Physical properties of cellulose sound absorbers produced using recycled paper

Cellulose products made from recycled paper can be utilized as sound absorbing and insulation materials. Cellulose is a sound absorbing material composed of paper, and is thus environmentally friendly and recyclable. In this study, the physical properties of a sound absorber produced using cellulose were investigated. The investigated properties were proof against climate, color change, thermal conductivity, and NRC (noise reduction coefficient). To obtain adequate NRC for the cellulose sound absorber, porous cellulose materials were foamed. Cell size distribution results showed that the most common size range for the cells was 10–25 μm, followed by 25–50 μm. Thermal conductivity of the cellulose sound absorber with a density of 55 kg/m3 was measured to be 0.039 W/m K. Further, NRC of the absorber with a density of 36 kg/m3 and a thickness of 60 mm was measured to be 0.75.