Substitute products for urea in application of reactive dyes to cotton fabrics

During dyeing/printing of cellulosic fibres with reactive dyes, the addition of urea to the pad-liquor or print-paste is recommended and it is considered by textile printers that such addition results in brighter and more level prints. Specific action of urea in continuous dyeing or printing with reactive dyes is highly complex and different opinions have been expressed to explain the results obtained under different conditions of application regarding the role played by ureal .8• Main functions of urea during continuous application of reactive dyes have been found to be the increasing solubility of dye in reaction medium, controlling evaporation of water during drying and swelling of cotton, thereby facilitating the dye-fibre reaction.