Title: Acoustical Evaluation of Carbonized and Activated Cotton Nonwovens Authors
|Jiang, N. - LOUISIANA STATE UNIV|
|Chen, J. Y. - LOUISIANA STATE UNIV|
Submitted to: Bioresource Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 3, 2009
Publication Date: December 15, 2009
Citation: Jiang, N., Chen, J., Parikh, D.V. 2009. Acoustical Evaluation of Carbonized and Activated Cotton Nonwovens. Bioresource Technology. 100(24):6533-6536. Interpretive Summary: The main application of the activated carbon fiber (ACF) focuses on personal safety, (protective clothing and masks), water/air purification, and heat and electrical insulation. However, there is a lack of reports on ACF for acoustical applications. Textile fabrics and particularly nonwovens have been commonly used for sound absorption, because of a special structure formed by fiber in nonwoven fabrics. ACF nonwoven fabrics have two levels of porous structures: macro pores among fibers, and micro pores on the surface of the activated carbon fiber. This unique fabric architecture renders a great potential for ACF nonwovens to be used as high performance and cost effective acoustical materials. Our experimental findings show that the nonwoven composites with cotton as a surface layer had significantly higher sound absorption than the glass fiber surfaced composite in the frequency range of 100 to 6400 Hz.
Technical Abstract: An activated carbon fiber nonwoven (ACF) was manufactured from cotton nonowoven fabric. For the ACF acoustical application, a nonwoven composite of ACF with cotton nonwoven as a base layer was developed. Also produced were the composites of the cotton nonwoven base layer with a layer of glass fiber nonwoven, and the cotton nonwoven base layer with a layer of cotton fiber nonwoven. Their noise absorption coefficients and sound transmission loss were measured using the Bruel & Kjaer impedance tube instrument. Statistical significance of the differences between the composites was tested using the method of Duncan’s grouping. The study concluded that ACF composite exhibited a greater ability to absorb normal incidence sound waves than the composites with either glass fiber or cotton fiber. The analysis of sound transmission loss revealed that the three composites still obeyed the mass law of transmission loss. The composite with the surface layer of cotton fiber nonwoven possessed a higher fabric density, and therefore showed a better sound insulation than the composites with glass fiber and ACF.