Showing papers on "SISAL published in 2005"

A study of the mechanical properties of randomly oriented short banana and sisal hybrid fiber reinforced polyester composites

Abstract: The mechanical performance of short randomly oriented banana and sisal hybrid fiber reinforced polyester composites was investigated with reference to the relative volume fraction of the two fibers at a constant total fiber loading of 0.40 volume fraction (Vf), keeping banana as the skin material and sisal as the core material. A positive hybrid effect is observed in the flexural strength and flexural modulus of the hybrid composites. The tensile strength of the composites showed a positive hybrid effect when the relative volume fraction of the two fibers was varied, and maximum tensile strength was found to be in the hybrid composite having a ratio of banana and sisal 4 : 1. The impact strength of the composites was increased with increasing volume fraction of sisal. However, a negative hybrid effect is observed when the impact strength of the composites is considered. Keeping the relative volume fraction of the two fibers constant, that is, banana : sisal = 0.32 : 0.08 (i.e., 4 : 1), the fiber loading was optimized and different layering patterns were investigated. The impact strength of the composites was increased with fiber loading. Tensile and flexural properties were found to be better at 0.40 Vf. In the case of different layering patterns, the highest flexural strength was observed for the bilayer composites. Compared to other composites, the tensile properties were slightly higher for the composite having banana as the skin material and sisal as the core material. Scanning electron micrographs of the tensile and impact fracture surfaces of the hybrid composites having volume fraction 0.20 and 0.40 Vf were studied. The experimental tensile strength and tensile modulus of hybrid composites were compared with those of theoretical predictions. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1699–1709, 2005

Microstructure and mechanical properties of waste fibre–cement composites

Abstract: This paper examines the microstructure of composite materials containing fibrous wastes (as reinforcement in granulated blast furnace slag or ordinary Portland cement matrices). Both secondary and back-scattered electron imaging and energy dispersive X-ray spectroscopy were used for compositional analysis. Evaluation of both fractured and cut surfaces provided the morphological and bonding information that was related to mechanical performance obtained from flexural tests. Sisal and Eucalyptus grandis pulps showed satisfactory bonding to the cement matrix, with fibre pullout predominating as indicated by high values of energy absorption. In contrast banana pulp reinforced composites exhibited fibre fracture as the main failure mechanism. In all analysed composites, partial fibre debonding and matrix micro-cracking were dominant at the interfaces. However, there was no evidence of a porous transition zone or massive concentration of calcium hydroxide at the interface.

Surface modification of sisal fibers: Effects on the mechanical and thermal properties of their epoxy composites

Abstract: The aim of this paper is to evaluate the mechanical and thermal properties of sisal fiber reinforced epoxy matrix composites as a function of modification of sisal fiber by using mercerization and silane treatments. The changes introduced by the treatments on the chemical structure of sisal fibers have been analyzed by infrared spectroscopy (FTIR). Thermal behavior of both sisal fibers and composites has been studied by thermogravimetric analysis (TGA). Both treatments clearly enhanced thermal performance and also mechanical properties of fibers, being other physical properties also modified. Mercerization, above all when combined with silanization, led to significant enhancement on mechanical properties of composites as a consequence of increasing mechanical properties of fibers and improving fiber/matrix adhesion. POLYM. COMPOS., 26:121–127, 2005. © 2005 Society of Plastics Engineers

Effect of sisal fibre orientation on electrical properties of sisal fibre reinforced epoxy composites

Abstract: Different directionally oriented sisal fibre reinforced epoxy resin composites have been prepared by compression moulding. The effect of temperature and frequency variation on dielectric constant ( e ′), dielectric dissipation factor (tan δ ) and on a.c. conductivity ( σ a.c. ) of the samples was measured. Measurements were in the temperature range 24–180 °C and in the frequency range 1–20 kHz. The sisal fibre epoxy composites were oriented parallel and perpendicular to the electric field. It was found that the dielectric constant, tan δ and a.c. conductivity increased with increasing temperature. The dependence of dielectric constant, tan δ and a.c. conductivity with frequency has also been studied and it was found that e ′ and tan δ of the epoxy and 0 and 90° oriented sisal fibre epoxy composites decreased with increasing frequency and a.c. conductivity increases with increasing frequency. Near the transition temperature of the epoxy the observed properties showed anomalous behaviour. Peaks for dielectric constant, tan δ and a.c. conductivity were observed. Clear relaxation peaks for tan δ around 169 °C were observed in epoxy resin, shifting to the lower temperature side with increasing frequency. The relaxation time of epoxy and 0 and 90° oriented sisal fibre epoxy composites has been calculated and it was found that τ ( s ) was 4.09×10 −5 , 5.52×10 −5 and 5.47×10 −5 , respectively at 100 °C. Semi log plots show that e ′ T / e ′ P tan δ T /tan δ P and σ a.c.T / σ a.c.P can be represented as follows e ′ T / e ′ P = k log f + c , tan δ T / tan δ P = a log f + b and, σ a . c . T / σ a . c . P = l log f + m

Effects of fibre surface treatment on fracture-mechanical properties of sisal-fibre composites

Abstract: Sisal fibre reinforced composites, one class of a broad range of eco-composite materials, were studied in connection with the effects of fibre surface treatment on their fracture-mechanical properties. Previous investigations on sisal fibre and its composites have been fully reviewed [1], which provided an impetus for this research. Two fibre surface treatment methods, chemical coupling based on silane and oxidization based on permanganate and dicumyl peroxide, together with untreated sisal fiber composites were used to set up different levels of interface bonding strength. The interface effects on the mechanical properties and fracture toughness of sisal fibre reinforced vinyl-ester composites were completely assessed based on the test results obtained and theoretical analyses. Many aspects of studies reported in this paper are original, such as single fiber pull-out tests and toughness evaluation of sisal composites aided by scanning electron microscopy. The results showed that fibre surface treatment c...

Effect of layering pattern on dynamic mechanical properties of randomly oriented short banana/sisal hybrid fiber-reinforced polyester composites

Abstract: Dynamic mechanical test methods have been widely employed for investigating the structures and viscoelastic behavior of polymeric materials to determine their relevant stiffness and damping characteristics for various applications. Randomly oriented short banana/sisal hybrid fiber–reinforced polyester composites were prepared by keeping the volume ratio of banana and sisal 1 : 1 and the total fiber loading 0.40 volume fraction. Bilayer (banana/sisal), trilayer (banana/sisal/banana and sisal/banana/sisal), and intimate mix composites were prepared. The effect of layering pattern on storage modulus (E′), damping behavior (tan δ), and loss modulus (E″) was studied as a function of temperature and frequency. Bilayer composite showed high damping property while intimately mixed and banana/sisal/banana composites showed increased stiffness compared to the other pattern. The Arrhenius relationship has been used to calculate the activation energy of the glass transition of the composites. The activation energy of the intimately mixed composite was found to be the highest. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 2168–2174, 2005

Effect of Treatment of Maleic Anhydride on Mechanical Properties of Natural Fiber: Polystyrene Composites

Abstract: In the present work, banana, hemp, and sisal fibers are employed as fillers for the formation of natural fiber:polystyrene composites in the ratios of 55:45, 50:50, 45:55, and 40:60 (wt/wt). The natural fibers were treated with maleic anhydride. The Young's modulus, flexural modulus, impact strength, and Shore-D hardness all decreased with increasing amounts of fibers in the natural fiber:polystyrene composites. The sisal fiber composites show the highest mechanical strength for all ratios. A maleic anhydride treatment shows significant improvement in Young's modulus, flexural modulus, impact strength, and Shore-D hardness compared with the untreated fiber composites.

Injection molding of long sisal fiber–reinforced polypropylene: Effects of compatibilizer concentration and viscosity on fiber adhesion and thermal degradation

Abstract: A two-step process was used to obtain long sisal fiber-polypropylene (SF/PP)–reinforced thermoplastic composites, using maleic anhydride grafted polypropylene (MA-g-PP) as a compatibilizer. At a first stage, modified polypropylenes (mPP) were used for an extrusion impregnation process, for the preparation of composite pellets containing about 70 wt% of SF. SF/mPP pellets with a large aspect ratio were prepared by continuous extrusion impregnation of a continuous SF yarn, using a single screw extruder and an adequate impregnation die. The mPP used were MA-g-PP and regular polypropylene (PP), modified by reaction with different amounts of an organic peroxide. The composite pellets were thus dry blended with regular PP pellets in an injection machine hopper, and injection molded to obtain composite tensile specimens with a minimum quantity of modified polypropylene, minimum fiber breakage and thermal degradation, and excellent mechanical properties. It is shown that the fiber breakage is reduced to a minimum, even for recycled composites, due to the presence of the low-viscosity polymer layer wetting the SF fibers. The bulk composite effective viscosity and the fiber breakage extent and thermal degradation during the injection-molding step are found to be closely related. Blending with much less expensive mPP at the impregnation stage optimizes the amount of expensive MA-g-PP. POLYM. ENG. SCI., 45:613–621, 2005. © 2005 Society of Plastics Engineers

Fracture behavior of sisal fiber–reinforced starch-based composites

Abstract: Fil: Alvarez, Vera Alejandra. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnologia de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingenieria. Instituto de Investigaciones en Ciencia y Tecnologia de Materiales; Argentina

Characterization and treatments of pineapple leaf fibre thermoplastic composite for construction application

Abstract: In recent years natural fibres appear to be the outstanding materials which come as the viable and abundant substitute for the expensive and nonrenewable synthetic fibre. Natural fibres like sisal, banana, jute, oil plam, kenaf and coir has been used as reinforcement in thermoplastic composite for applications in consumer goods, furniture, low cost housing and civil structures. Pineapple leaf fibre (PALF) is one of them that have also good potential as reinforcement in thermoplastic composite. It is the objective of the current research to characterize PALF and to investigate the effect of fibre treatment on the mechanical properties of PALF reinforced polypropylene (PP) composite. PALF was prepared from raw pineapple leaf. It was then chemically treated to hinder the water content. Both PP and PALF were compounded using two-roll mill machine prior to compression moulding via hot press machine to form a sheet. After forming the composite sheet, samples were prepared for tensile test (ASTM D638), flexural test (ASTM D790) and impact test (ASTM D256). Scanning Electron Microscope (SEM) was used to investigate the miscibility between the fibre and matrix. It was found that PALF contain 87.56% holocellulose, 78.11% alpha cellulose, 9.45% hemicellulose and 4.78 % lignin. The chemical constituents obtained were in the range to data reported in literatures. It was also observed that the flexural modulus and strength of treated PALF reinforced PP composite increased linearly with increment of fibre loadings. This trend was similar for impact strength where it exhibited a slight reduction at the initial stage but increased later as the fibre loading increased. The study has demonstrated that the optimum fibre loading for the best performance of the composite achieved was 30 wt%. This was clarified further by SEM where fibres and matrix have shown better miscibility at 30 wt% of treated PALF.

Mechanical Properties of Sisal/Coir Hybrid Fibre Reinforced Natural Rubber:

Abstract: Natural rubber was reinforced with various concentrations of sisal and coir fibres. Green strength measurements were carried out to determine the fibre orientation. The rubber–fibre interfacial bon...

Method for polishing wheel from sisal fiber

Abstract: A polishing wheel is made up of short sisal hemp fibres, synthetic resin, plant fibres and inorganic compound through proportionally mixing, drying, hot die pressing and trimming.

Mechanical Properties of Wood Polymer Composites Prepared from Agro-Waste and HDPE

Abstract: Wood polymer composites based on untreated and maleic anhydride treated banana, hemp, and sisal fibers with HDPE resin are prepared in different ratios of 55:45, 50:50, 45:55, and 40:60 (wt/wt), respectively. Young's modulus and flexural modulus decrease with increase in fiber amount in the polymer. Maleic anhydride-treated fiber composites show highest Young's modulus and flexural modulus. The impact strength and shore-D hardness is also observed to be higher in maleic anhydride-treated fiber composites than in the untreated fiber composites.

Weibull analysis of microbond shear strength at sisal fibre–polyester resin interfaces

Abstract: An analysis has been made of the tensile strength of sisal fibres and the interfacial adhesion between fibres and polyester resin droplets. Density and microscopy methods were used to determine the cross-sectional area of the sisal fibres. The average tensile strength of treated sisal fibres decreased by a modest amount following treatment with 0.06 M NaOH. However, this treatment resulted in a substantial increase in the interfacial shear strength at the sisal fibre to polyester resin interface. Weibull analysis has been used successfully to analyse variability in tensile strengths and interfacial shear strength using probability of failure plots. Scanning electron microscopy has revealed the shape of resin droplets on the surface of treated and untreated sisal fibres and contact angles are much lower for droplets on treated fibres. Damage to the surface of fibres has been examined following shear testing. Weibull analysis is an effective tool for characterising highly variable fibre properties and evalu...

Transport and flame properties of natural fibre reinforced polymers

Abstract: The authors studied the thermal conductivity, water absorption and linear burn rate of natural fibre reinforced polymers (NFRP). High density polyethylene (HDPE) and degradable starch-based polymers were used as matrices.Discrete sisal (Agave Sisalacea) fibres were used as reinforcement. The effect of fibre content, moisture and void fractions on thermal conductivity was studied. From water absorption tests, it was determined that water diffusion in NFRPs corresponds to a Fickian process only in the early stages of diffusion. Diffusivities were obtained for that case. Linear burn rate experiments showed that sisal reinforced polymers burn twice as fast as unreinforced HDPE specimens, however the reinforced specimens show better structural integrity during burning than the unreinforced ones, probably due to an increase in viscosity and melt strength due to the presence of reinforcing fibres.

Influência da adição e da modificação química de uma carga mineral nanoparticulada nas propriedades mecânicas e no envelhecimento térmico de compósitos poliuretano/sisal

Abstract: This work deals with filler hybridization effects, by the addition of a nanoparticulate mineral filler (bentonite), on the mechanical performance of compression molded Polyurethane/sisal composites with 25 wt % fiber content. Composite tensile and impact properties were evaluated as a function of mineral filler content (0-10 wt %) and chemical modifications. Thermal aging effects onf tensile (s, E, e) properties of selected composites were also ascertained. The mineral filler (Brasgel PA sodium bentonite) was employed in the following forms: a) as received; b) treated with a 0,6N HCl solution; c) chemically modified with dodecyl dimethyl benzyl ammonium chloride (Dodigen) and d) chemically modified with cetyl trimethyl ammonium bromide (Cetremide). Our results show that bentonite addition increases the mechanical properties of PU/sisal composites and that best overall mechanical performances was achieved with addition of the hydrochloric acid trated mineral filler. Thermal aging for short times (up to 4 days) led to small increases in composite's elastic modulus na tensile strengths, which was attributed to post-curing of the matrix. Long thermal exposure (32 days) led to decreases in composite tensile properties (s, E, e), which was attributed to oxidative degradation of both: matrix and sisal fibers. The most thermally resistant composite was the hybrid (PU/sisal-bentonite) whose mineral filler was chemically modified with Cetremide. DRX and SEM data indicate the hybrids with organofilized bentonites to be composed of micro and nanocomposite structures.

Evaluation of the influence of chemical treatment on the tensile strength of sisal fibresby a weibull distribution analysis

Abstract: Mercerisation is a common chemical treatment for sisal fibres since it can be used to increase their interfacial adhesion to various polymeric matrices. The influence of this treatment on fibre tensile strength from the point of view of a Weibull distribution is reported. A hundred non-treated sisal fibres were individually tested and the accordance of their tensile strength to a Weibull distribution was analysed. The need to measure the diameter of each fibre being tested in order to estimate its tensile strength was studied. Sisal tensile strength was found to follow a Weibull distribution and to decay with the increase of the severity of the chemical treatment (0.25, 0.5, 1, 2, 5 and 10% w/w NaOH aqueous solution). The values showed an initial decrease of tensile strength, a plateau in the range of 3 to 6% and finally a steep decrease as the concentration was further increased. However, only the 10% treatment showed a statistically significant decrease of fibre tensile strength within a 90% confidence level. Comparisons are included throughout the paper regarding the widely used simplified statistical mean analysis when reporting fibre tensile strength values and its implications on the estimations.

Infiltracao de sal de aluminio em fibras de sisal para obtencao de fibras de alumina

Abstract: Sisal is a renewable agricultural resource adapted to the hostile climatic and soil conditions particularly encountered in the semi-arid areas of the state of Rio Grande do Norte, located in Northeastern Brazil. Consequently, sisal has played a strategic role in the economy of the region, as one of few options of income available in the semi-arid. Find new options and adding value to products manufactured from sisal are goals that contribute not only to the scientific and technological development of the Northeastern region, but also to the increase of the family income for people that live in the semi-arid areas where sisal is grown. Lignocellulosic fibers are extracted from sisal and commonly used to produce both handcrafted and industrial goods including ropes, mats and carpets. Alternatively, added-value products can be made using sisal to produce alumina fibers (Al2O3) by biotemplating, which consists in the reproduction of the natural fiber-like structure of the starting material. The objective of the study reported herein was to evaluate the conditions necessary to infiltrate aluminum salt (Al2Cl6) into sisal fibers and heat-treat the structure to convert it into alumina fibers. The sisal fibers were pre-treated in NaOH, immersed in a saturated solution of (Al2Cl6) and sintered between 1400 °C and 1650 °C. The resulting fibers were then characterized by X-ray diffraction and scanning electronic microscopy. The results revealed the transformation only of the surface of the fiber into a-Al2O3 which yielded limited resistance to handling. Improved infiltration methods have been studied to allow transformation of the bulk structure of sisal into alumina thus increasing the mechanical strength of the resulting alumina fibers.

Dog bed made from sisal material

Abstract: A pet bed such as a dog bed made with sisal material. The dog bed includes an outer covering and a filler material, at least one of which is made from sisal material.

Research Progress of Friction Properties for Fibre Reinforced Resin Matrix Composites

Abstract: The recent research progress in fibre reinforce resin matrix composite materials was reviewed. The friction characteristics and wear mechanism were discussed, the modification of resin based matrix was presented, the effect of fibres on the friction and wear mechanism was summarized. Especially, the properties of sisal and sisal fibre reinforced material were indicated. It is considered that the new research will be focused on the use of sisal reinforced materials.

Reforço de solo laterítico com fibras de sisal de distribuição aleatória, tratadas superficialmente com EPS reciclado.

Abstract: The high costs of the civil engineering construction requires the necessity to develop studies about the process of the stabilization and reinforcement which improves some geotechnical soils properties being part of the constructive specifications The reinforcement technique of the soils with the inclusion of natural fibers has been studied for many researchers It has showing efficient by improving many properties of the soil engineering which results in an interesting composite material for the geotechnical engineering This composite is named fibersoil at this research Experiments was done at the laboratory to evaluate the effect of the addition sisal fibers in the lateritic soil which will establish the mechanical behavior of the material through compaction tests, at the energy of the Normal Proctor and CBR The shear strength was done through the direct shear test Therefore, in the present investigation sisal fiber was randomly included in to the soil at four different percentages of fiber content with 0,25% to 1% by weight of raw soil and also considered different lengths between 10 to 25mm The objective of this research is to contribute to the study on the effect of the sisal fibers with superficial treatment with recycled expanded polystyrene (EPS) inhibiting the absorption of water With base in the results obtained in this work, it was noticed that the addition treated sisal fibers randomly distributed presented significant improvements in the mechanical properties of lateritic soil, transforming it in a product of better qualification for application in works of civil engineering, and that the polymer used it was shown quite applied to the proposed analysis, promoting decrease of the water absorption of the sisal fibers

Coupling Agent Effect on the Tensile Strength Properties of Sisal Fiber-plastic Composites

Abstract: The fiber-plastic composites were made from the compounding of plastic (polypropylene) and sisal (Agav e sisala n a ) fiber with or without addition of coupling agent (Maleic anhydride grafted polypropylene). The tensile strength (Modulus of Elasticity-MOE, Modulus of Rupture-MOR) of the composites were evaluated in the three different conditions, i.e. air dry condition (control), 24 - hour immersion in cold water and 2-hour immersion in boilingwater. The results showed that the addition of coupling agent enhanced the properties of the composites. These properties did not significantly change although the composites were immersed in cold water as long as 24 hours. However, immersion in boiling water for 2 hours, tended to decrease MOR and MOE of the composites.