COLOUR OF CORRIEDALE WOOL AND ITS EFFECT ON DYEING.

The objective of the essay was to study the effect of wool scoured color on the color acquired after dyeing and the interaction between wool yellowness with different light stains in Corriedale wool. According to the value of yellowness index (Y-Z) measured using a Hunterlab spectrophotometer, 5 homogeneous carding webs were prepared (mean Y-Z values of -0.84, 0.74, 2.50, 4.77 and 7.79, respectively). A dyeing procedure was performed using three acid colorant: Blue Erionyl AR, Yellow Erionyl A-3G and Red Erionyl A-3G. Color measurements of dyeing samples using the CIELAB L* a* b* system were carried out. The total color difference (ΔE) of the dyed samples was calculated from L*, a*, b* coordinates. Significant effects (P<0.001) of dye and carding web initial color were found on all color parameters. ΔE values increased with increasing values of initial Y-Z, the yellower the sample was, the higher the ΔE that presented. The position of cut off point in the Y-Z scale from which difficulties in staining were evident, was under 0.74. In conclusion, a difference in color in dyed wool with pastel shades can be visually detected even starting from low values of scoured color, and these differences vary with dyes used.