What are the performance of reactive dyes

1. dissolved

Quality activated dye products are well used in good water solution. The concentration of the solubility and the preparation of the dyeing solution is related to the selected bath ratio, the amount of electrolyte, the dyeing temperature, and the amount of urea. The solubility of active dyes is very different. See each theory. The solubility listed refers to the range allowed during the application of the dye. Active dye applied to printed or rolled dyes should be selected with a variety with a solubility of about 100 grams / liter. It is required that the dye is completely dissolved, no turbidity, no color points. Thermal water can accelerate dissolution, and urea has a soluble effect, and electrolytes such as salt and Yuanming powder will reduce the solubility of dyes. When the active dye is dissolved, the alkali agent should not be added at the same time to prevent hydrolysis of the dye.

The measurement method of active dye solubility has a vacuum filtration method, spectrophotia and filter paper spots. The filter paper spots are easy to operate, suitable for the actual use of the factory. During the measurement, first prepare a series of different concentrations of dye solutions, stir at room temperature (20 ° C) for 10 minutes to fully dissolve the dye. Use a 1 ml -scale fluid tube to reach into the middle of the test solution, stirring and sucking three times while stirring. Then draw the 0.5 ml test solution, drop it vertically on the filter paper on the cup mouth, and repeat it once. After drying, the test solution seepage ring, the previous concentration of the previous gear without obvious spots as the solubility of the dye, is represented by grams / liters. Some active dye solutions, which shows the turbid colloidal solution after cooling, can be penetrated evenly on the filter paper, and the spots are not used. It does not prevent normal use.

2. diffusion

Prowment refers to the ability of dye to move inside the fiber, and the temperature has the diffusion of geological dye molecules. Dyes with large diffusion coefficients, high response rates and color fixing efficiency, and the degree of dyeing and permeability. The quality of the diffusion performance depends on the structure and size of the dye, the larger the molecule, the difficult to spread. Dyes that are affinity with fibers are strongly adsorbed by the fiber, and it is difficult to diffuse. Usually, it increases the temperature to accelerate the spread of dyes. Add electrolyte to the dye solution, and the diffusion coefficient of the dye decreases.

The diffusion performance of the dye is usually a thin film method. Take the sticky film (glass paper) and immerse them in distilled water. The thickness of the pre -immersion is 2.4 wires, and the thickness of 4.5 wires after immersion for 24 hours. During the measurement, this film is stacked into a certain thickness according to needs, and pressed on the glass plate to remove bubbles. Then sandwiched in the middle of the two splints with a rubber cushion ring, one of which there is a round hole in the middle of the splint. The dyeing solution can only spread to the film layer through this hole. , Then rinse with water to observe the number of layers of the dye -dye -dyeing film and the color wheat of dyes in each layer of dye. There is a certain correlation between the number of diffusion layers and semi -dyeing time. The semi -dye time is short and the number of diffusion layers is large.

3. Directability

Directability refers to the ability to be absorbed by fibers in the dyeing solution. Active dyes with high solubility are often low. Continuous rolling dyes and printing should be low. The dyeing equipment of the bath, such as rope -like dyes and twisted gauze staining, should be preferred to use high direct dyes. The dyeing method of rolling rolling (cold rolling pile), the dyeing fluid is transferred to the fiber by dipping, and it is easy to get evenly dye with a slightly lower dye.

The direct size of the active dye is represented by a balanced dye percentage (ie, color) or the RF value of the color layer analysis.

4. Live in response

The reactivity of active dyes usually refers to the strength of the dye and cellulose hydroxyl group. The dyes with strong reactivity can be completed at room temperature and weak alkali, but the stability of the dyes in this reaction is relatively poor, easy to be easy Lost the ability to be stained by hydrolysis. The weakly reactive dye needs to be combined with the cellulose key under temperature conditions, or the hydroxyl group of the fiber gauze with a strong alkali agent is used to promote the dye response to the fiber.

The reactivity of the active dye in the same model is roughly the same. The strength of the reactivity depends on the chemical structure of the dye activated base. The second is the connection group between the dye body and the active group, which has a certain impact on the reactivity of the dye. In addition, affected by the pH value, the general pH value increased, and the response speed increased. As for the temperature, it is also a factor affecting the reaction speed. The temperature increases and the response speed is fast. Each temperature increases at 10 ° C, the reaction speed can be increased by 2 to 3 times. Therefore, after printing, after drying or steaming, the dye can respond to the fiber.