Natural Dyeing of Wool by Madder (Rubia tinctorum L.) Root Extract Using Tannin-based Biomordants: Colorimetric, Fastness and Tensile Assay

In this work, the natural dyeing behavior of woollen yarn with madder ( Rubia tinctorum L .) root extract was studied. The effects of different tannin-rich plants ( Rhus coriaria , Eucalyptus , Terminalia chebula , Quercus castaneifolia , Pomegranate ) extract as biomordants and alum (as a chemical mordant) with two mordanting procedures (pre- and metamordanting) on color characteristics of the dyed samples were also investigated. The CIEDE2000 values, color strength ( K/S ), washing fastness and tensile property of the mordanted and dyed samples were assessed. Visually, a range of hues from orange to brownish-red were obtained. In general, pre-biomordanted samples with Rhus coriaria (10 %owf), Eucalyptus (10 %owf), Terminalia chebula (5 %owf), Quercus castaneifolia (5 %owf) and Pomegranate (5 %owf) showed almost the same color difference (Δ E 00 ) and wash fastness values compared to those treated with 3 %owf alum. Finally, it was concluded from the comparative studies that the biomordants have good potential to be considered as alternatives to the common chemical mordants.