Composite Sound-Absorbing Materials Using Electrospun PS Fibrous Membranes and Needle-Punched PET Non-Woven Fabrics

: This work addresses the challenge of improving the sound absorption at medium and low frequencies by developing an advanced and low-cost porous composite utilizing the unique properties of PS fibrous membranes. A novel multi-layer hybrid, consisting of sound absorption nonwovens (SAN, 10 mm needle-punched PET nonwovens) and electrospun polystyrene (PS) porous membranes, is developed. The formation and the effect of the porous structure on the sound absorption property are studied. The results show that the surface structure is affected by the solvent, relative humidity and temperature. Furthermore, electrospun PS fibrous membranes have smaller pores and narrower pore size distribution but higher porosity, which have better sound absorption properties. The average sound absorption coefficient of commercial sound absorption PET nonwovens with thickness of 1 cm is 0.188, however, the coefficients of the hybrids are 0.335, 0.343, 0.395 and 0.430 when the sound absorption PET is combined with electrospun PS layer with thickness of 0.4 mm, 0.8 mm, 1.2 mm and 2.0 mm respectively. The average sound absorption coefficient of hybrids with electrospun PS layer with porous surface is 0.468, indicating that the sound absorption of SAN can be significantly improved by composing with electrospun PS layers. Moreover, the porous surface can further improve the sound absorption properties. Therefore, the combination of electrospun membranes with porous structure and needle-punch nonwovens would be an efficient way to improve the sound absorption performance. The composite materials have the advantage of the low cost, light weight and good sound absorption effect, which have a broad prospect in sound absorption fields.