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The study investigates the potential of coconut husks in purifying biogas, a common issue in the use of biogas due to the high costs and environmental impact of expensive purification technologies. The study used an experimental setup generating biogas from kitchen waste and analysed its composition using an industry-standard biogas analyser. Coconut husks could remove hydrogen sulphide (H2S), with a high percentage removal efficiency of 54% at a column length of 0.5 m from the inlet. Based on the results, 2 kg of coconut husk could purify 837 L of biogas, with a removal efficiency of approximately 62%, before exhaustion. This suggests that coconut husks can be used in biogas purification to remove H2S, which is the most challenging component as it can corrode metal parts when used at high concentrations above 750 ppm. Further research is needed on large-scale purification using coconut husks at high pressure to allow more gas adsorption by the purification media.

The study investigates the potential of coconut husks in purifying biogas, a common issue in the use of biogas due to the high costs and environmental impact of expensive purification technologies. The study used an experimental setup generating biogas from kitchen waste and analysed its composition using an industry-standard biogas analyser. Coconut husks could remove hydrogen sulphide (H2S), with a high percentage removal efficiency of 54% at a column length of 0.5 m from the inlet. Based on the results, 2 kg of coconut husk could purify 837 L of biogas, with a removal efficiency of approximately 62%, before exhaustion. This suggests that coconut husks can be used in biogas purification to remove H2S, which is the most challenging component as it can corrode metal parts when used at high concentrations above 750 ppm. Further research is needed on large-scale purification using coconut husks at high pressure to allow more gas adsorption by the purification media. [ABSTRACT FROM AUTHOR]

Coir fibre, derived from the husk of coconuts, is a natural resource and they are biodegradable and renewable. By incorporating them, any product can become more lightweight and durable, meeting the global desire for eco-friendly and efficient designs. This study has the potential to significantly alter the design of components such as switches and enclosures and it has an international research impact on engineering applications. Coir fibres and Hexagonal-Boron Nitride (h-BN) possess superior mechanical, thermal and physical qualities when reinforced with polymers. Hence novel study is carried out to examinecoir fibre/h-BN reinforcement in epoxy polymer composites. Response Surface Methodology via Box-Behnken Design (BBD) is utilized to investigate the mechanical properties such as Tensile Strength, Impact Strength and Young’s Modulus of coir fibre/h-BN reinforced epoxy polymer composite. The effect of input parameters onresponse is evaluated through regression equation and analysis of variance by using statistical Minitab software. The response optimization represents the maximum Young’s modulus (1597 MPa) by combining coir fibre (5 wt%), Coir fibre powder size (75 μ m) and h-BN (1 wt%). The response optimization portrays the maximum Ultimate Tensile strength(36.83 MPa) by combining coir fibre (1 wt%), coir fibre powder size (220 μ m) and h-BN (3.78 wt%). The response optimization reveals the maximum Impact strength (98.35 J m ^−2 ) by combining coir fibre (5 wt%), coir fibre powder size (225 μ m) and h-BN(1 wt%). This work emphasises the use of composite materials that are environmental friendly in a variety of industries such as automotive, electrical, etc.

Sandwich panels (modular panels) promote optimal solutions to some major issues prevailing in the construction industry such as increased energy consumption by building elements, excessive disposal of constructional waste and unproductive time spent during construction. Hence, the inclination towards sandwich elements has been increased vastly deviating from conventional building construction materials and methods. However, the potentiality of using locally available natural materials for the development of sandwich panels is a salient sustainable approach that needs to be addressed. This study evaluates the current and potential materials used in modular panels and key properties of sandwich panels including mechanical, thermal insulation, and sound insulation properties. Moreover, various test methods followed, and standards specified to investigate the mechanical, thermal and acoustic insulation properties are also discussed. The possibility of using coconut fibre as a locally available natural alternative core material to polyurethane core of sandwich panels has been evaluated using simulations based on the material properties obtained from literature. The study identifies coconut fibre as a potential alternative core material for sandwich roof panels as it reflects nearly similar thermal behaviour to polyurethane.

Vacuum oven heat treatments were done to enhance the properties of coir fibre for improved performance in composites. Their effects on the mechanical properties of coir fibres were investigated. As received (AR) coir fibres were subjected to heat treatment temperatures of 80 oC and 160 oC for 6 hours at each temperature in a vacuum oven. The effects of the heat treatment temperature on AR coir fibres were statistically analyzed using ANOVA, F-tests, Fisher Pairwise grouping and Fisher Individual Tests for Difference of Means (FITDM) with Minitab-18 Software. This was done to determine the significance of these heat treatments on the tensile properties of AR coir fibres. Fisher Pairwise grouping and FITDM show that strength and elongation of AR coir fibres differed significantly from coir fibres heat-treated at 80 oC. The tensile strength of AR coir fibres was found to be, respectively, 49% and 24% lower than coir fibres treated at 80 oC and 160 oC. The stiffness of coir fibres (AR) was found to significantly increase after heat-treating at 160 °C, while the elongation at break of AR was 44% higher. The strength distributions obtained from the tensile test data were subjected to two-parameter Weibull statistics. AR coir fibres displayed Weibull moduli that were 16% and 56% higher than coir fibres treated at 80 oC and 160 oC, respectively. SEM was conducted on the samples to delineate the morphological changes affecting the properties of coir fibres.

Abstract Natural fibre reinforced polymer composites are often a better substitute to man-made fibre reinforced polymer composites because of their wide availability, economical, recyclability and biodegradability. In this paper, natural fibre reinforced polymer composites are made using coir/ fly ash as reinforcements. Influences of polymer types, natural fibre (coir) length and wt. % of fly ash on tensile and flexural behaviors are investigated. General purpose resin, Vinyl ester and Isophthalic resin are the different polymers used in making samples. The samples are prepared according to Taguchi Design of Experiments using L9 orthogonal array. To explore the significance of participating factors such as polymer type, natural fibre (coir) length and wt. % of fly ash on the tensile and flexural behaviors, ANOVA is implemented. Regression equations reveal that the type of polymer influences tensile and flexural behaviors more than that of natural fibre (coir) length and wt. % of fly ash.

This paper addresses the potential alternative green construction technology utilising agricultural waste. Research on precast self-compacting concrete beam (PSCC-B) incorporating banana skin power (BSP) as cement replacement, and coir fibre (CF) as filler, was conducted. In this research, the materials and mechanical properties of the self-compacting concrete (SCC) with added BSP and CF were investigated. The study encompasses two trial mix comprising different percentages of BSP and CF. Two (2) control beams and six (6) beams containing various percentages of BSP and CF were cast and tested under a four-point loading test with a shear span-to-depth ratio of 1.7. From the results obtained, it was observed that an innovative mix ratio of SCC with 0.4% BSP and 0.5% CF enhances its compression strength and tensile strength by up to 7% and 59%, respectively. Likewise, modulus of elasticity for SCC with various ratios of BSP and CF recorded values in the range of 31–43 GPa, which is similar to or higher than most normal concrete. The flexural test results showed that PSCC-B with 0.4% BSP and 0.5% CF attained the highest ultimate flexural load, slightly lower deflection, and less crack width compared to the other beams.

Many researchers have investigated alternative sources to overcome the problem of conventional building material polluting the environment by the development of green self-compacting concrete in the construction industry. The best alternative solution is to utilise non-conventional construction materials like agricultural wastes. Meanwhile, self-compacting concrete (SCC) is considered as high strength as well as high-performance concrete. The demerits, which include tensile and flexural strength, can be improved by incorporating coir fibres. The utilisation of coir fibres also modifies self-compacting concrete performance after cracking and improves the toughness. This study defines an experimental investigation of the mechanical properties of self-compacting concrete containing coir fibres (CF) with different percentages being 0%, 0.2%, 0.5%, 1%, and 1.5% at 7- and 28-days water curing. The mechanical properties include the slump flow and compressive and tensile strength were examined. The outcomes demonstrated that a required slump flow for self-compacting concrete was achieved using coir fibres up to 1%, beyond which it reduced the slump significantly. The length of fibre and proportion of fibres directly affected the workability. The compressive strength was 10% to 15% enhanced with the incorporation of coir fibres up to 0.5%; after that, the strength was slightly reduced, and tensile strength was 30% to 50% improved compared to conventional self-compacting concrete up to 1% of coir fibres incorporation in the SCC mix, after which it rapidly reduced.

Calcined seashell (CSS) powder and treated coir fibre (CF) are well-established additives for reinforcing poor soils. However, the absence of specific mix designs to optimize the mix additives makes it difficult to predict their combined effect on improving the mechanical behaviour of poor soils. This research explores the use of response surface methods to find the optimal proportions of CSS and CF for enhancing the mechanical properties of a tropical residual soil. This study uses a combination of Analysis of Variance (ANOVA) and regression models to examine how the independent variables of the CSS content, CF content, and curing duration influence the responses of the Unconfined Compressive Strength (UCS), Flexural Strength (FS), and Indirect Tensile Strength (ITS). The findings show that the optimal mix of 9.06% CSS, 0.30% CF, and 12 days of curing significantly improved the UCS, FS, and ITS by roughly six, four, and three times, respectively. Microstructural analysis revealed that the formation of calcium-aluminate-hydrate and calcium-silicate-hydrate are the primary components responsible for the enhanced mechanical properties of the treated soil. [ABSTRACT FROM AUTHOR]

Calcined seashell (CSS) powder and treated coir fibre (CF) are well-established additives for reinforcing poor soils. However, the absence of specific mix designs to optimize the mix additives makes it difficult to predict their combined effect on improving the mechanical behaviour of poor soils. This research explores the use of response surface methods to find the optimal proportions of CSS and CF for enhancing the mechanical properties of a tropical residual soil. This study uses a combination of Analysis of Variance (ANOVA) and regression models to examine how the independent variables of the CSS content, CF content, and curing duration influence the responses of the Unconfined Compressive Strength (UCS), Flexural Strength (FS), and Indirect Tensile Strength (ITS). The findings show that the optimal mix of 9.06% CSS, 0.30% CF, and 12 days of curing significantly improved the UCS, FS, and ITS by roughly six, four, and three times, respectively. Microstructural analysis revealed that the formation of calcium-aluminate-hydrate and calcium-silicate-hydrate are the primary components responsible for the enhanced mechanical properties of the treated soil.

Vacuum oven heat treatments were done to enhance the properties of coir fibre for improved performance in composites. Their effects on the mechanical properties of coir fibres were investigated. As received (AR) coir fibres were subjected to heat treatment temperatures of 80 oC and 160 oC for 6 hours at each temperature in a vacuum oven. The effects of the heat treatment temperature on AR coir fibres were statistically analyzed using ANOVA, F-tests, Fisher Pairwise grouping and Fisher Individual Tests for Difference of Means (FITDM) with Minitab-18 Software. This was done to determine the significance of these heat treatments on the tensile properties of AR coir fibres. Fisher Pairwise grouping and FITDM show that strength and elongation of AR coir fibres differed significantly from coir fibres heat-treated at 80 oC. The tensile strength of AR coir fibres was found to be, respectively, 49% and 24% lower than coir fibres treated at 80 oC and 160 oC. The stiffness of coir fibres (AR) was found to significantly increase after heat-treating at 160 °C, while the elongation at break of AR was 44% higher. The strength distributions obtained from the tensile test data were subjected to two-parameter Weibull statistics. AR coir fibres displayed Weibull moduli that were 16% and 56% higher than coir fibres treated at 80 oC and 160 oC, respectively. SEM was conducted on the samples to delineate the morphological changes affecting the properties of coir fibres. [ABSTRACT FROM AUTHOR]

This paper addresses the potential alternative green construction technology utilising agricultural waste. Research on precast self-compacting concrete beam (PSCC-B) incorporating banana skin power (BSP) as cement replacement, and coir fibre (CF) as filler, was conducted. In this research, the materials and mechanical properties of the self-compacting concrete (SCC) with added BSP and CF were investigated. The study encompasses two trial mix comprising different percentages of BSP and CF. Two (2) control beams and six (6) beams containing various percentages of BSP and CF were cast and tested under a four-point loading test with a shear span-to-depth ratio of 1.7. From the results obtained, it was observed that an innovative mix ratio of SCC with 0.4% BSP and 0.5% CF enhances its compression strength and tensile strength by up to 7% and 59%, respectively. Likewise, modulus of elasticity for SCC with various ratios of BSP and CF recorded values in the range of 31–43 GPa, which is similar to or higher than most normal concrete. The flexural test results showed that PSCC-B with 0.4% BSP and 0.5% CF attained the highest ultimate flexural load, slightly lower deflection, and less crack width compared to the other beams. [ABSTRACT FROM AUTHOR]

One way to obtain more benefit from coconut waste is to utilise coir fibre (CF) as reinforcement in biodegradable plastics. The current work aims to study the effect of CF on the performance of a thermoplastic starch (TPS)/poly(lactic acid) (PLA) blend. TPS/PLA/CF biocomposites with a constant TPS: PLA ratio of 60:40 by weight and various concentrations of CF (2.7, 5.5, 8.2, and 10.9 wt%) were fabricated using a twin-screw extruder and then injection moulded into dumbbell-shaped specimens for property testing. The obtained TPS/PLA/CF biocomposites exhibited improved stiffness and hardness, corresponding to the stronger hydrogen bond interaction between starch and PLA and/or starch and CF and the increased PLA crystallinity. Due to the reinforcing effect, the biocomposites also exhibited lower extensibility, tensile strength and impact strength compared to the TPS/PLA blend. Incorporating CF enhanced compatibility between the TPS and PLA phases; however, it also caused reduced melt flow ability, increased shear viscosity, and a decreased shear thinning effect of the blend. The resulting TPS/PLA/CF biocomposites could potentially be used to produce bio-based and biodegradable injection-moulded products. Unlabelled Image • Effect of coir fibre (CF) on properties of TPS/PLA (60/40 w/w) blend was investigated. • TPS/PLA/CF biocomposites with CF content of 2.7–10.9 wt% were fabricated by extrusion. • TPS/PLA blend and its biocomposites with CF exhibited a co-continuous structure. • CF enhanced compatibility between TPS and PLA phases and increased crystallinity of the blend. • CF played a role as reinforcement to improve stiffness and hardness of the TPS/PLA blend. [ABSTRACT FROM AUTHOR]

Cement stabilised rammed earth (CSRE) is used in the construction of load bearing walls. CSRE elements under compressive loads experience sudden catastrophic shear failures. Such brittle failures shall be avoided in the CSRE structures. The addition of short discrete randomly oriented fibres to CSRE can help avoid such catastrophe failures, where the fibres can bridge across the crack and help inhibit the crack propagation. The paper deals with studies on the effect of coir fibre reinforcement on the behaviour of CSRE under compression. The influence of fibre volume fraction, cement content and moisture content on the strength and stress–strain characteristics of CSRE has been investigated. Five fibre volume fractions (VF), 0.0, 0.5, 1.0, 1.5 and, 2.0%, two cement contents (7 and 10%), and two moisture conditions were considered. The compressive strength of fibre reinforced CSRE increased by 10–30% for 1% VF. The strain at peak stress and the failure strains have significantly increased with the addition of fibres indicating the improved ductility and the post peak response of the material. The energy absorption capacity of CSRE increased by 2–5 times for an increase in the fibre volume fraction from 0 to 2%. The sudden catastrophic shear failures observed in the cement stabilised rammed earth under compression can be eliminated by the addition of short randomly oriented coir fibres. The fibre volume fraction of 1% is the optimum. [ABSTRACT FROM AUTHOR]

This study explores the possibility of using sustainable materials in the form of fly ash as a precursor in alkali activation (AA) reactions, as well as coir fibres as discrete reinforcement. For enhancing the longevity of fibres in an alkaline environment and improving the mechanical performance of the soil–fibre composite, an effort was made in this study to physically coat the natural fibre surface with linseed oil and turpentine oil. The effect of surface treatment on coir fibres was initially analysed by field emission scanning electron microscopy and energy dispersive x-ray tests. To evaluate the effects, unconfined compressive strength, indirect tensile strength, and flexural strength tests were performed at 7 and 28 days of curing on AA-treated soil reinforced with treated and untreated coir fibres. The test results demonstrated that treated fibres significantly enhanced the mechanical properties of the AA-treated soil in terms of peak stress and post-peak behaviour. [ABSTRACT FROM AUTHOR]

Indian coir industry is one among the small-scale cottage industries which contributes a great amount to the economy of India. India and Sri Lanka are the top two international producers, and they account for 90% of world coir manufacturing. The modern digital technologies can monitor the physical, chemical and microbiological properties in agriculture sector and can analyse the data in a faster manner. This paper highlights the large opportunities of deep learning in agriculture as an intelligent method for classifying and predicting the quality of the raw materials and thereby correlating into suitable products in the agricultural sector. Here we gathered the dataset from Central Coir Research Institute, Alappuzha, tested the chemical properties and applied several decision tree algorithms on the dataset and compared for analysis. This paper focuses specifically on a hybrid method with the usage of the back-propagation in deep learning and fuzzy logic decision tree. Experimental results reveal that the proposed method shows an accuracy of 98.75%. The comparison results with various decision tree-based classification algorithms, such as C4.5, ID3, CART, Naïve Bayes, fuzzy, MLP, verify the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

Highlights • NaHCO 3 treatment contributes to increase fibre density, stiffness and reduce thermal stability. • Epoxy composites achieve higher tensile and flexural strength than polyester composites. • Polyester composites reach higher tensile and flexural modulus than epoxy composites. • The alkaline treatment does not affect the mechanical strength of the composites. • Higher tensile and flexural moduli are obtained in 96 or 168 h of alkaline exposure. Abstract This work evaluates a new eco-friendly surface treatment method for coir fibres based on sodium bicarbonate (NaHCO 3). The fibres are treated with 10 wt% NaHCO 3 solution for different periods of time (24, 96 and 168 h). A 2141 Full Factorial Design is established to investigate the effect of the type of matrix (epoxy and polyester) and treatment time (24, 96 and 168 h) on the mechanical properties of coir fibre composites. X-Ray diffraction (XRD) analysis reveals that the treatment does not promote a complete change of cellulose-I into cellulose-II. However, the degradation of hemicellulose and pectin of the fibre surface is evidenced by the thermogravimetric (TGA) curves. The chemical treatment contributes to increase the fibre density and to reduce its thermal stability. Single fibre tensile tests reveal a gradual increase in the elastic modulus attributed to the treatment time factor. Epoxy composites presented higher tensile and flexural strength in comparison to polyester composites, which exhibit higher tensile and flexural modulus. The alkaline treatment does not affect the mechanical strength of the composites. However, higher tensile and flexural moduli are obtained when the treatment time increases to 96 or 168 h. The proposed treatment proves to be feasible and efficient to increase the stiffness of coir fibre composites, besides being less damaging to the environment after disposal when compared to strongly alkaline solutions such as NaOH. [ABSTRACT FROM AUTHOR]

The study is to develop an appropriate environmental friendly building material that would be sourced, obtained locally and used for construction of structures at a low cost by using termite mound soil, reinforced with 0%, 1%, 2%, 3%. and 4% coir fibres. Physical and mechanical tests were conducted on the different composition samples after curing. The particle size distribution showed that clay had the largest percentage with a moisture content of 3.53%, specific gravity of 2.0, liquid limit of 30.5% and plastic limit value of 25.4. The compressive strength test showed a decrease with increase in fibre content from 1% upward, modulus of rupture test showed that increase in fibre content leads to a corresponding increase in rupture while the modulus of elasticity test showed that from 3% to 4% fibre content, a decrease in the elasticity occurred. It can be concluded that low fibre inclusion into compressed termite mound brick is feasible if fibre content do not exceed 2% and thus can be used for both load and non-loading bearing structures.

Purpose: In this work, coir fibre with varying fibre content was selected as reinforcements to prepare polymer-based matrices and the problem of reduced fibre-matrix interfacial bond strength has been diluted by chemical treatment of coir fibres with alkali solution. Design/methodology/approach: The effect of fibre loading, solution concentration and soaking time on the impact strength of the composites were analyzed using statistical techniques. Response Surface Methodology (RSM) approach was used to model and optimize the impact properties of coir-polyester composites. Findings: The impact strength of coir fibre reinforced polyester composite depends mainly on the fabrication parameters such as fibre-polyester content, soaking time, concentration of soaking agent and adhesive interaction between the fibre and reinforcement. Research limitations/implications: The mechanical properties of any coir polyester composite depend on the nature bonding between the fibre and reinforcement. The presence of cellulose, lignin on the periphery of any natural fibre reduces the bonding strength of the composite. This limitation is overcome by fibre treatment over sodium hydroxide to have better impact properties. Practical implications: Now days, natural fibre reinforced composites are capable of replacing automotive parts, subjected to static loads such as engine Guard, light doom, name plate, tool box and front panels etc. These materials can withstand any static load due to its higher strength to weight ratios. Originality/value: The effect of fibre loading, solution concentration and soaking time on the impact strength of the composites were analyzed using statistical techniques. Response Surface Methodology (RSM) approach was used to model and optimize the impact properties of coir-polyester composites. The impact strength of NaOH impregnated coir fibre reinforced polyester composites was evaluated. [ABSTRACT FROM AUTHOR]

A successful attempt has been made to develop coir fibre composites reinforced with graphene, epoxy and carbon fibre. The carbon fibres were arranged in an intercalated manner, which is similar to the coir fibres. The percentage composition of graphene was varied as 1, 2, 4 and 6% by weight of the holding matrix. Suitable surface modifications were done by treating natural fibres by 5% NaOH and 0.3% KMnO4 for better adhesion of fibre and epoxy resin. Sonication and cetyl trimethyl ammonium bromide treatments were also done to achieve the fine scattering of graphene in the epoxy matrix in order to achieve better mechanical behaviour. Moulds were made as per D638 American Society for Testing and Materials (ASTM) standards. The treated fibres were then arranged in the mould by the conventional hand layup technique. Tensile testing was carried out to determine the mechanical properties of the composites. Two-way analysis of variance was used as a statistical tool to find the effect of parameters such as 'Percentage composition of graphene' and 'Type of mould' on the modulus of the composites. Fourier transform infrared spectroscopy was conducted to determine the interferential adhesion and homogeneous distribution of fibres in the composite matrix. At last, field emission scanning electron microscopy analyses were also done to the specimens before and after tensile testing to determine the morphology of different entities present in the composites. [ABSTRACT FROM AUTHOR]

This work deals with the surface modification of Coir fibre through graft copolymerization process. Graft copolymerization of methyl methacrylate (MMA) onto coir fibre was carried out with Potassium per sulphate (PPS) as an initiator under the catalytic influence of Ferrous ammonium sulphate (FAS) in aqueous medium. Control and grafted coir fibres were subjected to evaluation of properties like tensile strength, flexural rigidity, density, water absorbance and light fastness studies. It was observed that MMA grafted coir fibre shows more resistance towards water and light fastness when compared with that of control coir fibre. Further morphological, structural changes and thermal stability of control and grafted coir fibre have also been studied by SEM and TGA techniques. For statistical significance the Analysis of variance (ANOVA) were studied and the P values obtained were less than 0.05 which revealed that the value was highly significant for the improvement of physical properties on coir fibre by graft Co- polymerization.

This paper presents the effect of coir fibres on the compaction and unconfined compressive strength of a bentonite-lime-gypsum mixture. The coir fiber content varied from 0.5 to 2 %. The results indicated that the dry unit weight and the optimum moisture content of a bentonite – lime mix increased with the addition of gypsum. The unconfined compressive strength of the bentonite increased with the increase in the lime content up to 8 %. Beyond 8 %, the unconfined compressive strength decreased. The dry unit weight of the reference mix decreased, and the optimum moisture content increased with the addition of coir fibre. The unconfined compressive strength of the bentonite + 8 % lime mix increased up to 4 % with the gypsum. Beyond 4 %, the unconfined compressive strength decreased. The unconfined compressive strength of the reference mix increased with the addition of coir fibre up to a fibre content of 1.5 %. The unconfined compressive strength of the reference mix-coir fibre composite was less in comparison to the reference mix. The unconfined compressive strength of the bentonite increased with the addition of lime and gypsum and with the increase in the curing period. The improvement in the post-peak region was better for the reference mix with reinforced coir fibres as compared to the unreinforced reference mix. The improved post-peak behaviour of the bentonite-lime-gypsum-coir fibre mixture could boost the construction of temporary roads on such problematic soils. Further, its use will also provide an environmental motivation for providing a means of consuming large quantities of coir fibres.

Abstract A full factorial design (2231) has been used to investigate the effect of the use of sodium hydroxide fibre treatment, Portland cement and uniaxial pressure on the physical and mechanical properties of hybrid short coir fibre reinforced composites (HSCoirFRCs). The response variables considered in this work were the apparent density, porosity, tensile and flexural strength, the modulus of elasticity and the Charpy impact resistance. The alkali treatment contributed not only to reduce the apparent porosity, but also to increase the mechanical properties of the HSCoirFRCs. A reduction of the impact resistance and an increase of the apparent density was also identified after treatment. Cold pressing significantly affected the physical and mechanical properties of the HSCoirFRCs. Higher pressure levels enhanced the wettability of the fibres and, consequently, the mechanical performance of the composites. The incorporation of cement microparticles as a second reinforcement phase was however not effective, leading to decreased strength and an increased apparent density of the materials. The HSCoirFRC structure can be considered an economical and sustainable alternative for future secondary structural parts in lightweight transport applications. [ABSTRACT FROM AUTHOR]

Over the last few decades, a significant amount of research has been focused on the use of natural fibres as reinforcement in polymers, due to their intrinsic properties such as sustainability, easy availability and processing, biodegradability and moderate mechanical strength. Among natural fibres, coir is a low-cost fibre extracted from coconut palm which is extensively produced in Brazil. A full factorial design was carried out to investigate the effects of the manufacturing and composition parameters on the mechanical and physical properties of short coir fibre-reinforced composites (SCoirFRCs). The random short fibres were mixed with epoxy polymer and compacted by uniaxial pressure. The physical and mechanical responses, namely, apparent density, impact resistance, flexural strength and modulus, were investigated under a design of experiment approach. SCoirFRCs fabricated with 35% of fibre volume fraction, 375 g/m2 of fibre grammage and HY956 epoxy hardener type achieved higher flexural modulus and impact resistance, while those consisting of 30 vol% of coir fibres, HY956 type and 300 g/m2 of grammage revealed higher flexural strength. The findings revealed that the mechanical properties of SCoirFRCs are substantially dominated by the properties of the matrix phase and fibre wettability. [ABSTRACT FROM AUTHOR]