Color point, color flower
cause:
Excessive or premature addition of salt or soda will cause the dissolved dyes to agglomerate or even precipitate, leading to uniform distribution of the dye on the fabric surface and inside and outside of the fabric, resulting in uneven color, even color, color stains; active yellow sensitive to alkali In the initial period of alkali addition, the color absorption rate is high, and the color is fixed on the side of the absorption edge, and the migration and dyeing properties are poor. Therefore, it is easy to cause uneven absorption and form color flowers.
Responses:
1. Within the range of conventional dyeing depth, the amount of salt should not exceed 70g/L;
2. Adding sequence: add dyeing auxiliaries (water softener, leveling agent) and take it evenly; warm up to 40-50°C, add the dye solution and fully dissolve; add less salt after several batches. Do not add dyes together with salt or add salt first.
3. Suction time must be sufficient, as much as possible to improve the color absorption rate, in order to reduce the alkali concentration before the dye concentration, is conducive to reducing the degree of dye after the addition of alkali.
4. The amount of soda ash should not be less. Because the soda ash has strong buffering ability against pH, its concentration is between 5 and 25 g/L and the pH value is between 11 and 11.2, which is enough to meet the requirements of the dye-fiber bonding reaction. Therefore, as long as the shade of the dyed silk is maintained, the pH of the foot water after dyeing can be maintained at approximately 11. Excessive amount of soda ash will increase the tendency of dye aggregation, and active yellow is particularly prominent.
5. The amount of soda ash must be less than the first time and added in batches. This is very important for the activity of green blue and active bright yellow.
Because the active yellow color has a low color-receiving rate, the concentration of the dye solution is higher before alkali fixation, and the addition of more soda ash can easily cause dye aggregation and cause quality problems. Reactive yellow is sensitive to alkali. In the initial stage of fixing, the more soda ash is added, the faster the coloration is and the easier it is to color flowers.
6. The dyeing bath can be added 1.5 ~ 2g / L of active leveling agent, such as Shanghai Conton spinning leveling agent L-800 or demulsified leveling agent RG133, can make the dye in saline solution The dissolved state is significantly improved. However, the amount should not be more, otherwise it will reduce the dyeing rate.
Color difference, cylinder difference
cause:
Reactive green blue and active bright yellow have different dependencies on the relevant factors of the dyeing process. Therefore, if the relevant factors of the dyeing process are unreasonable or are not carried out according to the dyeing process, it will inevitably lead to instability in the fixation rate of active cyan blue and active yellow, which will lead to fluctuations in the proportion of blue and yellow dyes on the fiber. , produce color or cylinder difference.
Responses:
1. The temperature should be stable at 80 ~ 85 °C. In this temperature range, the color of active cyanine and active yellow is synchronized. the best. Above or below this temperature, the staining reproducibility decreases.
2. The activity of active cyan blue and active yellow is different from that of salt. When the depth of dyeing is around 2% (owf), salt is used. The amount of 50 ~ 60g / L is appropriate. If the amount is too high or too low, the color synchronization of the two will be affected.
3. The concentration of soda directly affects the color fixation rate of active green blue and active yellow (the effect on yellow is greater than that of blue). The amount of soda ash must be strictly controlled, otherwise it will affect the color depth and reduce the color reproduction. Sex.
4. The dyeing bath ratio has different influence on the activity rate of active turquoise blue and active tender yellow (it has a great influence on turquoise blue). The bath ratio should be strictly controlled to ensure the depth of coloration and the stability of shade.
5. The yellow color of active yellow is much lower than that of active green blue, and the second color-receiving rate is much higher than that of active green blue. Therefore, in different dyeing time periods, the shades and shades of the colors are different. In other words, Reactive Blue and Reactive Yellow are highly dependent on the dyeing time and require special attention.
Therefore, on the basis of achieving a color balance in the color-adsorption stage, and then properly holding for a certain period of time, it is not only favorable for level dyeing and transfection, but also is conducive to the stability of color shade. The alkali fixing time should be sufficient to ensure that the active yellow and turquoise blue can achieve a relatively stable maximum color yield. Active turquoise blue is poor in diffusivity, weak in response, and lags behind yellow in color. Therefore, by appropriately increasing the dyeing time, it is possible to reduce the chromatic aberration of colors and cylinder differences.
6. Since the direct activity of active turquoise blue is higher than that of active yellow, and then the washability is relatively poor, it is necessary to strengthen soaping. Weak soaping is not enough or the degree of soaping is not the same, not only will reduce the wet fastness, but also cause a significant cylinder difference.
Poor wet fastness
cause:
The active Cuiras blue has a large molecular weight, lacks a linear structure, and has poor diffusion. Especially in the process of secondary absorption, the adsorption rate of the dye is much higher than the diffusion rate, resulting in the formation of overlapping accumulation of dyes on the fiber surface.
In addition, the reaction of the active turquoise blue is relatively weak, the fixation rate is low, there are many unfixed dyes remaining on the fiber, and the washability is poor, resulting in low wet fastness and poor level dyeing and transfection; due to the activity of bright yellow on alkali The agent is very sensitive. In the initial stage of secondary absorption, the phenomenon of “instantaneous coloration†is serious. In addition, the color is fixed by suction, and the fixed dyes have a certain degree of retardation on the adsorption of the dye on the surface of the fiber without diffusion. Effect, resulting in too much floating color, affecting wet fastness and level dyeing; Active Turquoise Blue and Reactive Brilliant Yellow have poor solubility stability in salt and alkali solutions. Once too much or too early to add salt and soda, it is easy to produce condensation. , Which severely affects the uniform adsorption and uniform diffusion of the dye, excessively early floating color, and decreased color fastness.
Responses:
1. Improve the dissolving state of the dye and prevent the dye in the dye solution from coagulating.
2. Reduce the dye uptake rate during the dyeing process (mainly at the initial stage of alkali addition).
3. Improve the diffusion and dyeing effect of dyes and increase the fixation rate (mainly active turquoise blue).
4. Strengthen soaping after dyeing to reduce the amount of floating dye dyes.
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