Cationic applications for union dyeing wool/cotton blends

Wool/cotton blends pretreated with biguanide for union dyeing have poor colorfastness to laundering and wet crocking, this limiting use for outerwear. Wool/cotton blends showed no increase in K/S above 0.266 g biguanide/100 mL. Aftertreating these fabrics with a cationic fixative gave higher K/S va lues for cotton but lower values for wool and for the blends, improved color stability to laundering but lower colorfastness to crocking. Alternatively, fabrics treated with resins and choline chloride and subsequently dyed with neutral metallized dyes produced union and level shades with high K/S values. The colorfastness was excellent for laundering and moderate to good for wet crocking, thus overcoming biguanide limitations.