Natural Fiber Composites Research Articles

Micromechanical Model for Predicting the Tensile Properties of Guadua angustifolia Fibers Polypropylene-Based Composites.

In this paper, the one-dimensional tensile behavior of Guadua angustifolia Kunth fibre/polypropylene (PP+GAKS) composites is modeled. The classical model of Kelly–Tyson and its Bowyer–Bader’s solution is not able to reproduce the entire stress–strain curve of the composite. An integral (In-Built) micromechanical model proposed by Isitman and Aykol, initially for synthetic fiber-reinforced composites, was applied to predict micromechanical parameters in short natural fiber composites. The proposed method integrates both the information of the experimental stress-strain curves and the morphology of the fiber bundles within the composite to estimate the interfacial shear strength (IFSS), fiber orientation efficiency factor , fiber length efficiency factor and critical fiber length . It was possible to reproduce the stress-strain curves of the PP+GAKS composite with low residual standard deviation. A methodology was applied using X-ray microtomography and digital image processing techniques for the precise extraction of the micromechanical parameters involved in the model. The results showed good agreement with the experimental data.

Fabrication of light-weighted acoustic absorbers made of natural fiber composites via additive manufacturing

Synthetic fiber is still considered the best sound absorptive material. However, due to the health concern of synthetic fiber usage, researchers are trying to find another viable alternative. A microperforated panel (MPP) is a promising alternative that relies on the concept of a Helmholtz resonator for sound absorption. MPP possessed excellent acoustic resistance and a considerable range of absorption bandwidth. In this paper, MPP made of natural fiber composite was fabricated and its acoustic absorption was measured using a two-microphone impedance tube method as per ISO 10534-2 standard. Later, the tensile strength of the fabricated acoustic absorbers was measured using an Instron Universal Testing Machine as per ASTM D638. The idea of employing additive manufacturing, better known as the 3D printing technique, is proposed to produce lightweight MPP. The 3D printing technique provides design freedom and is less tedious in creating complex and light structures. The 3D printing technique has various important parameters, and infill density is one of the parameters. It was found that the reduction of infill density leads to a decrease of the MPP’s mass and thus, slightly affects the resonance frequency of the MPP, still within the mid-frequency spectrum. It was also noted that the increment of air gap thickness leads to the shifting of MPP’s resonance frequency to a lower frequency range. The tensile strength of the 3D printed samples decreases with a decrease in infill density. A sample with an infill density of 100% has the highest tensile strength of 22 MPa, and a sample with an infill density of 20% has the lowest tensile strength of 12 MPa.

High performance natural fiber composites from mat and UD flax reinforcements backed with a mat Binder: A study of mat fiber surface fibrillation

The natural fiber composites (NFC) market is growing at fast rate in markets such as automotive interiors, construction and wind energy. The major driving force is the rise in demand for lightweight and environmentally sustainable materials. This research aims at developing high performance NFC, made from hybridizing short flax fibers and unidirectional flax filaments in the fabrication of mat and combined UD flax-mat reinforcement, by studying the mechanical surface fibrillation of the short flax fibers to improve the fiber–matrix load transfer. The results show an increase in the longitudinal tensile properties up to about 500 mill revolutions, after which a deterioration of the fiber structure occurs with corresponding reductions on properties. However, fibrillation reduces permeability to liquid resin, except in the transverse direction of UD flax-mat reinforcement. Globally, the mechanical fibrillation has a positive impact on mechanical properties and fracture behavior while impregnation can be further improved to ease manufacturing.

Static Structural Analysis of Automobile Hood using Natural Hybrid Fiber Composite

Natural fibres are a kind of renewable source and a replacement generation of reinforcements and supplements for polymer-based materials. The event of natural fibres composite materials or environmentally friendly composites has been a hot topic recently because of the increasing environmental awareness. Natural fibres are one such skilful material that replaces the artificial materials and its connected product for the less weight and energy conservation applications. the appliance of natural fibres bolstered compound composites and natural-based resins for replacement existing synthetic polymer or glass fibres reinforced materials in large. Automotive and aircrafts industries are actively developing different styles of natural fibres, primarily on hemp, flax and sisal and bio resins systems for their interior components. High specific properties with lower costs of natural fibres composites are making it attractive for various applications. within the gift study automobile hood is analysed for hybrid material. From the analysis it's evident that the material is maintaining its structural integrity for given loading condition.

Approaches of material selection, alignment and methods of fabrication for natural fiber polymer composites: A review

The recent superiority of the composite materials is cautiously focusing on environmental adoption of natural fiber composites. The major source of the natural fiber materials covered in the globe, especially natural fibers, is plant-based, animal-based and mineral-based. Eco friendly based material can save the environment and recycling of the material is possible, as well as important criteria. Hence engineers ultimately focused on natural fiber polymer matrix materials to save the environment, pollution control, plastic manipulation, etc. The literature work was studied to identify natural fiber material possession. The major goal of the present review was to identify material characterization and appropriate application, mainly offering to enhance mechanical properties, flexural strength, electrical properties, thermal properties etc. The major consequence of the natural fiber is hydrophilic treatment. There is poor interfacial adhesion between the addition/filling substances and poor mechanical characteristics. All of these shortcomings constitute a critical issue. This review presents numerous sorts of natural and synthetic polymers, natural fibres such as jute, ramie, banana, pineapple leaf fibre, and kenaf, etc.; short and long fibre loading methods, fibre fillers in micro and nanoparticle, American society of testing and materials (ASTM) standard plate dimensions, fabrication methods such as hand lay-up process, spray lay-up process, vacuumed-bag, continuous pultrusion, and pulforming process, etc.; industries and home appliances such as automotive parts, building construction, sports kits, domestic goods, and electronic devices. The review lists various material combinations, fibre loading, fillers, and matrix that can aid in the improvement of material properties and the reduction of failures during mechanical testing of composites.

Prediction of the equilibrium moisture content based on the chemical composition and crystallinity of natural fibres

Natural fibre-based materials offer various advantages compared to synthetic fibres, however their applications are limited mainly due to their hygroscopic properties, which are affected by their chemical composition, microstructure and the porosity of the plant cells of which the fibre is composed. Therefore, this work investigates the hygroscopic behavior of natural fibres to obtain a better understanding of the relation of the chemical composition of the fibres, their crystallinity, and their equilibrium moisture content. The crystallinity index was determined to include amorphous cellulose into the developed models. Nine biomass samples were selected (flax, hemp, jute, spruce, bamboo, corn stalks, palm leaves, rice husk and wheat straw) to construct models via linear regression to predict the moisture sorption behavior of natural fibres. Thorough statistical (ANOVA, RMSE) analysis showed that the developed models are relevant and descriptive. From all major plant cell wall constituents (lignin, crystalline cellulose, amorphous cellulose and hemicellulose), it is hemicellulose’s hygroscopicity that is largely responsible for the moisture uptake of the fibres, with (amorphous) cellulose and lignin playing a (much) smaller role. This study has improved the understanding of the hygroscopic behavior of natural fibres, and is important for optimal application of these fibres in composite materials.

Development of Natural Fibre-Reinforced Polymer Composites Ballistic Helmet Using Concurrent Engineering Approach: A Brief Review

In this decade, all researchers and industry players compete to develop sustainable product design by exploring natural fibre composites in product design development. One of the essential methodologies in creating composite products is concurrent engineering (CE). Industrial design and production engineering should be involved in the development of ballistic helmets. This publication aims to provide a quick overview of the evolution of natural fibre composite ballistic helmet designs. This manuscript is still in its early stages, but it already includes a summary of the progress of ballistic helmet design from 1915 to the present. Renewable materials, such as natural fibre, should be highlighted as an alternative to synthetic composites in developing a sustainable ballistic helmet design. Furthermore, launching the design development process for a ballistic helmet demands a CE strategy that includes multi-disciplinary knowledge. Computational modelling aids in the development of ballistic helmet designs, reducing the time and cost of manufacturing ballistic helmets. The ergonomic component of ballistic helmet design is also crucial, as is the thermal comfort factor, which can be handled using natural fibre composites with thermal solid insulating characteristics. The development of natural fibre composite ballistic helmets can be used as a consideration in the future as a revolution to create a sustainable design. Finally, this review can be used as a guide for industrial designers. In conclusion, this review might be utilized as a reference for industrial designers due to a shortage of studies, especially in producing product-related natural fibre.

Banana Fibers as a Sustainable Acoustic Absorbing Materials: A Review

This paper presents an investigation reviewed on various research topics of the natural fibers in worldwide and Thailand. Practically, the traditional synthetic fibers for noise absorbed purpose are human and environmental harmful, thus the natural fibers might be the alternative way for consumers. The characteristics of natural fibers commonly are lightweight, high strength, but less pollution and low cost. Furthermore, the agriculture wastes would be value-added and reduced on the particulate matters (PM) 2.5 communities’ nuisance from the incineration affecting human health, environment and global warning in advance. In the present, the traditional materials using for noise absorbent are derived from synthetic fibers such as asbestos and fibers glass, mostly 20 - 45 % of asbestos fibers that World Health Organization (WHO) mentioned the hazard of asbestosis regarding on lung cancer, pleurisy lung cancer and ovarian cancer about 107,000 people per year. In general, the natural fibers are classified on 3 configurations: Cellular, fibrous and granular types which are their different properties on noise reduction. Also, this review particularly presents a sound absorption coefficient (SAC) that relates to the main importance factors (for example of physical, chemical, mechanical, etc.) including an analysis of the potential chances to utilize on the sustainability of these green natural materials, especially banana fibers in Thailand.
 HIGHLIGHTS
 
 Many natural fibers are used for noise control as an alternative to the traditional ones. Natural fiber composites appear to be cheaper, lighter, and more environmentally friendly than glass fiber composites
 Many fibrous materials (for example, rice straw, coconut coir, banana fibers, etc.) have shown good sound-absorbing properties and heat insulation as well
 The physical, chemical, and mechanical properties of banana fibers, including the content of cellulose and lignin, can influence the ductility and elongation values, especially in the cultivated banana type
 The development of banana fiber reinforced paper pulp bio-composites was observed for its sound absorption coefficient
 
 GRAPHICAL ABSTRACT

Mechanical, wear and fatigue behavior of silane‐treated corncob biosilica toughened epoxy resin composite reinforced with prickly pear short fibers

AbstractThis research focused on investigating the mechanical, wear, and fatigue behavior of an epoxy composite toughened with corncob biosilica (CCB) and prickly pear fiber (PPF). The primary aim of this research was to improve the load bearing effect of high‐brittle matrix by adding eco‐friendly fiber and particle. The surface treatment on the fiber and particle was done using an amino silane, 3‐Aminopropyltrimethoxysilane (APTMS). The natural fiber composites are prepared by hand layup process and characterized in accordance with ASTM standards. The experimental results indicated that the addition of fiber and particles increased the tensile and flexural strength up to 61% and 50%, respectively. Similarly, it is noted that the biosilica particles improved the bonding and reduced the rate of wear of composites, as well as lowered the stress intensity factor. A lowest wear rate of 0.037 and COF of 0.38 were noted for EFC2 composite designation. The morphological study of the fractured composites revealed improved fiber adhesion to the matrix. This reduced intensity of stress, increased wear resistance and higher fatigue life ensures the composite's application in structural and industrial applications.

Fatigue behaviour and damage mechanisms under strain controlled cycling: Comparison of Flax–epoxy and Glass–epoxy composites

Recent research showed that strain-controlled (constant strain-amplitude) cycling may be ideal for natural-fibre-composite (NFC) fatigue testing, since enforcing constant strain-rates eliminate the apparent modulus ‘improvement’ reported by several stress-controlled studies. This article re-examines Flax-reinforcement as an alternative to Glass by fatigue testing under constant strain-amplitude. Two Glass–epoxy crossply configurations ([0/90]3S, [±45]3S) are tested alongside four commonly-studied Flax–epoxy layups ([0]16, [0/90]4S, [±45]4S, quasi-isotropic [0/45/90/-45]2S). Fatigue endurance plots for all layups are modelled by linearised logarithmic strain-life relationships, for which unique parameters are identified. Evolution of several mechanical phenomena (stiffness damage, inelasticity, peak-stress) are evaluated as potential indicators of progressive damage, correlated with SEM-observed microstructure cracking. Flax–epoxy specimens have superior resistance to stiffness loss, lower inelastic strains , and withstand higher stresses per-unit-density, when compared to similar Glass-specimens. Flax remains a promising alternative to Glass for mechanical reinforcement against fatigue degradation in engineering structures.

Effect of Process Parameters on the Fabrication of Hybrid Natural Fiber Composites Fabricated via Compression Moulding Process

ABSTRACT In the present work, an attempt has been made to fabricate hybrid natural fiber composites, consisting of a poly-lactic-acid (PLA) matrix reinforced with jute and sisal fibers, using die molding process. The processing conditions of the hybrid composites, such as heating temperature, compression pressure, and final mold temperature, have been optimized in the response of the resulting tensile and flexural strength. The reinforced hybrid composites have been developed in accordance with the Taguchi L9-based design of experimentation, and statistical analysis has been performed to understand the significance of the selected input parameters. Furthermore, scanning electron microscopic (SEM) analysis of the fractured samples has been performed to observe the mechanisms of failure and adhesive characteristics. The statistical analysis highlighted that all input process parameters have significantly contributed to the resulting tensile and flexural strength at 95% confidence level.

Thermal and vibrational analysis of flax fiber composite and effect of the addition of expandable graphite

Natural fiber composites are widely employed in various applications. Natural fiber offers outstanding mechanical qualities and a low weight-to-strength ratio compared to synthetic fiber. These materials cannot meet the job requirements in the automation, marine, and aircraft industries due to their extreme flammability. Various fire retardants can be employed to overcome this constraint. This research is focused on the qualities of flax fiber and how they alter when different quantities of expandable graphite are added. The thermal characteristics of the composite change after the inclusion of expandable graphite particles. The use of expandable graphite particles, which can resist greater temperatures, improves the thermal properties of composite materials. The thermal characteristics of flax fiber composite and expandable graphite flax fiber composites are compared; the expandable graphite flax fiber composite has more excellent thermal stability and flame resistance. Vibration testing was used to determine the dynamic properties of the sample. The logarithmic decrement technique derives damping parameters from the vibration response envelope curve. When compared to flax fiber composite, expandable graphite has better damping qualities. As a result, it can be concluded that adding expandable graphite particles to a composite material has a variety of effects on the composite's properties.

A review on the factors affecting the properties of natural fibre polymer composites

Improved quality natural fibre composites cannot be achieved without considering certain factors such as the degree of uniformity of the fibre, wettability of the fibre, fibre length, fibre volume fraction, type of matrix, interfacial bond strength, fibre orientation, compatibility of the fibre with the resin, processing parameters and manufacturing techniques among others. Their influences on the properties of the composites with typical examples from previous works were highlighted. The exact or approximate volume fractions of specific fibres in specific resins for optimal performance in composites are lacking. Epoxy, low density polyethylene, polystyrene and polyester resins were mostly used as matrix for natural fibre composites. Epoxy resins possess higher tensile and flexural strengths than polyester resins. Significant differences in the tensile strength and Young’s modulus of natural fibre polymer composites were observed with changes in the orientation and length of the fibres particularly when the differences in length are significant. Other relevant issues affecting natural fibre composites were buttressed with the aim of improving the properties of natural fibre polymer composites for advanced applications.

Flax-based natural composites hierarchically reinforced by cast or printed carbon fibres

Plant-derived natural fibres hold great potential as renewable and sustainable reinforcing elements in structural composites. However, a broader use of natural fibre composites requires further improvements in their mechanical properties, to reach performance comparable to carbon fibre-reinforced polymers. In this study, we exploit discontinuous carbon fibres in rheologically modified inks to controllably reinforce flax-based laminates in specific directions. The carbon fibres are incorporated by tape casting or 3D printing approaches directly on the pre-aligned flax structures. With the help of quasi-static flexural tests and dynamic mechanical analysis, we show that the elastic modulus, the strength, and the damping behaviour of the flax-based composites can be significantly enhanced by controlling the relative orientation of the hierarchically structured carbon and flax fibres. The flexural stiffness of composites reinforced with carbon fibres oriented along and perpendicular to the flax fibres increases, respectively, 62% and 146% relative to the carbon-free reference. This is accompanied by a 1.6-fold increase in loss modulus, which is a performance indicator for damping. The experimentally observed stiffening of the flax-based structures can be described using simple beam theory. By combining reinforcing elements of different length scales with readily available manufacturing techniques, this work shows the potential of hierarchical structuring in improving the mechanical performance of flax-based composites.

Abrasive Jet Machining of Incense Stick Ash Filled Luffa-Human Hair Based Sustainable Bio-composite Using Taguchi Based GRA

ABSTRACT In this research, a new class of partially biodegradable epoxy-based sustainable bio-composite is developed in house by using blend of luffa cylindrica (LC) and short human hair (SHH) as fiber and diverse weight proportions (0, 5, 10,15 and 20 wt.%) of incense stick ash (ISA) as filler through the conventional hand lay-up method. The presently developed hybrid natural fiber composites are characterized for their density and porosity and subsequently, investigated for their machinability through abrasive jet machining (AJM) process. Two grits of silicone carbide (SiC, 300 µm and 600 µm) and combination of aluminum oxide (Al2O3) and glass powder (90 µm) are used as the abrasives. The material removal rate (MRR) and surface roughness (Ra) of the machined surface are acquired according to Taguchi design of experiment. The significance of the control factors (type of composite, gas pressure, standoff distance and type of abrasive) is identified through ANOVA and ideal factor setting for optimum individual responses are established. Moreover, simultaneous optimization of multi performance characteristics is also attempted through Grey Relational Analysis (GRA) method. The outcomes from the confirmation runs showed an improvement in the predicted optimal machining parameters for individual as well as the multiple performance characteristic in AJM of the newly developed ISA filled LC-SHH fiber polymer composite.

A review on the limitations of natural fibres and natural fibre composites with emphasis on tensile strength using coir as a case study.

Natural fibres such as coir, jute, flax, and hemp have been considered for technical applications. These fibres, though with some desirable qualities such as low density and environmental compatibility, possess the common property of non-uniformity along their length and, as a result, variable diameter and variable cross-sectional area. Several other factors, such as gauge length, fibre species and origin, strain rate, method of extraction of the fibres, porosity and pore size distribution, have been identified to influence the tensile strength of natural fibres and limit their applications in composites. Besides, several authors have used different diameters for the same type of natural fibre, such as coir, resulting in significant inconsistency in the tensile properties. For the same type of coir fibre, and from tensile strength reports from ten authors, an average tensile strength of 120.97 ± 42.30 MPa was obtained. The average number of fibres used in most cases for the tensile test was less than the requirement for natural fibres. All these factors were addressed with the aim of improving the overall properties of natural fibres and their composites.

A Study of the Flexural Properties of Jute Fabric Reinforced Epoxy Composite: Experimental and Uncertainty Analysis

ABSTRACT The variability in natural fiber composite properties has always been problematic due to the dispersion in their mechanical properties resulting from fiber misalignment, irregular crosssection, fiber length, and geometry, which impacts their reliability. This issue of reliability has greatly affected the selection process of natural fiber composites as opposed to the synthetic fiber counterparts when it comes to strength, stiffness, failure strains, and energy absorption criteria. Stiffness is one property which greatly depends on the span length and load-bearing capacity of the material, which makes it an important criterion during product design. In this study, flexural properties of the jute fabric composite were studied through experiment and uncertainty analysis using various distribution functions. Jute epoxy composite at 38% fiber volume fraction was fabricated, and samples were machined using abrasive water jet machining as per ASTM D7264 standard for bend test. The samples were experimentally tested for bending strength, modulus, and failure strains, and uncertainty analysis was done to further analyze their failure behavior. Experimentally tested samples showed multimode bending failure such as M(CAT) and M(TAB) as per ASTM D7264.

Integrated analysis of lncRNAs and mRNAs by RNA-Seq in secondary hair follicle development and cycling (anagen, catagen and telogen) of Jiangnan cashmere goat (Capra hircus).

BackgroundAmong the world’s finest natural fiber composites is derived from the secondary hair follicles (SHFs) of cashmere goats yield one of the world's best natural fibres. Their development and cycling are characterized by photoperiodism with diverse, well-orchestrated stimulatory and inhibitory signals. Long non-coding RNA (lncRNAs) and mRNAs play important roles in hair follicle (HF) development. However, not many studies have explored their specific functions in cashmere development and cycling. This study detected mRNAs and lncRNAs with their candidate genes and related pathways in SHF development and cycling of cashmere goat. We utilized RNA sequencing (RNA-Seq) and bioinformatics analysis on lncRNA and mRNA expressions in goat hair follicles to discover candidate genes and metabolic pathways that could affect development and cycling (anagen, catagen, and telogen).ResultsWe identified 228 differentially expressed (DE) mRNAs and 256 DE lncRNA. For mRNAs, catagen and anagen had 16 upregulated and 35 downregulated DEGs, catagen and telogen had 18 upregulated and 9 downregulated DEGs and telogen and anagen had 52 upregulated and 98 downregulated DEGs. LncRNA witnessed 22 upregulated and 39 downregulated DEGs for catagen and anagen, 36 upregulated and 29 downregulated DEGs for catagen and telogen as well as 66 upregulated and 97 downregulated DEGs for telogen and anagen. Several key genes, including MSTRG.5451.2, MSTRG.45465.3, MSTRG.11609.2, CHST1, SH3BP4, CDKN1A, GAREM1, GSK-3β, DEFB103A KRTAP9–2, YAP1, S100A7A, FA2H, LOC102190037, LOC102179090, LOC102173866, KRT2, KRT39, FAM167A, FAT4 and EGFL6 were shown to be potentially important in hair follicle development and cycling. They were related to, WNT/β-catenin, mTORC1, ERK/MAPK, Hedgehog, TGFβ, NFkB/p38MAPK, caspase-1, and interleukin (IL)-1a signaling pathways.ConclusionThis work adds to existing understanding of the regulation of HF development and cycling in cashmere goats via lncRNAs and mRNAs. It also serves as theoretical foundation for future SHF research in cashmere goats.

Effect of Nanofillers on Mechanical and Water Absorption Properties of Alkaline Treated Jute Fiber Reinforced Epoxy Bio Nanocomposites

ABSTRACT Natural fiber composites (NFCs) are gaining popularity in various technical sectors due to their environmental friendliness and low cost. In this study, alumina and magnesia were employed as nanofillers in various compositions of alkaline-treated and untreated jute fiber reinforced epoxy bio nanocomposites (BNCs). The synergetic effect of surface treatment and nanofillers was investigated in terms of mechanical properties (compression and interlaminar shear), water absorption behavior, and morphology of composites. Significant improvements in compressive and interlaminar shear strengths were reported, as well as a substantial decrease in the proportion of water absorbed. The optimal nanofiller concentration was observed at 3% in both alkaline-treated and untreated jute fiber-reinforced epoxy BNCs. The results demonstrate that nanofillers combined with surface treatment can significantly improve the strength and water absorption properties of jute fiber reinforced epoxy BNCs.

Dynamic Mechanical Analysis, Biodegradability and Water Absorption Behavior of Permanganate Treated Woven Fabrics/Polyvinyl Alcohol Composites

ABSTRACT Natural fiber composites are the recent upcoming materials used in structural and other general engineering applications. They are more popular because of their biodegradability, lightweight, more strength-to-weight ratio, easy availability, eco-friendliness, and sustainable material features. But natural fibers are available in the form of dust particles, hemicellulose, lignin, and other waste substances, due to the existence of these particles strength and internal bonding could vary. To improve strength and contact area between fabric/matrix, chemical treatment is very much necessary. In the present work, plain woven banana fabrics (PWBFs)/polyvinyl alcohol (PVA) biodegradable composites were prepared to understand the effect of potassium permanganate (KMnO4) solution with 0.5, 1, 2, 3, and 4% concentrations for 4 hours, test samples were fabricated by using hand lay-up method as per ASTM standards, tested for dynamic mechanical analysis. From the experimental results, it was observed that 1% KMnO4-treated composite got the best results as compared to untreated and other sets of treated composites. Hence for further analysis, biodegradability and water absorption analysis were carried out for a duration of 60 days, from experimental results it was noticed that KMnO4 treated composites required more time to completely biodegradable in normal soil and increases the surface roughness as well as decreased the water absorption.