Thermal insulation and sound absorption properties of poplar blend nonwovens

Poplar fibers, with their prominent hollow lumen structure, demonstrate significant potential as sustainable raw materials for thermal and acoustic insulation applications in various industries such as automotive interiors, construction materials, and technical textiles. Natural fiber-based materials are increasingly valued for their cost-effectiveness, biodegradab ility, and favorable physical properties. This study examines the thermal insulation and sound absorption properties of eco-friendly nonwoven fabrics developed from blends of poplar and hollow polyethylene terephthalate (PET) fibers. Nonwovens were prepared using carding and needle-punching techniques with blend ratios of 0:100, 30:100, and 60:100, coded as PET, PO30, and PO60, respectively. The fabrics were evaluated for air, light, and water vapor permeability, as well as thermal resistance and sound absorption performance. Blended nonwovens exhibited up to 92% lower air permeability and reduced light transmittance compared to 100% PET, while water vapor permeability remained similar. The PO60 fabric demonstrated the highest thermal resistance of 0.1209 K m²/W, an 8% improvement over PET. Sound absorption coefficients, measured via the impedance tube method, showed enhanced performance in mid-to-high frequencies, with maximum values of 0.38, 0.58, and 0.78 at 6300 Hz for PET, PO30, and PO60, respectively. The results confirm that increasing poplar fiber content enhances the thermal and acoustic properties of nonwovens. These properties make poplar-based nonwovens ideal for automotive applications such as noise-dampening panels and seat insulation, construction materials like eco-friendly wall linings and soundproofing systems, and technical textiles for protective apparel in extreme conditions. This work underscores the value of poplar fibers as high-performing and sustainable alternatives for diverse industrial applications.