2010 Volume 34 Issue 4 Pages 317-324
Nonwoven polyester sound absorption materials are environmentally friendly, practical for working conditions, recyclable, and highly durable. For these reasons, they now are finding wide use in traffic systems such as railcars and automobiles, etc. In this study, we first focused on airflow resistance in surface layers to make progress the sound absorption characteristics of the frequency band at 500 Hz-2 kHz and improve those of high frequency band, by laying nonwoven polyester spunbond sheets at the surface of the based material. This proved effective in obtaining better sound absorption characteristics, as we could reduce the thickness of the absorption material by 25%. Our second aim was to find the correlation between thickness, airflow resistance, frequency, and sound absorption characteristics, as these parameters determine the effectiveness of porous sound absorption materials.
