When dyeing a fiber material with a reactive dye, adding urea to the pad or slurry results in a better printing effect. As a dye thickener, a hydrotrope.
Function: increase the solubility of the dye in the reaction medium (increased solubility of a large amount of dye in a small amount of water), control the evaporation of water during the drying process and the swelling of cotton, slow down the drying process, thereby promoting the reaction of dyes and fibers, allowing the dye to have More time reacts with the fibers and produces a deeper hue that enhances the brightness and strength of the dye used. It retains moisture even when dry and increases the color of the dye during the stationary phase. Urea can be used together with thickeners for screen printing, painting or direct dye applications. Urea helps the dye penetrate the fabric. Moisture is an important part of these dyes and chemical reactions, and urea helps to absorb water into the chemical reaction.