Comparative study on sound absorption coefficient of various jute composite materials

Abstract

Natural fibre composites are getting attention in noise reduction applications replacing conventional materials. They are being used in passive noise control in which jute is showing its prominence. Though conventional sound absorbing materials are used for passive control, they can be replaced by natural fibres as they are abundantly available and are inexpensive. The present work is to test samples prepared from various jute materials with epoxy resin as bonding agent. Jute materials used for study are jute mats 190GSM, 420GSM and felt woven jute composites. Plain jute mat samples are designated as JM composites and samples prepared in combination of jute mat and felt woven jute are designated as JMW. The sound absorbing coefficient study is carried out experimentally using two microphone impedance tube test setup as per ISO 10534-2. Sound absorption coefficient comparative studies are carried out on perforated and sandwiched samples with air gap. It is observed that layered felt woven jute composites are having higher sound absorption coefficient than jute mat composites when several combinations of these are analyzed. This might be due to felt woven jute composites are having lesser density. Maximum noise reduction coefficient of 0.97 at 1250 Hz and 0.96 at 622 Hz in 1/3rd octave frequency band is obtained for 190GSM and 420GSM layered felt woven jute composites respectively. Maximum noise reduction coefficient of 0.93 at 922 Hz is recorded for 190GSM mat and felt oven jute composite samples with 20 mm thickness and 10 mm air gap. A comparative study is carried out between jute composites and glass wool fibre with 50 mm thick. It is observed that 420GSM samples are having better sound absorption properties than 190GSM sample in low frequency band because of better bonding capabilities. © Proceedings of 2020 International Congress on Noise Control Engineering, INTER-NOISE 2020. All rights reserved.