The alkaline dyeing method has the advantages of effectively removing oligomers, shortening the dyeing time, color stability and energy saving.
1. Can further improve the refining effect:
Because there are more oils on the synthetic fiber, it is difficult to completely remove the remaining oils, slurries, etc. with the existing refining methods, so it is easy to cause uneven dyeing or even colored flowers, and the dyeing bath is alkaline during alkaline dyeing At the same time, the basic leveling agent is added, which also has the effect of degreasing and desizing, which can effectively improve the problem of insufficient washing in the pretreatment process, which is conducive to the rationality and simplification of the dyeing process.
2. It can prevent the re-adhesion of the residue of alkali-reduced dispersion:
If you want to get a soft feel and high quality for synthetic fiber fabrics, it is more ideal to use intermittent alkali reduction, but its decomposition products, caustic soda, etc. are difficult to be washed completely, resulting in the increasing concentration of residues in the working fluid. The higher, if dyed in an acid bath, the residue of the dispersion is easy to re-stain and cause color flowers, and when dyeing in an alkaline bath, the residue of its decomposition products can be dissolved in the dye bath, which can prevent the alkali from reducing the residue of the dispersion Attached again.
3. It can prevent the coagulation of oligomers:
There are some cyclic linear oligomers in polyester. These oligomers transfer to the surface of the fiber during dyeing and fall off into the dyeing bath, which is easy to coagulate and adhere to the fabric or cylinder; while in the alkaline dyeing bath, due to the low The polymer is soluble in alkaline solutions and does not cause dyeing quality problems.
4. It can improve the quality of dyed products and the reproducibility of dyeing:
When dyeing under acidic conditions, the surface of the polyester fabric has a rough feeling, and under alkaline conditions it has a lubricating feeling, so when dyeing in an alkaline bath, it is possible to reduce wrinkles, which are likely to occur in the acid dyeing bath. Scratches, scratches, etc., and it can also give the dyed fabric a soft hand, thereby improving the quality of the dyed product. At the same time, the application of alkaline leveling agent has an excellent buffering ability to the pH value in the dyeing bath, so that the dyeing After the pH value is basically the same, it is helpful to reduce the cylinder difference and improve the reproducibility of dyeing.