Abstract
A new sound absorbing material made from 100% softwood
fibres by means of a foam-forming technique is
introduced. In foam forming, a wet foam is created by
mechanically mixing water, fibres and a surfactant. The
air bubbles keep the wet fibres separate, and a highly
porous fibre network is formed during drying. The sound
absorption of foam-formed structures was measured by
means of an impedance tube. The results showed that
foam-formed softwood materials possessed a competitive
sound absorption coefficient compared to different types
of commercial sound absorber materials. The material is
based on 100% softwood fibres without added binders and
is semi-rigid and does not completely recover from
compression. Improvement in the strength properties of
softwood material can be obtained by using starch or
cellulose microfibrils. The material could be used in
indoor applications, for example, in replacing mineral
wool acoustic ceiling panels or polyester non-woven
materials in office acoustics products.
| Original language | English |
|---|---|
| Pages (from-to) | 131-143 |
| Journal | Building Acoustics |
| Volume | 23 |
| Issue number | 3-4 |
| DOIs | |
| Publication status | Published - 2016 |
| MoE publication type | A1 Journal article-refereed |
Keywords
- noise control
- sound absorption
- foam forming
- natural fibre
- organic fibre
- softwood