Dyeing method of reactive dyes
Reactive dyes dyeing cotton, the most commonly used dyeing methods: dip-dyeing, in addition to rolling dyes. Dip-dyeing: dip-dyeing can be divided into three dyeing methods: one-bath one-step method, one-bath two-step method and two-bath method.
A: one-bath one-step method: dyeing is carried out in alkaline bath, that is, fixing the color at the same time of dyeing. This method is simple in process, short in dyeing time and convenient in operation. The stability and hydrolysis of dyes in dyeing bath under alkaline conditions.
B: one-bath two-step method: first dye in neutral bath. When dye dyeing is close to equilibrium, alkali agent is added in the dyeing bath, and the PH value is adjusted to fix the PH value. (generally 11) at this time, dye and fiber achieve covalent combination to achieve the purpose of fixing color. One bath two step method is a more reasonable dyeing method in reactive dye dip-dyeing. And has good leveling effect, so cotton knitting dyeing commonly used this method.