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Despite cheap and sustainable in nature, the use of natural fiber composites is limited due to their high moisture absorption, poor fiber-matrix interface, and lack of data on evolution of properties when subjected to environmental factor such as temperature and humidity. The aim of this research is to study the interdependence of moisture regain, hydrophobic treatment, and the mechanical properties of jute fiber-reinforced composite materials. Composite samples made from treated and untreated jute fiber-reinforced composites were exposed to humid environment and their moisture regain, mechanical properties and fiber-matrix interface was tested at given time intervals until four weeks. The composites produced with hydrophobic treated reinforcement showed lesser moisture regain and improvement in the tensile and flexural strengths compared to untreated fabric composite. A clear improvement in fiberresin interface was observed by scanning electronic microscopy. The dynamic mechanical analysis of treated and untreated composites was conducted in a temperature range 20-140 °C. An increase in the storage modulus of treated composite materials was noted as compared to untreated ones. Furthermore, it was concluded that developed composite loss their mechanical properties linearly with immersion time. However, this aging was slow in treated fabric composites especially hybrid fluorocarbon and fluorocarbon. [ABSTRACT FROM AUTHOR]

The aim of this study is to investigate waste streams as a source of recyclable raw material for fiber composite production. Globally, vast volumes of waste are produced daily that are not recycled effectively. In this work, three different raw material sources are examined; industrial, construction and municipal solid waste streams. All three sources produce wastes that are currently underutilized. Usage areas for the waste material include use as a reinforcing fiber, as part of the plastic matrix or as a filler. The industrial sector produces more homogenous waste, while waste from municipalities is mixed. Irregular material flow, the varying condition of the waste and different pretreatments used pose difficulties for recycling. Furthermore, some materials are industry-specific and may be produced in only certain areas. Despite these difficulties, huge amount of potentially useful exploitable waste is available and using different waste streams as a part of wood-plastic composite production can reduce waste volumes disposed to landfill. [ABSTRACT FROM AUTHOR]

This study focuses on optimizing drilling parameters to minimize delamination, circularity error, and cylindricity in natural fiber composites through a comprehensive full factorial Design of Experiments (DoE) combined with Grey Relational Analysis (GRA). The novelty of this work lies in its systematic integration of these methods to evaluate the effects of spindle speed, feed rate, and drill type (HSS, HSS-Co, and Solid Carbide) on hole quality, providing a robust framework for multi-response optimization. Results reveal that feed rate is the most significant factor, with optimal conditions – lower feed rates (0.04 mm/rev) and moderate speeds (1592 rpm) – delivering reduced delamination and improved hole quality. Among the tested drills, Solid Carbide demonstrated superior performance with the lowest delamination and cylindricity errors. This study highlights the potential of systematic parameter optimization to advance eco-friendly composite manufacturing and enhance drilling precision.

Utilizing industrially discarded bio-waste as a bio-reinforcement for polymer composite is one way to find alternate solution for harmful, conventional man-made vitreous fibers. In this work, one such agro waste, tamarind fruit fiber is tested comprehensively for its potentiality as a reinforcement in unsaturated polyester matrix to optimize the mechanical properties. 40 wt% fiber content provides optimum properties, while further addition of fiber reduces the strength due to ineffective bonding between the fiber and the matrix. This is revealed in the microscopic images of the fractured tensile specimens. The experimental results are verified and correlated with the Hirsch's and Series models and found that Hirsch's model agrees well with the experimental results. Thermal stability and aquatic properties are ascertained by the degradation temperature and the water absorption characteristics in fresh and sea water. The diffusion coefficient is found to follow pseudo-fickian behavior. Comprehensive analysis of this material confirms its applicability for light weight automotive and marine applications. [ABSTRACT FROM AUTHOR]

Building, naval, and automotive industries have deep interest in eco-friendly, lightweight, stiff and strong materials. In addition, materials with low thermal conductivity are desirable in many applications where energy savings and thermal comfort are needed. In response to these requirements, sandwich panels were manufactured using glass and jute fiber composite skins bonded to different cores: balsa wood, Divinycell and honeycombs. These honeycombs, as well as the skins, were manufactured by the vacuum infusion technique using polyester resin and jute, glass and carbon fiber fabrics. In this work, the thermal properties and density of the sandwich panels were measured and compared. [ABSTRACT FROM AUTHOR]

Natural fibers are lighter, less expensive, and less abrasive than synthetic fibers such as glass or carbon, and provide a resource that is both renewable and biodegradable. This study uses surface treatments and flock fiber based Z -axis reinforcement technology to improve the strength and fracture toughness properties of natural fiber composites (NFCs), thus increasing their ability to bear loads. The enhancement of performance properties will expand applications of NFCs in industries such as automotive and housing/construction industries. NFCs will also provide a more sustainable, environmentally friendly, and inexpensive structural material alternative over traditional resin reinforced glass or carbon fiber composite materials. [ABSTRACT FROM AUTHOR]

The use of biofiber, or natural fiber, composites by the U.S. automotive industry is on the rise. Biofiber composites are now being considered a meaningful alternative to glass fiber composites. This paper examines the current status of biofiber composites in the automotive sector. The investigation highlights the progress of the application of different types of non-woody and woody cellulosic fibers for designing and fabricating composite automotive components. The improvements in the processing techniques, production methods of different biofiber composites, and the potential applications of these composites in the automotive sector have been taken into consideration. The global emerging trends towards designing and deploying biofiber composite components by leading manufacturers are discussed. Further this study highlights the strengths and obstacles encountered for commercialization and adoption of biofiber composite materials. Current research priorities and global sustainability initiatives further offer insight to future trends. [ABSTRACT FROM AUTHOR]

The present study is focused on tribological and multiscale analysis for the machined surfaces of bi-directional flax fibers reinforced polypropylene composites. This is to track the multiscale effect of the helix angle of the cutting tool, related to its kinematic, on the cutting mechanisms. The results show that the helix angle has significant effect on the tribological performances which affect the tribo-contact interaction between the flax fibers and the cutting edge. The fibers orientation in the woven reinforcement has significant effect on the surface quality. The multiscale analysis reveals the pertinent scales that activate the helix angle effect. [ABSTRACT FROM AUTHOR]

In this work, a novel treatment on plant fibers is presented and its effect on the mechanical properties and water absorption of vinyl ester matrix composites is analyzed. The treated fibers used in this study consisted in alkaline-treated jute fibers and alkaline-treated jute fibers coated with polyhydroxybutyrate (PHB). Bending tests and IZOD impact tests were performed to evaluate the mechanical performance of the composites. The samples were immersed in water (at room temperature and at 80℃) and the water sorption and flexural modulus were measured in time. Flexural strength and impact energy were measured on dry specimens and the detrimental effect of water on those properties was evaluated by testing the samples after the immersion tests. The composites manufactured with alkali-treated fibers coated with PHB showed the best performance in terms of water absorption and mechanical properties. [ABSTRACT FROM AUTHOR]

The mechanical properties of flax and jute woven fabrics were investigated and compared with each other. Mechanical properties of the yarns and fabrics were characterised and compared for each scale. The fabric structure, yarn physical properties, fibre cross-section, and fibre molecular structure parameters of the fabric were investigated. FTIR and TGA thermogram analyses were applied to the fabrics to characterise them. The fabric tensile strength was attributed to the composite tensile strength, but there was not a direct relation. The tensile strength of natural fibre fabrics was determined as significantly reduced depending on the temperature increase. This condition should be considered as an important limitation for composite applications. [ABSTRACT FROM AUTHOR]

Due to the increasing importance of natural fiber reinforced polymer composites, a large number of papers published about fabrication of these materials, but yet the secondary manufacturing performance knowledge of such materials is rather limited. Understanding cutting performance of a novel natural fiber (cotton) reinforced polymer composite is the primary interest of this work. In the first part of the study, suitable cutting tool geometry was designated through milling tests and the results of cutting force, burr formation, and chip morphology. One flute left helix WC (Tungsten Carbide) tool was the most suitable tool geometry for cotton-fiber reinforced polymer milling. The optimum cutting parameters were selected with the designed quantitative scoring procedure for combined evaluation of cutting force and burr formation results. According to the evaluation system, the optimum cutting parameters were found as 25 m/min cutting speed and 200 mm/min feed rate. Three form of burr which are roll-over, poisson and entrance burr, and short ribbon shape chips with linty look were observed due to the embedded cotton fibers in LDPE matrix. At the end of the study, the benchmarking cutting force tests were conducted with pure low density polyethylene material and results compared with the cotton-fiber reinforced polymer. [ABSTRACT FROM AUTHOR]

The objective of this work is to infuse nanoclay particles into the banana fiber and study the morphological and structural characteristics. Nanoclays were infused into the fibers by shear induced force with the aid of alkaline (NaOH) chemical treatment. About 6 wt.% of nanoclays were infused into the banana fibers by this method. The short banana fiber reinforced epoxy composites were prepared by resin casting method in which the critical length (lc) and critical volume fraction (Vfc) of the fibers were determined. The nanoclay infused fibers were compared with untreated and alkaline treated fibers. The result suggests a positive effect on tensile, interfacial, and thermal properties of fibers due to nanoclay infusion. The tensile, shear, and dynamic mechanical analysis (DMA) of composites were studied, and the result shows superior improvement of these properties in nanoclay infused fiber composites. [ABSTRACT FROM AUTHOR]

Most design approaches use the experimental elastic modulus as input variable to describe the material properties. In most cases the uncertainty and the variability of the modulus are neglected. In the worst case this can lead to bad estimations of the material performance and more iterations to the final solution. The purpose of this work is to reconcile the Young's modulus of three configurations ([0]10, [0]20 and [± 45]10) of flax-epoxy composites obtained by different techniques including acoustic impulse, tensile and bending tests, according to ISO and ASTM standards. Results obtained with these techniques all show different levels of variability in Young's modulus values. A fuzzy logic model is used to obtain a simplified view of linguistic variables representing the modulus of elasticity and to reconcile different modules by including the uncertainty inherent to the different measuring techniques. Results have shown a strong potential for fuzzy logic to reconcile the disparity of Young modulus of natural fiber composites. [ABSTRACT FROM AUTHOR]

Conventional materials selection system was replaced with sophisticated software tools by rapid changing technology. The growing environmental concerns and regulations widely among the industry, especially in automobiles, force us to explore the natural fiber materials as a replacement for synthetic materials which is in common use. As a result of extensive research and development, new natural fiber reinforced composite materials are emerging and the database of materials growing exponentially. The decision of selecting optimized materials was complicated, as it involves diversified choice of materials, coupled with various influencing criteria for the selection process. To abstain from deciding inappropriate materials, the technology of expert system software tools can help us in the appropriate materials selection. The objective of this research was to explore the implementation of Analytical Hierarchy Process (AHP) using the expert choice software tool for deciding optimum natural fiber reinforced composite materials by considering main criteria and sub-criteria in the hierarchical model. The final judgement was performed with different scenarios of sensitivity analysis, giving priority to the environmental factors and sustainability. The result shows that the natural fiber composite material hemp and polypropylene gained the higher rank in the selection process and almost compliant with the requirements of industrial product design specification and can be recommended to automotive component manufacturers to enforce green technology. [ABSTRACT FROM AUTHOR]

This paper explores the ultraviolet (UV) weathering performance of high density polyethylene (HDPE) composites with different biofiber fillers and coupling agent. Biofiber polymer composite (BFPC) material samples were prepared using oak, cotton burr and stem (CBS) or guayule bagasse as fiber source HDPE as resin, and two different coupling agents. Weathering variables included exposure to UV radiation and moisture cycles for up to 2200 h. Each variable can degrade BFPC matrix independently or synergistically. The impact of weathering was measured through the changes in the surface matrix, mechanical properties and thermal stability of BFPC as a function of biofibers types and coupling agents. The coupling agent treated composites showed color shift (ΔE) and variable surface degradation. Water absorption of the weathered samples continued to increase after 10 days of immersion. Flexural stiffness, strength and impact properties of weathered samples decreased regardless of fiber type or coupling agent. Minimal linear thermal expansion was noted in weathered composites with coupling agents. Overall coupling agent helped to retain the mechanical properties of composites after exposure to UV weathering. [ABSTRACT FROM AUTHOR]

This study investigated the combination of two different optimization paths (phase compatibilization and manufacturing process optimization) on the microstructure (fiber dimensions, matrix crystallinity and matrix molecular properties) and mechanical properties (flexural and tensile moduli, impact strength, and tensile stress at yield) of flax fiber/postconsumer recycled plastic composites. A two-step optimization methodology was adopted. First, the material composition was optimized by phase compatibilization using maleic anhydride grafted polypropylene (MAPP) and maleic anhydride grafted ethylene octene metallocene copolymer (EO-g-MAH) as additives. Then, the manufacturing process (extrusion followed by injection) was optimized in terms of temperature profile and screw speed for extrusion, as well as barrel temperature profile, mold temperature, injection speed, injection pressure, injection time and back pressure for injection. The results showed that, besides good fiber-matrix interfacial adhesion, the combination of both optimization paths promoted an optimum balance between components degradation and composite homogeneity (good fiber and additives dispersion in the matrix), leading to better mechanical properties. It is shown that this optimization procedure was able to improve all the mechanical properties of the composites, as well as being effective in terms of performance and costs. [ABSTRACT FROM AUTHOR]

The monotonic uniaxial tensile behaviour of hemp-fiber-reinforced high density polyethylene (HDPE) was investigated at different values of hemp fiber volume fraction (vf) and strain rate (ɛ.). A normalized stress–strain family of curves was generated. An exponential normalized monotonic model was developed. A general uniaxial monotonic model was developed from the normalized model to simulate the stress–strain relationship at different values of ɛ. and vf. A modified Harris mechanistic model and a linear model were proposed to incorporate the effect of vf and the absorbed moisture into the developed model. [ABSTRACT FROM AUTHOR]

The development of polymer composites containing natural fibers as a sustainable alternative material for certain engineering applications, particularly aerospace and automotive applications, is a popular area of research. In this study, the mechanical properties of flax, jute and jute/carbon woven fabric composites were investigated and compared with those of 3 K carbon woven fabric composites. The results of this study demonstrate the utility of natural fibers in composite applications. Furthermore, it is observed that the mechanical properties of natural fibres are significantly affected by changes in temperature. Experimental results prove that the mechanical properties of natural fiber composites are significantly lower than those of carbon fiber composites, but the hybridization of carbon and jute fibers can result in a composite material with enhanced mechanical properties. [ABSTRACT FROM AUTHOR]

The present paper investigates the acoustic properties of natural fiber reinforced composites. Fibers from orange tree pruning were obtained and subject to different treatments in order to obtain mechanical, thermomechanical and chemi-thermomechanical pulps. These pulps were used as reinforcement for a polypropylene matrix. The obtained composite materials were submitted to acoustical tests in an impedance tubes device. The transmission losses obtained against the fiber content were obtained and discussed. Latter it was researched the influence of the fiber treatments on the soundproof characteristics. A numerical method was used to preview the acoustic insulation of the materials against the sound frequency. Finally the results were compared with that of the most usual lightweight soundproof solutions. [ABSTRACT FROM AUTHOR]

The final features of natural fiber composites (NFCs) depend on the integrated characteristics of their constituents. In the industry today, natural agro waste fibers are evaluated using a limited number of criteria. In this work, a combined multi-criteria evaluation stage technique (CMCEST) is introduced as a simple efficient systematic indicator to enhance evaluation of the available natural agro wastes for polymeric composites. In this proposed technique, criteria affecting the proper selection of natural agro waste fibers were combined and divided into sequence stages as follows: single-evaluation-criterion (SEC), combined-double-evaluation-criterion (CDEC), combined-tripleevaluation- criterion (CTEC), etc. These stages are based on combined physical, mechanical, and economic evaluation criteria and can be extended to several further stages to include other beneficial characteristics. The effectiveness of this technique was demonstrated by evaluating coir, date palm, jute, hemp, kenaf, and oil palm fibers simultaneously. This combined evaluation criteria can lead to more informative decisions regarding selection of the most suitable fiber type for polymeric composites. The CMCEST enhancements can reveal new potential fiber types through better evaluation schemes, help achieve clearer indications of the capabilities of available agro wastes to enhance composites, and determine proper ecological waste management practices. Utilizing the proposed technique, the date palm fiber type was found to be quite promising due to beneficial characteristics revealed in CTEC, which provides a reasonable, cheap, and eco-friendly alternative material suitable for different applications. [ABSTRACT FROM AUTHOR]

Highlights: [•] Increasing fiber content decreased tensile strength and strain. [•] Tensile modulus was increasing with increase in fiber content. [•] SEM showed fiber/matrix poor adhesion. [•] Impact strength was decreasing with increase in fiber content. [•] Lower thermal stability with increase in fiber content was observed. [Copyright &y& Elsevier]

Abstract: The present paper explores the aptness of old newspapers as a source of reinforcing fibers for composite materials. Different percentages of newspaper fibers, obtained by wet (ONPF) and by dry processes (CONPF), were compounded with polypropylene (PP). A coupling agent was added to the compound to improve the interface between matrix and reinforcing fibers. Tensile test were performed to obtain the mechanical properties of the composite materials. Composite materials reinforced with sized glass fiber (GF) were also prepared and tested. The mechanical properties of the materials were compared. A fiber tensile strength factor (FTSF) and a fiber tensile modulus factor (FTMF) were proposed to evaluate the contribution of the reinforcement fibers to the tensile properties of the composite materials. Finally a pump body, made with GF/PP composites was modeled and tested to obtain the nodal stresses and deformations under nominal pressure. A list of ONPF, CONPF reinforced composite materials was proposed to replace the GF/PP. A body pump was mold injected with a CONPF/PP composite, was assembled in a water pump and tested under nominal working conditions. [Copyright &y& Elsevier]

The main objective of this article was to study the capillary effects during the impregnation of polypropylene resin in the jute fiber mats. The static equilibrium contact angles between polypropylene matrix and fibers were measured and the dynamic impregnation of matrix in the fiber mats was researched in detail. The results show that the static contact angles are clam-shell shape. The capillary effects present little values in the dynamic impregnation. The preparation for low void composites should be performed below the critical resin flow velocity of 0.13 µm/s for polypropylene resin and 0.21 µm/s for polypropylene/maleated polypropylene blend resin, respectively. [ABSTRACT FROM AUTHOR]

This paper reports a bio-based vanillin-derived epoxy (VDE) resin for bio-based natural fiber-reinforced composites. VDE monomer was synthesized, and curing agents, namely, 4,4´-diaminodiphenyl methane (DDM) and isophorone diamine, were used. The prepared VDE resins with various curing parameters were characterized using FTIR, NMR, tensile test, bending test and water contact angle. Further, the interfacial adhesion feasibility of VDE resins on cellulose film was studied through the single-lap shear joint examination and compared with a commercial epoxy, DGEBA. The VDE-DDM resin exhibited excellent interfacial adhesion with cellulose than VDE-IPDA and DGEBA-DDM resins. The cured VDE-DDM thermoset showed a tensile strength of 86.0 ± 6.5 MPa, thermal stability of 241.0 °C at T d5% , and an elastic modulus of 2.9 ± 0.3 GPa, which is better than the commercial epoxy resin. Besides, the developed VDE-DDM resin was used to fabricate treated-jute fiber (TJF)-reinforced composites. The bio-based VDE-DDM/TJF composite's flexural strength was higher than the commercial epoxy resin composite, DGEBA-DDM/TJF. Furthermore, the phosphorus moiety of the VDE-DDM resin endows flame retardancy to the VDE-DDM/TJF composite during combustion. Overall, the appealing properties of bio-based VDE-DDM/TJF composite render environment-friendly and high-performance structural applications., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

In recent times, there is a growing demand for low-cost raw materials, renewable resources, and eco-friendly end products. Natural fibers are considered as strong candidates to be used as a potential reinforcement for composite manufacturing. In the current study, natural fibers extracted from banana peel were coated with bacterial cellulose through a green biosynthesis approach as well as by a simple slurry dipping method. Thus, natural fibers from banana peel waste were used the first time, to produce bacterial cellulose-natural fiber composites. SEM analysis revealed good interaction between the hybrid fibers and the epoxy matrix. Thermal gravimetric analysis results revealed that the degradation temperature increases because of the addition of bacterial cellulose on fiber surface, which improves the thermal stability. The maximum thermal decomposition temperature (405°C) was noticed for nanocomposites reinforced by banana fibers with bacterial cellulose deposited on their surface. Whereas the lowest weight loss was also found for the same sample group. The highest tensile strength (57.95 MPa) was found for SBC-BP/epoxy, followed by DBC-BP/epoxy (54.73 MPa) and NBP/epoxy (45.32 MPa) composites, respectively. Composites reinforced by both types of hybrid banana fibers shown comparatively higher tensile performance as compared with the neat banana peel fiber-epoxy composites, which can be attributed to the high strength and stiffness associated with the bacterial cellulose. Overall, this study suggests a successful and green route for the fabrication of natural fiber-reinforced composites with improved properties such as tensile strength and thermal stability. [ABSTRACT FROM AUTHOR]