How to avoid dyeing of polyester fabric at high temperature and high pressure?

Part 1. Dye selection

When choosing dyes, the initial uptake rate of several color matching dyes should be similar. In addition, if the initial uptake rate of the selected dyes is high, it is easy to cause stains. Generally speaking, when dyeing polyester with dispersing material, the initial dyeing rate is close, and the initial dyeing rate is slow, the quality is better, and the color matching compatibility is similar. For example, E type for light color, SE type for medium color, XF and SF type for dark color can basically dye the deep, medium and light polyester with good effect.

Part 2. Selection of additives

The dispersant also has a greater influence on the high temperature and high pressure dyeing of polyester, because different dispersants have different HBL values, and the dispersing ability is also different. Because the dyeing temperature of disperse dyes on polyester is 80-100°C, the dispersant is required to have a higher dispersing ability, that is, the HBL value is high, and the cloud point is better than 100°C. The practice of major dyeing factories has proved that anionic dispersants and non-anionic dispersants have a higher cloud point and are ideal dispersants.　　

Part 3. Control of heating rate

The heating rate is also an important factor in the production of colored flowers. After reaching the glass transition temperature of polyester, if the temperature rises too fast, the dye will quickly dye the fiber, forming local dyeing and causing colored flowers and color patches. If the initial dye uptake rate is High, the color is more serious. Therefore, in the dyeing heating process, it can be controlled in three stages with different heating rates.

The first stage is the normal temperature rise to 75°C. In this stage, the disperse dyes will hardly dye the fiber, and a faster heating rate of 2-3°C can be used.

The second stage is 75-110°C. This temperature zone is the fastest stage for dyeing. Slow heating must be used, and it is appropriate to control it at 0.8-1°C.

The third stage is 110-130°C. In this stage, the dyeing will be exhausted, and the heating rate of 1.5-2°C can be used.