Investigation of the Sound Absorption Performance of Cellulosic Fine Fibres Fabricated from Agricultural Waste Fibres |Chapter 2 | Agricultural Sciences: Techniques and Innovations Vol. 3

Noise pollution today has caused several detrimental effects on the population, affecting both the health and behaviour of individuals. The advancement of controlling noise by sound absorption offers an excellent opportunity to study the acoustic attenuation technique of various natural porous materials. Hence, there is a growing interest in developing new materials that enhance the optimal utilisation of natural resources, particularly renewable resources. This paper presents a new study on agro-waste-based fine fibre for acoustic application prepared by enzymatic treatment and mechanical hammering. The main objective of this study was to determine the sound absorption characteristics of the acoustic material of fine cellulose fibres. Enset fine fibre (ENF), Banana fine fibre (BNF), Jute fine fibre (JNF), and Sisal fine fibre (SNF) were fabricated by defibrillation of finer fibres from the surface of neat mats (fabrics) into micro and fine-scale fibres with the help of enzymatic treatment (alpha-amylase) and then mechanical hammering. The study was conducted using the impedance tube method, and the sound absorption properties of lignocellulosic micro and fine fibres in a frequency range of 500 to 5500 Hz were studied by changing the thickness. The experimental results revealed that the sound absorption coefficient of ENF started near 0.01 at 1000 Hz and tended to increase at a slower rate up to 2700 Hz. It reached around 0.3 at 3000 Hz and 0.69 at 3800 Hz. Similarly, the sound absorption coefficient of BNF started near 0.05 at 1000 Hz and tended to increase rapidly up to around 2250 Hz. It reached around 0.54 at 2300 Hz up to 4000 Hz. Nevertheless, the sound absorption coefficient of ENF and SNF increased slowly with increasing frequency. The SEM image showed that ENF, JNF, and SNF had more of a porous space and void region than BNF. Due to this, BNF had a lower sound transmission loss value than other fine-fibrous materials. The experimental results also revealed that excessive water would increase the porosity of homemade fine fibres, therefore lowering their airflow resistivity of fine fibrous, thereby decreasing sound absorption and dramatically increasing sound transmission loss.

 

Author(s) Details

Alhayat G. TEMESGEN
Wollo University, Kombolcha Institute of Technology, Kombolcha, Ethiopia and Chemnitz University of Technology, Chemnitz, Germany.

 

H.Cebulla
Chemnitz University of Technology, Chemnitz, Germany.

 

J. Kaufmann
Chemnitz University of Technology, Chemnitz, Germany.

 

 

Please see the book here:- https://doi.org/10.9734/bpi/asti/v3/5262