| The purpose of this study is to provide a better understanding of acoustical properties of nonwovens, and to model the noise control behavior in terms of material and treatment parameters. A review of existing models on sound absorption of fibrous materials, coupled with experimental data will help in modeling sound absorption in multi-layer needle-punched nonwoven fabrics of different fibers: hemp, polylactide, polypropylene, and glassfiber. The effects of several treatments, which the materials may undergo during sound absorber manufacturing, namely alkalization, compression and heat treatments are investigated. The collected data is evaluated by experts. Expert evaluation further provides information about market demands for sound absorbers, and the perception of the designed nonwovens through the eyes of professionals. This research provides a contribution to the body of knowledge on the sound absorption properties of nonwovens, and provides a better understanding of the effects of some manufacturing processes on nonwovens' noise control performance and contributes to the wider adoption of nonwovens as sound absorbers. |
