Journal articles: 'Kevlar'

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Khusiafan, Firas J. "Use of KEVLAR ® 49 in Aircraft Components." Engineering Management Research 7, no. 2 (September 27, 2018): 14. http://dx.doi.org/10.5539/emr.v7n2p14.

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Aircraft industry is also finding its way to adapt on the increasing demand not only considering aircraft safety and customer requirements, but also on the increasing legislative requirements in terms of resource efficiency and gas emissions. This document explores Kevlar 49’s application on aircraft components and why this material is specifically selected for such applications above any other Kevlar type of materials. Its functions, properties, advantages and disadvantages are discussed together with some alternative materials in lieu of Kevlar 49. In order to provide credible information, literature search was conducted using significant keywords in Google Scholar and journal repository Deepdyve. Kevalr ® 49 is considered an exceptional material for reinforcement to produce aircraft components. It has high tensile strength, lightweight, inert on some conditions, stiff, and resilient. However, Kevlar’s has poor compressive strength, workability and is overly stiff for some applications. Another disadvantage is its cost, though it was shown to belong to a middle ranged material relative to carbon fiber and Boron. But overall, there are extensive applications in aircraft components that are now continuously using this material as reinforcement with other materials like carbon and boron to arrive on an ideal blend of product.

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Neufeld, Mackenzie, Ahmed Samir Ead, and Eric Lepp. "Design of a Braided Composite Badminton Racket on Solidworks." Alberta Academic Review 2, no. 2 (September 18, 2019): 57–58. http://dx.doi.org/10.29173/aar64.

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Current badminton rackets are typically made out of steel, aluminium, or carbon fibre. Although these materials perform acceptably, there are some downsides to their properties. However, these non-ideal characteristics of badminton rackets may be overcome with the usage of different manufacturing materials, specifically braided composites. An example of a braided material is KevlarⓇ. Kevlar is a heat resistant and high strength synthetic fibre that can be manufactured into braids using a maypole braiding system. These Kevlar braids can then be manipulated to a preferred shape for the curing process. In order to come up with a feasible design to base the prototype, a 3D modelling software (SolidWorksTM) is used. This ensures geometrical viability and possible to manufacture of the prototype. Modeling a badminton racket on Solidworks required the modelling of a racket head, and handle. The head was created using 2 ellipses, one of which acted as a skeleton, or mould for the Kevlar braid, and the other was a hollow ellipse which encompassed the mold and acted as the Kevlar braid. The solid ellipse was created in two halves, each having either an extrusion or a hole in the ends. This allowed them to easily attach to form a full ellipse. Once modeled, the solid ellipse was 3D printed to act as the curing mandrel, an internal skeleton for the Kevlar braids. In order to attach the head to the handle, a three-part connector piece was created and 3D printed. The rod of the racket was not created with an internal skeleton because the flexibility would falter. Instead, the Kevlar braids were slid off the material after curing and attached to the racket heads connector piece. In order to have a balanced weight ratio throughout the racket, the grip was created with an internal 3D printed skeleton. This structure allowed for a feasible, flexible, and strong Kevlar based product.

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Radić, Vlado. "Kevlar and ballistic protection." Vojnotehnicki glasnik 44, no. 6 (1996): 79–87. http://dx.doi.org/10.5937/vojtehg9601079r.

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Hosur, M. V., Jessie B. Mayo Jr., E. Wetzel, and S. Jeelani. "Studies on the Fabrication and Stab Resistance Characterization of Novel Thermoplastic-Kevlar Composites." Solid State Phenomena 136 (February 2008): 83–92. http://dx.doi.org/10.4028/www.scientific.net/ssp.136.83.

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Kevlar has demonstrated the ability to protect well against ballistic threats but has low resistance to puncture. Correctional Kevlar has shown good resistance to puncture. However, the fabric is expensive, difficult to manufacture because of its tight weave construction, and has limited protection against ballistic threats. In an effort to produce materials that are less bulky, more flexible, and resistant to puncture, thermoplastic-Kevlar (TP-Kevlar) composites have been examined. Kevlar fabric was impregnated with thermoplastic film using a hot press to produce the composites. Static and dynamic puncture resistant properties of the TP-Kevlar composites were investigated using a National Institute of Justice (NIJ Standard 0115.00) Stab Tower. The TP-films used in this study were polyethylene, Surlyn, and co extruded-Surlyn, which is a co extrusion of Surlyn and polyethylene. Response of the polyethylene (PE)-Kevlar composites, Surlyn-Kevlar composites, and co extruded (COEX)-Kevlar composites to spike and knife threats under static and dynamic conditions were compared with that of neat Kevlar. The infusion of thermoplastic films into the Kevlar fabric was shown to dramatically increase puncture resistance during quasi-static and dynamic testing with spikes. The TP-film type also made a difference when examining the resistance on a comparative basis of the TP-Kevlar targets. The TP-Kevlar composite targets showed more resistance to quasi-static spike testing than quasi-static knife testing. Weapon comparisons revealed that the TP-Kevlar composite targets had more resistance to dynamic knife testing than dynamic spike testing.

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Mahbub, Rana Faruq, Lijing Wang, Lyndon Arnold, Sinnappoo Kaneslingam, and Rajiv Padhye. "Thermal comfort properties of Kevlar and Kevlar/wool fabrics." Textile Research Journal 84, no. 19 (May 23, 2014): 2094–102. http://dx.doi.org/10.1177/0040517514532157.

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Recent research on ballistic vests has focused on comfort performance by enhancing thermal comfort and moisture management. Kevlar/wool fabric has been developed as a potential material for ballistic vests. This study investigates the thermal comfort properties of woven Kevlar/wool and woven Kevlar ballistic fabrics. In this context, the thermal resistance, water-vapor resistance, moisture management performance, air permeability and optical porosity of 100% Kevlar and Kevlar/wool ballistic fabrics were compared. The effects of fabric physical properties on laboratory-measured thermal comfort were analyzed. This study also presents the fabric bursting strength and tear strength for comparison. Experimental results showed a clear difference in thermal comfort properties of the two fabrics. It was found that Kevlar/wool possesses better moisture management properties and improved mechanical properties than Kevlar fabric.

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Muhammad Amir, Siti Madiha, Mohamed Thariq Hameed Sultan, Ain Umaira Md Shah, Mohammad Jawaid, Syafiqah Nur Azrie Safri, Shukri Mohd, and Khairul Anuar Mohd Salleh. "Low Velocity Impact and Compression after Impact Properties on Gamma Irradiated Kevlar/Oil Palm Empty Fruit Bunch Hybrid Composites." Coatings 10, no. 7 (July 3, 2020): 646. http://dx.doi.org/10.3390/coatings10070646.

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This work investigates the dynamic impact response of Kevlar/oil palm empty fruit bunch (EFB) hybrid composite structures with/without gamma radiation under low velocity impact (LVI) and compression after impact (CAI) test. The layering pattern Kevlar/oil palm EFB/Kevlar (K/OP/K) was applied in this work. Irradiation with gamma ray with various doses were applied from 25–150 kGy. LVI results shows that hybrid Kevlar/oil palm EFBs (Kevlar/OPEFB) that were not irradiated have greater impact resistance as compared to irradiated hybrid Kevlar/OPEFB. It was also observed that the hybridization of Kevlar/OPEFB with gamma irradiation helped to improve the compressive residual strength of the composites. It was found that Kevlar/OPEFB hybrid composites with the layering sequence K/OP/K can withstand up to 35 J of impact energy, with the optimum gamma radiation dose at 50 kGy.

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Zhang, Shui, Guo Zhong Li, and Hai Yan Yuan. "Effect of the Chemical Treated Kevlar Fiber on the Behaviors of Cement Mortars." Advanced Materials Research 306-307 (August 2011): 758–61. http://dx.doi.org/10.4028/www.scientific.net/amr.306-307.758.

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This work aims to evaluate the effect of Kevlar fibers with chemical treatment on the flexural strength, compressive strength and impact resistance of cement mortar. The experimental results exhibit that Kevlar fiber with a larger percentage can increase the flexural strength and improve the impact resistance of cement mortar, and the reinforcement effect of Kevlar fiber with chemical treatment is more obvious. The surface morphology of Kevlar fiber and the fracture surface of cement mortar reinforced with Kevlar fiber were observed by SEM, and the reinforcement mechanism of the Kevlar fiber on cement mortar was discussed.

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Stopforth, Riaan, and Sarp Adali. "Experimental Investigation of the Bullet-proof Properties of Different Kevlar, Comparing .22 Inch with 9 mm Projectiles." Current Materials Science 13, no. 1 (October 1, 2020): 26–38. http://dx.doi.org/10.2174/2666145413666200206121427.

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Background: Results of an experimental study are given involving high-impact ballistic tests using .22 inch diameter ammunition (commonly known only as .22 ammunition) with the target set up as a combination of different numbers and weights of Kevlar layers. These experimental tests are conducted as literature indicating that the .22 projectiles are not as effective as with larger calibre ammunition. Present work is part of a research study to assess the safety limits of Kevlar layers of different weights against various calibre projectiles. Objective: The objective is to obtain test data to determine the number of Kevlar layers and weights needed for the design of safe bullet proof vests capable of stopping various size ammunition. In the present study, results are given for .22 inch ammunition, which provide data on the characteristics of high-speed ballistic penetration of .22 bullets into Kevlar layers and stopping distances in gel/Kevlar combinations. Methods: Tests were performed with Kevlar fabrics of different weights of Gram per Square Meter (GSM) to provide a comparison among different Kevlar fabrics as well as with different number of Kevlar layers. The tests were conducted with the use of a chronograph in a controlled test environment. The penetration depth in ballistic gelatine was recorded. Results: The results identify the number of layers of Kevlar required to stop a .22 projectile and the relationship between the different layers and weights of Kevlar materials. The results of the .22 projectile penetration are compared with those of different 9 mm Parabellum projectiles to assess the effect of different size ammunition on the bullet-proof capabilities of Kevlar. Experimental data on the penetration depths of different types of bullets into the gel/Kevlar combinations are presented using various graphs. Conclusion: The .22 projectiles perform similar penetration depths compared to that of 9 mm projectiles, and therefore cannot be considered as ineffective ammunition as literature has indicated.

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Gu, Dapeng, Bingli Fan, Fei Li, Yulin Yang, and Suwen Chen. "Wear Process Analysis of the Polytetrafluoroethylene/Kevlar Twill Fabric Based on the Components’ Distribution Characteristics." Autex Research Journal 17, no. 4 (December 20, 2017): 295–302. http://dx.doi.org/10.1515/aut-2016-0015.

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Abstract Polytetrafluoroethylene (PTFE)/Kevlar fabric or fabric composites with excellent tribological properties have been considered as important materials used in bearings and bushing, for years. The components’ (PTFE, Kevlar, and the gap between PTFE and Kevlar) distribution of the PTFE/Kevlar fabric is uneven due to the textile structure controlling the wear process and behavior. The components’ area ratio on the worn surface varying with the wear depth was analyzed not only by the wear experiment, but also by the theoretical calculations with our previous wear geometry model. The wear process and behavior of the PTFE/Kevlar twill fabric were investigated under dry sliding conditions against AISI 1045 steel by using a ring-on-plate tribometer. The morphologies of the worn surface were observed by the confocal laser scanning microscopy (CLSM). The wear process of the PTFE/Kevlar twill fabric was divided into five layers according to the distribution characteristics of Kevlar. It showed that the friction coefficients and wear rates changed with the wear depth, the order of the antiwear performance of the previous three layers was Layer III>Layer II>Layer I due to the area ratio variation of PTFE and Kevlar with the wear depth.

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Chang, Chang-Pin, Cheng-Hung Shih, Jhu-Lin You, Meng-Jey Youh, Yih-Ming Liu, and Ming-Der Ger. "Preparation and Ballistic Performance of a Multi-Layer Armor System Composed of Kevlar/Polyurea Composites and Shear Thickening Fluid (STF)-Filled Paper Honeycomb Panels." Polymers 13, no. 18 (September 13, 2021): 3080. http://dx.doi.org/10.3390/polym13183080.

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In this study, the ballistic performance of armors composed of a polyurea elastomer/Kevlar fabric composite and a shear thickening fluid (STF) structure was investigated. The polyurea used was a reaction product of aromatic diphenylmethane isocyanate (A agent) and amine-terminated polyether resin (B agent). The A and B agents were diluted, mixed and brushed onto Kevlar fabric. After the reaction of A and B agents was complete, the polyurea/Kevlar composite was formed. STF structure was prepared through pouring the STF into a honeycomb paper panel. The ballistic tests were conducted with reference to NIJ 0101.06 Ballistic Test Specification Class II and Class IIIA, using 9 mm FMJ and 44 magnum bullets. The ballistic test results reveal that polyurea/Kevlar fabric composites offer better impact resistance than conventional Kevlar fabrics and a 2 mm STF structure could replace approximately 10 layers of Kevlar in a ballistic resistant layer. Our results also showed that a high-strength composite laminate using the best polyurea/Kevlar plates combined with the STF structure was more than 17% lighter and thinner than the conventional Kevlar laminate, indicating that the high-strength protective material developed in this study is superior to the traditional protective materials.

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11

Callender, Rhonda L., and Andrew R. Barron. "Novel route to alumina and aluminate interlayer coatings for SiC, carbon, and Kevlart® fiber-reinforced ceramic matrix composites using carboxylate–alumoxane nanoparticles." Journal of Materials Research 15, no. 10 (October 2000): 2228–37. http://dx.doi.org/10.1557/jmr.2000.0320.

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SiC, carbon, and Kevlart® fibers were coated with carboxylate–alumoxane nanoparticles and their calcium-, lanthanum-, and yttrium-doped analogs; firing to 1400 °C formed uniform aluminate coatings. Optimum processing sequences were determined. Both carboxylate–alumoxane- and ceramic-coated fibers were examined by field emission scanning electron microscopy, microprobe analysis, and optical microscopy. Coatings produced were stable to thermal cycling under air at 1400 °C. Fiber-reinforced ceramic matrix composites were prepared and results from 3-point bend tests for carbon/Kevlar®-fabric-reinforced ceramic matrix composites (CMCs) and carbon-fiber-reinforced CMCs were determined. Flexure strength for carbon-fiber- and carbon/Kevlart®-fiber-reinforced alumina CMCs was determined.

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Hancox, N. L. "Kevlar aramid fiber." Materials & Design 14, no. 5 (January 1993): 312–13. http://dx.doi.org/10.1016/0261-3069(93)90147-n.

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Whalley, W. B., B. J. Smith, and J. P. McGreevy. "Decay of Kevlar." Journal of Materials Science Letters 5, no. 3 (March 1986): 342. http://dx.doi.org/10.1007/bf01748099.

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Lou, Ching Wen, Wen Hao Hsing, Chien Teng Hsieh, and Jia Horng Lin. "Mechanical and Physical Property Evaluations of Kevlar/Polyester Complex Nonwoven Fabrics." Applied Mechanics and Materials 457-458 (October 2013): 61–64. http://dx.doi.org/10.4028/www.scientific.net/amm.457-458.61.

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Geotextiles made of nonwoven fabrics can be used in different fields, such as groynes, dams, seawalls, revetments, dunes, and hillsides, and the structures of nonwoven fabrics can be changed accordingly. This study explores the influence of different content of Kevlar fibers on the mechanical and physical properties of Kevlar/Polyester (PET) complex nonwoven fabrics. As specified in a nonwoven fabric manufacturing process Kevlar fibers and PET fibers are blended with various ratios to form Kevlar/PET complex nonwoven fabrics, which are then tested for tear strength, air permeability, and water permeability. The experiment results show that increasing Kevlar fibers reduces the tear strength, air permeability, and water permeability.

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Oh, Jong Ho, Jin Ho Bae, Jeong Hyeon Kim, Seul Kee Kim, and Jae Myung Lee. "Thermal and Mechanical Properties of Rigid Polyurethane Foam with Kevlar Aramid Pulp." Materials Science Forum 951 (April 2019): 89–93. http://dx.doi.org/10.4028/www.scientific.net/msf.951.89.

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Kevlar-polyurethane foam (PUF) was manufactured by adding Kevlar pulp, which has excellent mechanical strength and thermal performance, to PUF for the purpose of improving the performance of existing PUF. The mechanical strength of Kevlar-PUF was evaluated for each weight ratio (0.2, 0.4, 0.6, 0.8, and 1.0 wt.%) of fiber, as the performance of PUF was improved by the addition of Kevlar fiber. Compression tests were carried out at four temperatures (20, −50, −110, and −163 °C) in consideration of the service environment, where Kevlar-PUF is used as insulation of LNG storage systems. The fracture characteristics of the compressed specimen are also analyzed. The thermal conductivity of the foam at room temperature (20 °C) and low temperature (−20 °C) is measured according to the weight ratios. The addition of a certain amount of Kevlar fibers increases the compression resistance of PUF and improves the properties of the material.

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Lou, Ching Wen, An Pang Chen, Ya Yuan Chuang, Jan Yi Lin, Mei Chen Lin, and Jia Horng Lin. "Manufacturing Techniques and Mechanical Properties of Recycle Kevlar®/PET Composite Nonwoven." Advanced Materials Research 627 (December 2012): 831–34. http://dx.doi.org/10.4028/www.scientific.net/amr.627.831.

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Kevlar® fiber has characteristics of thermostability, high modulus, low elongation, impact resistance, chemical resistance and high performance. Therefore, in this study Kevlar® fiber was used to reinforce the nonwoven fabrics. In this research, the content of the Kevlar® fiber was varied as 0 wt%, 5 wt%, 10 wt%, 20 wt%, and that of 15D PET fiber was changed as 70 wt%, 65 wt%, 60 wt%, 50 wt% accordingly when the Low-Tm polyester fibers was constant as 30 wt%. These fibers were used to manufacture the Kevlar®/PET composite nonwoven by nonwoven processing. Afterwards, the mechanical properties of the Kevlar®/PET composite nonwoven was measured both at cross direction and machine direction.

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Lin, Jia Horng, Ruo Si Yan, Rui Wang, Cheng Wang, and Ching Wen Lou. "Evaluation of Static Impact Resistance in Nonwovens/Glass Plain Fabric Sandwich Structural Hybrid Laminates." Advanced Materials Research 910 (March 2014): 258–61. http://dx.doi.org/10.4028/www.scientific.net/amr.910.258.

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This paper reveals the manufacturing process and static impact resistance of sandwich structural hybrid laminates composed of high-resilience bonding polyester /Kevlar intra-ply hybrid nonwovens and E-glass woven fabric. The effects of various weight ratio of Kevlar fiber on the mechanical behaviors, including tensile strength, tear strength, bursting strength and puncture strength, were evaluated. The experimental results indicated that the tensile strength and fracture work were both enhanced with the increase in Kevlar content. The tear strength on CD and MD exhibited opposite trends when varying the Kevlar content. The static bursting and puncture resistances were both enhanced with the promotion of Kevlar content. The failure mechanisms of the breakages were also analyzed.

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Zan, Xiu Ping, Jing Li, and Cai Yun Yang. "Study on the Relationship between Structures and Properties of Kevlar String." Advanced Materials Research 332-334 (September 2011): 865–69. http://dx.doi.org/10.4028/www.scientific.net/amr.332-334.865.

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The relationship between structures and properties of Kevlar string was studied scarcely before, although the string was used in aerospace, spaceflight, ocean and the like. Kevlar braiding strings were designed and braided with different braiding angle, different core yarn content and different twist, and stretching properties were measured and analysed in the paper. The result shows that the bigger braiding angle is and the more core yarn content is, the higher break load is and the lower break elongation is. Besides, rupture analysis proves that braiding Kevlar bundles take hold of core Kevlar bundles tightly, both form an inseparable integrity almost during stretching. As a result, a special phenomena occurs, core Kevlar bundles are broken into several segments.

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Liu, Qi Xia, Tao Ji, Qiang Gao, Li Rong Yao, Fei Yan Wang, and Qun Ren Qiu. "Preparation and Properties of Kevlar or Polysulfonamide Pulp Reinforced Activated Carbon Fiber Paper." Advanced Materials Research 1120-1121 (July 2015): 654–58. http://dx.doi.org/10.4028/www.scientific.net/amr.1120-1121.654.

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In this paper, Kevlar or Polysulfonamide (PSA) pulp were used to replace plant fiber pulp partially or completely and by adjusting their ratios and a variety of Kevlar or PSA pulp reinforced activated carbon fiber paper (ACFP) were prepared via wet-laid paper making technology. The influences of addition of Kevlar or PSA pulp on the permeability, mechanical property, filtration performance, adsorption property of ACFP were discussed by maintaining the addition content of activated carbon fiber unchanged. Results showed that with the addition content of Kevlar or PSA pulp increased, the permeability and filtration performance of ACFP decreased obviously, while the bursting strength and the static CCl4 adsorption performances were firstly increased and then decreased. Generally, the permeability and filtration performance of Kevlar pulp reinforced ACFP were slightly worse than that of PSA pulp reinforced ACFP, while the bursting strength as well as the static CCl4 adsorption properties of Kevlar pulp reinforced ACFP were better than that of PSA pulp reinforced ACFP.

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ZYSKIN, M., and KAREN S. MARTIROSYAN. "SIMULATION OF THE ELASTIC PROPERTIES OF REINFORCED KEVLAR-GRAPHENE COMPOSITES." International Journal of Nanoscience 11, no. 03 (June 2012): 1250024. http://dx.doi.org/10.1142/s0219581x1250024x.

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The compressive strength of unidirectional fiber composites in the form of Kevlar yarn with a thin outer layer of graphene was investigated and modeled. Such fiber structure may be fabricated by using a strong chemical bond between Kevlar yarn and graphene sheets. Chemical functionalization of graphene and Kevlar may be achieved by modification of appropriate surface-bound functional (e.g., carboxylic acid) groups on their surfaces. In this report we studied elastic response to unidirectional in-plane applied load with load peaks along the diameter. The 2D linear elasticity model predicts that significant strengthening occurs when graphene outer layer radius is about 4% of kevlar yarn radius. The polymer chains of Kevlar are linked into locally planar structure by hydrogen bonds across the chains, with transversal strength considerably weaker than longitudinal one. This suggests that introducing outer enveloping layer of graphene, linked to polymer chains by strong chemical bonds may significantly strengthen Kevlar fiber with respect to transversal deformations.

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Santos, Thiago F., Caroliny M. Santos, Rubens T. Fonseca, Kátia M. Melo, Marcos S. Aquino, Fernando R. Oliveira, and José I. Medeiros. "Experimental analysis of the impact protection properties for Kevlar® fabrics under different orientation layers and non-Newtonian fluid compositions." Journal of Composite Materials 54, no. 24 (April 7, 2020): 3515–26. http://dx.doi.org/10.1177/0021998320916231.

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Use of colloidal silica suspensions impregnated in Kevlar® fabrics is new avant-garde of protection equipment for stab wounds and piercing objects. Kevlar® fabrics impregnated with non-Newtonian fluids have been used for protection against sharp blows, mainly due to their lightweight, good flexibility, and superior resistance properties. The aims of this investigation are to demonstrate that Kevlar® fabric impregnated with shear thickening fluids could be improved its performance through the use Aminopropyltrimethoxysilane, as well as by increasing the concentration of silica nanoparticles in its composition. Friction tests on yarns showed that Kevlar® yarns with shear thickening fluids (sample C3—25% Silica and 75%polyethylene glycol with 38% aminopropyltrimethoxysilane), presented higher strength values (10.5 N) when compared with other samples. Impact resistance tests showed that Kevlar® samples with highest concentration shear thickening fluids nanoparticles and oriented fabric layers (C3 OR) presented better performance regarding to penetration depth of stabs P1 (17 mm), S1 (18 mm) and as well as residual energy dissipation, when compared with the standard and other samples. Addition of shear thickening fluids cause reduction in the flexibility of the Kevlar® fabrics, producing sample with 42.74% less flexibility than the standard sample (C3). Adhesion tests for C3 samples exhibited more stable wettability and spreading rate, i.e., a greater adhesion of shear thickening fluids in Kevlar® fabrics than other samples due to its composition (higher concentration of nanoparticles and superior amount of silane agent). Finally, results showed that the shear thickening fluids composition as well as Kevlar® layers orientation should be used to improve the performance of Kevlar® fabrics under impact tests.

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Jia, Zhao. "Properties of Kevlar Fibers by Surface Modification." Applied Mechanics and Materials 401-403 (September 2013): 688–91. http://dx.doi.org/10.4028/www.scientific.net/amm.401-403.688.

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The surface of Kevlar fiber was modified by hydrogen peroxide solutions (H2O2) in this article. The interfacial properties of Kevlar fiber/epoxy composites were investigated by the single fiber pull-out test (SFP). The results showed that the interfacial shear strength (IFSS) of Kevlar /epoxy composites was remarkbly improved after surface modification and the breaking strength has not been affected appreciably. It provided an efficient method to make the surface modified Kevlar fiber for the application for the advanced composites at a lower production cost.

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Mahbub, Rana Faruq, Saminathan Ratnapandian, Li Jing Wang, and Lyndon Arnold. "Evaluation of Comfort Properties of Coated Kevlar/Wool Ballistic Fabric." Advanced Materials Research 821-822 (September 2013): 342–47. http://dx.doi.org/10.4028/www.scientific.net/amr.821-822.342.

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Multiple layers of ballistic fabrics are extensively used in the production of soft body armour. The importance of comfort and hence its evaluation for these fabrics is gaining significance among present day researchers. This research compares 100% Kevlar ballistic fabric and Kevlar/wool ballistic fabric focussing on two aspects of comfort, namely the evaluation of surface roughness and the ability to transport moisture. A water repellent treatment was applied to the ballistic Kevlar/wool fabric. The effects of the treatment on the Kevlar/wool fabric were examined as well.

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Bakar, Noor Haznida, Koay Mei Hyie, Ahmad Safwan Ramlan, Mohd Khalid Hassan, and Aidah Jumahat. "Mechanical Properties of Kevlar Reinforcement in Kenaf Composites." Applied Mechanics and Materials 465-466 (December 2013): 847–51. http://dx.doi.org/10.4028/www.scientific.net/amm.465-466.847.

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The development of high-performance materials made from natural resources are increasing worldwide in recent years. Natural fibres offer both cost savings and reduction in density when compared to Kevlar fibres. However, the strength of natural fibres is not as great as Kevlar. The following preliminary research investigated the use of Kevlar fibres in kenaf composites as a possible to improve the impact properties. The impact properties of Kevlar reinforced in kenaf composites was studied by using DYNATUP 9250 drop weight machine. According to the standard ASTM D638 Kevlar fibres in different weight percentage of 10,15,20 and 25 wt% were reinforced with kenaf/epoxy composites by using hand lay-up combined with cold-press method. It is clearly observed that the impact strength and hardness were increased with the addition of weight percentage of woven Kevlar in the kenaf composites. The highest energy was recorded at 12.76 J by hybrid composite in combination of 2Kevlar/Kenaf/2Kevlar. The microstructure observation of impacted hybrid samples indicated that the delamination area was increased with the increasing of the impact energy.

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Jesuarockiam, Naveen, Mohammad Jawaid, Edi Syams Zainudin, Mohamed Thariq Hameed Sultan, and Ridwan Yahaya. "Enhanced Thermal and Dynamic Mechanical Properties of Synthetic/Natural Hybrid Composites with Graphene Nanoplateletes." Polymers 11, no. 7 (June 26, 2019): 1085. http://dx.doi.org/10.3390/polym11071085.

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The aim of the present research work is to enhance the thermal and dynamic mechanical properties of Kevlar/Cocos nucifera sheath (CS)/epoxy composites with graphene nano platelets (GNP). Laminates were fabricated through the hand lay-up method followed by hot pressing. GNP at different wt.% (0.25, 0.5, and 0.75) were incorporated with epoxy resin through ultra-sonication. Kevlar/CS composites with different weight ratios (100/0, 75/25, 50/50, 25/75, 0/100) were fabricated while maintaining a fiber/matrix weight ratio at 45/55. Thermal degradation and viscoelastic properties were evaluated using thermogravimetric analysys (TGA), differential scanning calorimetric (DSC) analysis, and a dynamic mechanical analyser (DMA). The obtained results revealed that Kevlar/CS (25/75) hybrid composites at 0.75 wt.% of GNP exhibited similar thermal stability compared to Kevlar/epoxy (100/0) composites at 0 wt.% of GNP. It has been corroborated with DSC observation that GNP act as a thermal barrier. However, DMA results showed that the Kevlar/CS (50/50) hybrid composites at 0.75 wt.% of GNP exhibited almost equal viscoelastic properties compared to Kevlar/epoxy (100/0) composites at 0 wt.% GNP due to effective crosslinking, which improves the stress transfer rate. Hence, this research proved that Kevlar can be efficiently (50%) replaced with CS at an optimal GNP loading for structural applications.

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SHCHERBAN, V., A. PETKO, O. KOLISKO, Y. SHCHERBAN, and L. HALAVSKA. "SOFTWARE MODULES AND PROCEDURES OF A COMPUTER PROGRAM FOR DETERMINING THE TENSION OF A KEVLAR THREAD WHEN KNITTING USING A RECURSOR ALGORITHM." HERALD OF KHMELNYTSKYI NATIONAL UNIVERSITY 295, no. 2 (May 2021): 271–74. http://dx.doi.org/10.31891/2307-5732-2021-295-2-271-274.

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Improving the process of knitting fabrics from Kevlar complex threads on flat knitting machines is to create the minimum necessary tension in the area of formation of the knitted fabric. To ensure this, it is necessary to determine the change in relative tension in the refueling zones of Kevlar complex threads on flat knitting machines. These zones are formed by arranging the thread guides, tension compensation devices, tension devices and thread break control devices in the working area of the supply system to form a spatial filling line for each specific knitting machine. This complex task for flat knitting machines should be based on the use of specially designed computer programs. Given the specifics of processing Kevlar complex threads on flat knitting machines, when determining the relative tension in each zone, it is necessary to use a recursion algorithm, when the output tension of Kevlar complex threads from the previous zone will be the input for the next zone. When determining the tension of Kevlar complex threads, their interaction with the guides of Kevlar complex threads, tension compensation devices, tension devices and devices for controlling the breakage of Kevlar complex threads, it is necessary to take into account the value of Kevlar complex thread diameter, its physical and mechanical properties, deformation, deformation the coefficient of bending stiffness when determining the actual angle of coverage of the guide surface. Ensuring the minimum necessary tension in the area of formation of the knitted fabric will allow to obtain the parameters of the loop structure of property and tactical equipment of servicemen capable of protecting the human body from fire, cold, cutting, barbed weapons, shock and shotgun impact. Minimizing the tension in each zone of the line of Kevlar complex threads on flat knitting machines will reduce the probability of breakage, which is important for improving knitting processes from the standpoint of improving the productivity of flat knitting machines and product quality. Mathematical support of a computer program requires the development of models of thread guides, tension compensation devices, tension devices and thread break control devices, taking into account the real physical and mechanical properties of Kevlar complex threads and real geometric and structural parameters of structural elements of the feed system.

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Lin, Jia Horng, Jia Hsun Li, Jing Chzi Hsieh, Wen Hao Hsing, and Ching Wen Lou. "Physical Properties of Geotextiles Reinforced by Recycled Kevlar Selvages." Applied Mechanics and Materials 749 (April 2015): 295–98. http://dx.doi.org/10.4028/www.scientific.net/amm.749.295.

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Kevlar fiber are artifical fibers that have been globally commonly used due to their attributes of a high modulus, a low elongation, an impact resistance, a chemical resistance, and thermostability. Therefore, this study proposes nonwoven geotextiles by corporating with recycled Kevlar unidirectoinal selvage with a low production cost, crimped polyester (PET) fibers, and low-melting-point PET (LPET) fibers. The content of LPET fiber is specified as 20 wt%, while the content of Kevlar fiber varies as 0 wt%, 5 wt%, 10 wt%, 15 wt%, and 20 wt%. The optimal tear strength of 195 N occurs with a content of Kevlar fiber being 20 wt%.

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Manigandan, S. "Determination of Fracture Behavior under Biaxial Loading of Kevlar 149." Applied Mechanics and Materials 766-767 (June 2015): 1127–32. http://dx.doi.org/10.4028/www.scientific.net/amm.766-767.1127.

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The high crystalline fiber Kevlar 149 has a major industrial application and it is extensively used in aerospace industries due to its significant properties of ultra-high modulus, high strength, low density, high flame resistance. Kevlar 149 has an advantage over K 49, since it absorbs less moisture and has high compression strength [3]. In order to explore the vast application, this paper investigates the fracture response of the Kevlar material computationally, when they are subjected to biaxial loading in both tensile and compression. This loading is done to understand the response of the Kevlar how far they poor in compression and rich in tensile. The fiber induced with epoxy is to form as an effective reinforcement. Here the fiber taken as Kevlar 149 & K-49 and the epoxy resin. For easy understanding a sample of two flat plates is considered as a composite structure of standard size, which under goes the biaxial loading computationally using Abaqus/CAE. The pictorial data’s are taken from the post processing study and the data’s can be used to investigate the fracture mechanism of Kevlar 149 & K-49, under different types of strain loading. The output results of Kevlar 149 is compared with K-49 to analyze the behavior of fiber undergoes the biaxial loading both compressive and tensile and also the merits and effective utilization of K-149. It is suggested that this method can be applied to other type of composite materials.

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Abdelal, Nisrin R., and Steven L. Donaldson. "Interlaminar fracture toughness and electromagnetic interference shielding of hybrid-stitched carbon fiber composites." Journal of Reinforced Plastics and Composites 37, no. 18 (July 18, 2018): 1131–41. http://dx.doi.org/10.1177/0731684418787642.

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In the current study, the production of multifunctional hybrid-stitched composites with improved interlaminar fracture toughness and electromagnetic interference shielding effectiveness is reported. Unidirectional carbon fiber-epoxy composite laminates stitched with Kevlar, nylon, hybrid stitched with both Kevlar and nylon and unstitched were prepared using resin infusion process. Representative specimens from unstitched and stitched composites were tested using rectangular waveguide and Mode I double cantilever beam tests. The Mode I experimental results showed that composite stitched with Kevlar exhibited the highest crack initiation interlaminar fracture toughness (GIC-initiation), whereas composite stitched with nylon exhibited the highest maximum crack propagation interlaminar fracture toughness (GIC-maximum). The four-hybrid stitching patterns exhibited higher GIC-initiation than the unstitched and stitched with nylon composites and lower than stitched with Kevlar composite, whereas they had higher GIC-maximum than the unstitched and stitched with Kevlar composites, although lower than stitched with nylon composite. The electromagnetic shielding effectiveness experimental results showed that stitched composites exhibited improved shielding effectiveness compared to unstitched composites. For example, composite stitched with nylon had highest shielding effectiveness value of 52.17 dB compared by the composite stitched with Kevlar which had 40.6 dB. The four hybrid-stitched composites exhibited similar shielding effectiveness with an average value of 32.75 dB compared to the unstitched composite shielding effectiveness of 22.84 dB. The experimental results comply with the initial goal of this study to manufacture multifunctional hybrid stitching composites with combined properties between Kevlar and nylon-stitched composites.

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Lin, Jia Horng, Chen Hung Huang, Yu Chun Chuang, and Ching Wen Lou. "Preparation and Sound Absorption Evaluation of PET/Kevlar/PU Foam Composite Boards." Advanced Materials Research 910 (March 2014): 222–25. http://dx.doi.org/10.4028/www.scientific.net/amr.910.222.

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Factories have increased the mechanical equipment on a mass scale as a result of quick growth of global industry, and the unbearable sounds that machines create while operating become noise. Therefore, versatility of building materials that are highly correlated to human habitat has been gaining attention. This study combines and then needle-punches fire-retardant polyester (PET) fibers and recycled Kevlar selvages to make PET/Kevlar nonwoven fabrics, which are then combined with Polyurethane (PU) foams, a product yielded after Polyol and Isocyanate (MDI) foam and cure, to form PET/Kevlar/PU foam composite boards. During the process, PET fibers and Kevlar fibers are blended with various ratios and the density of the PU foams is varied. The resilience rate, burst strength, and sound absorption of the resulting composite boards are tested. The test results show that increasing Kevlar selvages can heighten the resilience rate but decreases the burst strength of the composite boards.

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31

Zhang, Guotao, Yanguo Yin, Ting Xie, Dan Li, Ming Xu, and Congmin Li. "Tribological properties of the epoxy resin-based solid lubricant coating modified by Kevlar fibers." Industrial Lubrication and Tribology 70, no. 9 (November 19, 2018): 1706–13. http://dx.doi.org/10.1108/ilt-09-2017-0259.

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Purpose This paper aims to obtain high mechanical and good tribological properties of epoxy resin-based coatings under dry friction conditions. Design/methodology/approach Bonded solid lubricant coatings containing Kevlar fibres were prepared by a spraying method. The friction and wear properties of the coatings were experimentally investigated with a face-to-face tribometre under dry friction conditions. Scanning electron microscopy, energy dispersive X-ray spectroscopy and 3D laser scanning technologies were used to characterise the tribological properties. The action mechanism of the Kevlar fibres on a solid lubricant transfer film was also analysed. Findings Adding Kevlar fibres can significantly improve the wear resistance of the coatings. When the Kevlar fibre content increases, the tribological properties of the coatings improve and then worsen. Superior properties are obtained with 0.03 g of Kevlar fibres. Appropriately increasing the load or speed is beneficial to the removal of the outer epoxy resin and the formation of a lubricant film. During friction, the solid lubricants wrapped in the epoxy resin accumulate on the surface to form a transfer film that shows a good self-lubricating performance. In the later friction stage, fatigue cracks occur on the solid lubricant film but cannot connect to one another because of the high wear resistance and the entanglement of the rod-like Kevlar fibres. Thus, no large-area film falls from the matrix, thereby ensuring the long-term functioning of solid lubricant coatings. Originality/value Epoxy resin-based solid lubricant coatings modified by Kevlar fibres were prepared, and their friction and wear properties were investigated. Their tribological mechanisms were also proposed. This work provided a basis for the analysis of the tribological properties and design of bonded solid lubricant coatings containing Kevlar fibres.

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Fernandez, John. "From Kaolin to Kevlar." Journal of Architectural Education 58, no. 1 (September 2004): 54–65. http://dx.doi.org/10.1162/1046488041578239.

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Lin, Jeng-Shyong, and Hsien-Tang Chiu. "Hydrolysis of Kevlar Fibres." Polymers and Polymer Composites 9, no. 4 (May 2001): 239–46. http://dx.doi.org/10.1177/096739110100900402.

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Aldajah, Saud, Yousef Haik, Kamal Moustafa, and Ammar Alomari. "High and Low Speed Impact Characteristics of Nanocomposites." Advanced Materials Research 1105 (May 2015): 62–66. http://dx.doi.org/10.4028/www.scientific.net/amr.1105.62.

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Nanocomposites attracted the attention of scientists due to their superior mechanical, thermal, chemical and electrical properties. This research studied the impact of adding carbon nanotubes (CNTs) to the woven Kevlar laminated composites on the high and low speed impact characteristics. Different percentages of CNTs were added to the woven Kevlar-Vinylester composite materials. An in-house developed drop weight testing apparatus was utilized for the low speed impact testing. Two different concentrations of the CNTs were added to a 15-layer woven Kevlar laminates, 0.32 wt% and 0.8 wt%. The results showed that: The 0.32 wt % CNT sample enhanced the interlaminar strength of the composite without enhancing the energy absorption capacity whereas, the 0.8 wt % CNT sample did not improve the impact resistance of the Kevlar composite.For the high speed impact tests, a bulletproof vest was prepared using woven Kevlar, resin, and CNTs at 1.5 w% percentage. The ballistic shooting was carried out by a professional shooter using a 30 caliber and 9 mm bullets for the tests. The CNT bulletproof sample bounced back the 30 caliber copper alloy bullet with no penetration.

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35

Azrin Hani Abdul, Rashid, Ahmad Roslan, Mariatti Jaafar, Mohd Nazrul Roslan, and Saparudin Ariffin. "Mechanical Properties Evaluation of Woven Coir and Kevlar Reinforced Epoxy Composites." Advanced Materials Research 277 (July 2011): 36–42. http://dx.doi.org/10.4028/www.scientific.net/amr.277.36.

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The utilization of coconut fibers as reinforcement in polymer composites has been increase significantly due to their low cost and high specification of mechanical properties. Whereas kevlar fibers has widely used as the core material in flexible body armors due to its great mechanical properties, such as high strength, light weight, good chemical resistance and thermal stability. The research work is concerned with the evaluation of high speed impact and flexural test of hybrid textile reinforced epoxy composites. Samples were prepared from coir yarn, kevlar yarn, interlaced of coir and kevlar yarn with different warp/weft orientation and pure epoxy as control specimen. The woven samples were produced using handloom and the composites specimens were prepared using hand lay-up technique. From the results obtained, it was found that woven kevlar composites samples displayed the highest impact properties while it exhibits the lowest flexural properties. Results also showed that the composite plate for woven coir yarn (warp) and kevlar yarn (weft) has the flexural strength and impact strength of 17 MPa and 67 kJ/m², which presented as the nearest properties to woven Kevlar composite respectively. These results indicate that coir as a natural fiber can be used as a potential reinforcing material for high impact resistance such as body armors in order to reduce the usage of synthetic materials whilst utilizing the natural resources.

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36

Hsing, Wen Hao, Ching Wen Lou, Ching Wen Lin, Jin Mao Chen, and Jia Horng Lin. "Effects of the Content of High Strength Polyethylene Terephthalate Fiber and Kevlar Fiber on Properties of Geotextiles." Applied Mechanics and Materials 365-366 (August 2013): 1082–85. http://dx.doi.org/10.4028/www.scientific.net/amm.365-366.1082.

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Geotextiles have been commonly used globally, making the control of material selection to influence geotextiles properties an important research topic. This study aims to explore the effects of the ratio of high-strength polyethylene terephthalate (HPET) fiber to Kevlar fiber on hybrid geotextiles. At the first stage, HPET and polyethylene terephthalate (PET) fiber are combined to make HPET/PET hybrid geotextile and then tested for porosity and water permeability, determining the optimum HPET/PET ratio. At the second stage, with a content of 60 % PET fibers, HPET fibers and Kevlar fibers are mixed with various ratios to form Kevlar/HPET/PET hybrid geotextiles. The experimental results show that with an increase in the content of HPET fibers, the porosity and water permeability of the Kevlar/HPET/PET hybrid geotextile decrease.

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37

Lou, Ching Wen, Ting Ting Li, Jan Yi Lin, Mei Chen Lin, and Jia Horng Lin. "Effects of Processing Parameters on Constant-Rate Puncture Resistance Behaviors of Compound Fabrics." Applied Mechanics and Materials 365-366 (August 2013): 1078–81. http://dx.doi.org/10.4028/www.scientific.net/amm.365-366.1078.

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The effect of Kevlar fibers amount, number of layers, thermal bonding and fabric type on constant-rate puncture resistance of low-cost compound fabrics are discussed. Therein, compound fabrics were prepared by nonwovens and woven fabric via needle-punching and thermal bonding processes. The result shows that, Kevlar fibers amount and number of layers are both positive to improvement of puncture resistance. And thermal bonding process increases the wearer safety of puncture-resistance materials. For different kinds of fabrics, compound Kevlar fabric shows the maximum puncture resistance.

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Song, Ying Deng, Bin Tai Li, and Li Ying Xing. "Structure and Compressive Property of Heterocyclic Aramid Fiber." Materials Science Forum 898 (June 2017): 2158–65. http://dx.doi.org/10.4028/www.scientific.net/msf.898.2158.

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The F-3 fiber is a trade name of a recently developed type of heterocyclic para-aramid fibers in China. To investigate the relationship between structure and compressive properties for F-3 fiber, the structural parameters and compressive strength have been analyzed in detail compared with the Kevlar-49 fiber. The structural parameters were determined by wide-angle X-ray diffraction (WAXD) analysis and sonic velocity method. The results showed that the orientation of chains of F-3 fiber was higher than that of Kevlar-49 fiber. The results of the tensile recoil method showed that F-3 and Kevlar-49 fibers had approximate compressive strength. The analysis of relation between structure and mechanical properties suggested that the combination of orientation parameter and shear modulus between adjacent chains resulted in the approximate compressive strength of F-3 and Kevlar-49 fibers.

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Smith, A. P., A. Garcia, and H. Ade. "Quantitation of the Lateral Orientational Order in Poly(p-Phenylene Terephthalamide) Fibers with X-ray Linear Dichroism Microscopy." Microscopy and Microanalysis 4, S2 (July 1998): 812–13. http://dx.doi.org/10.1017/s1431927600024181.

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Determination of internal structure of complex polymeric materials often requires a variety of analytical techniques. One technique that we have developed and recently employed for the first time for quantitative analysis is x-ray linear dichroism microscopy. With sensitivity to the presence and orientation of specific chemical functionalities within polymer molecules, x-ray linear dichroism microscopy provides a powerful tool to probe the internal structure of such molecules. We have used this ability to quantitatively analyze the lateral orientational order (tangential and radial orientation of transverse sections) within different grades of poly(p-phenylene terephthalamide) (Kevlar) fibers.Kevlar fibers are highly crystalline and possess a complicated internal structure that exhibits lateral radial orientation. Figure 1 shows x-ray micrographs of (a) Kevlar 149, (b) Kevlar 49 and (c) Kevlar 29 fibers imaged at a photon energy specific to the aromatic functionality.

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Erkliğ, Ahmet, and Mehmet Bulut. "Experimental investigation on tensile and Charpy impact behavior of Kevlar/S-glass/epoxy hybrid composite laminates." Journal of Polymer Engineering 37, no. 2 (February 1, 2017): 177–84. http://dx.doi.org/10.1515/polyeng-2015-0538.

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Abstract The aim of this study is to evaluate the effect of hybridizing Kevlar and glass fibers on the tensile and Charpy impact properties of their composites. Produced hybrid samples were designed as unbalanced and asymmetric structures in terms of different mixing ratios between woven Kevlar and S-glass fibers, and their tensile properties were determined using ASTM standards. A series of Charpy impact tests were performed to evaluate the amount of impact strength and absorbed energy by impacting each side of the hybrid composite samples. When the hybrid samples were impacted on the surface of the Kevlar side, they exhibited higher impact resistance compared with glass side impact. The resulting degree of hybridization effects showed that addition of Kevlar layers instead of glass layers contributed a significant increase in impact strength and absorbed energy of the overall composite laminate.

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41

R, Seshagiri, Vinod Vivian G, and Anne Miriam Alexander. "Bullet Proof Vest using Non-Newtonian Fluid." International Journal of Students' Research in Technology & Management 3, no. 8 (November 5, 2015): 451–54. http://dx.doi.org/10.18510/ijsrtm.2015.384.

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Bullet proof vests, made of Kevlar are used for preventing projectiles from injuring humans. Soft armours are capable of protecting humans from low energy projectiles while hard-plate reinforced armours use metal plates, which weigh over 14+ kg for protection against high energy projectiles. NonNewtonian fluids which have time dependent properties (particularly viscosity) are prepared and tested for energy absorbing properties.It was proved that when Kevlar was used with Oobleck sample, the deformation produced in test plate was reduced considerably as compared to that of only Kevlar sample.

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42

Yang, Jianxia, Yitong Guo, Lan Yao, Qingqing Ni, and Yiping Qiu. "Effects of Kevlar volume fraction and fabric structures on the mechanical properties of 3D orthogonal woven ramie/Kevlar reinforced poly (lactic acid) composites." Journal of Industrial Textiles 47, no. 8 (July 11, 2017): 2074–91. http://dx.doi.org/10.1177/1528083717720204.

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The proposed 3D orthogonal woven ramie/Kevlar reinforced poly (lactic acid) composite in this paper is a new type composite in which the 3D orthogonal structure has great advantages of high impact and delamination resistance due to the Z yarns and the hybridization of natural and manmade fibers provides not only partial environment friendly benefit but also efficient compensation for the relatively low mechanical properties from pure natural fibers. Eight types of the aforementioned composites were designed and fabricated. The results showed that as the volume fraction of Kevlar was increased, the tensile properties showed increasing trends, while the flexural properties were predominantly dependent on the fabric structures, especially, the weft yarns properties in the first and second layers from the upper and bottom surfaces. Furthermore, the impact strength was enhanced as the volume fraction of Kevlar increased to 5.5% and leveled off when Kevlar yarns continuously increased.

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Kumar, Saurabh S., Rajesh G. Babu, and U. Magarajan. "Ballistic Performance Evaluation of Kevlar-Glass Fibre Hybrid Composite Laminate against Medium Velocity Impact." Advanced Materials Research 1165 (July 23, 2021): 47–64. http://dx.doi.org/10.4028/www.scientific.net/amr.1165.47.

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In this paper, the post ballistic impact behaviour of kevlar-glass fibre hybrid composite laminates was investigated against 9×19 mm projectile. Eight different types of composite laminates with different ratios of kevlar woven fibre to glass fibre were fabricated using hand lay-up with epoxy matrix. Ballistic behaviour like ballistic Limit (V50), energy absorption, specific energy absorption and Back Face Signature (BFS) were studied after bullet impact. The results indicated that as the Percentage of glass fibre is increased there was a linear increment in the ballistic behaviour. Addition of 16% kevlar fabric, composite sample meets the performance requirement of NIJ0101.06 Level III-A. Since the maximum specific energy absorption was observed in Pure Kevlar samples and the adding of glass fibre increases the weight and Areal Density of the sample, further investigations need to be carried out to utilize the potential of glass fibre for ballistic applications.

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Hyie, Koay Mei, Noor Haznida Bakar, Ridzuan Jazlan, A. Jumahat, and Anizah Kalam. "The Compressive Properties of Kevlar/Kenaf Hybrid Composites." Applied Mechanics and Materials 763 (May 2015): 19–24. http://dx.doi.org/10.4028/www.scientific.net/amm.763.19.

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Natural fibres are aimed to replace or at least to reduce the dependence of the industrial sector against low degradability of raw material. Hence, this study is performed to investigate the effect of stacking sequence and fibre orientation on the compressive properties of Kevlar/kenaf hybrid composites. Previous study suggested that treated kenaf fibres improved the fibre’s properties. Therefore, kenaf fibres was treated with NaOH of 6% concentration for 12 hours before rinsed and dried to be used in this study. The stacking sequence was varied for different weight percentage of woven Kevlar from 0 wt% to 23 wt%, while the kenaf fibres were arranged at 0° and 90° orientation, respectively. The compressive properties of the Kevlar/kenaf fibre hybrid composites were investigated using Instron Universal Testing Machine (ASTM standard D3410M). Stereo-zoom was used to identify the fibre orientation and the bonding between the fibres and matrix. For stacking sequence, the study showed that the arrangement of kenaf fibres on the middle part, “sandwiched” between Kevlar on the outer part, gave the best compressive performance. The sample in 0° orientation exhibited better compressive strength and modulus than 90° orientation. The outcome of this research has shown significant increase of compressive strength with the addition of kenaf fibre replacing the Kevlar.

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Jing, Xiang Hai, Yu Yan Liu, Yu Xi Liu, and Hui Feng Tan. "Preparation and Properties of Shape Memory Epoxy Resin Composites." Applied Mechanics and Materials 214 (November 2012): 12–16. http://dx.doi.org/10.4028/www.scientific.net/amm.214.12.

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Kevlar fiber and carbon fiber reinforced shape memory epoxy composites were prepared respectively. The fold-deploy shape memory properties of the composite system were studied at the temperature which was 30°C higher than the glass transition temperature of resin. The results shows that shape fixed rate and shape recovered rate of the composites are decreased with the increase of Kevlar and carbon fiber volume. The shape fixed rate of Kevlar fiber reinforced shape memory composite is higher than that of carbon fiber reinforced shape memory composite, but the shape recovered rate of the former is much lower than the latter.

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46

Sima, Elena, and George Bălan. "Analysis of Stresses and Displacements of Thin Coating Structures." Materials Science Forum 887 (March 2017): 41–45. http://dx.doi.org/10.4028/www.scientific.net/msf.887.41.

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This paper addresses the problem of open thin coatings of constant thickness made from Kevlar composite material. Kevlar is an organic polymer fiber 5 times stronger than steel taken at the same weight. Therefore, this fiber has been used successfully in producing composite materials. In this paper, the generic name of Kevlar designates the composite material having the following characteristics: E=7,6×104MPa; θ=0,34; ρ=1700kgcm3. The program COSMOS/M with which the study was conducted and broadcasted was The Structural Research and Analysis Corp. The analysis was carried out by the finite element method.

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47

Lin, Chia Chang, Ting Ting Li, Ching Wen Lou, Jan Yi Lin, and Jia Horng Lin. "Investigations on Dynamic Puncture Behaviors of Integrated Composite Reinforced with Varying Fabrics." Applied Mechanics and Materials 365-366 (August 2013): 1070–73. http://dx.doi.org/10.4028/www.scientific.net/amm.365-366.1070.

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The dynamic puncture resistance of multi-layer integrated composite which was comprised of glass fabric reinforcement or Kevlar fabric reinforcement and nonwovens were discussed as related to recycled Kevlar fibers amount, number of layer and K-ply position for purpose of cost reduction and performance improvement. The result shows that, 20 wt% Kevlar fibers contained in nonwovens have the optimum puncture resistance. And the dynamic puncture force increases linearly with number of layers, and also improves proportionally as increasing number of K-ply. The resultant multi-layer composite is expected to be used as body armor interlayer and packaging materials.

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48

Mohammed, Tawfeeq W., Dalmn Yaseen Taha, and Rafal R. Abdul-Ilah. "Evaluation of Composite Material used in the Wings of Typical Airplane based on Stress Analysis." European Journal of Engineering Research and Science 3, no. 11 (November 25, 2018): 37–41. http://dx.doi.org/10.24018/ejers.2018.3.11.921.

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This research has focused on the evaluation of raw materials that used in the wings of modern airplane. These materials either would be fiberglass, carbon-fiber or aramid based composites like Kevlar. These common materials have been selected and evaluated depending on experimental data obtained from mechanical tests. These tests include: hardness, tensile strength and bending stress. The tests based on ASTM standards for mechanical properties. The results show increasing in the hardness value of graphite-epoxy by 9% comparing with that of fiberglass and by 18% comparing with that of Kevlar-epoxy. The results also show an increasing in the maximum tensile strength of graphite-epoxy by 2.9 times to that of fiberglass and by 5.5 times to that of Kevlar-epoxy. Furthermore, the results of bending stress test show increasing of the maximum strength of Kevlar-epoxy by 30% comparing to that of glass fiber and by 75% comparing to that of graphite-epoxy.

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Lou, Ching Wen, Po Ching Lu, Ying Huei Shih, Hsuan Mao Yeh, and Jia Horng Lin. "Manufacturing Technique and Property Evaluations of Sandwich-Structured Nonwoven Composites." Advanced Materials Research 910 (March 2014): 161–64. http://dx.doi.org/10.4028/www.scientific.net/amr.910.161.

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This study aims to examine the thickness of a sandwich structure and the lamination number of the Kevlar nonwoven fabrics o n the punch resistance strength and impact resistance strength of the nonwoven composites. Kevlar nonwoven fabrics and Nylon/low-melting-point polyethylene terephthalate (LPET) nonwoven fabrics are laminated with various combinations to form sandwich-structured nonwoven composites. The experiment results show that an increasing number of Kevlar nonwoven fabrics results in low dynamic and constant rate puncture resistance but high impact strength; and conversely, an increasing thickness of sandwich-structured nonwoven composites causes high dynamic and constant rate puncture resistances but low impact strength.

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Lin, Ching Wen, Wen Hao Hsing, Ching Wen Lou, Jin Mao Chen, and Jia Horng Lin. "Manufacturing Technique and Property Evaluation of Eco-Friendly Kevlar/PET/Nylon Composite Geotextile." Applied Mechanics and Materials 365-366 (August 2013): 1157–60. http://dx.doi.org/10.4028/www.scientific.net/amm.365-366.1157.

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This study produces composite geotextile, and evaluates its effectiveness of being used for soil protection. Kevlar fibers, high strength polyethylene terephthalate (HPET) fibers, recycled polyethylene terephthalate (RPET) fibers, and nylon grids are made into Kevlar/PET/Nylon composite geotextiles, which are then tested for air permeability, and tensile, tearing, and bursting strength. The experimental results show that when the ratio of Kevlar fibers to HPET is 0/40, the resulting composite geotextile has the optimum mechanical properties, where the tensile strength is approximately 990 N, tearing strength is approximately 890 N, bursting strength is approximately 3700, and an air permeability is around 35 cm3/cm2/s.

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Journal articles on the topic 'Kevlar'

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