What is the principle of reduction and cleaning of polyester yarn?

Disperse dye is a kind of non-ionic dye with strong hydrophobicity and simple structure, which exists in the form of single molecule, particle, particle aggregate, etc. After dyeing, the combination of dyes and polyester fibers is full-covered, semi-covered, adsorption, etc., and polyester fabrics need high temperature setting to achieve the effect of clothing wearing. Disperse dyes are vaporized when the temperature exceeds 130 °C. The tendency (sublimation) is easy to cause poor fastness of the fabric.

Reduction cleaning after dyeing is to remove unfixed dyes on fibers and improve the color fastness of yarns or fabrics. The principle of reduction cleaning is to remove unfixed dyes on fibers according to the structural characteristics of disperse dyes.

One is that the ester group, amide group and cyano group in the disperse dye molecule are easily hydrolyzed in high temperature and high pH liquid.

The second is that the azo group in the disperse dye undergoes reductive decomposition in the presence of a reducing agent, and the color group changes or fades.

The third is that the hydroxyl groups in disperse dyes will be ionized under alkaline conditions, resulting in a decrease in the dye uptake rate.

During reduction cleaning, the dyes half-coated on the fibers, the dyes adsorbed on the fibers, and the dyes remaining in the dye liquor are hydrolyzed, decomposed, or ionized in the presence of high temperature, high alkali, and reducing agent, and the chromophore It loses its color and is dissolved in water to be discharged to improve the color fastness of polyester yarn or fabric.

Polyester yarn cleaning agent CY-315 is an environmentally friendly reducing agent. Its reducing potential is lower than that of hydrosulfite, and its ability to capture electrons is slightly greater than that of hydrosulfite, so its reducing ability is slightly stronger than that of hydrosulfite. CY-315 is stored in dry and ventilated place at room temperature. It is an inorganic compound with fairly stable chemical properties. Even if it is dissolved in water at room temperature, it has good stability and will not be hydrolyzed or decomposed. It is a weak inert chemical compound. Taste. Compared with insurance powder, this is the advantage of CY-315. The application process of CY-315 is the same as that of hydrosulfite. Through the following experimental test, compare the cleaning effect of CY-315 polyester yarn and the cleaning effect of hydrosulfite