Influence of sea polymer removal on sound absorption behavior of islands-in-the-sea spunbonded nonwovens

Abstract

This work presents the results of efforts focused on the development of relatively lightweight and fibrous acoustic webs. For this objective, nonwoven webs that contain bicomponent filaments with islands-in-the-sea cross sections were produced by spunbonding, which involves the extrusion of sea and island polymer melts through dies, cooling and attenuating the bicomponent filaments by high-velocity air streams. Nylon 6 and polyethylene were used as the island and sea polymers, respectively. Webs were hydroentangled with high-pressure water jets prior to the dissolving process to obtain fiber entanglement. Sea polymer was removed from the spunbonded nonwovens by using a reflux dissolution setup. Weight, thickness, air permeability, pore size and sound absorption coefficients of the nonwoven samples were measured before and after the sea polymer removal. Results demonstrated that sea polymer removal led to further bicomponent filament fibrillation, which affected sound absorption positively. The structure with the higher number of island fibers had better acoustical properties. Lightweight and fibrous acoustic nonwovens can be obtained with the method given in this study.