What is the cause of polyester dyeing stains？

1. The choice of additives

The emulsification stability of the bulking agent is not good, oily matter will precipitate at high temperature, and the dye will condense and appear color points. The oil stains on the fabric have not been cleaned up, and the bulking agent is released during dyeing, and the dye is condensed. It is recommended to add a high temperature resistant dispersant.

2. Uneven chemical materials and defoamers are generated after high temperature generates oil points

The dyestuff is not homogenized and filtered directly into the dyeing machine; when the temperature of the grey cloth in the dyeing vat reaches 80℃, it will foam the hanging cloth, and the defoaming agent will be produced when the operating temperature is too high.

3. Improper control of dyeing heating speed

Some dyes have poor dispersibility and improper dyeing temperature control. Too fast will cause dye spots; dispersant or penetrating agent is not resistant to high temperature and cause secondary separation of dyes to form dye spots; some additives need to be added separately (high solid content) when adding additives (high solid content), not operating as required Suspended dots are combined with dyes to form dye dots; some color dots are very small and present a dot-like distribution and can only be found by careful observation, and are different from the color light of dyeing cloth. That's because the dye itself contains insoluble substances, and the dispersion of these dyes is destroyed during the manufacturing process and cannot enter the fiber. This situation mostly occurs in light-colored or brilliant-colored systems; the diffusion effect of red dyes may not be good, and a diffusing agent needs to be added to solve it.

If a leveling agent is added to the dyeing list, but a dispersant is not added, the dispersibility is insufficient, the dyes will aggregate, and color spots will be produced.