Soaping agent + reducing agent (sodium sulfide or thiourea dioxide) + alkali (caustic soda or soda ash), but many domestic dyeing factories do not use soaping agent.
Soaping agent: non-ionic surface active agent, which is conducive to dissolving and dispersing floating color and preventing re-staining. The commonly used flat addition of O and nonylphenol polyoxyethylene ether Np10 have good effects.
Cationic surfactant: It is especially suitable for completely removing disperse dyes adsorbed in spandex, and significantly improving the color fastness of polyester/spandex dyeing (especially dark) (black nylon staining can reach 4-5)
Reducing agent: Compared with sulphur powder, thiourea dioxide has the advantages of small smell, low dosage and high sustainability (high unit price)
When the fuses are used in an overflow dyeing machine, most of the reducing cleaning liquid will be wasted by the oxygen in the air when sprayed, and the open-width washing can be used less.
Foreign manufacturers have tried to drive away the air in the overflow dyeing machine with nitrogen in advance, and found that it can greatly reduce the amount of insurance powder.