Mechanical recycling and industrial reintegration of post-industrial stretch textile waste

Abstract

Elastane-containing textiles represent a challenging post-industrial textile waste stream for mechanical recycling because residual elastomeric filaments may contribute to fibre entanglement, persistent yarn fragments and heterogeneous fibre assemblies. This study screened mechanical recycling routes for a post-industrial textile waste composed of 68 wt% polyester, 29 wt% viscose and 3 wt% elastane, and then assessed industrial reintegration of selected fibre fraction. Among the evaluated configurations in a single laboratory trial, an alternating shredding–carding–shredding–carding (SCSC) sequence with TechSpin CT2 met the predefined visual-opening criterion provided the highest mean fibre length among the SCSC conditions (17.6 mm; SD 4.81 mm) The selected route yielded approximately 68% useable fibrous material. The recovered fibres were incorporated at 47.5 wt% ring-spun yarn with a tenacity of 16.5 cN/tex. Relative to the available virgin-yarn reference, tenacity was approximately 25% lower and mass irregularity and imperfections were higher. The yarn was nevertheless converted into four woven fabric variants under industrial conditions, demonstrating manufacturability within the tested route rather than equivalence to a virgin-fibre system. A screening-level gate-to-gate hotspot assessment of the laboratory fibre recovery stage estimated 4.1–4.3 kg CO2-eq per kg of useable recycled fibre. This estimate is not a full life cycle assessment and is not suitable for direct comparison with virgin fibres. These findings establish a proof of technical reintegration for this specific waste stream, but the absence of independently replicated recycling trials, an elastane free control and an equivalent virgin fabric, limits causal and comparative interpretation.