thermal stability of the PBS matrix. The composites have potential in industrial agricultural mulching film applications due to their sustainability characteristics.

Improving interfacial shear strength of fique fibres using an acrylic coating.

Natural fibres have proven to be a potential alternative to replace synthetic fibres in some composite materials applications. However, drawbacks such as impregnation difficulties and the poor fibre-matrix interface limit the use of natural fibres in high-performance applications. This work proposes using an acrylic resin to coat the fibre surface to enhance the interfacial compatibility among fique fibres and polyester resin. Pull-out tests revealed an improvement in the interfacial shear strength of about 110% for coated fibres. Furthermore, nanoindentation test, Micro Raman spectroscopy and scanning electronic microscopy indicated that the acrylic resin eliminates the gap at the fibre/matrix interface seen in the uncoated fibres. Observed behaviour could be attributed to a better chemical bonding between the fibre and matrix and is also hypothesised that the elastic characteristic of the coating helps to transfer loads effectively from the matrix to the fibre.

The use of natural fibers in stone mastic asphalt mixtures: a review of the literature

The use of natural fibers in stone mastic asphalt mixtures: a review of the literature

Mapping the recent advancements in bast fiber reinforced biocomposites: A review on fiber modifications, mechanical properties, and their applications

Fiber reinforced polymer composites (FRPCs), due to their multifunctional properties, have already occupied a significant place in various applications such as aerospace, automotive, marine, structural engineering, and healthcare industries. Lightweight FRPCs are preferred over heavier materials because of some key advantages, such as high strength-to-weight ratio, corrosion resistance, design flexibility, fatigue resistance, damping properties, and electrical and thermal insulation properties. Though synthetic fibers such as carbon, glass, aramid fiber reinforced composites are found to provide better performance, these fibers are expensive as well as impose adverse impacts on the environment. Currently, bast fiber reinforced biocomposites (BFBCs) are receiving increasing attention due to their biodegradability, availability, low cost, and higher strength-to-weight ratio. Researchers are working rigorously on BFBCs to unveil their optimal properties. BFBCs can be disposed of easily without affecting the environment. BFBCs, with their sustainable and biodegradable properties, notably promote the use of natural fibers particularly bast fibers and minimize the consumption of expensive and non-degradable synthetic fibers reinforcements in the composite industry. This paper provides an overview of the use of different natural fibers in reinforcing polymer composites for various applications to achieve sustainability. The influence of various fibrous preforms of bast fibers on the mechanical behavior of BFBCs, and their prospects are comprehensively reviewed.

Анализ механических свойств и характеристик свободных колебаний полимерного композита на основе переплетенных обработанных волокон джута

Introduction: Recently, the use of natural fibers have been increased to replace the use of synthetic fibers to save our environment from waste disposal problems, natural fibers have a lower level of mechanical properties. The purpose of work: This study examines the effect of treating the surface and deeper layers of jute fiber on the mechanical behavior and characteristics of free vibrations of a composite material based on it. The methods of investigation: due to the uniform distribution of stresses in the WARP and WEFT directions, four-layer basket weave jute fibers were used in this study. Result and discussion: the mechanical and free vibration properties of composite materials are significantly improved when NaOH is applied to jute fibers because it eliminates the weak matrix material lignin and makes the fibers stiffer and stronger. However, increasing the percentage of NaOH and soaking time for the fibers in NaOH solution have little effect on these properties. The highest value of tensile strength and tensile modulus are found 50 ± 1.17 MPa and 1.94 ± 0.23 GPa respectively seen in case of basket weave jute fiber composite with 1 hour treatment. Tensile strength and tensile modulus increase about 12 % and 40 % over the stokes value, respectively. Similarly the value of flexural strength and flexural modulus are found 95 ± 1.17 MPa and 3.99 ± 0.23 GPa respectively in case of basket weave jute fiber composite with 1 hour treatment. It also shows the highest value of fundamental frequency 77.837 Hz.The presence of an O-H bond in the composite, as revealed by FTIR study, gives it a hydrophilic character and limits its use in humid environments. The fiber to matrix ratio is shown in SEM images.

Variability Analysis of Compressive and Flexural Performance of Coconut Fibre Reinforced Self-Compacting Concrete

Self-compacting concrete (SCC) is a high-performance material that flows freely and consolidates without segregation or bleeding. This study investigated the effectiveness of incorporating coconut fiber into SCC to improve its strength and toughness. Three mixtures with coconut fiber inclusions of 0.2%, 0.4%, and 0.6% by weight of cement were used. The addition of coconut fiber reduced the workability and passing ability of the concrete, but all mixes met the SCC specification. The CFRSCC with 0.2% had the highest compressive and flexural strengths. The study concluded that adding 0.2% coconut fiber to SCC can increase its strength. The use of natural fibers like coconut can enhance the properties of concrete and could be an alternative to synthetic fibers, especially in regions where natural fibers are locally available and cost-effective.

Flexural strength and flammability of pineapple leaf fiber (PALF)/fire retardants reinforced polymer composites

The use of natural fibers as reinforcement in composite materials, such as pineapple leaf fiber (PALF), has been extensively studied. However, it is important to note that natural fiber-reinforced polymer composites are often associated with high flammability. The aim of this paper is to investigate the mechanical properties and fire retardancy of Pineapple Leaf Fiber (PALF) reinforced polymer composites treated with various flame retardants. The PALF composites were treated with different fire-retardant additives, including ammonium polyphosphate (APP), aluminum hydroxide (ALH), and magnesium hydroxide (MH), at varying ratios (10 wt%, 20 wt%, and 30 wt%). The flexural properties of the PALF composites were assessed using a Universal Testing Machine (UTM) in accordance with ASTM D7264. The flammability testing was conducted following the Underwriters Laboratories 94 (UL-94) using standard ASTM D635 and ASTM D3801. The results of flexural tests indicated that PALF-reinforced polymer composites containing 10% MH as fire retardant exhibited the highest flexural strength (102.96 MPa). Scanning Electron Microscopy (SEM) was employed to analyze the fracture behavior of PALF-reinforced polymer composites with different fire-retardant additives. The SEM analysis revealed various characteristics including fiber pull-out, fiber breakage, inhomogeneous structural distribution (in cases of APP, MH, ALH), presence of undesired bubbles, and fiber–matrix cracking. In terms of fire retardancy, the most promising results were obtained with the addition of 20% and 30% APP. These compositions achieved V-1 and V-0 ratings respectively, in the vertical UL-94 flammability test. Notably, the horizontal test demonstrated that the composites containing 30% APP did not sustain burning and exhibited no burning rate. Similarly, the composite with 20% APP self-extinguished before the first mark without any observable burning rate.

Investigation on Mechanical Properties of Hybrid Natural Fiber Reinforced Polymer Composite

The use of natural fibers in composite is increasing day by due to eco-friendly nature of the fibres and reuse of waste. Natural fibers can be classified according to their source of origin such as plant fiber, mineral fiber, and animal fiber. In the present article, epoxy was taken as the matrix and wool fiber for reinforcement with flax flax fiber for fabricating the composite using the hand layup technique. The impact of the hybridization of flax and wool fibers on the mechanical properties of natural fiber reinforced polymer composite was investigated. These fibers were blended in varying percentages with fixed fiber content of 5% [(100% flax fiber), (40% wool/60% flax fiber), (50% flax/50% wool fiber), (60% wool fiber/40% flax), (100% wool fiber)] with epoxy resin and sampled as F5, WF23, WF2.5, WF32, and W5 respectively. Tensile strength, flexural strength, and impact strength were investigated through experimentation. All hybrid composites outperformed non-hybrid wool fiber composites in terms of mechanical properties. The wool fiber is poor in mechanical strength which was compensated by high strength of flax fiber.

Properties and applications of bamboo and bamboo fibre composites

Bamboo fibre is a cellulose fibre that is produced from a bamboo tree. The starch-rich fibre is produced from the part of the bamboo through the process of alkaline hydrolysis. The internal structure of bamboo fibre is filled with various pores, due to which the moisture absorption is slightly higher than normal, which make it effective to generate static electricity. Bamboo fibre does not have free electrons, due to which it is antistatic. Bamboo can grow naturally without the use of pesticides as it is not eaten by insects. A wonderful bacterium is found in bamboo, called bamboo kun. The products of bamboo fibre are eco – friendly and bio – degradable having anti-bacterial properties. Bamboo has a higherspecific tensile strength than the synthetic fibres. The main properties of bamboo are their light weightiness and high tensile strength.. The main chemical components are cellulose, hemicellulose and lignin. Excess of lignin reduces the tensile strength of bamboo, hence currently work is being done to reduce the amount of lignin. The bamboo fibres can be used in many forms in the engineering products. The natural structure of bamboo and their excellent mechanical properties demonstrate the usefulness of bamboo fibres. Bamboo fibre is a natural orogenic product, it is used in the textile industry, paper industry,constructionindustry, automobileandsports goods in form of composite materials due to the excellent properties of bamboo. The development and use of natural fibre has become a centre of research. In this work discusses about internal and external structure of bamboo fibre, the factors that influence their mechanical properties and applications of the bamboo and bamboo fibres.

Investigation of Chemical Treatments to Enhance the Mechanical Properties of Natural Fiber Composites

A sustainable approach to composites is leading to the use of natural fibers rather than synthetic materials, like carbon or glass, for reinforcement. However, the higher moisture absorption of natural fibers impairs the composite’s mechanical properties. Therefore, to improve the mechanical properties, some chemical treatments like silane and fluorocarbon can be performed to reduce the moisture absorption of natural fibers. In this study, flax was used as reinforcement, and epoxy was used as a matrix. In the first part of the study, flax reinforcement was treated with different concentrations of silane (20, 40, and 60 g/L) and fluorocarbons (80, 100, and 120 g/L). Moisture regains (MRs), absorbency, and tensile strength were measured at reinforcement levels. According to the results, reinforcements treated with 60 g/L silane (S3) and 120 g/L fluorocarbons (F3) exhibited the lowest MR values of 7.09% and 3.06%, respectively, whereas water absorbency was significantly reduced. The sample treated with 120 g/L fluorocarbons required 300 seconds extra time to absorb the water as compared with the untreated sample, whereas samples S3 and F3 showed an increase in tensile strength by 20.16% and 34.80% when compared with untreated reinforcement flax reinforcement. In the second part of the study, untreated and treated flax reinforcements were combined with an epoxy matrix for composite fabrication. MR and mechanical tests (tensile, flexural, and Charpy impact tests) were performed. Results revealed that treated flax-reinforced composites exhibited lower MR values 0.86% for F3 and 0.42% for S3, respectively. The tensile, flexural, and pendulum impact strengths of silane-treated reinforced composite sample C.S3 were increased by 15.07%, 117%, and 20.01%, respectively, compared with untreated reinforced composite samples. Consequently, both chemical treatments improve composite mechanical performance as well as service life.

Mechanical properties evaluation of carbon nanotube/sisal fiber/marble dust reinforced polymer based composites

In current circumstances the use of natural fibers is improved extremely in vehicle segment as prospective renewable and biodegradable constituents. The automotive industry currently uses natural fibre reinforced polymer composites for a wide range of panelling components in wagons, as well as for several interior components. It's a plastic that can stand in for glass-fiber-reinforced varieties when necessary. This study focusses on how marble dust and multi-walled carbon nanotubes scatter in sisal fibre and epoxy. The composite was made using 1 wt% marble dust particles and 0, 0.5, 1, 1.5, and 2 wt% of multi-walled carbon nano tube (CNT). Mechanical parameters were determined using ASTM-standard testing process, and test composites were cut to those specifications. The results proved that the nanotube composite with a 1.5 wt% increase in nanotubes possessed improved mechanical properties. Adding 1.5% carbon nanotubes increased tensile strength by 12.14%, and adding 2% CNT increased tensile strength by 14.85%. Meanwhile, flexural strength improved by 72.6% and 124.8%, respectively, after the addition of CNT at the indicated weight percentages to preserve their dimensional stability.

Review on Modifications of Sisal Fibers for Textile Applications

Properties of sisal fibers such as high coarseness and poor drapability made the fibers less suitable in production of conventional textiles compared to synthetic fibers. The environmental consciousness and depletion of petrochemical resources have attracted researchers on investigating the use of natural fibers in the industrial production of conventional textiles. Sisal is among highly researched natural fibers due to its features such as strength, recyclability, availability, low processing cost, light weight and ease process ability. This paper reviews possible modifications of sisal fibers to enhance performance in conventional textiles applications.

Reinforcement of cementitious mortars with hemp fibers and shives

Abstract Polypropylene, steel, and carbon fibers are used to increase the ductility and toughness of concrete materials. In recent years, studies on the use of natural fibers have increasingly continued. Among natural fibers, hemp fiber has the highest tensile strength value. The aim of this study was to discuss and present the results of the experimental study on the use of cement-based hemp shives and fibers to increase the ductility of mortars. Another aim is to increase the use of hemp in the construction field by using more economical and natural fibers. Various binders and different amounts of fibers and shives were added and their effects on flexural strength were investigated. Water absorption and flexural tests and scanning electron microscope and X-ray diffraction analysis were performed on the produced samples. Particle and hole size distributions and stereo microscope images of the samples are given. The use of hemp fibers was observed to improve flexural strength, while shives were not significantly improved flexural strength.

A comprehensive review on the use of natural fibers in cement/geopolymer concrete: A step towards sustainability

The construction industry is shifting towards environmentally friendly products due to the rising demand for non-renewable raw materials, their high energy consumption, and, most importantly, their detrimental environmental effects. High levels of solid waste produced by raw materials release dangerous gases like nitrous and Sulphur oxides, which are very harmful to the environment. In recent years, the usage of fibers has tremendously increased to make significantly robust structures. For sustainable, waste-free development, manufactured fibers can be replaced with natural fibers without compromising on the requirements. This study considers various natural fibers like basalt, coconut/coir, banana, sugarcane bagasse, hemp, kenaf, bamboo, jute, sisal, abaca, and cotton, and their effects on fresh and hardened concrete have been discussed. This article also reviews the composition, preparation, and processing procedures of various natural fibers, and their potential applications in building materials are highlighted. Future research avenues are identified, and possible negative impacts and limitations are discussed. Our findings confirm the feasibility of standard concrete using natural fibers in cement or geopolymer concrete. Lastly, this review compiles insights from numerous sources to aid academia and the construction industry in developing eco-friendly materials.

Accelerated aging of polymer composite from Pennisetum purpureum fibers with recycled low-density polyethylene

The use of natural fibers (NF) as reinforcement in polymer composites have been an interesting option to improve their mechanical properties and to decrease production costs since several crops can produce large amounts of NF with low cost. This is particularly attractive for polymer waste recycling that depends of the production of cheap materials to be economically viable. Elephant grass ( Pennisetum purpureum schum) is a tropical climate plant of fast growth with high potential for production of NF. However, studies on the use of P. purpureum fibers as reinforcement in polymers, mainly for recycled polymers, have been restricted. The aims of this study was to evaluate the action of the P. purpureum fibers on the properties of composites using matrix of low-density polyethylene waste (LDPE-w) as well as to verify the behavior of recycled polymer when submitted to the accelerated photochemical aging using UVA radiation. LDPE-w and LDPE-w composite with P. purpureum fibers (LDPE-composite) were analyzed at different aging times by tensile and impact tests, melt flow rate, scanning electron microscopy and Fourier transform infrared. It was verified that P. purpureum fibers induce defects in matrix of LDPE-w, decreasing the performance of mechanical properties. Similar effect also occurs when LDPE-w is submitted to the first hours of accelerated aging. On the other hand, effects of stabilization of the degradation on the polymer matrix can be attributed to the P. purpureum fibers at high aging times. Thus, P. purpureum presents high potential for use as reinforcement in recycled thermoplastic waste.

Magnesium phosphate cement incorporating sheep wool fibre for thermal insulation applications

The increasing use of synthetic fibres in clothing and the high quality of sheep wool fibre (SWF) from the Australian and New Zealand market leads to a decline in the interest in SWFs produced in European countries, considering them as waste that could be valorised within the framework of a circular economy. The use of natural fibre in cement-based composites presents the main issue of durability due to the alkaline pH media of conventional cement. The use of a low-pH cement could improve the viability of combining natural fibres in this low-pH cement as matrix for developing composites. One of these low-pH cements is magnesium phosphate cement (MPC). As a ceramic material the MPC presents high thermal conductivity (∼1 W m−1 K−1) to be used as isolating material. The present work combines MPC formulated with an industrial by-product (low-grade magnesium oxide; LG-MgO) and Spanish SWF, to develop new sustainable cement-based materials (Sust-MPC-SWF) for thermal building insulation applications. The physical, thermal, and mechanical properties of Sust-MPC-SWF were evaluated to determine the optimal formulation through a design of experiments (DoE). Thirteen formulations designed by DoE were conducted with different sheep wool fibre/cement (SWF/C) and sheep wool fibre/extra water (SWF/EW) ratios. A statistical model was obtained and the optimal formulation (SWF/C = 0.36 and SWF/EW = 0.25) was validated. The increase in SWF content led to an enhancement of thermal and acoustic insulation properties of Sust-MPC-SWF, with similar results to other building materials commercialized with these features.

Artificial intelligence for the prediction of the physical and mechanical properties of a compressed earth reinforced by fibers

The use of natural fibers as a reinforcing product in the production of compressed earth blocks can be considered as an effective means for the environment and savings. This study presents a prediction a model- and simulation-based approach using artificial neural networks (ANN) to predict tensile strength and compressive strength. of earth-friendly concrete containing different types of natural fibers. A group of data with eight influencing characteristics; cement, fiber, sand, fiber length, fiber tensile strength, clay, silt, age used for model formation and validation were collected from the literature. The output was compressive strength and tensile strength. The combination of root mean square propagation and stochastic propagation gradient descent with the momentum method is used to train the ANN. Using various validation criteria such as coefficient of determination (R), root mean squared error (RMSE) and mean absolute error (MAE), the ANN model was validated and compared to two machine learning (ML) Random Forest (RF) techniques and Multilayer Perceptron (MLP). A sensitivity analysis was also performed to validate the robustness and stability of these models. The experimental results showed that the ANN model performed better than other models and, therefore, it can be used as a suitable approach to predict the compressive strength of environmentally friendly earth concrete.