NON-WOVEN FABRIC FOR SOUND ABSORBING MATERIAL, SOUND ABSORBING MATERIAL, AND MANUFACTURING METHOD OF NON-WOVEN FABRIC FOR SOUND ABSORBING MATERIAL

To provide a non-woven fabric for sound absorbing material, the sound absorbing material having excellent sound absorbing performance in a low frequency region and a high frequency region, excellent productivity, and excellent quality as well, and a manufacturing method of the non-woven fabric for the sound absorbing material.SOLUTION: A non-woven fabric for sound absorbing material of the present invention contains staple fibers A having a fineness of 0.4 to 0.9 dtex in the amount of 30 to 80 mass%, and contains a staple fiber B having a fineness of 1.1 to 20.0 dtex and a flat cross section with flatness of 2.0 to 4.0 in the amount of 20 to 70 mass%, and a passage coefficient of the staple fiber A shown in the following formula (1) falls within the range of 15 to 260. The passing coefficient=(fineness×strength×√elongation×√number of crimps×√crimp degree)/(fiber length) (1), where .SELECTED DRAWING: Figure 1 【課題】本発明は、低周波領域と高周波域の吸音性能に優れ、生産性に優れるとともに、品位にも優れた吸音材用不織布、吸音材および吸音材用不織布の製造方法を提供することを課題とする。【解決手段】本発明の吸音材用不織布は、繊度が０．４～０．９ｄｔｅｘの短繊維Ａを３０～８０質量％含有し、繊度が１．１～２０．０ｄｔｅｘ、扁平度が２．０～４．０の扁平断面を有する短繊維Ｂを２０～７０質量％含有し、前記短繊維Ａの下記の式（１）に示す通過係数は１５～２６０の範囲内である。通過係数＝（繊度×強度×√伸度×√捲縮数×√捲縮度）／（繊維長） （１）＜繊度（ｄｔｅｘ）、強度（ｃＮ／ｄｔｅｘ）、伸度（％）、捲縮数（山／２５ｍｍ）、捲縮度（％）、繊維長（ｃｍ）＞【選択図】図１