Sound insulating structure

摘要

The disclosure relates to a sound insulating structure formed on an automobile floor panel on which at least one of a vibration and a sound is incident. This structure includes a covering layer for covering the panel and a cushioning layer for reducing an impact of the at least one of the vibration and the sound. This cushioning layer is interposed between the covering layer and the panel and made of a nonwoven fabric. This nonwoven fabric includes 5-95 wt % of a first fiber and 5-95% of a second fiber, wherein the total amount of the first and second fibers is 100 wt %. This first fiber has a fineness within a range from 1.5 to 40 deniers, a first melting point, and a first portion including polyethylene terephthalate. The second fiber has a fineness within a range from 1.5 to 15 deniers, a core portion, and a sheath portion covering the core portion. A majority of the core portion includes polyethylene terephthalate. The sheath portion includes an elastic copolyester which has a second melting point that is lower than the first melting point and is not higher than 200 DEG C. The elastic copolyester is prepared by copolymerizing polyethylene terephthalate and at least one other monomer. The sound insulating structure has a high sound-transmission-loss factor within a so-called road-noise frequency range and an adequate cushioning effect and is particularly superior in sound insulating at a normal temperature (15 DEG -40 DEG C.).