Basic dyeing of disperse dyes

First, disperse dyes basic dyeing:
When disperse dyes dye conventional polyester, the general dye bath is controlled in the acidic (pH value is 5 ~ 6). Because of the acidic conditions of dyeing, most disperse dyes have the most pure color light and higher dyeing rate. However, polyester artificial silk fabric must be treated by alkali reduction to produce pits on the fiber surface, which can make the feel soft, gloss, drape, etc., further improve, but the fabric after alkali reduction is still inevitably alkaline, so there is a disperse dye alkaline dyeing method. Disperse dyes that can be dyed in an alkaline bath are called disperse dyes for basic dyeing.

Second, the advantages of disperse dyes basic dyeing:
The basic dyeing method has the advantages of effectively removing oligomers, shortening dyeing time, stabilizing color light and saving energy.

1, can further improve the scouring effect:

Because there are more oils on the synthetic fiber, it is difficult to completely remove the remaining oils and slurps by the existing scouring method, so it is easy to cause uneven dyeing and even colored stains. While the dyeing bath is alkaline in the alkaline dyeing process, the alkaline levelling agent is added at the same time, which has the effect of removing oil and desizing, and can effectively improve the problem of insufficient washing in the pre-treatment process. It is beneficial to the rationality and simplification of dyeing process.

2, can prevent alkali reduction dispersion residue reattachment:

Synthetic fiber fabric to get a soft feel, high quality, the use of intermittent alkali reduction is a more ideal method, but its decomposition, caustic soda and other difficult to be completely washed, resulting in the concentration of dispersion residue in the working liquid is getting higher and higher, if in the acid bath dyeing, the dispersion residue is easy to dip back to cause color flowers, and in the alkaline bath dyeing, the decomposition residue can be dissolved in the dye bath. Thus, the re-adhesion of alkali decrement dispersion residue can be prevented.

3, can prevent the condensation of oligomers:

There are some cyclic straight chain oligomers in polyester, which transfer to the fiber surface, fall off into the dyeing bath, and stick to the fabric or cylinder body easily. In the alkaline dye bath, because the oligomer can dissolve in the alkaline solution, it will not cause the quality problem of dyeing.

4, can improve the quality of dyeing products and dyeing reproducibility:

When dyeing under acidic conditions, the surface of polyester fabric has a rough feeling, while under alkaline conditions there is a sense of lubrication, so when dyeing in alkaline bath, it can reduce the problems such as wrinkles, scrapes, scratches and so on that are easy to appear in acidic dyeing bath, and it can also give dyed fabric a soft feel, thereby improving the quality of dyed products. The application of alkaline levelling agent has an excellent buffering ability to the pH value in the dyeing bath, so that the pH value is basically the same before and after dyeing, which is conducive to reducing the cylinder difference and improving the reproducibility of dyeing.

Third, the disadvantages of disperse dyes basic dyeing:
Because the structure of conventional disperse dyes contains ester group, acyl amino group, cyanide group, etc., it is easy to hydrolyze the dyes under neutral or alkaline conditions, resulting in the change of dye light and the loss of dye strength. Therefore, dyeing under alkaline conditions requires screening of dyes.

4. Disperse dyes that can be used for alkaline dyeing:
1. Dianix AC-E of DESstar Company should choose alkaline stabilizer JPH95 when used, the stabilizer has good buffering, can make the dyeing bath always maintain a pH value of 9.5±0.5 during the dyeing process, and has excellent chelation and masking metal ions, which can effectively protect the dye to prevent decomposition. Can dissolve oligomers in polyester

2. Kayalon polyester Yellow E-3GL, orange E-2GL, red E-2GL and blue E-BR are suitable for light medium color dyeing. Kayalon polyester Yellow Brown 3RL 200, Kayalon polyester Ruby 3GL-S, Kayalon polyester Blue 2R-SF, suitable for medium and dark color dyeing.

3. Japan Sumitomo Public School Company Sumikaron Yellow SR, red E-3BR, blue E-R and Japan Mitsui East Asia Miketon polyester MQ series disperse dyes can also be used for basic dyeing, these dyes mainly include anthraquinone and heterocyclic type.

The K/S value of the above dyes is above 95%, and the color difference can reach 4 ~ 5.