Sound insulation materials in the traditional sense are rigid, which are usually dense and bulky, while common porous materials have almost no sound insulation ability. Herein, a fiber-based flexible porous composite is presented as sound insulator fabricated via single-sided coating finishing on the one side of a nonwoven framework and has been demonstrated for high performance noise reduction. The enhanced acoustic insulation is identified to be structure dependent of the area density and microstructure of the sound insulator and the type of filler. The flexible sound insulator exhibits ≈100% enhancement in broadband acoustic insulation over the whole frequency range compared to the bare nonwovens. And the most sound transmission loss (STL) of at the peak is up to 37 dB, which is about 30 times that of bare nonwovens. Furthermore, the novel sound insulator has an admirable dual-gradient structure in which the concentration gradient of coating finishing agent is opposite to the pore gradient. Therefore, sound insulation capacity of the sound insulator exhibits obviously anisotropy according to the incident direction of sound waves. This flexible porous material for broad-band sound insulation has an easy and inexpensive scalable production, demonstrating its great potential for lightweight requirements for specific applications.

传统意义上的隔音材料是刚性的，通常是致密且笨重的，而普通的多孔材料几乎没有隔音能力。本文中，提出了一种基于纤维的柔性多孔复合材料，作为通过在非织造框架的一侧上进行单面涂层精加工而制成的隔音体，并已被证明具有高性能的降噪效果。增强的隔音材料被确定为取决于隔音材料的面积密度和微观结构以及填料类型的结构。与裸露的非织造布相比，柔性隔音材料在整个频率范围内的宽带隔音性能均提高了约100％。峰值处的最大声传输损耗（STL）高达37 dB，约为裸无纺布的30倍。此外，该新型隔音体具有令人赞叹的双梯度结构，其中涂层整理剂的浓度梯度与孔梯度相反。因此，根据声波的入射方向，隔音器的隔音能力表现出明显的各向异性。这种用于宽带隔音的柔性多孔材料具有易于制造，价格低廉的可扩展生产能力，证明了其在满足特定应用的轻量化要求方面的巨大潜力。