The Influence of Durable Press Finishing on Shade Changes of Dyed Cellulose Fabric

Summary

Possible applications of polycarboxylic acids (PCA) for textile finishing processes have already been subject of investigation for some years and few of them are in commercial use nowadays. Their perspective is greatest for creaseproof finishing but further investigations have been undertaken for their usage in the field of flame retardancy and antimicrobal finishing as well.
The influence of chosen PCA and its catalyst on shade changes of cotton material dyed with different reactive dyes is spectrophotometrically determined in the investigations described here. Fabrics treated are cured employing two completely different technologies. One is conventional curing, and it is compared with the new and innovative microwave treatment performed at laboratory as well as on industrial planar machines.
Shade changes are more pronounced, in the case of all reactive dyes applied, when the usual quantity of Sodium hypophosphite monohydrate (SHP) catalyst is applied. Minimal shade changes are obtained with citric acid, especially when a second catalyst is applied, because of decreased well-known reducing influence of hypophosphyte catalyst. It is as well determined, that the ratio of CA in a BTCA/CA mixture has a significant influence on shade changes, and it is recommendable not to use higher ratio than 1/1 BTCA/CA.
The results of wrinkle recovery angles of dyed and cured material confirm the assumption of lower cellulose affinity after the dyeing process for further estherification reaction with PCA carboxylic groups, which is more pronounced with higher dyestuff concentrations.

This paper was first published on the earlier Egytex website. The text above is the summary that was published there.