چكيده لاتين :
Wool and nylon 6 knitted fabrics were dyed using three commercial direct dyes which are suitable for nylon and wool fabrics. The dyed samples were aftertreated, using two different syntans and full backtan. When all dyeings were subjected to two consecutive ISO C06 wash tests, it was found that all aftertreatments
provided an improvement on wash fastness. However aftertreatment of the dyeing
using full backtan, improved wash fastness to the greater extent than commercial and synthesized syntans. This improvement for C.1. Direct Yellow 12 is higher, since this dye belongs to class A, which has low wash fastness property; thus, the full backtan
in this case is more effective. Although the full backtan is effective in improving the wash fastness of direct dyes on nylon 6 and wool, but, the aftertreatment is rarely used owing to the toxicity of potassium antimony tartarate because it can impair the handle and the light fastness of dyeing as well as impart a shade change in dyeing. An aftertreatment with a syntan has mostly replaced the full backtan as a means of improving the wash fastness of direct dyes on nylon 6 and wool. Syntans offer the advantage of being applied in single stage process and do not suffer from the disadvantage
displayed by their natural counterpart, however it is generally accepted that an aftertreatment with a syntan is not as effective as an aftertreatment with the full backtan.
