The aim of this research was to investigate the recycling of cotton waste garments by fibre regeneration. Easy care finished cotton fabrics and indigo dyed waste denim garments were successfully purified, dissolved in a suitable solvent and spun into fibres. The physical properties of the resultant fibres were compared with standard lyocell fibres spun from wood pulp and the fibres regenerated from the cotton waste garments exhibited improved mechanical and molecular properties relative to the typical fibres regenerated from wood pulp. Furthermore the results have indicated that a suitable blend of wood pulp and pulp reclaimed form cotton based waste garments can produce fibres with properties that are intermediate to cotton and lyocell fibres. The results suggest an alternative approach to fibre resource management by converting cotton based waste garment through regeneration processing into second lifetime cellulosic fibre. The approach will contribute to the reduction of both economic and environmental impact of waste garments and better management of resources required for production of cotton and synthetic fibres.

Dimethylol dihydroxyethylene urea (DMDHEU)-treated cotton fabrics were treated with alkali or alternatively acid followed by alkali for increasing time periods, and their effectiveness in removing the crosslinking agent was investigated by surface (X-ray photoelectron spectroscopy) analysis, bulk analysis, crease recovery angle performance and solubility in specific solvents. The cellulose yield after the chemical stripping processes was established and the effect of the acid and alkali treatments on the degree of polymerisation of the resultant cellulose determined. Surface and bulk analyses and solubility tests suggested that alkali alone could not remove the DMDHEU from the crease-resist-treated cotton fabric. However, a sequential acid/alkali treatment effectively removed the easy-care finish from the cotton fabric and produced a commercially viable yield of cellulose.

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This paper investigated the supramolecular properties and accessibility of fibres regenerated from cotton-based waste garments and compared to typical lyocell fibres.The supramolecular and accessibility properties of the cotton-based waste garments fibres regenerated from three sources (waste denim garments, easy care finished cotton fabrics and a blend of cotton-based waste garment with wood pulp) were analyzed and compared to the lyocell fibres. The Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) spectroscopy and Wide Angle X-ray Diffraction (WAXD) analyses indicated that the fibres from cotton waste garments had supramolecular properties similar to the typical lyocell fibres. The exception was spun from the cotton pulp reclaimed from easy care treated cotton fabrics and maybe related to increased amorphous cellulose content in its structure. The fibre's accessibility by reagents behaviour correlated well with the supramolecular properties. The results indicate that the waste garment purification process may affect the properties of the pulp and hence the supramolecular properties of the resultant fibres. Further research on the purification and regeneration of fibres from waste garments may lead to the use of cotton waste garments as an alternative feedstock source to the lyocell process.

The wash durability of the easy care finish Dimethylol Dihydroxyethylene Urea (DMDHEU) on cotton fabric under ISO 105 CO6 and CO9 test conditions and extended domestic laundering conditions was investigated by surface and bulk sensitive techniques, in particular X-ray photoelectron spectroscopy, elemental analysis and crease recovery angle performance. The presence of the finish was detected at the fibre surface through the N (1 s) photoelectron signal and saturation of the fibre surface with finish was demonstrated. The stability of the DMDHEU to ISO 105 CO6 and ISO 105 CO9 washing and domestic laundering was investigated and the durability of the DMDHEU finish on cotton demonstrated. The type of cross-linking between the DMDHEU and the cellulosic polymer chains was studied and related to the crease recovery performance. The implications for recycling of the treated fibre via fibre regeneration are discussed.