Be sure to understand the 10 key issues in reactive dye dyeing operations
1Why is it required to use a small amount of cold water to mix the slurry before mixing, and the mixing temperature cannot be too high?
Use a small amount of cold water to mix the slurry first to make the dye easily and fully wet. If you pour the dye directly into the water, the outer layer of the dye will form a gel and wrap the dye particles, making it difficult to wet the inside of the dye particles. It is difficult to dissolve, so you should first mix it with a small amount of cold water and then use hot water to dissolve it.
If the temperature of the chemical material is too high, it will cause hydrolysis of the dye and reduce the dye fixation rate.
2Why should you add materials slowly and evenly?
This is mainly to prevent the dye from dyeing too fast. If the dye is added quickly at one time, the dyeing speed will be too fast, which will make the outer layer of the fiber dark and the inner layer shallow, which will easily cause stains or streaks.
3Why do you need to dye for a certain time after adding the dye (for example: 10min) Start adding salt at the rear?
Salt is a dye accelerator. When the dye reaches a certain level, it has reached saturation and it is difficult to continue dyeing. Adding salt is to break this balance, but it will take about 10-15 minutes before adding salt to promote dyeing. The dye can be fully penetrated and evenly penetrated for a certain period of time, otherwise it will easily cause stripes and color flowers.
4Why should salt be added in batches?
The purpose of adding salt in stages is to promote dyeing evenly, so as not to promote dyeing too quickly and cause color blooming.
5Why does it take a certain period of time (such as 20 minutes) to solidify after adding salt? Color.
There are two main reasons: A. to allow the salt to melt evenly in the tank and fully promote dyeing; B. to allow the dyeing to enter the saturation state and reach equilibrium, and then add alkali to fix the color to achieve a high Dyeing amount.
6Why does adding alkali become “fixed color”?
Adding salt to reactive dyes can only promote dyeing, but adding alkali will stimulate the activity of reactive dyes, causing the dye and fiber to react (chemical reaction) under alkaline conditions, thereby fixing the dye on the fiber, so it is called “Color fixation” is also due to the chemical reaction of this kind of color fixation, achieving higher fastness. Once solidified, the color print will be difficult to achieve evenly.
7Why should the alkali be added in stages?
The purpose of adding it in batches is to make the color fixation uniform and prevent color blooming.
If added at one time, it will easily cause excessive concentration of local residual liquid and accelerated fiber reaction, which will easily cause color blooming.
8Why must the steam be turned off first when adding materials?
(1) The purpose of turning off the steam before adding ingredients is to reduce the stripe difference and prevent color blooming.
(2) When the temperature on both sides of the controlled cylinder rises above 3℃, the coloring will be affected. If the temperature exceeds 5℃, stripes will appear. If the temperature exceeds 10℃, it will stop
(3) The machine is undergoing maintenance.
(4) Someone has tested that the temperature in the cylinder is basically uniform before and after the cylinder is turned for 10-15 minutes after steaming, and is equal to the surface temperature, so when adding materials, whether H202 is added during chlorine boiling or coloring Domestic dyes, salts, and soda ash should be turned off before adding materials.
9Why ensure the process holding time after adding alkali?
The holding time should be calculated after adding alkali and when the temperature rises to the process holding temperature. Only by cutting the boards according to the process holding time can the quality be guaranteed, because the holding time is determined based on the certain amount of dye required. The laboratory that determines how long the reaction takes will also proof the sample at this time.
10Several kinds of shearing that do not follow the process regulations cause unstable quality.
(1) The time has not yet reached the “right” color shear board.
Due to plate making problems, material weighing problems, cloth weight and liquor ratio, etc., problems will cause color deviations. If the color is “corrected” before the time is up, this abnormal situation should be reported to the squad leader or craftsman, no matter what , shortening the process and holding time, the dye reaction is not sufficient, the color does not change, the dyeing is uneven, there is no fullness, and the fastness is also a problem.
(2) The board is cut early and the replenishment is inaccurate.
Dyeing can only be stable when the process heat preservation time is reached. The earlier the cutting time, the greater the change and the more unstable. If the cutting time is not up, (after boiling, scouring, washing, and blow-drying Send it to the craftsman for color inspection. Between the time of placing the order and weighing the materials, the actual heat preservation time of the vat cloth has been extended. At this time, the dyeing has also increased. After adding the supplementary material, the vat cloth is too dark and needs to be lightened again. .)
(3) Extending the time to cut the board is of no benefit.
After the insulator is cut, the dye reaction has ended, and it is useless to dye it again. Instead, some of the dye that has been dyed will be re-hydrolyzed.
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AAAThe stained dye is re-hydrolyzed.
AAADFWGREGTR
Disclaimer:
Disclaimer: Some of the texts, pictures, audios, and videos of some articles published on this site are from the Internet and do not represent the views of this site. The copyrights belong to the original authors. If you find that the information reproduced on this website infringes upon your rights, please contact us and we will change or delete it as soon as possible.
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