Investigation of factors affecting ozone yellowing in denim products

Abstract The aim of this study was to determine the source of ozone yellowing observed in denim trousers and to identify the most appropriate process flow to minimise it. For this purpose, standard pre‐washing, stone washing, and hypochlorite bleaching processes were applied to denim trousers. Subsequently, the effects of neutralisation type (with peroxide or hydroxylamine sulphate), antiperoxide treatment (with or without), cleaning process (with or without) and the duration of the softening process (0 min, 5 min and 15 min) were examined. In the experimental trials, a total of eight different fabrics were used, four of which were produced from virgin fibres and four from recycled fibres. Accordingly, it was also determined whether fabric type (virgin or recycled) had an effect on ozone yellowing. The inclusion of fabrics containing recycled fibres represents a novel aspect, allowing for the evaluation of fabric type (virgin vs. recycled) on ozone yellowing.