EFFECT OF NANOSILICA CONTENT ON LONGITUDINAL AND TRANSVERSE TENSILE PROPERTIES OF UNIDIRECTIONAL KENAF COMPOSITE

2015 ◽  
Vol 76 (11) ◽  
Author(s):  
Norhashidah Manap ◽  
Aidah Jumahat ◽  
Napisah Sapiai
Keyword(s):  
Tensile Properties ◽  
Tensile Modulus ◽  
Tensile Tests ◽  
Filament Winding ◽  
Fracture Mechanisms ◽  
Premature Failure ◽  
Pull Out ◽  
Transverse Tensile ◽  
Kenaf Fibre ◽  
Kenaf Composites

Nowadays, continuous natural fibre reinforced polymer nanocomposites have attracted substantial attention among researchers due to various benefits possesses by the natural fibres. Kenaf fibre has become one of the high potential candidates to replace synthetic fibres in polymer composite. Kenaf fibre exhibits good strength and modulus properties, low density, non-abrasive during processing and biodegradable. This study is aimed to evaluate the effect of nanosilica on longitudinal and transverse tensile properties of unidirectional (UD) kenaf composite. The UD kenaf composite samples were prepared based on three different nanosilica content; i.e. 5, 13 and 25 wt.%. The samples were prepared using filament winding and vacuum bagging techniques. The 0o and 90o tensile tests were conducted in accordance to ASTM standard D3039 in order to obtain longitudinal and transverse tensile properties of unmodified and nanosilica-modified kenaf composites. The fracture surfaces of the specimens were observed using scanning electron microscope in order to identify fracture mechanisms involved during tension. The results showed that the addition of nanosilica reduced longitudinal tensile Young’s modulus, strength and failure strain of the kenaf composite. SEM micrographs revealed incomplete resin wetting and  fibre pull-out mechanism at high nanosilica content that contributed to premature failure of the kenaf composites.  However, it was found that the addition of nanosilica improved transverse tensile properties of kenaf composites since these properties were mostly governed by the properties of the matrix. A stiffer matrix improved the transverse tensile modulus and strength of kenaf composites. 

EFFECT OF FIBRE TREATMENT ON LONGITUDINAL AND TRANSVERSE TENSILE PROPERTIES OF UNIDIRECTIONAL KENAF COMPOSITE

2015 ◽  
Vol 76 (11) ◽  
Author(s):  
Norhashidah Manap ◽  
Aidah Jumahat ◽  
Napisah Sapiai
Keyword(s):  
Tensile Properties ◽  
Strain Curve ◽  
Natural Fibre ◽  
Filament Winding ◽  
Fracture Mechanisms ◽  
Positive Effects ◽  
Transverse Tensile ◽  
Kenaf Fibre ◽  
Naoh Treatment ◽  
Kenaf Composites

Kenaf fibre has become one of the best candidates to be used as reinforcement material in polymer composite. However, the adhesion between natural fibre and polymer is weak due to different polarity of natural fibre and hydrophobic polymer. This affects the properties of the composite. One of the method to overcome this compatibility issue is by treating the fibre using sodium hydroxide (NaOH). This study is aimed to evaluate the effect of NaOH treatment on longitudinal and transverse tensile properties of kenaf composites using three different concentration (3, 5, and 7 wt. % NaOH). The kenaf composite test specimens were prepared using filament winding and vacuum bagging techniques. The 0o and 90o tensile tests were conducted in accordance to ASTM standard D3039 in order to obtain longitudinal and transverse tensile properties of treated and untreated kenaf composites. The fracture surfaces of the specimens were observed using scanning electron microscope in order to identify fracture mechanisms involved during tension. NaOH treatment on kenaf fibre resulted in a significant improvement in longitudinal tensile modulus, strength and failure strain. This also indicates an improvement in toughness property as this can be observed through a larger area under graph of tensile stress-strain curve. The SEM micrographs showed that the interfacial adhesion between kenaf fibre and epoxy matrix was improved when the kenaf fibre was treated using NaOH. Therefore, NaOH treatment give positive effects on longitudinal and transverse tensile properties of kenaf composites. Kenaf composite treated with 7wt% NaOH showed the highest tensile strength for both longitudinal and transverse fibre directions.

scholarly journals Kenaf Fibre Reinforced Polypropylene Composites: Effect of Cyclic Immersion on Tensile Properties

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
W. H. Haniffah ◽  
S. M. Sapuan ◽  
K. Abdan ◽  
M. Khalid ◽  
M. Hasan ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Tensile Properties ◽  
Room Temperature ◽  
Tap Water ◽  
Tensile Modulus ◽  
Polypropylene Composites ◽  
Preliminary Results ◽  
Kenaf Fibre ◽  
The Difference ◽  
Number Of Cycles

This research studied the degradation of tensile properties of kenaf fibre reinforced polypropylene composites due to cyclic immersion into two different solutions, as well as comparison of the developed composites’ tensile properties under continuous and cyclic immersion. Composites with 40% and 60% fibre loadings were immersed in tap water and bleach for 4 cycles. Each cycle consisted of 3 days of immersion and 4 days of conditioning in room temperature (28°C and 55% humidity). The tensile strength and modulus of composites were affected by fibre composition, type of liquid of immersion, and number of cycles. The number of immersion cycles and conditioning caused degradation to tensile strength and modulus of kenaf fibre reinforced polypropylene composites. Continuous and cyclic immersion in bleach caused tensile strength of the composites to differ significantly whereas, for tensile modulus, the difference was insignificant in any immersion and fibre loadings. However, continuous immersion in the bleach reduced the tensile strength of composites more compared to cyclic immersion. These preliminary results suggest further evaluation of the suitability of kenaf fibre reinforced polypropylene composites for potential bathroom application where the composites will be exposed to water/liquid in cyclic manner due to discontinuous usage of bathroom.

scholarly journals Enhancement of Mechanical Properties of Flax-Epoxy Composite with Carbon Fibre Hybridisation for Lightweight Applications

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 109 ◽  
Author(s):  
Hom Nath Dhakal ◽  
Mohini Sain
Keyword(s):  
Carbon Fibre ◽  
Tensile Properties ◽  
Composite Laminates ◽  
Failure Modes ◽  
Epoxy Composite ◽  
Hybrid Composites ◽  
Environmental Scanning Electron Microscopy ◽  
Tensile Modulus ◽  
Tensile Tests ◽  
Flax Fibre

The effect of unidirectional (UD) carbon fibre hybridisation on the tensile properties of flax fibre epoxy composite was investigated. Composites containing different fibre ply orientations were fabricated using vacuum infusion with a symmetrical ply structure of 0/+45/−45/90/90/−45/+45/0. Tensile tests were performed to characterise the tensile performance of plain flax/epoxy, carbon/flax/epoxy, and plain carbon/epoxy composite laminates. The experimental results showed that the carbon/flax fibre hybrid system exhibited significantly improved tensile properties over plain flax fibre composites, increasing the tensile strength from 68.12 MPa for plain flax/epoxy composite to 517.66 MPa (670% increase) and tensile modulus from 4.67 GPa for flax/epoxy to 18.91 GPa (305% increase) for carbon/flax hybrid composite. The failure mechanism was characterised by examining the fractured surfaces of tensile tested specimens using environmental scanning electron microscopy (E-SEM). It was evidenced that interactions between hybrid ply interfaces and strain to failure of the reinforcing fibres were the critical factors for governing tensile properties and failure modes of hybrid composites.

Influence of Different Matrices on the Tensile and Impact Properties of Treated Kenaf Composites

2016 ◽  
Vol 1133 ◽  
pp. 136-140
Author(s):  
Noor Haznida Bakar ◽  
Koay Mei Hyie ◽  
A. Jumahat ◽  
Eli Nadia A. Latip ◽  
Anizah Kalam ◽  
...  
Keyword(s):  
Epoxy Resin ◽  
Tensile Properties ◽  
Testing Machine ◽  
Low Velocity ◽  
Impact Properties ◽  
Weight Percentage ◽  
Kenaf Fibre ◽  
Naoh Solution ◽  
Kenaf Composites ◽  
The Impact

This study investigated the mechanical behavior of the treated and untreated kenaf with different matrix resin (epoxy and polyester) using the tensile and low velocity test. The long kenaf fibre was treated with 6% of sodium hydroxide (NaOH) solution for twelve hours in room temperature. The tensile properties of composites at different weight percentage (10,15,20 and 25%) were studied by using Instron Universal Testing Machine according to the standard ASTM D638. Impact test was conducted using an instrumented drop tower device at 10J incident energy level according to the standard ASTM D3763. The results of the study indicated that the epoxy resin reinforced with treated kenaf fibre exhibited higher tensile properties. On the other hand, the impact properties of polyester resin reinforced with treated kenaf fibre show better matrix bonding compared to those with epoxy resin matrices.

scholarly journals Tensile Properties and Microstructure of Single-Cellulosic Bamboo Fiber Strips after Alkali Treatment

Fibers ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 26 ◽  
Author(s):  
Abeer Adel Salih ◽  
Rozli Zulkifli ◽  
Che Husna Azhari
Keyword(s):  
Tensile Strength ◽  
Tensile Properties ◽  
Alkali Treatment ◽  
Tensile Modulus ◽  
Fiber Surface ◽  
Tensile Tests ◽  
Bamboo Fiber ◽  
Alkali Concentration ◽  
Soaking Time ◽  
Cellulosic Fiber

The study systematically explored the effect of alkali concentration and soaking time on the microstructure and tensile properties of single-cellulosic Buluh Semantan. Scanning electron microscopy and tensile tests were conducted to determine the effects of different alkali treatments on the properties of the single-cellulosic bamboo fibers. In particular, the effects of NaOH concentration and soaking time on the tensile properties of the single-cellulosic bamboo fiber were investigated. The single-cellulosic bamboo fiber was immersed in 2, 4, 6, and 8 wt.% aqueous NaOH solutions for soaking times of 1, 3, 6, 12, 18, and 24 h. The tensile properties of the fiber increased after each alkali treatment. The alkali concentration and soaking time significantly affected the fiber properties. The ultimate tensile strength of the single-cellulosic Buluh Semantan treated with 2 wt.% NaOH for 12 h decreased to 214 MPa relative to the fibers that experienced water retting. The highest tensile strength herein was 356.8 MPa for the single-cellulosic fiber that was soaked for 12 h in 4 wt.% NaOH. Comparatively, the tensile strength of the single-cellulosic bamboo fiber that was soaked for 12 h in 8 wt.% NaOH was 234.8 MPa. The tensile modulus of the single-cellulosic fiber was 12.06 GPa after soaking in 8 wt.% NaOH for 18 h, indicating that a strong alkali treatment negatively affected the stiffness and suitability for use of the fibers in applications. The topography of the fiber surface became much rougher after the alkali treatments due to the removal of hemicellulose and other surface impurities. The alkali treatments substantially changed the morphology of the fiber surface, suggesting an increase in wettability.

Über die mechanische Bedeutung der Holzstrahlen | The mechanical relevance of wood rays

2003 ◽  
Vol 154 (12) ◽  
pp. 498-503 ◽  
Author(s):  
Ingo Burgert
Keyword(s):  
Beech Wood ◽  
Tensile Tests ◽  
Deciduous Tree ◽  
Biological Design ◽  
Transverse Tensile ◽  
Radial Reinforcement ◽  
Radial Strength ◽  
Transverse Tensile Strength ◽  
Strength And Stiffness ◽  
Technical Solutions

Three investigations into the mechanical relevance of wood rays were combined for this article. The main objective was to show, that, apart from physiological functions, rays also significantly influence the radial strength and stiffness of wood. In the first approach twelve deciduous tree species with various proportions of fractions of rays were examined for their transverse tensile strength and stiffness. The second approach was based on the comparison of the radial mechanical properties of wood with a very high proportion of fraction of rays and beech wood with a normal volume. In these two investigations the mechanical relevance of rays could only be deduced indirectly. By isolating big rays of beech and carrying out tensile tests on the tissue, we found direct evidence for the mechanical relevance. The results are discussed with regard to their biomechanical relevance. The importance of a radial reinforcement for the wood is underlined. Moreover, the principle of multi-functionality in nature is emphasized in keeping with a possible transfer of biological design to technical solutions.

scholarly journals Chemical and physical interactions of regenerated cellulose yarns and isocyanate-based matrix systems

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bernhard Ungerer ◽  
Ulrich Müller ◽  
Antje Potthast ◽  
Enrique Herrero Acero ◽  
Stefan Veigel
Keyword(s):  
Mechanical Performance ◽  
Tensile Force ◽  
Tensile Modulus ◽  
Tensile Tests ◽  
Size Exclusion ◽  
Regenerated Cellulose ◽  
Hydrolytic Cleavage ◽  
Yarn Twist ◽  
Exclusion Chromatography ◽  
Physical And Chemical

AbstractIn the development of structural composites based on regenerated cellulose filaments, the physical and chemical interactions at the fibre-matrix interphase need to be fully understood. In the present study, continuous yarns and filaments of viscose (rayon) were treated with either polymeric diphenylmethane diisocyanate (pMDI) or a pMDI-based hardener for polyurethane resins. The effect of isocyanate treatment on mechanical yarn properties was evaluated in tensile tests. A significant decrease in tensile modulus, tensile force and elongation at break was found for treated samples. As revealed by size exclusion chromatography, isocyanate treatment resulted in a significantly reduced molecular weight of cellulose, presumably owing to hydrolytic cleavage caused by hydrochloric acid occurring as an impurity in pMDI. Yarn twist, fibre moisture content and, most significantly, the chemical composition of the isocyanate matrix were identified as critical process parameters strongly affecting the extent of reduction in mechanical performance. To cope with the problem of degradative reactions an additional step using calcium carbonate to trap hydrogen ions is proposed.

scholarly journals Microstructure, Hardness, and Tensile Properties of Vacuum Carburizing Gear Steel

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 300
Author(s):  
Wu Chen ◽  
Xiaofei He ◽  
Wenchao Yu ◽  
Maoqiu Wang ◽  
Kefu Yao
Keyword(s):  
Tensile Properties ◽  
Tensile Tests ◽  
Case Depth ◽  
Strain Hardening Exponent ◽  
Austenitizing Temperature ◽  
Vacuum Carburizing ◽  
Experimental Steel ◽  
Strain Behavior ◽  
Carburized Steel ◽  
Vacuum Carburization

We investigated the effects of the austenitizing temperature on the microstructure, hardness, and tensile properties of case-carburized steel after vacuum carburization at 930 °C and then re-austenitization at 820–900 °C followed by oil quenching and tempering. The results show that fractures occurred early with the increase in the austenitizing temperature, although all the carburized specimens showed a similar case hardness of 800 HV0.2 and case depth of 1.2 mm. The highest fracture stress of 1919 MPa was obtained for the experimental steel when the austenitizing temperature was 840 °C due to its fine microstructure and relatively high percentage of retained austenite transformed into martensite during the tensile tests. We also found that the stress–strain behavior of case-carburized specimens could be described by the area-weighted curves of the carburized case and the core in combination. The strain hardening exponent was about 0.4 and did not vary with the increase in the austenitizing temperature. We concluded that the optimum austenitizing temperature was around 840 °C for the experimental steel.

scholarly journals Influence of Mechanical Vibration Moulding Process on the Tensile Properties of TiC Reinforced LM6 Alloy Composite Castings

2011 ◽  
Vol 66-68 ◽  
pp. 1207-1212 ◽  
Author(s):  
Mohd Sayuti ◽  
Shamsuddin Sulaiman ◽  
B.T. Hang Tuah Baharudin ◽  
M.K.A.M. Arifin ◽  
T.R. Vijayaram ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Titanium Carbide ◽  
Tensile Properties ◽  
Mechanical Vibration ◽  
Weight Fraction ◽  
Tensile Tests ◽  
Alloy Matrix ◽  
Remarkable Effect ◽  
Moulding Process ◽  
Particulate Reinforced

Vibrational moulding process has a remarkable effect on the properties of castings during solidification processing of metals, alloys, and composites. This research paper discusses on the investigation of mechanical vibration mould effects on the tensile properties of titanium carbide particulate reinforced LM6 aluminium alloy composites processed with the frequencies of 10.2 Hz, 12 Hz and 14 Hz. In this experimental work, titanium carbide particulate reinforced LM6 composites were fabricated by carbon dioxide sand moulding process. The quantities of titanium carbide particulate added as reinforcement in the LM6 alloy matrix were varied from 0.2% to 2% by weight fraction. Samples taken from the castings and tensile tests were conducted to determine the tensile strength and modulus of elasticity. The results showed that tensile strength of the composites increased with an increase in the frequency of vibration and increasing titanium carbide particulate reinforcement in the LM6 alloy matrix.

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