Application of Polyester Nonwoven Fabric as AbsorbingMaterial for Wedges in an Anechoic Room

摘要

Polyester nonwoven fabric is promising as a new sound absorbing material. It offers several advantageous points as a next-generation sound absorbing material as follows: (1) Polyester nonwoven fabric does not produce minute particles during or after fabrication. (2) Polyester consistsonly of C, H, and O – no chemical binder is used to produce polyester nonwoven fabric that we used(Kanebo Sepatone; Kanebo Ltd.). For that reason, it is entirely non-toxic. (3) Polyester nonwovenfabric may be recycled from PET bottles. Therefore, it is environmentally friendly. Moreover, theabsorption coefficient is estimated to be good as that of conventional materials such as glass wool.Nevertheless, detailed information on its acoustical characteristics remains unavailable. Therefore, wemeasured the absorption coefficient of polyester nonwoven fabric in the form of a board and a wedge. Results show that the absorption coefficient is as good as that of glass fiber. We produced wedges made of polyester nonwoven fabric to cover all walls of a room (8.7 m W × 8.6 m D × 5.0 m H). The inverse-square law of this anechoic room was measured based on the method specified in ISO 3745. Results show that wedges made of polyester nonwoven fabric provide good absorption characteristics for actual use for anechoic rooms.