4 common problems of acid dye dyeing nylon

Horizontal, horizontal strip

1. Cause analysis: The nylon fiber on the fabric has differences in chemical or physical characteristics.

① The physical differences of the yarn, including the number of yarn chips, the number of fiber roots in the yarn, or the fiber of the fiber, the difference between the end of the single -rooted fiber in the yarn or the difference between the end curling of the multi -rooted fiber;

② Chemical differences are derived from the different content of fiber amino. This difference may be produced in the process of spraying the wire, the heat of the heat, or in the process of the wire. For example, the unevenness of the super molecular structure produced by the nylon fiber during treatment, such as the difference in crystallization and orientation in the fiber

The leather core structure is uneven.

2. Solution:

① Strengthen the titter detection, and there are differences in different choices for light, white or white.

② Choose a dye with good coverage and uniform dyes. The coverage and uniformity of decentralized dyes are better than acid dyes. You can choose to add part of the decentralized dyes. Color flowers caused by bidding dye 1. Analysis of reasons: The content of amino groups in the middle and end of the nylon is less and the saturation value is low. When two or more dyes are dyed, they will compete with the staining position, which is the so -called competition competition. If the dye selected in the dyeing rate and affinity are large, the color of the fiber dye will be different in different dyeing time, resulting in poor samples and poor performance.

2. Solution: Select the upper dye curve, similar affinity, good compatibility, and the dyeing series suitable for production machines. Master the dye dye dye performance, and when selecting the dye, we must comprehensively consider the upper dyeing rate, upper dye curve, uniform dye, color fastness performance, and sensitivity to the temperature and uniform agent.

① Fully consider the compatibility of the dye to use several dyes to dye, and the appropriate dye should be used to control the amount of dye. Generally, the same company should be selected as the same company. Even if the dyes of different companies have to be used to fight, they should try to choose dyes with similar dye curves, similar starting temperature, and similar sensitivity to the temperature and uniform agent. Try to avoid bidding.

② Pay attention to the differences in dye sample dyes. Some dyes are not obvious when small sample dyeing, but it is completely exposed in large production. For example, when producing lake green and peacock blue, if acidic blue and acidic yellowing are used, similar problems will occur. This is due to the large molecular structure of acid -emerald blue, which is very different from the acid yellow upper curve, which causes bidding. If you use an acidic green basket to fight with the acidic green with yellow light, you will basically solve the problem of bidding. The color flower nylon stain caused by process conditions has high requirements for the process. The process conditions are important factors that affect the color and uniformity of dyeing products, such as temperature and pH value, which can affect the quality of the product. Unreasonable craftsmanship is prone to suffering from uniform dye differences, color flowers, color willows, color differences, and poor accuracy.

1. The impact of the initial dyeing temperature and temperature increase rate temperature is a thermoplastic fiber. Therefore, the dyeing rate of fiber has a lot to do with the temperature. The dyeing temperature must be higher than the glass -based temperature of the fiber (35 ~ 50 ° C). Nylon fiber began to adsorb dyes at 40. As the temperature rises and the upper dyeing rate is accelerated, the upper dyeing process can be basically completed at 100C. Although the dyeing can be basically completed when the temperature is 100C, the continued heating can help the dye. Migration, so as to improve uniformity. However, if the heating rate is not well controlled, it is easy to cause uneven dyeing. The effect of temperature on the dye dyeing rate is also different due to the different dyes. The upper dye rate of uniform dye dyes gradually increases with the temperature increase; After ° C, it started to increase rapidly with the rise of temperature. Especially within the temperature range of 65 ~ 85 ° C, controlling the heating rate is the key to the success or failure of nylon dyeing. If it is not controlled properly, it will cause the problem of fast coloring, poor migration, and difficult to repairs. If the shrinking dye dyeing nylon is used, the starting temperature should be room temperature. At the temperature section of 65 ~ 85 ° C, strictly control the temperature increase rate of about 1 C/min, and add a uniform dye to 95 ~ 98C, insulation 45 ~ 60m I n. In addition, the dyeing performance of this fiber also changes with the thermal treatment conditions before the dyeing, and the fiber dyeing rate after dry thermal fiber decreases significantly.

2. Control the pH nylon fiber dyeing, when the pH value of the dyeing fluid is relatively high, the dye is rarely dyed; when the pH value of the dyeing liquid drops to a certain value, the dye will begin to be dyed, and it will soon reach saturation. Continue to continue Reduce the pH value of the night dye, and the upper dye has no significant increase. However, when the pH value is further dropped to 3, the amount of dyeing upper dye increased sharply, and an over -propelled adsorption occurs. When the nylon fiber is dyed under the condition of low pH, it will also be hydrolyzed, especially after an ultra -compact adsorption, the pH value in the fiber is lower than the solution, the hydrolysis is accelerated, and more amino groups, fiber, fiber after hydrolysis, fiber, fiber, fiber, fiber, fiber, Increasing the degree of concentration, it can adsorb more dyes, which is more likely to produce uneven dyeing. Therefore, according to the actual situation, the pH value can be increased by the light to reduce the phenomenon of color flowers. When weakly acidic dye dyeing nylon, the pH value of the light -dyeing color is generally controlled at 6 ~ 7 (commonly used ammonium acetate regulation), and the amount of dyeing agent is increased to enhance the uniform dye and avoid dyeing flowers. High, otherwise the color of the color will be dark; the dye dyeing pH value is 4 ~ 6 (the commonly used acetic acid and ammonium acetate regulation), and add an appropriate amount of acetic acid to the pH value during the heat preservation process to promote the dye dye.

3. Pay attention to the selection and dosage of uniform dyeing agents for the characteristics of nylon dyeing uniformity and poor coverage. A small amount of anion or non -ion -type dyeing agent should be added to the dye bath. It can be used in the same bath with the dye during dyeing, but it can also be treated before dyeing with a uniform dye. Purple -type uniform dyeing agent is linked into negative ions in the dye bath and enters the fiber. First of all, occupy a limited dye seat on nylon fiber, and then gradually replace the dye with the temperature increase during the dyeing process, reducing the combination between dyes and fibers Speed, achieve the purpose of uniform dyeing; non -ion -type dyeing agent is combined with hydrogen bonds with dyeing baths in the dye bath, and then gradually decomposed to release dyes during the dyeing process, and is adsorbed by fibers. The addition of uniform dyeing agents can significantly improve the dyeability and capacity of the cover. However, with the increase of the concentration of the auxiliary, the upper dye rate decreases, resulting in the decrease in the exhaustion rate to varying degrees, so the amount of even dyeing agent should not be too much. Because the even -dyeing agent is in addition to the effect of the even dyeing during the dyeing process, it also has a resistance to infection. If the amount of uniform dyeing agent is too large, it will reduce the acid dye. The upper dyeing rate will increase the concentration of the dyeing residual liquid, resulting in poor sample color difference and poorly active performance. Generally, the amount of evenly dyeing agents is large when dyeing; when dyeing is dark, the amount of dyeing agent is small.

In the process of storage and transportation, yellow -changing nylon light fabrics often occur local mild yellow change phenomena, affecting the appearance and quality of the plant.

1. Cause analysis: Pollutants and BHT (butyl hydroxyl benzoethyl ether) and nylon have a chemical reaction on the plastic packaging bag, causing color variation and led to yellow change.

2. Solution: Use antiphenol yellow variables to be immersed or soaked.