Acoustical Performance of Cotton Nonwoven Composites

This paper studied acoustical properties of cotton nonwoven composites on two application cases: cotton nonwoven used as a composite base layer and carbonized and activated cotton fiber (ACF) nonwoven used as a composite surface layer. Sound absorption and sound insulation of the cotton nonwoven composites were measured using the Brül & Kjaer impedance tube instrument. The instrumental data were analyzed statistically and compared with other experimental nonwoven composites composed of glassfiber, polypropylene fiber, and ramie. The study concluded that the use of the cotton ACF as a composite surface layer exhibited a greater ability to absorb normal incidence sound waves. The composite with the surface layer of cotton fiber nonwoven also exhibited an enhanced ability of sound insulation. The analysis also revealed that the activated carbon fiber composite with a cotton base layer would be 4.6 times lighter in weight, 14% higher in low-frequency absorption, and 7% higher in high-frequency absorption, in comparison with the composite having a glassfiber surface layer and a polypropylene fiber base layer.