1. Strengthen the pretreatment of the fabric
The oil or oil stains contained in the fabric have a greater affinity for synthetic fibers such as hydrophobic polyester, so it is not suitable to be washed. Especially during pre-setting, the oil stains penetrated into the fiber, making washing more difficult. Desizing, scouring, bleaching and other pre-treatments to remove impurities and clean the fabric. For some fabrics containing more chemical fiber components such as polyester, when scouring and washing procedures are adopted, highly efficient scouring detergents and washing equipment must be selected. However, the auxiliaries must be washed after washing, otherwise it is easy to form a tar-like substance with the dye and stain the fabric.
2. Strictly prevent dye aggregation
Commonly used dispersants, etc., have a good diffusion and stability effect on the dye in the dye bath during the heating process. However, this diffusion effect tends to decrease with the increase of temperature, and its levelness (comprehensive reaction of slow dyeing, migration and hiding) is also poor, and the color is not bright enough and pure.
The following three points must be paid attention to when using high-temperature levelling agent:
Properly master chemical operation. The cohesion and association of disperse dyes are directly related to factors such as temperature, concentration, time, and additives.
Therefore, the following points should be paid attention to when chemical materials:
To use warm hydration materials below 50℃, the temperature must not be too high. For example, Disperse Scarlet S-3GFL has good dispersing performance below 50°C, but serious association precipitation will occur when it is above 80°C.
Water consumption for chemical materials should be as much as possible. If the bath ratio is too small, the dispersion effect of the dye will often be reduced. Practice shows that 1:10~15 is appropriate.
The dispersant or levelling agent should be fully dissolved in warm water, and there should be no granular or paste.
The chemical material should not be too early, and it is best to use it with the chemical, otherwise, the association tendency of the dye will increase. Regardless of dyes and auxiliaries, they must be filtered with a sieve before use.
3. Avoid and reduce the generation of lakes as much as possible, and the chemical materials should be carried out according to the regulations, and a certain wetting and dispersing agent can also be added to help the dyes to evenly spread without generating lakes.