Closed loop mechanical recyclability of post-consumer waste wool fabrics based on fibre length retention

• Mechanical recycling has little effect on the tensile strength of wool or cashmere fibres. • Initial mean fibre length is negatively correlated to the percentage retained mean fibre length after mechanical recycling. • Mean fibre length after mechanical recycling is close in value to the distance between the feed rollers and opening roller. • Sorting of textile waste and modulation of process settings can be optimised to retain higher fibre length. • A Recycling Index is introduced to estimate how many times wool or cashmere can be recycled in a closed-loop process.