Home » Information » Industry Encyclopedia » Polyester, Wool, Nylon, Viscose And Nitrile: How To Dye Fabrics Made of Five Fiber Blends?

Polyester, Wool, Nylon, Viscose And Nitrile: How To Dye Fabrics Made of Five Fiber Blends?

Views: 0 Author: Site Editor Publish Time: 2024-02-26 Origin: Site

Inquire

1. The pH of the dye bath should be controlled at 5 to 6

The pH of the dye bath should be controlled at 5 to 6, which must be adjusted with acetic acid. It is best to use 1 to 2 g/L ammonium acetate or sodium acetate as a buffer. Do not use the so-called "buffer" containing inorganic acids (S-1, C1-). Dyeing acid”. Because acetic acid does not act on cellulose fibers and can adapt to a variety of dyes, such as disperse, cationic, weakly acidic, blended (D type) and other direct dyes that are resistant to weakly acidic media [see "Printing and Dyeing" 1993 (9): 18 ]; Even if one-bath two-step or two-bath dyeing is used, the residual acid on the fabric can be easily neutralized and cleaned; it will not affect the diffusion of disperse dyes.

2. It is very important to add dispersants and anti-staining agents

Since the dyes used in the dyeing of multi-fiber blended interwoven fabrics are numerous and mixed, agglomeration is easy to occur during the dyeing process, and contamination of the agglomerates occurs, thus causing dyeing defects; add dispersant IW (flake) 1~ in the dye bath 2 g/L or WA (liquid) 3~6mI/L, which can effectively resist aggregation. If the anti-staining agent TA-309 (Shanghai Auxiliary Factory) is added at 1 to 2 mL/L, it can not only increase the synergistic effect of anti-coagulation, but also significantly reduce the degree of mutual contamination of fibers with dyes, thus improving the clarity of the dye color. strength and color fastness.

In fact, these two additives can also prevent direct dyes from contaminating nylon and wool to a certain extent. According to other information, Nevadine AN is relatively stable to acid, alkali and hard water, and is a high-grade leveling agent for wool and nylon dyeing. When its dosage is increased to 5% to 8% and boiled for 30 to 60 minutes, The color on the nylon will be obviously clear and pure, and the dyeing defects of the nylon can be repaired. This additive can reduce the staining of nylon, and will not produce foam and block the fabric during operation, allowing dyeing to proceed smoothly.

Therefore, adding this additive in actual production can prevent the nylon from being oversaturated with dyes due to repeated dyeing with various dyes. At the same time, there is no need to add nylon spinning dyes to avoid interactions that affect the effect. increase cost.

3. It is advisable to use medium and low temperature disperse dye carrier method for dyeing.

In recent years, due to the increasing number of polyester-containing multi-fiber blended interwoven fabrics, many additive manufacturers (companies) are developing carriers. In fact, each carrier has certain adaptability to fabrics. It is necessary to choose products that have a large puffing effect on polyester, have little impact on other fibers, do not contain carcinogens and organochlorines, and are easy to deload.

There are very few black dyes suitable for carrier dyeing. It is planned to use disperse blue 2BLN 3.5% (owf), red 3B 2.2% (owf) and yellow SE. 3R 1.8% (owf), very good blackness. It is not suitable to use dispersed black EX for a variety of upper fiber blended fabrics. SF (300%); Sometimes in order to adjust the color, high-temperature dyes can be used in small amounts, but they cannot be used as the main color.

4. The heat preservation and dyeing time is longer than that of single fiber

Because a piece of fabric contains more than three fibers, usually three related dyes are added. The more dyes are added to the same bath, the worse the dispersion of the dye bath will be, so dispersants and anti-contamination agents should be added to prevent aggregation and mutual contamination. In order to further allow the dye adsorbed on the fiber to continue to diffuse, migrate and dye, the time needs to be appropriately extended. Practice has proved that only after long-term boiling and dyeing can the dye uptake rate of various dyes be improved, and the color will be clear and pure, and have a certain color fastness.

Therefore, the dyeing time of multi-fiber blended fabrics is 1/2 or 1/3 longer than that of single fiber fabrics. If various overflow dyeing machines are used, due to the frequent collision between the dye and fiber in the dye bath and the high heat, the extension time can be appropriately reduced; while jig dyeing machines and yarn dyeing machines (regardless of hank or package yarn dyeing), Especially for spray-type yarn dyeing machines and room-temperature flip-type garment dyeing machines, if the dyeing time is extended, the dyeing time can be appropriately increased in order to achieve a dyeing balance and ensure quality.

5. Reasonable selection of dyes and increase in dosage of disperse dyes

While dyeing polyester, its dyeing rate for nylon is also very high (because it is not restricted by the terminal amino groups of nylon and can dye nylon through hydrogen bonds and van der Waals forces), sometimes even higher than polyester; if there is acidity Or the presence of neutral or direct dyes, the color on nylon will be supersaturated. Therefore, there is no need to use additional nylon dyes. Before the dyeing is completed, if the hue of nylon does not match that of other fibers, you can choose a weak acid dye of the corresponding color to supplement the color (flattening). The dyeing method is similar to that of wool. When selecting dyes, the compatibility and directness of various dyes should be consistent to reduce the phenomenon of competing dyes. If cross-dying occurs, in order to ultimately achieve a dyeing balance and reduce mutual staining, in addition to extending the holding time, the actual dosage of dyes for various fibers is increased by 20% to 50% compared with the actual dosage of a single fiber.

This is the dyeing characteristic of multi-fiber blended fabrics, that is, there is a large amount of dye residue in the foot water, and it needs to be fully washed before it can be washed away. Of course, if there is less viscose fiber, such as when the content is only 10% to 15%, if additional dye is added to 7% to 8% of the total mass of the fabric (owf), it will often turn into dark brown. In order to achieve an ideal dye uptake rate of direct dyes, appropriate electrolytes (such as Na2S04) can be added before final dyeing to promote dyeing without changing the color of other dyes. In order to ensure good dispersion of the dye bath, it is important not to add electrolytes at the beginning of dyeing.

6. Select the appropriate dyeing machine based on fiber performance and content.

For example, "five-in-one" fabrics should be dyed on a differential constant-speed jig dyeing machine, because rope dyeing results in too much lint, which affects the quality of the finished product; and "three-in-one" knitwear is best dyed on a circulating overflow dyeing machine. The yarn is dyed first and then knitted. It can not only achieve dyeing through in a long dyeing process, but also use small liquor ratio dyeing to save dye; it can also avoid flash points after dyeing the garment due to the slippage between the knitting points exposed without dyeing through. Defects.

"Three-in-one" sweaters are easily deformed when dyed, affecting dimensional stability, and the appearance is not clear enough. In addition, the dyeing bath ratio on the flip-type garment dyeing machine is high, the cost is high, and the wastewater discharge is large, all of which need to be improved. The water quality of pre-treatment and entire processing cannot be ignored. No matter what kind of fiber is used, textiles must be pre-treated before dyeing.

The purpose is to remove grease and impurities in the textile process and in the fiber itself, purify it and ensure its proper wool effect and whiteness. In addition, 100-150 mg/kg soft water should be used throughout the dyeing process; generally 0.5-2 mL/L dispersing chelating agent can be added to improve it, especially when river water and deep well water are used.

7. The water quality of pre-treatment and entire processing cannot be ignored.

No matter what kind of fiber is used, textiles must be pre-treated before dyeing. The purpose is to remove grease and impurities in the textile process and in the fiber itself, purify it and ensure its proper wool effect and whiteness. In addition, 100-150 mg/kg soft water should be used throughout the dyeing process; generally 0.5-2 mL/L dispersing chelating agent can be added to improve it, especially when river water and deep well water are used.

polyester