Disperse Emerald Blue S-GL dyeing “discoloration”
“Color flowers, color difference, color For printing and dyeing factories, “traces” are the most troublesome thing that cannot be dealt with every day, especially Yanlan and Cuilan, which are the natural enemies of dyeing masters! Today I will give you a detailed introduction to the influencing factors of Cuilan in polyester dyeing. I believe it will be of great help to improve the first-time OK rate and reduce repairs.
Dispersed 60# Emerald Blue S-GL is a high-temperature dye with a macromolecule anthraquinone structure
Factors that should be considered when dyeing:
 Select simultaneous high-temperature dyes, and try to avoid incompatibility of non-high-temperature dyes in the dyeing formula.
 Cuilan is very sensitive to pH value. The amount of acetic acid should not be less. Ensure that the dyeing pH value is controlled between 4 and 5.5 before and after dyeing. If necessary, add pH sliding agent.
 The key factor affecting the dyeing stability of Cuilan is the high-temperature leveling agent, which has an excellent retarding effect, but the amount should not be too much, otherwise the color will change. Shallow, salt-resistant leveling agent will be better (mainly because the recycled water has a high salt content).
 During the production of dyes, a large amount of diffusion agents, anti-settling agents and other additives are added, which are sensitive to water quality. Calcium and magnesium ions in the water easily combine with dyes to produce color spots, especially It is iron ions that have the greatest impact. Chelating dispersants must be added, which is good for the color purity and brilliance of the cloth surface.
 The glass transition temperature of polyester is as low as 70-80°C. After reaching 80°C, disperse dyes begin to dye, and the dyeing speeds up at 90°, with 110° being the fastest! At this time, it is easiest to control the temperature rise rate within 1°C/min; it is best to keep the temperature for ten minutes at 90°C, 110°C, and 120°C. For high-temperature S-GL dyeing, the dyeing temperature should be increased to 135°C. The dyeing properties are the best, the dyeing is even, the discoloration is small, and the fastness is good!
 Disperse dye dyeing on polyester is different from other dyes. It is prone to sublimation and thermal migration, which affects color fastness and color change. During finishing, the setting temperature cannot be Too high is best around 160℃.
 Domestic one-component dispersed emerald blue S-GL has a relatively large molecular weight. Ordinary dispersed leveling agents have dispersing properties at medium and low temperatures, but may not be effective at high temperatures. The cloud point problem will be weakly positive, and the dispersion performance will be basically lost, which will cause the dye molecules to agglomerate and become larger, and the leveling power will decrease, resulting in colored flowers and stains. Be sure to choose a special leveling agent; the dye is recommended to use two-component emerald blue leveling dye. Well, domestic BGE emerald blue and imported emerald blue from DyStar and Huntsman.
 Analysis of the causes of yellowish and dark dyeing:
ØThe dyeing pH value is unstable, and as the dyeing temperature increases, the alkali The pH of the precipitation of chemical substances tends to be moderately alkaline.
ØReducing substances such as sodium lignosulfonate in the dye and formic acid or citric acid in the dye liquor have a great influence on the discoloration of Cuilan. It is best to add dye resist Salt S.
ØIt is recommended to avoid reused water if you are sensitive to green orchid green. When dyeing, the color will turn green and dark when exposed to iron ions. The color will also change slightly when exposed to copper ions. It absorbs the most Wavelength (λmax) 670nm, add chelating dispersant to reduce color change.
ØSet at as low a temperature as possible within the fabric requirements! </p