Perpetual colour: accessing the colourfastness of regenerated cellulose fibres from coloured cotton waste

In this work, waste cotton fabrics were chemically recycled to produce regenerated fibres, which retained the colour of the waste fabric. The colourfastness of the recycled fibres was measured and found to show no deterioration. The once-recylced fibres were subsequently recycled again through a similar approach, and some loss in colour intensity was noted in the twice-recycled fibres. However, the colourfastness of the twice-recycled fibres remained excellent. Finally, new colours were created via blending waste fabrics of different colours, a unique advantage achievable via a chemical recycling approach. Again, the colourfastness of the new blended colours was shown to be excellent. This work showed that the colourfastness and intensity of colour maintained for cotton fabrics, which had undergone a chemical recycling process twice.