International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395 -0056 Volume: 02 Issue: 05 | Aug-2015 www.irjet.net p-ISSN: 2395-0072 © 2015, IRJET ISO 9001:2008 Certified Journal Page 402 REINFORCEMENT EFFECT OF KEVLAR FABRIC ON THE MECHANICAL PROPERTIES OF EPOXY RESIN Prashant Ankolekar 1 , T. T. Hawal 2 , R. J. Naik 3 , Dr. T. R. Anil 4 1 Prashant Ankolekar, M.Tech Scholar, Dept. Of Mechanical engineering, KLS’ Gogte Institute of Technology, Belgaum, Karnataka, India. 2 T.T. Hawal, Faculty, Dept. of Mechanical Engineering, KLS’s Gogte Institute of Technology, Belgaum, Karnataka, 3 R. J. Naik, Faculty, Dept. of Mechanical Engineering, KLS’s Gogte Institute of Technology, Belgaum, Karnataka, 4 Dr. T. R. Faculty, Dept. of Mechanical Engineering, KLS’s Gogte Institute of Technology, Belgaum, Karnataka, ---------------------------------------------------------------------***--------------------------------------------------------------------- Abstract - In this study the effect of 10wt% Kevlar reinforcement on the mechanical properties of the epoxy has been evaluated. The epoxy resin used in the current investigation was Bisphenol A. Hand layup technique was used to prepare the composite. Results of the mechanical properties of composites were obtained by tensile, bending and compression tests. SEM was used to observe reinforcement and matrix fractures. Addition of Kevlar to the epoxy matrix led to a noticeable increase in the mechanical properties of the composite. A moderate rise in compression strength was observed. Key Words: Polymer matrix composites, Kevlar fabric, Mechanical properties, SEM analysis. 1. INTRODUCTION Epoxy resins offer unique combination of mechanical properties which are least formed by other thermoset materials. Most of the PMC’s are produced using epoxy resins as matrix due to its high mechanical properties. Varieties of techniques are being used to improve its mechanical properties; one of them is reinforcement of composites which is produced by combining various reinforcements with neat epoxy. Thus the properties of different individual materials are contributed in a single composite [1]. Aramid fiber such as Kevlar is very widely used reinforcement material in current use of composites. The high degree of toughness of the fibers made them tolerable to failure mechanism. The failure of aramid fibers or when they break, they do not scatter like glass but fail by a series of small fibril failures. Most of the energy is absorbed by these small failures and high toughness is formed [2]. Hybridization is also an approach to improve mechanical properties of epoxy resin. In this combination there is a reinforcement material which has a property by virtue of which the defect of other reinforcing material is covered up [3]. 2. EXPERIMENTAL 2.1MATERIALS Kevlar fabric 460gsm, with thickness 1.5mm supplied by Super safety services, Mumbai was used. The matrix material used was an epoxy from the family of thermoset polymers, named Bisphenol A (POLYFLEX GR 200-30) and hardeners viz., promoter (POLYFLEX SC 999-40), accelerator (POLYFLEX SC 999-30) and catalyst (ANDONOX KP-9) were supplied by Naptha Resins and Chemicals, Bangalore. 2.2 Specimen preparation: 10wt % Kevlar fabric corresponding to neat epoxy was weighed using digital weighing machine. The fabric was cut suitably to fit into the mold. The resin (90 wt %) was taken in a beaker and proportionate quantity of promoter, accelerator and catalyst were added to the epoxy resin. Once the hardeners were added, the mixture was stirred well using handheld electric blender. The mixture was kept aside and was allowed to settle down so that the bubbles rise and collapse. Two separate molds were used for tensile/bending test and compression test respectively. Once it was confirmed that all the bubbles were collapsed in the resin, the moulds were sprayed with releasing agent and a single layer of resin was slowly transferred into the mould, avoiding any turbulence. The releasing spray was meant for easy removal of the composite after curing. After this, the pre-cut Kevlar fabric of 460 gsm was laid on the layer of pre-poured resin in the mould. Rolling was facilitated to avoid formation of voids in the composite. Apart from assisting escaping entrapped gas, it also makes the resin to penetrate between the Kevlar fibers and enable thorough impregnation. Thus the porosity in the composite was controlled which otherwise would have be