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    New manufacturing process of carbon-carbon composites and their mechanical properties
    (2011) Naik, P.S.; Surendranathan
    This paper presents the synthesizing of carbon-carbon (CC) composites by preformed yarn (PY) method, by varying the percentage of carbon fiber volume. The PY used is carbon fiber bundle surrounded by coke and pitch which is enclosed in nylon-6. Three types of samples with fiber weight fractions of 30%, 40% and 50% respectively, are fabricated and tested. In each case, the PY is chopped and filled into a die of required shape and hot pressed at 600°C to get the carbonized composite. To obtain the graphitic structure, the specimen is heat treated at 1800°C followed by soaking for two hours. Further, one cycle pitch impregnation is done by hot isostatic pressing, to eliminate the voids. The characteristics such as hardness, compressive strength and creep, are studied. It is observed that, as the carbon fiber percentage increases the properties also improved, provided sintering is done at fairly higher temperatures. The superiority of the new class of CC composites made by the proposed PY technique over those obtained by the conventional methods is also demonstrated. © 2011 CAFET-INNOVA TECHNICAL SOCIETY.
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    Mechanical Properties of Natural Fiber Braided Yarn Woven Composite: Comparison with Conventional Yarn Woven Composite
    (Science Press bcanji@mail.sioc.ac.cn, 2017) RAJESH, M.; Jeyaraj, J.
    The effect of reinforcing natural fiber in the form of braided yarn woven fabric on mechanical properties of polymer composite was investigated. The results of braided yarn fabric composites were compared with the conventional yarn fabric composite and random oriented intimately mixed short fiber composites for the same percentage of fiber weight. The effect of intra-ply hybridization, by keeping two different natural fiber yarns along two different directions of a woven fabric, on mechanical properties of the woven fabric composite was also analyzed. Natural fiber braided yarn fabric reinforcement significantly increased the mechanical properties of the composites compared with that of the conventional woven fabric and short fiber reinforcements. Intra-ply hybridization of two different natural fibers improved the mechanical properties of the conventional woven fabric composite while it could not enhance the properties of the braided fabric composite. The improvement in impact property is very high compared to tensile and flexural properties due to the braided yarn fabric reinforcement. © 2017 Jilin University
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    Mechanical characterization of natural fiber intra-ply fabric polymer composites: Influence of chemical modifications
    (SAGE Publications Ltd info@sagepub.co.uk, 2017) RAJESH, M.; Jeyaraj, P.
    The influence of surface treatment (alkali, potassium permanganate, benzoyl chloride and silane) on the mechanical, dynamic mechanical and free vibration properties of intra-ply hybrid banana/jute woven fabric composite has been analyzed. Intra-ply woven fabrics are fabricated by keeping banana yarn in weft direction and jute yarn in warp direction of a basket-type woven fabric. Results reveal that the enhancement of tensile and flexural strengths of the composite due to the chemical treatment is marginal, except for the benzoyl chloride treatment. However, the chemical treatment results in better impact strength compared to the untreated composite. Tensile, flexural and impact strengths of the benzoyl chloride treatment increase by 10%, 30% and 50%, respectively, compared to untreated composite. It is evident from Fourier Transform-Infrared Spectra that benzoyl chloride treatment effectively removes the hemicellulose and lignin content. It is observed that benzoyl chloride and alkali treatment improves the dynamic mechanical characteristics. Experimental modal analysis carried out on intra-ply fabric composites reveals that benzoyl chloride treatment increases the natural frequency significantly compared to the untreated composite. © 2017, © The Author(s) 2017.
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    Dynamic mechanical and free vibration behavior of natural fiber braided fabric composite: Comparison with conventional and knitted fabric composites
    (John Wiley and Sons Inc. cs-journals@wiley.com, 2018) RAJESH, M.; Jeyaraj, P.
    Dynamic mechanical and experimental modal analysis has been performed on braided yarn woven fabric reinforced polyester composites and results are compared with those of conventional twisted yarn woven fabric and knitted woven fabric composites. The results revealed that storage modulus shows an increasing trend across conventional woven, knitted and braided woven fabric reinforcement, in that order. It is also observed that intra-ply hybridization enhances storage modulus and material loss factor of the conventional woven fabric and knitted woven fabric composites. It is also observed that knitted fabric composites have higher loss factors compared with conventional and braided fabric composites. Experimental modal analysis results reveal that the braided yarn fabric enhances the stiffness of the composite structure and hence results in higher natural frequencies while knitted fabric reinforcement enhances modal loss factor of the composite structure due the spiral orientation of yarns and large gaps associated with between the yarns in kitted fabric. POLYM. COMPOS., 39:2479–2489, 2018. © 2016 Society of Plastics Engineers. © 2016 Society of Plastics Engineers
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    Fracture toughness of flax braided yarn woven PLA composites
    (Bellwether Publishing, Ltd., 2021) Kanakannavar, S.; Jeyaraj, J.
    Flax fiber braided yarn plain woven fabric reinforced Poly Lactic Acid (PLA) bio-composites are fabricated using film stacking and hot-press compression molding method. Effect of fiber weight fraction on tensile and fracture properties of the bio-composites is studied and fractured surfaces are analyzed using scanning electron microscope (SEM) images. It is found that tensile modulus and strength increases by 62.11 and 59.75% respectively for 35 wt.% of the braided fabric reinforcement compared to pristine PLA. Fracture toughness study is performed on single-edge-notched-bend (SENB) specimens using three point bending method. It is found that plane-strain fracture toughness (KIC) and strain energy release rate (GIC) values of the PLA composites are 71.61 and 124% higher than pure PLA for 35 wt.% braided fabric reinforcement. KIC values of the braided fabric reinforced PLA composites are much high compared to similar natural fiber composites reported in literature. This is attributed to high resistance offered by the interweaving yarns of the braided fabric hence more energy is required to begin crack propagation compared to other typical forms of reinforcement. © 2021 Taylor & Francis Group, LLC.
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    Fabrication and mechanical properties of braided flax fabric polylactic acid bio-composites
    (Taylor and Francis Ltd., 2022) Kanakannavar, S.; Jeyaraj, J.
    This paper primarily describes the development of flax braided yarn fabric reinforced thermoplastic composites. Plain woven fabric is made by interlacing 3D braided yarn produced by solid braiding method. Tensile properties of braided yarn and woven fabric are evaluated. Solution casting is used prior to composite fabrication to prepare polylactic acid (PLA) and (natural fiber braided fabric) NFBF–PLA sheets. Followed by this, composite laminates are prepared using through film stacking and compression molding. Influence of number of layers of fabric and loading along warp and weft directions on mechanical properties such as tensile, flexural and impact properties are presented. It is observed that the reinforcement enhances the tensile, flexural and impact properties of the composite significantly for the warp loading. Results also clearly indicates that braided yarn fabric reinforcement have the potential for significant improvement of mechanical and thermal properties of PLA composites. © 2021 The Textile Institute.
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    Free Vibration of Flax Braided Fabric PLA Beam under Edge Compression
    (Taylor and Francis Ltd., 2022) Kanakannavar, S.; Jeyaraj, J.
    The present study focuses on the development of biodegradable composites to replace synthetic polymer-based composites for potential lightweight structural applications in the automobile, aeronautical, marine, and packaging industries. Initially, PLA and NFBF/PLA films are prepared by solution casting, and from these films, composite laminates are prepared by film sequencing and compression (hot-press) molding methods. First, the critical buckling load (Pcr) of composites is analyzed, and then, the influence of compressive load on natural frequency is studied. The critical buckling load-bearing capacity of PLA is enhanced with the reinforcement of NFBF (natural fiber braided yarn fabric). The composite with three layers of NFBF registered the highest critical-buckling load (Pcr) of 374.19 N, and this value is 172.13% high compared to the virgin PLA. Similarly, the natural frequency of the NFBF composites approaches minimum when the applied load is equal to the corresponding Pcr. However, a significant increase in the fundamental frequency is noticed when the applied load is higher than the Pcr. © 2021 Taylor & Francis.
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    Biodegradation properties and thermogravimetric analysis of 3D braided flax PLA textile composites
    (SAGE Publications Ltd, 2022) Kanakannavar, S.; Jeyaraj, J.; Thalla, A.K.; RAJESH, M.
    Recent advances in the development and application of bio-based (natural fiber and biopolymer) composites are gaining broad attention because the resulting polymer completely degrades and does not release harmful substances. In this study, natural fiber 3 D braided yarn textile PLA (Polylactic acid) bio-composites are developed by film sequencing followed by hot-press compression molding. Bio-deterioration and thermal stability of the composites are analysed for storage, machining, transportation, and in-service uses in different environmental conditions (compost and thermal). Composite samples with different fiber wt.% (0, 22, 44) are exposed to compost soil. Tensile testing is performed under different configurations to characterise the tensile properties. Prepared bio-composite specimens are evaluated for weight loss and reduction in tensile properties over soil burial time, to observe the rate of biodegradation of braided yarn textile bio-composites. Fourier transform infrared (FTIR) and scanning electron microscopy (SEM) is employed to analyse the biodegradability of the composites. To study the thermal stability of the prepared bio-composites thermogravimetric (TG) analysis is carried out. Results showed that biodegradability, tensile properties and thermal stability of the composites are enhanced significantly with the reinforcement of 3 D braided yarn fabric. © The Author(s) 2021.
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    Tensile Behaviour of Double-Edge Notched Flax Braided Yarn Woven Fabric Reinforced PLA Composite
    (Korean Fiber Society, 2023) Kanakannavar, S.; Pitchaimani, J.; Goh, K.-L.
    Biodegradable composites were fabricated from poly-lactic acid (PLA) reinforced by flax braided-yarn woven fabric. Composites with different fabric content (corresponding to the 1, 2 and 3 layers of fabric respectively) were obtained by solution casting and compression moulding processes. Tensile fracture properties were evaluated using the double-edge-notch-tension (DENT) test. A scanning electron microscope was used to look at the fractographic features. Reinforcement of braided-yarn fabric resulted in enhanced tensile fracture strength (σf) and toughness of PLA composite. Fracture toughness (KIC) of the composite improved with the fibre contents, namely 64, 79 and 89%, which correspond to 1, 2 and 3 layers of fabric. The improvement in the tensile fracture characteristics of the composites could be contributed by the presence of an effective interfacial bonding of fibre matrix. © 2023, The Author(s), under exclusive licence to the Korean Fiber Society.
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    Relation between water absorption and mechanical properties of flax 3D braided yarn woven fabric PLA bio-degradable composites
    (SAGE Publications Inc., 2024) Kanakannavar, S.; Pitchaimani, J.
    Natural fibre (flax) plain type of woven fabric is developed by using solid braided yarn and is utilised as filler material and PLA (polylactic acid) as a matrix. Solution casting is then used to create sheets of pure PLA and flax fabric–PLA. Composites are manufactured by sheets sequencing technique using the hot compression moulding method. Water absorption, thickness swelling and flexural tests are performed in loading directions of warp and weft of the composites. Results revealed that the absorption of water and swelling of thickness are enriched with an addition of flax fabric. The weft direction loaded composite displayed greater values of water uptake and thickness swelling. The warp direction loaded composites demonstrated the highest flexural strength (92.3 MPa) and modulus (4.5 GPa) compared to weft direction loaded composites. These values are decreased after water absorption. © The Author(s) 2024.