Technology Of Reactive Dye Combined With Dicyandiamide For Fixing Color

In order to study

As a catalyst, the influence of the amount of 100g sodium bicarbonate on the printing performance of reactive / neutral dyes was changed. The mass fraction of dicyandiamide was changed to 0.5, 1, 2 and 3% respectively, and the printed cotton knitted fabric was printed after pretreatment.

Effect of mass fraction of catalyst on printing properties of reactive / neutral dyes in the same paste.

When the dicyandiamide catalyst was not added, the color depth of printing was only 74.3%; when the mass fraction of dicyandiamide was 0.5%, the color depth of printed fabric increased to 85.6%; however, with the further increase of catalyst mass fraction, the color depth of printing increased, but the range of raising was smaller.

When the mass fraction of dicyandiamide reaches 3%, the color depth of printing will even decrease. The reason for it needs further study.

Fig. 1 shows that the dicyandiamide catalyst does have a clear fixation effect on printing of reactive dyes under weak alkaline conditions.

In practical application, the catalyst mass fraction is 0.5%~1.0%.

The effect of 2.2 alkali agents on printing properties is that the reactive dyes can react with hydroxyl groups on cellulose fibers to form covalent bonds under alkaline conditions. Therefore, when the mass fraction of dicyandiamide is 1%, the mass fraction of alkali agents is 0.5%, 1%, 2% and 3% respectively. The influence of alkali mass fraction on printing properties is systematically studied.

In the absence of an alkali agent,

The color depth is only 52.8%. added 0.5% alkali agent, the color yield is obviously improved, the alkali agent has great influence on the dyeing performance of reactive dye printing. When the alkali agent mass fraction reaches 1%, the color yield is close to 90%. However, the quality of the alkali agent continues to increase, and the color yield has no obvious improvement. When the mass fraction reaches 3%, the color yield decreases.

Therefore, taking into account that the mass fraction of alkali is too common to affect the dye uptake of neutral dyes, the dosage of alkali agent is 1%.

2.3 effect of steaming time on printing performance.

In the process of fabric printing, the steaming time has a very important effect on the printing performance. Therefore, under other conditions, when the mass fraction of dicyandiamide is 1% and sodium bicarbonate is 1%, the 10,15,20min. is activated in 101~102 / C, and the K/S value and the amount of color increase are increased with the extension of time.

When the 20min is steamed, the dye uptake rate has reached 91.6%. Taking into account that the steaming time is too long, the efficiency will be affected. Therefore, the 20min of the reactive / neutral catalytic printing is suitable.

Fixing effect of neutral dyes.

The printing fabric was dyed with reactive dye M-3R2.5%, reactive dye M-3BE3.0%, reactive dye M-2GE1.5%, neutral yellow 0.1% and neutral brown 0.5%. The printing fabric was fixed with different concentration of fixing agent RFC. The effect of fixing agent concentration on the color fastness of printing fabric was studied.

For wet rubbing fastness, even if there is no fixing agent, it can reach more than 4. When the mass concentration of fixing agent RFC reaches 20g/L, the wet rubbing fastness reaches 4~5 level.

The printing fabric processed by this process has good wet rubbing fastness.

The fixing agent RFC has obvious effect on cotton color fastness, color fastness and color fastness.

Use

Neutral dye combined with dicyandiamide catalyzed fixation technology can obviously improve the color depth of printing, and reduce the dosage of alkali agent. Under weak alkaline conditions, reactive dyes can be used to dye cotton in the fabric without affecting neutral dye's dyeing on brocade and achieving good printing effect.

Reactive / neutral dyes with the same slurry catalytic printing technology for cotton brocade printing, the suitable conditions are: catalyst (dicyandiamide) 0.5%~1.0%, alkali agent 1%, steaming time 20min, and the wet rubbing fastness of printed fabric can reach 4 grade.

The wet rubbing fastness and color fastness of fixing agent RFC were improved when finishing printing fabric.