How To Use Vat Dye Exhaustion Method

reduction dyestuff Although the exhaustion dyeing method is divided into various methods, it is only a basic condition for each dye, and it is not only a certain condition. So this provides a wider range for color matching, of course dyes of the same kind are the preferred targets. The following is the actual situation of dyes dyed by a, B and C, for example:

(1) reduced orange (9), reduced blue (4) and reduced green (1) in the methylene group. Their dyeing rate at 45min, the relationship between the amount of sodium hydroxide, sodium chloride and temperature, and their coloring rate are shown in Figure 5-1.

As shown in Fig. 5-1, the content of alkali in the bath of reduced orange (9) is relatively high, which is the characteristic of methylene dyeing. If adding a small amount of sodium chloride and using a lower temperature, the impact on the color rate is not significant. Therefore, it can also be applied to B method dyeing. This means that this dye can be used as a complementary color to match the dyes of the B group.

Vat blue (4) is also better to use higher alkali concentration. The influence of temperature on color rendering rate was not very good. The dyeing conditions and the rate of coloring of dyes in the methylene group were significant, but the dye utilization rate was the highest at 40~60 degrees C 5-1. No dye can be added to the reduced blue (4), otherwise the dye will precipitate. Therefore, it can not match colors of dyes in group B and group C.

The effect of reducing green (1) on alkali concentration and temperature is not significant.

(2) the relationship between the temperature of reduction orange (11), reduced orange (18) and reduced black (27) in the B method group was also shown in Figure 5-2.

It can be seen from Figure 5-2. orange (11) it is best to dye in a slightly alkaline condition. The temperature is most suitable at 40~60 C, and the amount of sodium chloride added is 20g/L. The reduction orange (18) had little effect on the alkali content in the bath, and the salt content was satisfactory with 10g/L. Although they belong to group B, the suitable dyeing temperature is 60 C. The reduction of black has little effect on the concentration of alkali and salt in the bath. The most suitable dyeing temperature is 40 C, so it can also be dyed by propane.

(3) the relationship between the coloring rate of reduced yellow (26), reduced orange (1) and reduced red (46) and alkali concentration, salt content and temperature in the propane group are shown in Figure 5-3.

It can be seen from Fig. 5-3 that the reduction yellow (26) only has the best dyeing effect in light alkali. If the lye is too strong and the temperature rises to 60 degrees, the dye will be destroyed, so it can not match with the dyes of the methad group. The reducing orange (1) has no significant influence on the alkali bath, the salt concentration and the temperature in the bath. Therefore, it is not necessary to add the salt amount prescribed by the method. VAT red (46) has the best color in low alkali bath, and is suitable for 20 degree centigrade. When the salt content is increased to 40g/L, it can significantly improve the color rendering rate. If it matches with the dyes of the B method, it will waste the utilization rate of dyes.

Mastering the dyeing properties of common dyes can make them match properly. For example, the reduction green (1), the orange group (18) and the orange (1) of the propane group have no great influence on the alkali concentration and the temperature change. So they can match with a variety of dyes.

In the actual production, a small number of dyes are exceptions. For example, reduced orange (1) is a group of Alfa, but it does not need salt. The reducing blue (30) and reduced red (29) are in the group A, but they should be added with salt when they are dyed.

Fig. 5-3 dyeing conditions and coloring rate of dyes in propylene group

It is necessary to strictly control the temperature, but the reduction violet (9) is an exception. Therefore, it is not suitable for the dyestuffs of the group B and C. Color matching 。