scholarly journals Water Absorption Behaviour and Impact Strength of Kenaf-Kevlar Reinforced Epoxy Hybrid Composites

2016 ◽  
Vol 25 (4) ◽  
pp. 096369351602500 ◽  
Author(s):  
R. Yahaya ◽  
S.M. Sapuan ◽  
M. Jawaid ◽  
Z. Leman ◽  
E.S. Zainudin

Fibre reinforced polymer composites has been used in a variety of applications. Recently, there is increasing interest in the research on natural-synthetic fibre hybrid composite. In this study, water absorption behaviours and impact properties of woven kenaf-Kevlar hybrid composite were evaluated. In all samples, Kevlar (aramid fibres) was kept as the skin layers and kenaf as the core material. The experimental results revealed that the hybrid composites with high kenaf content shows low density (0.88g/m3) and contains a high content of the voids (25.67%). Similar finding observed in water absorption and thickness swelling test as the hybrid composite with higher kenaf content absorb more water absorption and low dimensional stability. Water absorption affects the impact strength of the composites. The impact strength decreased about 45.38 % (from 228.24 to 124.66kJ/m2) in sample H1), whereas, the highest impact strength decreased of about 78.52% (from 179.71 to 38.60 kJ/m2) was observed in sample H5). The result of this study is important for the further utilisation of woven kenaf in hybrid laminate composites.

2014 ◽  
Vol 660 ◽  
pp. 572-577
Author(s):  
Syarifah Yunus ◽  
Z. Salleh ◽  
M.A. Aznan ◽  
M.N. Berhan ◽  
A. Kalam ◽  
...  

This paper discusses the mechanical properties of woven kenaf/fiberglass hybrid composites which has been fabricating using vacuum bag technique. Kenaf fiber had chosen among others natural fibres due to its excellent mechanical properties and potential natural raw fiber to replace plastic or tobacco in manufacturing a multitude of products for the construction, automotive, textile and advanced technology sectors. This study investigates post impact tensile of kenaf hybrid composites and its surface fractured. The impact energy used consists of 4J, 6J, 8J, 12J and 16J. The specimens were clamped between two plate rings with an internal hole diameter of 18mm and impacted with hemispherical nose impactor shape with diameter size of 12.7mm. The results revealed that this kenaf hybrid composite showed significant decreasing of strength and modulus as increasing the impact energy. The damage area affected with fiber fracture occurred much later in fracture process due to high bending stresses.


Hybrid composites have been considered as modern materials for many engineering applications, yet there is still a major concern on the influence of stacking sequence configuration in hybrid composite laminates especially under impact loading. Therefore, the focus of this paper is to determine the optimized stacking sequence of glass/Kevlar fiber hybrid composite laminates under impact loading. Hybrid composite laminates were fabricated using vacuum bagging method with four different stacking sequences known as H1, H2, H3 and H4. Low velocity drop weight impact test (ASTM D7136) was conducted using a hemispherical nose impactor diameter of 12 mm with a mass of 6 kg at impact energy levels of 10 J, 20 J, 30 J, and 40 J. From the results obtained, H3 specimen which has a stacking sequence of glass fiber in the exterior part with Kevlar fiber in the interior part was concluded as the optimized stacking sequence with better impact resistance properties. H3 specimen recorded a higher value in peak load, maximum initiation energy, high impact strength, high strength to weight ratio and high total energy absorbed to weight ratio. In addition, it was observed that H3 specimen has less damaged area compared to H1, H2, and H4 specimens. This study contributes knowledge on the impact resistance properties of hybrid composite laminates which will be much useful for material selection and product development.


Natural and synthetic fiber reinforced hybrid composites replacing conventional metals. Because of their improved properties such as higher strength, light weight, low cost, bio-degradable and green composite. An attempt made to find the impact strength of hybrid composites. The fiber in woven mat form is added to matrix element with varying stacking sequences of symmetrical laminates. Six types of hybrid laminate composites having basalt and Kevlar fibers are the reinforcements in varying stacking sequences are produced using hand lay-up technique followed by compression molding. The impact strength of the produced composites is evaluated. Experimental results found that composite having stacking sequences of K-B-K-B-K-B-K has the highest value of impact strength of 24 Joules respectively. Scanning Electron Microscope (SEM) is used to examine the morphology of fractured surface of hybrid composites during testing. SEM images revealed that hybrid composite with K-B-K-B-K-B-K had less defects on its fractured surface compared to other counter parts of the hybrid composites.


Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2212
Author(s):  
Worawat Poltabtim ◽  
Ekachai Wimolmala ◽  
Teerasak Markpin ◽  
Narongrit Sombatsompop ◽  
Vichai Rosarpitak ◽  
...  

The potential utilization of wood/polyvinyl chloride (WPVC) composites containing an X-ray protective filler, namely bismuth oxide (Bi2O3) particles, was investigated as novel, safe, and environmentally friendly X-ray shielding materials. The wood and Bi2O3 contents used in this work varied from 20 to 40 parts per hundred parts of PVC by weight (pph) and from 0 to 25, 50, 75, and 100 pph, respectively. The study considered X-ray shielding, mechanical, density, water absorption, and morphological properties. The results showed that the overall X-ray shielding parameters, namely the linear attenuation coefficient (µ), mass attenuation coefficient (µm), and lead equivalent thickness (Pbeq), of the WPVC composites increased with increasing Bi2O3 contents but slightly decreased at higher wood contents (40 pph). Furthermore, comparative Pbeq values between the wood/PVC composites and similar commercial X-ray shielding boards indicated that the recommended Bi2O3 contents for the 20 pph (40 ph) wood/PVC composites were 35, 85, and 40 pph (40, 100, and 45 pph) for the attenuation of 60, 100, and 150-kV X-rays, respectively. In addition, the increased Bi2O3 contents in the WPVC composites enhanced the Izod impact strength, hardness (Shore D), and density, but reduced water absorption. On the other hand, the increased wood contents increased the impact strength, hardness (Shore D), and water absorption but lowered the density of the composites. The overall results suggested that the developed WPVC composites had great potential to be used as effective X-ray shielding materials with Bi2O3 acting as a suitable X-ray protective filler.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sekar Sanjeevi ◽  
Vigneshwaran Shanmugam ◽  
Suresh Kumar ◽  
Velmurugan Ganesan ◽  
Gabriel Sas ◽  
...  

AbstractThis investigation is carried out to understand the effects of water absorption on the mechanical properties of hybrid phenol formaldehyde (PF) composite fabricated with Areca Fine Fibres (AFFs) and Calotropis Gigantea Fibre (CGF). Hybrid CGF/AFF/PF composites were manufactured using the hand layup technique at varying weight percentages of fibre reinforcement (25, 35 and 45%). Hybrid composite having 35 wt.% showed better mechanical properties (tensile strength ca. 59 MPa, flexural strength ca. 73 MPa and impact strength 1.43 kJ/m2) under wet and dry conditions as compared to the other hybrid composites. In general, the inclusion of the fibres enhanced the mechanical properties of neat PF. Increase in the fibre content increased the water absorption, however, after 120 h of immersion, all the composites attained an equilibrium state.


Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1501 ◽  
Author(s):  
Soundhar Arumugam ◽  
Jayakrishna Kandasamy ◽  
Ain Umaira Md Shah ◽  
Mohamed Thariq Hameed Sultan ◽  
Syafiqah Nur Azrie Safri ◽  
...  

This study aims to explore the mechanical properties of hybrid glass fiber (GF)/sisal fiber (SF)/chitosan (CTS) composite material for orthopedic long bone plate applications. The GF/SF/CTS hybrid composite possesses a unique sandwich structure and comprises GF/CTS/epoxy as the external layers and SF/CTS/epoxy as the inner layers. The composite plate resembles the human bone structure (spongy internal cancellous matrix and rigid external cortical). The mechanical properties of the prepared hybrid sandwich composites samples were evaluated using tensile, flexural, micro hardness, and compression tests. The scanning electron microscopic (SEM) images were studied to analyze the failure mechanism of these composite samples. Besides, contact angle (CA) and water absorption tests were conducted using the sessile drop method to examine the wettability properties of the SF/CTS/epoxy and GF/SF/CTS/epoxy composites. Additionally, the porosity of the GF/SF/CTS composite scaffold samples were determined by using the ethanol infiltration method. The mechanical test results show that the GF/SF/CTS hybrid composites exhibit the bending strength of 343 MPa, ultimate tensile strength of 146 MPa, and compressive strength of 380 MPa with higher Young’s modulus in the bending tests (21.56 GPa) compared to the tensile (6646 MPa) and compressive modulus (2046 MPa). Wettability study results reveal that the GF/SF/CTS composite scaffolds were hydrophobic (CA = 92.41° ± 1.71°) with less water absorption of 3.436% compared to the SF/CTS composites (6.953%). The SF/CTS composites show a hydrophilic character (CA = 54.28° ± 3.06°). The experimental tests prove that the GF/SF/CTS hybrid composite can be used for orthopedic bone fracture plate applications in future.


Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2052
Author(s):  
Farah Hanan ◽  
Mohammad Jawaid ◽  
Md Tahir Paridah ◽  
Jesuarockiam Naveen

In this research, the physical, mechanical and morphological properties of oil palm empty fruit bunch (EFB) mat/woven kenaf fabric-reinforced epoxy composites have been investigated. The oil palm EFB/woven kenaf fabrics were varied, with weight ratios of 50/0 (T1), 35/15 (T2), 25/25 (T3), 15/35 (T4) and 0/50 (T5). The composites were fabricated using a simple hand lay-up technique followed by hot pressing. The result obtained shows that an increase in kenaf fiber content exhibited higher tensile and flexural properties. On the other hand, the opposite trend was observed in the impact strength of hybrid composites, where an increase in kenaf fiber content reduced the impact strength. This can be corroborated with the physical properties analysis, where a higher void content, water absorption and thickness swelling were observed for pure oil palm EFB (T1) composites compared to other samples. The scanning electron microscopy analysis results clearly show the different failure modes of the tensile fractured samples. Statistical analysis was performed using one-way ANOVA and shows significant differences between the obtained results.


2020 ◽  
Vol 856 ◽  
pp. 29-35
Author(s):  
Sweety Mahanta ◽  
M. Chandrasekaran ◽  
Sutanu Samanta

Aluminium matrix composites (AMCs) have emerged as the substitute for the monolithic (unreinforced) materials over the past few decades. The applications of AMCs are common in automotive, aerospace, defence and biomedical sectors due to its lower weight, high strength, high resistance against corrosion and high thermal and electrical conductivity. In this work, it is aimed fabricate a new class Al 7075 based hybrid composites reinforcing with nanoparticulates suitable for automotive application. Al7075 reinforced with fixed quantity of boron carbide (B4C) (1.5 wt.%) and varying wt % of flyash (0.5 wt.%, 1.0 wt.%, 1.5 wt.%) is fabricated using ultrasonic-assisted stir casting technique. Physical and mechanical characterization such as density, porosity, micro hardness, tensile strength and impact strength were estimated for three different compositions. The tensile strength and percentage increase in hardness value of the nanocomposite Al7075-B4C (1.5 wt. %)-flyash (0.5 wt. %): HNC3 found maximum as 294 MPa and 32.93%. In comparison with Al7075 alloy the impact strength of HNC3 shows the highest percentage of 9.31% respectively.


2020 ◽  
Vol 8 (5) ◽  
pp. 3210-3214

Variety of application use fibre reinforced composites because of their intrinsic properties in mechanical strength, renewability and low production cost compared to conventional materials. Natural fibres are environmentally friendly their use will not break the budget when used as an alternative to the regular materials. Reinforcement used in polymer is either man-made or natural. Man-made synthetic, metallic, semi-synthetic, polymer fibres have superior specific strength but their high cost of production limits its application and feasibility to make composites. Recently there is a rise in use of natural fibres from various natural resources which are available abundantly. Composites based on natural fibres have their advantages of cost in making the fibres from different vegetables, wood, animals and minerals. In this work a thorough and systematic inquiry regarding better utilization of sisal fibre for making value-added products has been carried out. Various hybrid composite test specimens as per ASTM were prepared with natural fillers such as sisal-pineapple-Kenaf fibres by using hand layup method. The physical and mechanical characteristics of prepared hybrid composite with sisal fibre, pineapple fibre and kenaf fibre are the main objective the research. The various mechanical properties of the hybrid composites like tensile strength, rupture strength, impact strength, shear strength, hardness, and wear strength are studied by standard experiment methods. The experimental results were discussed. The experiments exposed that the use of sisal fibre when compared with similar fibres in a composite increase the most of the physical properties like tensile, rupture, wear properties of the material where as impact strength of the material is lowered. Surface morphology of the sisal fibre after tensile loading is studied microscopically.


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