Rethinking the design of upholstered seating from a circular and acoustics-conscious perspective

The study presents a sustainable strategy to mitigate the environmental impacts of textile industry waste by converting them into innovative raw materials for the furniture sector, preventing landfill disposal. The approach involves replacing conventional polyurethane foam in armchair padding with nonwoven made from thermo-bonded fibers derived from pre-consumer textile waste of varied compositions (i.e., cotton, wool, synthetic). As well as the environmental outcomes, the research aims to provide a seat with excellent acoustic performance to enhance indoor comfort. Comprehensive acoustic and microstructural characterizations (i.e., normal incidence sound absorption, open porosity, pore size distribution, specific surface area and airflow resistivity) were performed on both the nonwoven textile waste and polyurethane foam before assembling and testing full seat prototypes. The fibrous matrix showed lower air permeable than the foamy one, with a reduced pore volume concentrated in micropores and mesopores. However, the greater specific surface area of the nonwoven textile led to higher normal incidence absorption, with differences up to 0.2 compared to polyurethane. These results affected the acoustic performance of the textile seat which exhibited a greater sound absorption area then the polyurethane seat, with differences up to 0.5 m² in the frequency range between 315 and 800 Hz. Further analysis combining nonwoven materials with eco-leather and fabric layers, highlighted the importance of using sound-transparent coverings to maximize acoustic performance. Life cycle assessment emphasized the sustainability of using nonwoven textile waste, showing reduced impacts on all categories. Transportation scenarios were also evaluated to minimize the environmental footprint associated with material logistics.