Thermal and Acoustic Behaviour of Sisal Fibre Reinforced Epoxy Composites

Abstract

The present work is carried out to enhance the insulation capability (both thermal and acoustic) of new class of composite material. i.e., it deals with thermal1and1acoustic behaviour of sisal fibre1reinforced1epoxy1composites. A theoretical one dimensional heat conduction model has been developed1based on1law of minimum thermal1resistance and equal law1of specific1equivalent thermal1conductivity. Few sets of short sisal1fibre reinforced1epoxy composite has been fabricated by simple hand layup technique with the fibre content1ranging from 0 to18.48 vol%. The effective2thermal2conductivity of sisal fibre reinforced1epoxy composites is obtained1experimentally with the help of Unitherm™ Model 2022 tester. The measurements are carried out as per the ASTM standard E 1530. An ANSYS package is used to find effective thermal1conductivity of composite based2on finite element method. The values of1effective thermal1conductivity obtained from the proposed model are validated against the experimental results. Experimentally2measured values are2then compared with2the values2obtained from the2proposed mathematical2model, the numerical2values and also with models2established earlier, such as Rule-of-Mixture2(ROM), Maxwell’s2model and Nielson-Lewis2model. The sound absorption coefficient of the composite1samples is measured1as1per ASME standard1E 1050 by2using Impedance Tube Tester.
From2the experimental2and numerical values of2effective thermal2conductivity, it is found that2the effective2thermal conductivity2of composite decreases2with increase2in fibre content. The comparison of effective2thermal conductivity2of proposed model and experimental results shows that the proposed2model fits2well with the2experimental data. A reduction of2about 17.63 % in2the value2of thermal conductivity is2recorded with2addition of 8.48 vol % 2of sisal fibre in neat epoxy1resin. From the experimental results of sound absorption2coefficient, at a frequency3of 125 Hz, the sound3absorption1coefficient of 1.48 Vol.% fibre content composite is found to be 0.049 which increases to 0.07 at 8.48 Vol. % of fibre content. Similarly, at 4000 Hz the maximum sound absorption coefficient for 8.48Vol. % fibre content was found to be 0.625. we can observe as1the fibre2content increases2from 1.84 Vol.% to 8.48 Vol.%, the sound2absorption coefficient also2increases. With2the increase2in the thickness2of the composite the3sound absorption 3coefficient also increases. However, increasing3the thickness3of3the composite beyond certain limit doesn’t affect the value of sound absorption coefficient. With3light weight3and reduced3heat conductivity3and improved sound absorption coefficient these sisal fibre reinforced3polymer composites3finds their3potential applications in3insulation boards, 3food containers, thermos flask, 3building3materials, interiors3of air crafts and automobiles etc.