Natural Fiber Composites Research Articles

Mechanical characterization of natural fiber composites prepared with untreated and treated ficus religiosa root fibers

Surface modification techniques are used to modify the surface of the natural fibers in order to improve the surface characteristics; in turn other relevant significant properties of the fiber and its composites. In the present work, epoxy composites have been prepared with the untreated and treated F. religiosa root fiber samples at 5, 10, 15, 20, and 25 wt.% fiber loading. Mechanical properties such as tensile, flexural and impact strength of the prepared composite specimens have been tested as per the ASTM standards. From the results, it has been identified that the strength of the proposed composites increases with the increase in fiber loading, and the composites made up of 20 wt.% of the NaOH solution treated fiber sample exhibits better properties under mechanical characterization study. Alkalization filled the holes, cracks, and pores on the outer layer of fibers and significantly improved the surface roughness, which was reflected in the improvement of the proposed composites.

Analysis of aging effects on the mechanical and vibration properties of quasi-isotropic basalt fiber-reinforced polymer composites

Eco-friendly natural fiber composites, such as basalt fiber composites, are gaining traction in material science but remain vulnerable to environmental degradation. This study investigates the mechanical and vibrational properties of quasi-isotropic basalt fiber composites subjected to aging in two different environments: ambient (30 ºC) and subzero (-10 ºC), both in distilled water until moisture saturation. Aged specimens absorbed 8.66% and 5.44% moisture in ambient and subzero conditions, respectively. Mechanical testing revealed significant strength reductions in tensile, flexural, impact, and short beam shear tests, with ambient-aged specimens showing the largest decline (up to 31.7% in flexural strength). Vibrational analysis showed reduced natural frequencies, particularly under ambient conditions (27.27%). Sound absorption tests showed that pristine specimens had the highest transmission loss, while moisture-rich ambient-aged specimens had the lowest. SEM analysis confirmed surface degradation, with fiber pull-out and matrix debonding contributing to property loss. This research provides valuable insights into the environmental limitations of basalt fiber composites, emphasizing the need for enhanced durability in eco-friendly materials.

Manufacturing and Characterization of Polypropylene-Paper Composites for Automotive Applications

The automotive industry is under significant pressure to curb greenhouse gas emissions from their products as the negative impacts on the environment are increasingly apparent. As such, there is significant interest within the industry to develop low-carbon footprint materials. Natural fiber composites are therefore appealing due to both their decreased carbon footprint, as well as their relatively low cost, low density, and beneficial acoustic properties. This research specifically focuses on the use of paper fibers as composite reinforcements. Paper offers additional benefits over other natural fiber types in that it is globally available, does not compete with food resources, and has well-established quality control techniques. The goal of this work was to study the manufacturing of polypropylene (PP)-paper fiber composites using a hybrid wet-lay/compression molding processing. The processing parameters studied included molding temperature, molding duration, and molding pressure. Paper composites were characterized for properties including flexural strength, impact strength, and water uptake rate. An optimal set of processing parameters was identified in which cycle time and energy inputs (e.g. temperature and pressure) were minimized while retaining desired material properties.

Dielectric characteristics of Mediterranean lignocellulosic fibers for functional biocomposite materials

Abstract The primary aim of this study is to investigate the dielectric properties of lignocellulosic fibers, a unique kind of natural fiber prevalent in the Mediterranean area. Comprehensive investigations were undertaken to determine the suitability of these fibers for functional biomaterials and to reveal their potential capabilities comparable to those commonly used in other parts of the world. More exploration of the electrical characteristics of agricultural waste fibers may lead to the development and improvement of a more comprehensive knowledge on their use in the production of practical eco-products. This will provide novel opportunities for ecologically conscious design. Based on the introduction of natural fibers and their advantages in biomaterials, this study will examine the parallel plate capacitor approach to assess the dielectric properties of biological fibers. Subsequently, the impact of maleic anhydride on the dielectric properties of natural fiber composites was demonstrated as a focused case study. Therefore, it is possible to develop a suitable database for the selection of visually appealing materials in order to enhance comprehensive knowledge of the intrinsic electrical properties and attributes of these materials. Consequently, this would result in the development of more practical strategies for designing environmentally friendly products in bio-electronics and the identification of novel biomaterials with potential applications in electronics.

3D‐printing continuous plant fiber/polylactic acid composites with lightweight and high strength

AbstractContinuous plant yarn‐reinforced polylactic acid (PLA) composites were produced through in situ 3D printing, focusing on how plant fiber attributes influence the crystallization, mechanical, and rheological properties of the printed composites. The aim of this study was to assess the viability of plant fibers as substitutes for synthetic ones in engineering additive manufacturing. Plant fibers promoted the crystallization of PLA due to their shear induction and nucleation agent induction effects. The inherent triangular void defect during printing decreased with increasing plant fiber‐volume fraction. Rheological analysis revealed a transition to more elastic behavior post‐fiber addition, indicating solid‐like properties. The tensile strength of flax fiber‐yarn/PLA composite (volume fraction of 50.79%) was 342.37% higher than that of pure PLA, with a 22.2% lower density than pure PLA. Flax fiber demonstrated a superior reinforcement effect than carbon fiber in compressive strength for 3D printed honeycomb sheets with lower energy consumption and footprint. Optimizing fiber characteristics holds promise for high‐performance 3D‐printed natural fiber composites, particularly in vehicle applications.Highlights Plant fiber/polylactic acid (PLA) composites were in situ printed with a volume fraction of 50.79%. Plant fibers promoted the crystallization of PLA during the printing process. The tensile strength of flax fiber/PLA increased by 342.3% with a 22.2% lower density than PLA. Flax fiber showed a better reinforcement than carbon fiber in a compressive test of printed honeycomb.

Fatigue analysis on flax-epoxy composites: insights and implications

This study investigates the performance of flax fiber and epoxy resin composites, focusing on fatigue testing, which is scarcely reported in the literature. Fatigue behavior is evaluated under full reverse bending loading conditions: R = −1. Apart of the definition of the classic S-N curve, the analysis deeply investigated the evolution of the hysteresis leaf generated during each cycle over the entire fatigue life. This approach allows evaluating interesting parameters such as the evolution of the loss factor and the apparent modulus over life, being these informations fundamental for practical application of natural-fiber composites in engineering applications.

Impact of different parameters in tribological properties of enset ventricosum/ terminalia arjuna fibers /SiO2 filler incorporation

Natural fiber composites have garnered considerable interest in recent years as sustainable substitutes for synthetic materials, owing to their environmental advantages, including renewability, biodegradability, and cost-effectiveness. Notwithstanding these benefits, there is a vital need to improve the mechanical and tribological characteristics of these composites for applications involving significant wear. This work used compression molding to make hybrid composites with natural fibers (NFs) and nano silicon dioxide (nSiO2) filler. The matrix material was epoxy, and the natural reinforcements were Enset ventricosum (EV) and Terminalia arjuna (TA) fibers. Tensile (TS), flexural (FS), and impact (IS) characteristics improved using 1:1 SiO2 filler and EV/TA fiber reinforcement. The combination of 6 wt% SiO2 and 45 wt% EV/TA improved mechanical performance. A high SiO2 filler (6 wt%) in polymer-based composites decreased Specific Wear Rate (SWR), according to Taguchi optimization. A better fiber-matrix interaction improves the mechanical characteristics of materials with fillers. This study optimized several responses using the new combined compromise solution (CoCoSo) method. Multi-criteria decision making is used here. This study introduces Method based on the Removal Effects of Criteria (MEREC) to determine objective criteria weights. Conclusions from experiments show ideal results. CoCoSo's optimization study showed that Enset ventricosum and Terminalia arjuna fiber (EV/TA) hybridization affected composites' tribological behavior.This hybrid fiber combination carried the most influence, followed by fillers. The optimal results were obtained with 6 wt% SiO2/25 wt% EV/TA Hybrid fiber, 1000 m Sliding distance (SD), 2 m/s Sliding speed (SS), and 10 N axial load (AL).

Synergistic effect on the mechanical, thermal, and tribology characteristics of modified natural fibre composites with perforated waste PET

Synergistic effect on the mechanical, thermal, and tribology characteristics of modified natural fibre composites with perforated waste PET

Properties of Multiple-Processed Natural Short Fiber Polypropylene and Polylactic Acid Composites: A Comparison

Natural fiber composites have gained increasing attention due to sustainability considerations. One often neglected aspect is the potential for the mechanical recycling of such materials. In this work, we compounded injection-molded polypropylene (PP) and polylactic acid (PLA) short cellulose fiber composites with fiber shares up to 40 percent by weight. Both matrix materials were reinforced by the addition of the fibers. We investigated a trifold full recycling process, where we subjected the materials produced in the first place to compounding, injection molding, testing, and shredding, and then repeated the process. Although the materials’ properties assigned to degradation were found to decrease with progressive recycling, attractive mechanical properties could be preserved even after the third reprocessing cycle.

Micromechanical analyses of unidirectional (UD) discontinuous flax fiber reinforced composites

Prediction of the strength and damage behavior of natural fiber composites is a challenging task due to computational difficulties resulting from large fiber aspect ratio, non-uniform fiber length distribution, and interface modelling. A computational micromechanical model, which solves the above-mentioned challenges by incorporating a novel representative volume element (RVE) generation algorithm inspired by Lennard-Jones potential, is developed to predict the tensile behavior of unidirectional (UD) flax/epoxy composites. Effects of fiber aspect ratio, fiber spatial distribution, interfacial and matrix properties on longitudinal modulus, strength, and the damage behavior of the flax/epoxy composites are extensively studied using the numerical model. The modulus and strength predicted by numerical model were compared with both analytical models and experimental results, which not only validated the numerical model but identified the limitations of analytical model. The longitudinal strength of flax/epoxy composites initially increased with fiber aspect ratio. Upon reaching certain fiber aspect ratio (25 in this study), strength predicted by both RVE (RVEs with many fibers) and unit cell (unit cells with two fibers) are close to experimental value (240 MPa). This finding provides confidence and guidance on how to use simplified unit cells to predict the strength of natural fiber composites with acceptable accuracy and much lower computational cost.

Numerical failure modelling of natural fibre composite coupons using X-ray computed tomography based modelling

Natural fibre composites offer versatile applications across industries while being superior in sustainability aspects compared to other composite types. To unlock their full potential, it is essential to understand their complex failure involving fibre failure, matrix cracking, and debonding at the fibre-matrix interface. Efforts to address these challenges focus on advanced numerical models, probing behaviour from micro to macro scales. However, these models face complexities in handling intricate failure modes given the non-uniform nature of natural fibres. To overcome these challenges, image-based modelling using X-ray computed tomography scans is proposed. This work’s novelty lies in integrating detailed microstructure information with a nonlinear calibration procedure to accurately model damage and failure in natural fiber composites. It marks a significant step toward developing a virtual testing model, paving the way for assessing composites with varying fiber content or fiber types.

Environmental behaviour of synthetic and natural fibre reinforced composites: A review

There has been an increasing interest in natural fibre-reinforced composites as viable alternatives to typical synthetic fibre composites as a result of increased environmental consciousness, which has led to the quest for materials that are more sustainable. This review paper aims to provide a comprehensive evaluation of the environmental performance of both natural and synthetic fibre-reinforced composites by summarizing relevant information. The article begins by discussing the advantages of natural fibres. These advantages include the fact that natural fibres are eco-friendly, Natural fibre composites demonstrate a significantly reduced carbon footprint and energy usage over their entire life cycle when compared to their glass fibre-reinforced counterparts. Furthermore, the biodegradability of natural fibres provides the opportunity for end-of-life recycling or disposal options that are more ecologically benign than those for synthetic fibre composites. This is because natural fibres are biodegradable and the research acknowledges that various factors, such as the specific fibre and matrix used, and the manufacturing procedures employed, can influence the environmental performance of natural fibre composites. Additionally, further research and development to optimize their performance and ensure their widespread adoption as sustainable alternatives to traditional composite materials. Natural fibre-reinforced composites are more environmentally friendly than traditional composite materials.

Microbial degradation of the waste jute fiber and sawdust fiber-based epoxy composites in drainage system

The non-biodegradable nature of polymers presents a considerable environmental hazard, mainly when they accumulate in drainage systems and pollute the water. The application of natural fiber composites has the potential to offer a feasible resolution to address this problem, as natural fibers possess inherent biodegradability. This study examined the degradation ability of epoxy composites made with 5 wt% waste jute fiber and 5 wt% waste sawdust fiber when subjected to drainage water for one year. The composites comprising jute fiber and sawdust demonstrated a reduction in tensile strength by 57 % and 40 %, respectively, because of biodegradation caused by microorganisms. The microorganism consumed the fiber for energy, resulting in significant weight and flexural strength loss. The weathered waste jute and sawdust fiber composite samples displayed an additional peak at a wavenumber of 1700 cm−1 for FTIR analysis, indicating the presence of the C=O group and reflecting CO2 production. The SEM image reveals the presence of clusters, biofilms, and colonies of microorganisms on the surface of the composites, indicating that the microbes were utilizing the fibers and matrix as a substrate for growth and multiplication. This research contributes to the understanding of the degradation mechanisms of sustainable composites and provides insight into the advancement of eco-friendly materials to reduce water pollution.

Damage and failure assessment of banana/ramie/epoxy composites using acoustic emission monitoring

In recent years, Composite materials that include natural fibers have played a significant role in aerospace, automotive industries, and other engineering applications. Due to its enhancing properties, the usage of composites has owing to an increase in day-to-day life. This research aims to develop a sustainable alternative material pronounced for environmental sustainability for surpassing synthetic fibers. Therefore, real-time monitoring and detection of the damage mechanisms in natural fiber composites are indispensable. In this regard, the acoustic emission (AE) technique lends itself to identifying the microscopic damage mechanisms in composite materials. Compression tests were performed in banana/ramie/epoxy composite specimens, and following consequences, the AE parameters (frequency, amplitude, counts, duration, energy rise time, etc.) were recorded. The novelty of this article is to detect the damage evolution and failure mechanisms of banana/ramie/epoxy composites under quasi-static compression with AE signal analysis for the first time. Findings showed that the stacking of hybrid reinforcing banana and ramie fiber improves the stress distribution, leading to enhanced load-carrying capacity (30.56 %), energy absorption (26.78 %), and stiffness (35.24 the compressive strength reached the maximum strength of the banana/ramie/epoxy composites%).This increase represents a substantial 30 % increase in AE energy absorption prior to failure, suggesting that the composite specimens experienced significant damage or extensive failure mechanisms Further, the AE parameters also showed that the AE energy under compression is relatively low and that frequency disperses between 70 and 150 kHz.

A Comparative Study on Various Natural Plant Fiber Composites

A Comparative Study on Various Natural Plant Fiber Composites

Factors affecting flexural and impact strength of natural fiber reinforced polymer composites: a review

The surging demand for energy-efficient products and their environmental implications are important propelling factors contributing to the growing popularity of natural fiber-reinforced polymer composites (NFRPCs) in several domains. NFRP composites diversification significantly influenced the study and their development in recent years. The intrinsic characteristics of natural fibers have posed difficulties in the growth and use of NFRPCs. A significant amount of study has recently been performed to solve these sorts of problems in order to enhance the performance of NFRPCs and their uses. This review article aims to provide a comprehensive overview of the chemical composition of natural fibers, their physical and mechanical characteristics, and factors affecting the flexural and impact strength of NFRPCs, such as type of fiber, weight percentage of fiber, fiber geometry, surface treatments, stacking, hybridization, orientation, fillers, and information accomplished with them. The product life-cycle evaluation and sustainability development of plant-based NFRCs and the growing uses of NFRPCs, focusing on the automobile sector, are also explored. Finally, multiple perceptions were concluded with the expectation that this study may contribute to future improvements in the flexural and impact strength of NFRPCs.

Investigation of the Mechanical Properties of Hybrid E-Glass and Mohair Fiber Reinforced Epoxy Composites

Natural fiber composites have significant potential to replace traditional materials used in industries due to their excellent tensile strength, stiffness, low specific weight, and superior thermal and insulating properties. Mohair fiber, also known as the Noble fiber and the Diamond fiber, is obtained from the Angora goat, an animal of Tibetan origin. Renowned for its brilliant luster and resilience, Mohair is a symbol of luxury and exclusivity. The primary objective of this study is to manufacture and test a new natural fiber composite that could potentially outperform existing materials in real-world applications. Specifically, the study aims to investigate the mechanical properties of this composite. Mohair has previously been identified as a fiber many times stronger than a strand of steel of similar dimensions. Incorporating these highly desirable properties of Mohair into an epoxy matrix is one of the novel aspects of this research. The testing procedure begins with the preparation of ASTM molds, concurrent treatment of the fibers, and the preparation of the binding material. Specimens are created both with and without the addition of electrical glass (E- glass) fibers. The next phase is curing, during which the epoxy is allowed to solidify, forming strong bonds. Once developed and cured, the composites are removed from their molds and undergo post-processing and finishing techniques. This study aims to understand the tensile and flexural characteristics of natural fiber composites reinforced with epoxy. Three fiber orientations—uniaxial, biaxial, and criss-cross—are employed to assess the changes in the mechanical properties of the composites. The results indicate that adding E-glass fibers in alternating layers of the composite significantly enhances both tensile and flexural strength. Statistically, the addition of the biaxial arrangement of fibers with E-glass fibers results in an 18.47% improvement in ultimate tensile strength, while the maximum flexural strength increases by 49.90%. Furthermore, the topography of the cracked surface is examined using field emission scanning electron microscopy, and the breaking of the fibers in all three directions is studied.

On the interlaminar mode II fracture toughness evaluation of glass Fiber/Epoxy composites with cotton and kenaf natural fibers utilizing acoustic emission features

Considering the widespread use of polymer composites due to their diverse engineering properties, the incorporation of natural fibers is a novel approach to enhance their environmental properties and acquire additional engineering benefits. Applying natural fibers in composites can offer a biocompatible solution to plastic and polymer composite waste issues. Studying the overall properties of composites made with these fibers is a novel area of research. Investigating effective methods for detecting defects and measuring mechanical properties, such as integrity, resilience to failure, and fracture toughness, is particularly crucial. In the current study, the effect of adding cotton and kenaf natural fibers on the resistance to delamination, which is the most common type of failure in laminated composites, is investigated in mode Ⅱ of loading. Specimens of woven glass/epoxy composites with natural fibers were fabricated using the hand lay-up method and end notched three-point bending test was performed. Using the methods provided in the JIS K 7086 standard, the moment of initiation of delamination is determined in the samples. The results demonstrate that only using the mechanical methods provided in the mentioned standard is not sufficient to determine the initiation of delamination. Hence, the acoustic emission can be employed for an easier and more accurate determination of the initiation of delamination. According to the obtained results, cotton and kenaf fibers show a significant increase in the interlaminar fracture toughness of woven glass/epoxy composites. Using cotton fibers shows 212% − 249% and employing kenaf fibers shows 144% − 281% increase in interlaminar fracture toughness respectively. Among the different acoustic emission data analytics, the cumulative energy method shows the lowest mean percentage deviation error of %2.59 among other examined diagnosing techniques.

Fiber and matrix-level damage detection and assessments for natural fiber composites

Fiber and matrix-level damage detection and assessments for natural fiber composites

Development of acrylonitrile–butadiene–styrene (ABS)/natural fiber composite filaments for innovative 3D and 4D printing

AbstractFruit wastes from the agro‐industry may be used in the preparation of polymer/natural fiber composites. In the current scenario, there is a growing need for sustainable materials that can reduce environmental impact while maintaining or enhancing material properties. One promising approach is the incorporation of natural fibers derived from fruit waste into polymers, which aligns with the global push toward eco‐friendly and circular economy solutions. This work was aimed at the development of filaments of acrylonitrile–butadiene–styrene (ABS)/natural fiber composites for 3D and 4D printing. The fibers used were banana (BAN) peel, orange (ORG) peel, cinnamon (CIN), and neem (NEEM) leaf fibers. The rheological, mechanical, and shape memory properties of the ABS/BAN and ABS/ORG composites were compared with those of the ABS/CIN and ABS/NEEM composites. A slight decrease in viscosity was observed with the addition of the natural fibers to ABS. The ABS/ORG composites showed the highest mechanical properties and good adhesion between the printed layers. The particulate eco‐friendly natural fibers can also be used as pigments, where different types of colors can be obtained. The ABS/natural fiber composites can be processed at the same processing conditions as ABS. The incorporation of natural fibers significantly increased the shape memory result. The use of ABS/natural fiber composites proved to be feasible for preparing the filaments and 3D/4D printing of objects.Highlights The properties of 3D/4D‐printed ABS/natural fiber composites were investigated. Banana and orange peel, cinnamon, and neem leaf fibers were used. Filaments of ABS/natural fiber composites were successfully obtained. The addition of the fibers to ABS decreased the viscosity and increased shape memory. Among the composites, ABS/orange peel showed the highest mechanical properties.