A comparative study of textile recycling techniques for dope-dyed cellulosic fibres: Viscose vs. lyocell-based...

The growing volume of textile waste poses a serious environmental concern, primarily due to the dyeing and finishing processes used in textile manufacturing. Much of the resulting waste is either incinerated or landfilled, releasing harmful chemicals into the air, soil, and water. Sustainable textile recycling is therefore crucial; however, existing methods face significant challenges, particularly due to the presence of dyes. Here, we demonstrate a closed-loop recycling strategy for dope-dyed cellulosic fibres using three solvent systems: viscose, N-methylmorpholine N-oxide (NMMO)-Lyocell, and Ioncell. Regenerated cellulose fibres were produced from dope-dyed viscose and compared in terms of processability, molecular integrity, mechanical performance, thermal stability, and colour retention. Among the tested routes, NMMO-Lyocell- and Ioncell processes yielded fibres with superior tenacity (up to ∼ 32 cN/tex) and minimal colour shift (ΔE < 1). In contrast, the viscose process led to partial depolymerisation and reduced strength. The findings establish that dope-dyed cellulosic fibres can be efficiently recycled without re-dyeing or significant loss of mechanical performance, offering a pathway toward circular textile manufacturing and reduced chemical burden in the fibre-dyeing sector.