Natural fibre composites (Engineering) Research Papers (original) (raw)

- by
- •
- Natural fibre composites (Engineering)
- by Yusuf Ulcay
- •
- Engineering, Materials Science, Natural fibre composites (Engineering), Polyethylene

The role of mechanical properties of composite material in dome contour design has been investigated. It has been shown that the optimal dome profile depends on the ratio of longitudinal Young's modulus to transverse Young's... more

—knitted fabrics find numerous applications in sportswear fabric industry, during their use it can be subjected to loading-unloading due to the body movements which can be indirectly affected by the dynamic elastic recovery value of the fabrics. The cyclic loads lead to the redistribution of fibers in the yarn structure, because they tend to get the minimum level of energy. Dimensional properties of knitted fabric are widely affected by the externally applied forces that could involve permanent deformation. Cotton/Spandex knitted fabrics are widely used for several applications. In this work, an attempt was done to analyze the effect of cyclic loading on cotton/spandex knitted fabric subjected to the different levels of cyclic loading under different values of initial extensions. Knitted fabric mechanical properties with different percentages of spandex were tested. The fabric properties and the number of cycles indicate the change of the residual extension and the drop in the fabric strength and stiffness.

Silk fibre has received attention in the biomedical sector rather than textile production because of its excellent biocompatibility properties in the past century. Although silk fibre properties are different from area to area, it has created an opportunity in the biomedical sector to develop new silk-based medical textile products. &is research work aimed to study the structural, physical, mechanical, and thermal properties of Ethiopian silkworm cocoon’s filament. Eri and mulberry silk fibre properties such as morphological structure, chemical properties, linear density, filament length, tensile strength, elongation, thermal property, and luster were measured using ES ISO and ASTM standard methods. Statistical analysis result showed that eri silk fibre from Arba Minch had water removal temperature between 100°C and 125°C with a degradation temperature of around 400°C and eri silk fibre from both Addis Ababa and Awassa had an almost similar water removal temperature around 100°C and...

- by Desalegn Atalie
- •
- Materials Science, Biomedical Engineering, Polymer Chemistry, Green Chemistry

The use of recycled materials has experienced a growing global interest in the last decades. Products like natural fibers are being studied to replace synthetic fibers in some applications because they are renewable resources that have a lower cost. Fibers can be used as reinforcement for covers of landfill sites, landfilling over soft soils, and evapotranspiration covers. The use of coconut fibers represent an opportunity to reduce the environmental issue waste of this fruit in tropical countries. The main objective of this research is to evaluate the load-settlement behavior of non-reinforced and reinforced sand with coconut fibers using either a random or a layered distribution. In that sense, plate load tests with both non-reinforced and reinforced sand were performed fixing the moisture content and percentage of fibers for all tests. The results show that the greatest settlement reduction is obtained with layered distribution. Conversely, random distribution provides more ductility and, consequently, the mixture can resist a highest load than layered distribution.

- by J.M. Girao-Sotomayor and +1
- •
- Composite Materials and Structures, Natural fibre composites (Engineering), Soil Reinforcement, Reinforcement

This work analyzes the modification on the surface of vegetable natural fibers caused by low pressure plasma treatment and evaluates the changes in mechanical properties of composites made of these fibers with thermoplastic polymeric matrices. Emphasis is given in analyzing the mechanisms that cause the morphological and chemical changes observed in the different fibers, as well as in understanding the mechanisms which improve fiber-matrix interface and, consequently, the mechanical properties of the composites. Significant results were found for polypropylene matrix composites reinforced with both flax and wood fibers, when these were treated by plasma of sulfur hexafluoride (SF6) gas, which modified the surface chemical characteristic. Thermoplastic starch matrix composites reinforced with coconut fibers also displayed significant improvement in mechanical properties after the fibers have been plasma treated with air and oxygen.

Natural fiber based filaments are economically, and environmentally friendly and they are sustainable which enables them to be applied in the production of novel composite materials. This research aims to produce 3D printed filaments composed of Poly lactic acid (PLA) reinforced with 5 wt%, 10 wt% and 15wt% of coconut fiber (CF) and coconut shell powder (CSP). These fillers were alkaline and silane treated in order to enhance the thermal properties. These fillers were characterized by FTIR, SEM and TGA analysis. The SEM images show that there are structural changes in the fillers after successive treatments. TGA results shows enhancement of thermal stability for CF by 10 °C whereas decreased by 10 °C for CSP. These fillers are melt blended with PLA as a polymer matrix and extruded as filaments. The filament which is reinforced with CSP holds good for 3D printing whereas, the filaments reinforced with CF clogged during the process of 3D printing due to the large diameter of the filaments.

Wind turbine is a device that converts kinetic energy from the wind into electrical power. Among all the parts of wind turbine such as blades, hub, gear box, nacelle, and tower; nacelle and wind turbine blades are generally made up of glass fibres and carbon fibres for better strength, low weight, and corrosion resistance. The main limitations of these materials are the availability, non biodegradable, health hazardous and their fabrication cost, hence the aim of this research is to replace these materials with natural fibers. In this research work, application of natural fibres reinforced polymer composites in wind turbine, requirements to the composites, their properties, constituents, manufacturing technologies, and defects will be reviewed; promising future directions of their developments also will be discussed. A wide variety of sources including coal, oil, coke, natural gas and nuclear materials have been used to generate energy. The consumption of energy has increased due to the increasing population and civilization. At the same time, the ecological awareness has become the major environmental issue in the global marketplace. In today's scenario the major threat for the environment is the ecological imbalance which is increases due to the toxic waste disposal. This issue has led to the increased interest on renewable and sustainable energy sources. The only concern for the sustainable development is minimum pollution and reduction in energy consumption [2]. The increasing interest in the direction of using renewable energy has led to the development of wind energy concept. The wind energy is a prominent renewable energy source and is a solution of global energy problem. Wind turbines or mills have been established to convert the kinetic energy of the wind into mechanical or electrical energy [3].

Bast fibers represent fibers that are obtained from the stem or stalk of the plants. Grasses such as sugar cane have stems which contain bundles of fibers, but they are not classified as bast fibers. The difference comes from the arrangement pattern of the fiber bundles; in regular bast fibers the bundles are in a definite ring pattern, while in sugar cane they are more randomly dispersed. Nowadays several varieties of sugar cane are used in agriculture. The sugar cane plants are known to grow best in tropical and subtropical regions. Sugar cane stalk characteristics vary considerably depending on variety. Typical commercial varieties grown under normal field conditions have a height of 1.5 to 3 meters and are 1.8 to 5 cm in diameter. The stalk surface can be greenish, yellowish or reddish in color and is covered with a thin waxy layer.

Fibres have been used in construction materials for a very long time. Through previous research and investigations, the use of natural and synthetic fibres have shown promising results, as their presence has demonstrated significant benefits in terms of the overall physical and mechanical properties of the composite material. When comparing fibre reinforcement to traditional reinforcement, the ratio of fibre required is significantly less, making fibre reinforcement both energy and economically efficient. More recently, waste fibres have been studied for their potential as reinforcement in construction materials. The build-up of waste materials all around the world is a known issue, as landfill space is limited, and the incineration process requires considerable energy and produces unwanted emissions. The utilisation of waste fibres in construction materials can alleviate these issues and promote environmentally friendly and sustainable solutions that work in the industry. This study reviews the types, properties, and applications of different fibres used in a wide range of materials in the construction industry, including concrete, asphalt concrete, soil, earth materials, blocks and bricks, composites, and other applications.

In recent years, Natural Fibre-Reinforced Composites (NFRC) making its impact in all applications, and they have reached their way into the field of Additive Manufacturing (AM) as well. This increases the demand for natural fibre based filaments in the field of AM. Hence, this research aims to develop filaments made of Polylactic acid (PLA) reinforced with Oil Palm Empty Fruit Bunch Fibre (OPEFBF) and to investigate its physical, thermal and mechanical properties. PLA with 10, 20, 30, and 40 wt.% of OPEFBF were melt blended, hot-pressed, and successfully extruded as filaments. Later, its physical, thermal, water absorption, biodegradation, and mechanical properties are investigated. OPEFBF reinforced filaments show lesser values of densities, increased Tensile Modulus (TM), better bio and thermal degradation compared to the pure PLA. However, its rate of water absorption is high with reduced Tensile Strength (TS) than the pure PLA. Later these filaments reinforced with different OPEFBF contents are 3D printed using Fused Deposition Modeling (FDM) technology. Filaments with lesser fibre content were easy to print. Filaments with 10 wt.% OPEFBF was continuously printed whereas, filaments with higher fibre content clogged in the nozzle. Overall, PLA reinforced with OPEFBF has been developed and successfully applied to the field of additive manufacturing by FDM.

Nowadays, the depletion of natural resources, growing population and raising environmental concerns have raised a tremendous interest in finding a sustainable alternative for creating new materials that are environmental friendly.
Agricultural biomass is the plant residue left in the plantation field after harvesting. This lignocellulosic material possesses a composition, structure and properties that make them suitable to be used in various conventional and modern applications. This renewable plant waste is abundant, biodegradable, low cost and low density that could be a principal source for production of fibres, chemicals and other industrial products. The uses of these materials are not only limited to composite, paper and textile applications, but are also progressing immensely to many other unlimited applications such as medical, nano technology, biofuel and pharmaceutical. These
expanding applications of agricultural biomass would not only help in reducing the environmental pollution but also provide an opportunity in developing renewable and sustainable material to be used in various advanced applications in the future. This would also help in generating employment and contributing to the improvement of people’s livelihood. The aim of this chapter is to discuss different types of agricultural
biomasses with its present applications and future potentialities.

- by SITI SUHAILY SURIP
- •
- Design, Biomass, Natural fibre composites (Engineering), Agricultural Biomass

This article is designed to review the developments in synthesis, modifications, and properties of epoxy monomers derived from both petroleum and renewable resources. It begins with the enhancement in epoxy monomer properties such as mechanical, thermal, adhesive, barrier, etc. by addition of flexible polymer and elastomers. It also explains the role of organic/inorganic fillers on epoxy monomers to achieve the desired properties for outdoor applications. The effects of chemical/physical treatments on fiber are reviewed and their improvements with epoxy monomers are also observed. The authors also suggest for further improvement of epoxy monomers to obtain various eco-friendly high-performance applications.

Biopolymer-based composites have attracted the attention
of researchers and industries due to their ecofriendliness
and environmental sustainability, as well as
their suitability for a number of applications. Biocomposites
containing natural fibers and biopolymers would be
the ideal choice in the development of biodegradable
materials for different applications. Polylactic acid (PLA)
is an environmentally interesting biopolymer, which also
has exclusive qualities, such as good transparency and
processability, glossy appearance, and high rigidity,
although it has some shortcomings as well, for example,
its brittleness and high rate of crystallization. PLA-based
natural fiber composites are entirely bio-based materials
with promising biodegradability and mechanical properties.
Several research studies have been carried out on
PLA and its composites to explore their potential to substitute
petroleum-based products, but until now there is
no comprehensive review with up-to-date research data
available in the literature. The aim of this review is to
highlight the trends in the research and development of
PLA and PLA-based natural fiber composites over the
past few years. This review article covers current
research efforts on the synthesis and biodegradation of
PLA, its properties, trends, challenges and prospects in
the field of PLA and its composites. PLA-based composites
are moderately abundant; and further research and
development is needed for cost reduction and broader
utilization.

- by Ramengmawii Siakeng and +2
- •
- Natural fibre composites (Engineering), Biopolymers, Polylactic acid Biocomposites

Composite materials, based on renewable and biodegradable natural fibers, derived from agricultural waste and wood industry residues, are increasingly utilized in a wide variety of applications. These products represent an ecological and inexpensive alternative to the traditional petroleum-based materials, as they significantly decrease the use of fossil fuels and reduce the greenhouse gas emissions. In addition, these materials have good mechanical properties and require lower consumption of energy for their production. On the other hand, wood-based industries and agriculture produce significant amounts of organic waste and residues which are still underutilized, as low value energy resources and organic waste is commonly disposed of by some of the traditional waste management techniques, such as landfilling, anaerobic digestion or composting. The use of organic agricultural and wood industry waste and residues in production of natural fiber-reinforced polymer composites (NFPCs) is an environmentally friendly, sustainable and economical alternative. This paper represents a review of the possibilities for application of organic waste and residues as reinforcements or additives in NFPCs on the basis of the existing scientific information in the respective field.

- by Petar Antov and +1
- •
- Biocomposites, Natural fibre composites (Engineering), Wood science and technology, Wood Technology

A full mechanical characterisation of three types of 3-D printed lattice cores was performed to evaluate the feasibility of using additive manufacturing (AM) of lightweight polymer-based sandwich panels for structural applications. Effects of the shape of three selected lattice structures on the compression, shear and bending strength has been experimentally investigated. The specimens tested were manufactured with an open source fused filament fabrication-based 3-D printer. These sandwich structures considered had skins made of polypropylene (PP)-flax bonded to the polylactic acid (PLA) lattice structure core using bi-component epoxy adhesive. The PP-flax and the PLA core structures were tested separately as well as bonded together to evaluate the structural performance as sandwich panels. The compression tests were carried out to assess the in-plane and out of plane stiffness and strength by selecting a representative number of cells. Shear band and plastic hinges were observed during the in-plane tests. The shear and three-point bending tests were performed according to the standard to ensure repeatability. The work has provided an insight into the failure modes of the different shapes, and the force-displacement history curves were linked to the progressive failure mechanisms experienced by the structures. Overall, the results of the three truss-like lattice biopolymer non-stochastic structures investigated have indicated that they are well suited to be used for potential impact applications because of their high-shear and out of the plane compression strength. These results demonstrate the feasibility of AM technology in manufacturing of lightweight polymer-based sandwich panels for potential structural uses.

In this paper a novel way of a digital analysis of fibers orientation with a five-step algorithm was presented. In the study, a molded piece with a dumbbell shape prepared from wood-polymer composite was used. The injection molding process was examined in experimental and numerical way. Based on the developed mathematical algorithm , a significant compliance of fiber orientation in different areas of the molded piece was obtained. The main aim of this work was fiber orientation analysis of wood-polymer composites. An additional goal of this work was the comparison of the results reached in numerical analysis with results obtained from an experiment. The results of this research were important for the scientific and also from the practical point of view. In future works the prepared algorithm could be used to reach optimal parameters of the injection molding process.

- by Grzegorz Janowski and +1
- •
- Composite Materials and Structures, Image Analysis, Natural fibre composites (Engineering), Matlab

The growing concern over environmental issues and the common interest to find a viable alternative to the use of glass or carbon composites reinforced has led to an increased attention about ecologically sustainable polymer composites. These “green” materials are made by natural fibers as reinforce, filled with natural-organic fillers, hence derived from renewable or biodegradable sources. At the same time, this relatively new class of materials faces several limits in comparison to traditional composites especially regarding the proprieties of resistance. This paper investigates the advantages on use a combination of natural fibers for improving the mechanical proprieties of “green” composite materials. At the moment, the common opinion is that green composites are not usable in structural applications, and, as consequence, have to be relegated to unworthy applications (as fillers). On the contrary, there are several evidences that mixing different natural fibers (in a practice usually called as “hybridization”) leads to increase these material proprieties. Even if usually quite limited in term of percentage, from time to time these improvements permit a net enlargement in the fields of applications for green composites. Following a large State of Arts on green composites, including potential benefits and limits of these materials, the paper proposes several examples of hybridization showing its effect on mechanical proprieties.

- by Ana Pavlovic and +3
- •
- Composite Materials and Structures, Composites, Experimental Design, Natural fibre composites (Engineering)

This research work is concerned with the development of unsaturated polyester composites reinforced with betelnut fibers. Moreover, the fibers were chemically modified by sodium hydroxide and its effects on the fiber/matrix interaction were also evaluated. Raw and chemically modified fibers have been used in different proportions for the preparation of these composites. The optimization of fiber proportions has been done in term of their tensile strength. The sodium hydroxide treatment effect of fibers was verified by FTIR analysis and the fibers morphological aspects of fibers by SEM. Likewise, the sound absorption coefficient of composites were studied using impedance tube method. The thermal analyses of composites were made using Thermogravimetric analysis. Compared with untreated fiber composites, there was an improvement in the tensile strength of the treated fiber composites. SEM micrographs of betelnut fiber surface revealed the rough and perforated surface of fibers. Whereas, the cross sectional of the betelnut fibers showed the bigger lumen structures. The sound absorption coefficients of composites increased as the frequency increased and thicker composites appeared to perform better than those of thinner ones. The thermal stability of the treated fiber composites was found to be higher than that of untreated fiber composites.

- by Muhammad Khusairy Bakri and +1
- •
- Materials Engineering, Mechanical Engineering, Thermal Engineering, Materials Science
- by Vinod K
- •
- Engineering, Natural fibre composites (Engineering)

Randomly distributed kenaf fibre with varying length (5-50mm) and weight fractions (25-40%) were used to reinforce epoxy resin to prepare environment friendly composites. Effect of fibre length with constant fibre loading on dynamic mechanical properties was studied and its effect on storage modulus, loss modulus and damping factor were investigated. Kenaf fibres were also subjected to alkali treatment to improve interaction with the epoxy resin. The mechanical properties of composites improved with the length and loading of fibres. Tensile strength, flexural strength and impact strength of composites at 40 wt% of fibre reinforcement improved by 46, 51 and 97% as compared to the composites containing 25 wt% of kenaf fibre. It was also observed that fibre folds developed during mixing became significant factor which limited the improvement in mechanical strength of kenaf epoxy composites. A few important predictive models namely rule of mixture, Haplin-Tsai, Nielson Chen and Manera models were compared with the experimental values obtained in this present study. Manera model predicted the experimental data most accurately. Alkali treatment improved the interface and its outcome reflected in the improved modulus that increased 21.76% in samples having 10mm length of kenaf fibre.

- by Rajnish Kumar and +1
- •
- Natural fibre composites (Engineering)

In this investigation, the effect of surface modifications of abaca fiber by alkali and benzene diazonium chloride on the tensile strength of abaca fiber reinforced polypropylene matrix composites was studied. Natural fibers are having low cost, low density and are biodegradable. All these points are on the positive side but they are hydrophilic. Their water absorption property limits the use of these fibers as potential reinforcement in the preparation of composites. Polymer matrix is hydrophobic in nature. This makes fiber and matrix incompatible and results in poor interfacial bonding between the fiber and the matrix. The main objective of this chemical treatment is to reduce their water absorption property and also to improve the compatibility with polymer matrix. Abaca/Polypropylene composites with 20-50 wt% fiber loading have been developed by hot compression moulding technique and were then analysed for tensile strength. The study revealed that the tensile strength of abaca composites increased upon alkali and benzenediazonium chloride treatment. The results show that tensile strength of the composites increased with increase in fiber loading up to 40% and beyond 40% it showed a decrease in tensile strength. From the observations in this study we can say that chemically treated abaca fibers can be used as promising materials as reinforcement in the preparation of bio composites.

Summary: The British Museum houses a significant collection of organic material from prehistoric Swiss lake dwellings (c.4000 to 500 bc) excavated in the late nineteenth century. The waterlogged, anaerobic, alkaline burial environment provided conditions suitable for the preservation of a range of organic materials including many textiles. The textiles, which represent a range of techniques and include fine complex weaves, netting and skeins, largely remain as treated at the time of excavation. Recent assessment of the condition of this textile collection, with a view to improving the storage and display of these rare survivals, has allowed nineteenth-century approaches to the recovery, treatment, mounting and display of archaeological materials to be documented. The collection has been rehoused in a suitable standardized storage system, preserving the original and highly informative historic mounts. Some of the textiles remain, however, at risk due to acidic mounting materials, broken glass or the fragments being insecure in their frames. The opportunity was also taken to assess the potential of this historic textile collection for detailed investigation, including fibre identification, technological study and dye analysis. A range of analytical techniques was employed, including macroscopic analysis, scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and Raman spectroscopy. Weave analysis and technological classification of the textiles was possible, even for textiles still in their original mounts. Many of the textiles showed signs of early consolidation and the presence of detrital material but, using SEM, fibre identification was possible in every sample examined. This demonstrated the use of flax fibres (Linum usitatissimum), lime/ linden (Tilia sp.) bast fibres and lime/linden bark showing various degrees of processing. The majority of the fibres examined showed evidence for low temperature or incomplete charring. Using FTIR a range of consolidants has been identified, including natural resins and a carbohydrate material, possibly a gum or sugar solution. The chemical condition of some of the fibres, determined by Raman spectroscopy, and the presence of consolidants and other detrital material, suggests that potential dye analysis and other forms of (bio)molecular analysis could be compromised for some of the collection. The results of this pilot study will guide the future conservation strategy for this historic collection and allow informed decisions to be made regarding future access for technical and scientific study.

- by Susanna Harris and +2
- •
- Prehistoric Archaeology, Textiles, Conservation, Textile Archaeology

Natural fibres will take a major role in the emerging " green " economy based on energy efficiency, the use of renewable materials in polymer products, industrial processes that reduce carbon emissions and recyclable materials that minimize waste. Natural fibres are a kind of renewable resources, which have been renewed by nature and human ingenuity for thousands of years. They are also carbon neutral; they absorb the equal amount of carbon dioxide they produce. These fibers are completely renewable, environmental friendly, high specific strength, non-abrasive, low cost, and bio-degradability. Due to these characteristics, natural fibers have recently become attractive to researchers and scientists as an alternative method for fibers reinforced composites. This review paper summarized the history of natural fibers and its applications. Also, this paper focused on different properties of natural fibers (such as hemp, jute, bamboo and sisal) and its applications which were used to substitute glass fiber.

Prosthetic socket is one of important part as it involved interface or connecting link between stump and prosthetic components. Besides the function-ality of socket itself, it also involved satisfaction on patient due to the force distribution and pressure on stump. Selecting the right liner is essential in order to ensure the prosthesis fits well and is comfortable to wear. The quality and comfort of a prosthetic socket and its design can determine the daily extent of period, as the patients can use their artificial limbs and lead as normal life as possible. Technological advancement has led to wider range of modern orthopedic and prosthetic device. Fibre reinforced composites are most widely used for upper-and lower-limb prostheses due to their superior strength and excellent biocompatibility. In this review, the use of fibre reinforced composite materials for prostheses are viewed. This review article intended to present general information regarding the structure and function of type and application for current prosthetic socket design for the benefit of the reader. This paper also discussed the comfort measurement of residual limb on prosthetic socket.

Composite materials are used in place of conventional material as they reduce the weight of the structure and increase the strength. Hybrid composite consists of two or more reinforcing fillers of different properties. In this investigation, a Tri layer Hybrid composites of Neem and Indian almond fruit fiber were prepared using hand layup method. Neem was used in outer layer and Indian almond fruit fiber was used in inner layer and vice versa while fabricating the hybrid composites. The tensile, flexural and impact properties of prepared hybrid composites were studied. The results displayed that the tensile and flexural properties of hybrid composite made with Neem as outer layer increased by 6.8% & 5.5% respectively compared to that of hybrid composite made with Indian almond fruit fiber as outer layer. The improvement of tensile and flexural properties was due to the presence of high strength Neem fiber at outer most layers. Moreover, the impact strength of hybrid composite made with Indian almond fruit fiber as outer layer exhibited better impact strength (5.1 kJ m −2) compared to the impact strength of hybrid composite made with Neem fiber as outer layer. The impact strength enhanced due to the surface cracks of Indian almond fruit fiber as it absorbs more impact energies while loading and finally improved the impact strength of hybrid composite.

- by R KARUPPASAMY
- •
- Natural fibre composites (Engineering)

This paper aims to synthesize and characterize an effective intumescent fire protective coating that incorporates halloysite as fire-retardant additive. The effect of the fire-retardant additives and their concentration on the fire protection performance of epoxy-carbon fibre composites were studied using cone calorimetry according to ISO-5660-1. Different modes of degradation, depending on the type and concentration of the additives were identified by analyzing the SEM images and cone calorimetry results. The fire behavior produced by the intumescent paints has demonstrated improvement of epoxy-carbon fibre composites thermal stability and fire performance.

More economical, lighter, more environmentally friendly composite can be produced as many purposes. Natural fibers have good prospective as reinforcements in polymer (thermoplastics, thermosets, and elastomers) composites. In this study, using of natural fiber as reinforced in composites is investigated becuse of the importance of green products and green production technologies. Physical and mechanical properties of reinforced natural fibers are given. ÖZET : Daha ekonomik, daha hafif ve daha çevre dostu kompozitler pekçok amaç için üretilebilir. Doğal lifler, polimer bazlı kompozitler için (termoplastik, thermoset ve elastomerler) takviye bileşen olarak bu amacı oldukça iyi bir şekilde yerine getirebilmektedir. Bu çalışmada, yeşil üretim ve yeşil üretim teknolojilerine vurgu yapmak için kompozitlerde doğal lif kullanımı araştırılmıştır. Takviye özelliği taşıyacak doğal liflerin fiziksel ve mekaniksel özellikleri verilmiştir.

Three-dimensional (3D) woven spacer composites have the advantage of being lightweight and strong for use in various segments of structural engineering and automobiles due to their superior mechanical properties than conventional counterparts. In this investigation, the influence of different cell geometries of 3D woven spacer fabrics, namely rectangular, triangular and trapezoidal with woven cross-links, upon their mechanical behaviours, especially compression energy, was studied through FEM (finite element method). Cell geometries were changed into different heights and widths and evaluated through simulation and experiments. Simulation of the structure was carried out by the Abaqus platform, and validation of the results was done for the rectangular structure. It was found that compression energy increases with an increment in width, while initially, it shows the tendency to increase and subsequently decrease with an increment in height for the rectangular structure. Compression energy increases with an increase in the angle of the triangular structure; however, it shows the opposite trend in the case of the trapezoidal structure. The outcome of the result shows good agreement between simulation and experimentation values of more than 94% accuracy.

- by lekhani tripathi and +1
- •
- Composites, Natural fibre composites (Engineering), Fibres and textiles, FIBRE REINFORCED CONCRETE

With growing environmental awareness, ecological concerns and new legislations, natural fiber-reinforced plastic composites
have received increasing attention during the recent decades. The natural fiber composites have many advantages over traditional
glass fiber composites, including lower cost, lighter weight, environmental friendliness, and recyclability. This article reports the findings
of the studies done on a new fiber, hitherto unexplored, extracted from Saccharum munja grass. The extracted fibers were further
treated using sodium hydroxide to improve its performance in composites. Both treated and untreated fiber-reinforced composites
were prepared by hand lay-up process using unsaturated polyester resin. Mechanical properties and thermal behavior of the composites
were evaluated. The improvement in properties was found for alkali-treated fiber composites. VC 2014 Wiley Periodicals, Inc. J. Appl.
Polym. Sci. 2014, 131, 40829

- by Ravindra Adivarekar and +1
- •
- Natural fibre composites (Engineering), NATURAL FIBRES
- by khalid Al Riyami
- •
- Natural fibre composites (Engineering)

Vegetable fibers are being increasingly used as reinforcement in polymer composites primarily due to their low cost, low density and good set of mechanical properties. In this work, the influence of fiber content and treatment on the tensile, flexural and impact properties of pineapple leaf fiber (Ananas Cosmosus (L.) Merr) reinforced unsaturated polyester composites were investigated. Fiber treatments included washing with detergent and immersion in alkaline solution (10% w/v) for up to 96h. Both treatments were carried out at room temperature. Compression molded composites were obtained at room temperature. Composite properties increased with fiber content and immersion times.

The potentiality of natural fiber-plastic composites using wood, jute, sisal, coir, or hemp, etc., as reinforcing fiber in a thermosetting resin matrix has received considerable attention from scientists all over the world. In polymer composite fabrication system, hybridization of jute fibers with synthetic fibers is one of the techniques adopted to overcome som e of the limitations (poor mechanical properties and moisture resistance) that have been identified for jute fiber reinforced composites. In the present study, the effect of hybridization on mechanical properties of jute and glass mat reinforced polyester composites has been evaluated experimentally. The development of composite materials based on the reinforcement of two or more fiber types in a matrix leads to the production of hybrid composites. In the present work, hessian jute cloth, non-woven E-glass and polyester resin were used to prepare jute/polyester, glass/polyester and jute-glass hybrid polyester composites by hand lay-up and heat press molding techniques and their mechanical properties were evaluated for different stacking sequences. In Jute/polyester and glass/polyester composites, mechanical properties such as tensile properties, bending properties and impact strength increase with the increases of stacking sequences. In case of jute-glass hybrid composites, the composites which content more glass layer than that of jute layer shows the higher mechanical properties. Water uptake (%) of these composites demonstrate that water absorption rate is initially higher for jute/polyester composite and at a stage it become steady (31.11%), but in case of glass/polyester and jute-glass hybrid composites the absorption rate is very low which is almost less than 1% due to the hydrophobic nature of glass fiber and polyester resin. Soil degradation test of all types of composites were evaluated and the deterioration of the mechanical properties revealed for all the composites where jute/polyester composites showed the higher degree but E-glass/polyester composites retained major portion of its original integrity and their hybrid declined more than glass but less than jute composites.

- by Mazharul Islam
- •
- Natural fibre composites (Engineering)

The effect of bio-fibres and bio-particles on the fracture toughness has been investigated. Epoxy resin is used as matrix material and different bio-fibers such as banana fiber, bagasse fiber, coconut fiber and particles such as silica and walnut shell particle with different wt% are added as reinforcing material. The mode I fracture toughness tests are conducted in a servo hydraulic universal testing machine. The results show that the fracture toughness of bio-composites reinforced
with 20wt% bagasse or 10wt% coconut fiber are 1.108MPa and 1.094MPa , respectively which are about 8% and 7% higher than neat epoxy. Addition of 2 wt% of silica with 20 wt% of bagasse shows 60% increment of fracture toughness with respect to bagasse and 72% increment with respect to neat epoxy. Hybridisation of bagasse with banana fibers shows 54% decrease in fracture toughness as compared to bagasse and 13% increase as compared to banana. The overall fracture toughness of hybrid bio-composite of 10 wt% coconut fiber and 20 wt% of walnut shell particle is 1.367MPa which is about 25% higher than coconut fiber reinforced bio-composite.

- by Wei Cui
- •
- Engineering, Natural fibre composites (Engineering), Carbon fibre, Shear Strength

The Recliner is a mechanism which allows the seat back to rotate forward & rearward direction from a pivot point at
the base of the seat back according to the passenger’s seating comfort. The aim of this paper is to design and optimise the
existing automotive seat recliner subjected to loading. The scope of the present work involves Finite Element Modelling
of Seat recliner assembly using HYPERMESH. Pre-processing steps such as updating of element type, material
properties, application of loads and Boundary conditions is performed using HYPERMESH. The element type considered
for the analysis is SHELL. The input file compatible to ANSYS platform is created using HYPERMESH and the same file
is imported into ANSYS Platform. The results in the form of stress and deformation are extracted using ANSYS. The
factor of safety for assembly is calculated based on Von Misses theory of Failure. Optimization is done in terms of
reduction in its weight and there by the cost of the seat recliner assembly. Thickness of various components of recliner
assembly satisfies the strength criteria and the factor of safety which is within the allowable limits.

—The hot section of the aircraft engine (e.g.: stator casing, turbine blades, etc.,) often gets contaminated with the scale, soil and dirt during its operation. These contaminations adhere strongly to the surface along with oxide build up due to the very high operating temperatures. It severely affects the performance of the gas turbine engine by decreasing its efficiency. As of now, chemical cleaning is the most widely used method by the engine manufacturers and maintenance service providers around the world to restore the material aesthetics and efficiency. Though there are number of cleaning chemistry which could successfully remove these contamination's from the surface, major shortcomings like processing time, disposal (some solvents and chemicals are toxic and not environmental friendly, requires special disposal procedures), user's health & safety and efficiency in cleaning the complex geometries and large parts makes the manufacturers and maintenance service providers to look for alternative cleaning methods. In this paper, some of the commercially available alternative cleaning methods are discussed along with their working principle, capabilities, applications, advantages and disadvantages. Keywords—Scale and oxide removal, jet engine alloys, alternative cleaning methods.

In the present work, the natural composites based on sugarcane bagasse fiber and/or coconut shell powder were processed using hand lay-up technique. The matrix selected was polyester. Three different types of composites were considered: polyester matrix ? sugarcane fiber, polyester matrix ? sugarcane fiber ? metal mesh and polyester matrix ? sugarcane fiber ? coconut shell filler. The sugarcane fibers were used in three forms: (1) chemically treated by NaOH, (2) chemically treated by HCl, and (3) untreated condition. In total, 9 types of composites were developed and studied for tensile, flexural and impact properties. The fracture surface of the tensile and flexural test samples was examined with the aid of scanning electron microscope to understand the bonding characteristics and the mode of failure. The key-findings from the present work are: (1) the composites reinforced with the NaOH treated sugarcane fiber and the metal mesh show superior tensile and impact properties whereas the composites reinforced with the NaOH treated sugarcane fiber show the best flexural properties, (2) NaOH treatment of sugarcane fibres has a significant effect in improving the mechanical properties by surface modification of fibres through OH-functional groups. In contrast, HCl treatment of sugarcane deteriorates the surface of the sugarcane by absorbing the electrons. The damaged surface results in weak bonding causing poor mechanical properties, (3) From the SEM analysis of the surface of the sugarcane fiber, it may be concluded that the surface condition of the sugarcane fibres decide the bonding with the matrix. The fiber pull-outs and porosities are less in the NaOH treated sugarcane reinforced composites. The fiber failure is the main mechanism of failure in the tensile test whereas the fiber debonding from the matrix is the main source of failure in the flexural test.

Article Info Depletion of fossil fuels and greenhouse gases is an essential issue in the development of the automotive industry. From the design stage, material selection becomes the most crucial factor. Therefore, this article discusses the development of lightweight automotive materials for increasing fuel efficiency and reducing carbon emissions. Material reliability is assessed by how much weight reduction can be achieved, production costs, safety and durability. Ferro materials (mild steel, High Strength Steel, and Advanced High Strength Steel), non-ferrous (aluminium and magnesium alloy), and Fiber Reinforced Plastics (FRP) have been proven to reduce the total weight of vehicles up to 12.6%. Confirmation of statistical data from the literature illustrates the possibility of using lightweight material to achieve zero CO2 emission. In addition, the 12.6% weight reduction still meets the vehicle safety factor. Abstrak Penipisan bahan bakar fosil dan gas rumah kaca adalah menjadi isu penting dalam perkembangan industri otomotif. Dari tahap disain, pemilihan material menjadi faktor terpenting dan yang pertama kali dipertimbangkan. Oleh karena itu, artikel ini membahas perkembangan material otomotif bobot ringan untuk peningkatan efisiensi bahan bakar dan pengurangan emisi karbon. Keandalan material dinilai dari seberapa besar pengurangan berat yang dapat dicapai, biaya produksi, tingkat keselamatan dan ketahanan. Material ferro (mild steel, High Strength Steel, dan Advanced High Strength Steel), non-ferro (paduan aluminium dan magnesium), dan Fiber Reinforce Plastics (FRP) terbukti dapat mengurangi berat total kendaraan hingga 12,6%. Konfirmasi pada data statistik dari literatur, memberi gambaran kemungkinan penggunaan material bobot ringan dapat mencapai zero CO2 emision. Selain itu, pengurangan berat 12,6% masih memenuhi faktor keamanan kendaraan.

The mechanical properties, such as tensile strength, young modulus, flexural strength, and hardness and Impact energy of chemically treated coir fibers reinforced polyester and polypropylene composites were studied with different fiber ratios of coir fibers. In this work, chemically treated fibers are reinforced with polymers by hand-lay-up method, and the tensile test was carried out to determine the strength of material, bending test was used to obtain the flexural strength of composite materials. In addition hardness and impact test also carried out. Results were found that the strength of the composites tends to decrease with the amount of fiber, which indicates ineffective stress transfer between the fiber and matrix for both composite. The properties such as flexural strength, hardness and impact energy has a rapid increase in 5% of fiber fraction and no significant effect by further increasing fiber content to both polymers. For the fiber loaded samples, 5% fiber reinforced for polyester and 10% fiber reinforced polypropylene matrix had the optimum set of mechanical properties. Coir fiber reinforced polypropylene specimens yielded better mechanical properties compared to the coir fiber reinforced polyester. . It is evident that types of polymer have well influence on the mechanical properties of the chemically treated coir reinforced polymer composites. Authors propose that the bonding between the matrix and chemically treated coir fiber must be increased in order to have improved mechanical properties at higher fiber content

Flax fiber reinforced epoxy composites were subjected to water immersion tests in order to study the effects of water absorption on the mechanical properties. Epoxy composites specimens containing 0, 1, 5 and 10% fiber weight were prepared. Water absorption tests were conducted by immersing specimens in a de-ionized water bath at 25 °C and 90 °C for different time durations. The tensile and flexural properties of water immersed specimens subjected to both aging conditions were evaluated and compared alongside dry composite specimens. The percentage of moisture uptake increased as the fiber volume fraction increased due to the high cellulose content. The tensile and flexural properties of reinforced epoxy specimens were found to decrease with increase in percentage moisture uptake. Moisture induced degradation of composite samples was significant at elevated temperature.

- by Umit HUNER
- •
- Natural fibre composites (Engineering)

Fibers obtained from different parts of the oil palm tree (Elaeis guineensis) have been under investigation for possible use in construction. Studies have been carried out investigating the engineering properties and possible applications of these fibers. However, the experimental methods employed and the values of mechanical and physical properties recorded by various authors are inconsistent. It has therefore become necessary to organize information which would be useful in the design of oil palm fiber cement composites and help researchers and engineers make informed decisions in further research and application. This review provides information about fibers from different parts of the oil palm, their properties, enhancement techniques, current and potential application in cement composites.

The retting process, carried out with warm inoculated water, has been evaluated as a potential method to modify the structure of fibers in order to prepare polymeric biocomposites. The efficiency of the method was tested by analyzing the final performances of the produced composites, prepared with reinforcing hemp fibers (Cannabis sativa L.) dispersed in poly(butylene succinate) (PBS) biopolymer matrix. It turns out that the retting process influences the chemical composition of fibers, removing lignin, pectin, waxes and minor components and, then, disaggregating the pectin-lignin matrix that bounds the elementary hemp fibers and creates fiber bundles. The process improves wettability of fibers as well as their compatibility with the polar functional groups of the polymeric matrix. The retting treatment, commonly applied to get higher fiber quality, helps improve the adhesion to the polymer matrix, thus creating a stronger interface and therefore superior composite performances. As a result, the composites, that always benefit from the presence of fibers in terms of mechanical properties, provide the best performances in the presence of retted hemp fibers, in particular with the composition of 20 wt%.

- by A. Zatta
- •
- Natural fibre composites (Engineering)

The furniture production with native species of bamboo has been thought within the Research Group LIGNO as an alternative to promote the development of poor rural communities in accordance with the Brazilian Federal Law 12484/2011. In this sense, the main objective of this research was to apply the technology of bamboo laminae utilization for the development of Higher Added Value Products (HAVP). Two different models of furniture were built, which were evaluated through three aspects: ergonomics, aesthetics, and stability. The utilization of glued laminated bamboo as the result of an engineering project is a little explored option, but it
presented positive results, because this material allows curved shapes, aesthetically attractive and ergonomic solutions, as well as it provides adequate resistance to the proposed utilization.

- by Victor De Araujo and +1
- •
- Composite Materials and Structures, Composites, Composite Materials, Natural fibre composites (Engineering)