Acoustic Performance of Gradient Density Nonwoven Textiles for Sound Absorption

Fei Mo

Article
2025 / Volume 8 / Pages 1107-1123
Received 12 September 2025; Accepted 15 October 2025; Published 26 December 2025
https://doi.org/10.31881/TLR.2025.1107

Abstract
This study presents the design, fabrication, and performance optimization of a high-performance acoustic textile engineered from a nonwoven composite structure, with the aim of enhancing sound absorption in critical acoustic environments. A monolithic composite with a continuous density gradient was fabricated using polyester (PET) staple fibers of two distinct linear densities: 3.3 dtex (3 denier) and 16.7 dtex (15 denier). Hereafter, we use denier consistently, and the abbreviations 3D/15D refer to 3 denier and 15 denier, respectively (conversion: 1 dtex ≈ 0.9 denier). The textile manufacturing process involved industrial carding to form fibrous webs, strategic layering of 100% 15D, a 50/50 blend, and 100% 3D PET webs, followed by mechanical consolidation via a needle-punching process. This technique creates a unique micro-to-macro fibrous architecture, transitioning from a low-density, coarse-fiber sound-incident layer to a high-density, fine-fiber back layer. This engineered structure establishes a gradient in airflow resistance, creating an improved gradient for acoustic impedance and thereby minimizing surface reflection under normal incidence. The influence of key structural parameters, including area density (1,200–1,800 g/m²) and thickness (15–25 mm), was systematically investigated, with the sound absorption coefficient measured according to ASTM E1050. An optimized composite textile (1,600 g/m², 20 mm) demonstrated superior absorption, achieving a Noise Reduction Coefficient (NRC) of 0.75 (based on normal incidence data), significantly outperforming a uniform control sample. This work validates a microstructural engineering strategy for developing advanced functional nonwoven textiles.

Keywords
nonwoven textiles, acoustic properties, needle-punching, polyester fibers