Precautions for disperse dye dyeing
2022-05-23
Disperse dyes are often used as a kind of dyes, especially in the textile industry. For some friends who have just come into contact with dyes, they don't know what matters to pay attention to in the dyeing process, which leads to some problems in the dyeing process. Today, let's explain to you the matters needing attention in the dyeing of disperse dyes. Let's have a look.
1. Pay attention to uneven dyeing
The uneven dyeing is mainly related to the ratio of dye flow rate and absorbance. In the stage of cloth color absorption, the liquid flow direction is changed every 8 cycles. Reducing the bath ratio from 1:12 to 1:6 can change the uniformity of the swimming stage, although the unevenness of the initial dyeing is obvious. In combination dyeing, only selecting dyes with similar diffusion properties is not enough to ensure level dyeing.
At this point, mixing is more important than. If the amount of three dyes used in color matching is the same, it is correct to use dyes with the same diffusion performance. However, if the dosage proportion of two dyes is large, and the diffusion of the third dye is lower, otherwise it absorbs faster than the other two dyes, which is easy to cause uneven dyeing.
2. Recrystallization
In the dyeing process, disperse dyes often cause recrystallization particles larger than 1nm due to repeated heating and cooling. When this situation is found, additional dispersant needs to be added to minimize recrystallization.
1. Pay attention to uneven dyeing
The uneven dyeing is mainly related to the ratio of dye flow rate and absorbance. In the stage of cloth color absorption, the liquid flow direction is changed every 8 cycles. Reducing the bath ratio from 1:12 to 1:6 can change the uniformity of the swimming stage, although the unevenness of the initial dyeing is obvious. In combination dyeing, only selecting dyes with similar diffusion properties is not enough to ensure level dyeing.
At this point, mixing is more important than. If the amount of three dyes used in color matching is the same, it is correct to use dyes with the same diffusion performance. However, if the dosage proportion of two dyes is large, and the diffusion of the third dye is lower, otherwise it absorbs faster than the other two dyes, which is easy to cause uneven dyeing.
2. Recrystallization
In the dyeing process, disperse dyes often cause recrystallization particles larger than 1nm due to repeated heating and cooling. When this situation is found, additional dispersant needs to be added to minimize recrystallization.
During dyeing, when the bath temperature is reduced from 130 ℃ to 90 ℃, some dyes will recrystallize, resulting in poor rubbing fastness of dyes, and even blocking the filter of high temperature and high pressure dyeing machine.
