Developing Acoustic Noise Barriers with Blending of Coir and Jute

Abstract

Problem statement: Noise control was one of the major requirements to improve the living environment. One of the methods to do that is provided by sound absorber. Commonly, multi-layer sound absorbers are applied to absorb broadband noise that was composed of perforated plates, air space and porous material. However, multi-layers sound absorbers effectiveness depends on their construction. This study was conducted to investigate the potential of using coconut coir fiber and jute fibre as sound absorber. The effects of porous layer backing and perforated plate on sound absorption coefficient of sound absorber using coconut coir fiber and jute fibre were studied. Approach: This material is made by blending coir and jute with different proportional ratio. The samples were tested at the acoustic lab of the psgtechs coe indutech, neelambur, Coimbatore according to ASTM E 1050-98 international standards for noise absorption coefficient. Results: The experiment data indicates that 70%coir and 30 %jute can improve noise absorption coefficient at low and high frequencies with significant increasing. 50mm thick layer coconut coir fiber and jute fiber with porous layer backing exhibit peak value at frequencies between 5000Hz to 6300Hz with maximum value of 0.72. The experimental results also found that the coconut coir fiber and jute fiber with 50:50 ratio gives lower value for higher frequency between 5000Hz to 63000Hz with value of 0.50. Conclusion: Noise absorption coefficient of coconut coir blended with jute fiber was increased at all frequencies. The results from the experimental tests show that70:30 ratio of coir and jute it has good acoustic properties at low and high frequencies and can used to be an alternative replacement of synthetic based commercial product. By using the porous layer and perforated plate backing to coconut coir fiber, the sound absorber panel shows a good potential to be an environmentally friendly product. This innovative sound absorption panel has a bright future because they are cheaper, lighter and environmentally compare to glass fiber and mineral based synthetic materials.