Classification of Acid Dyes According to Dyeing Ch
by : Rahul Sharma
Classification of Acid dyes According to Dyeing Characteristics
Acid Dyes are commonly classified according to their dyeing behaviour, especially in relation to the dyeing pH, their migration ability during and their washing fastness. The molecular weight and the degree of sulphonation of the dye molecule determine these dyeing characteristics. The original classification of this type, based on their behaviour in wool dyeing, is as follows:
- Level dyeing or equalising acid dyes;
- Fast acid dyes;
- Milling acid dyes;
- Super-milling acid dyes.
Milling is the process in which a woollen material is treated, in weakly alkaline solution, with considerable mechanical action to promote felting. Dyes of good fastness to milling are essential to avoid colour bleeding during the process.
