How to control the color difference between large and small samples in textile dyeing

First, cleaning method

Cold water cleaning

In cotton and its blended fabrics, the cotton component is dyed with direct dyes or reactive dyes and appears to have a floating color or darkening color. Generally, it is used to continue washing or adding 0.5-1L anti-staining cleaning agent LEFIMIN (Lay) in a water bath. Fei Min) washed. If the water hardness is high, 0.5 ~ 2g/L chelating dispersant can be added to improve. Do not use turbid river water or deep well water with high hardness.

2. Warm water cleaning

When the polyester blended fabric is dyed, there are many types of dyes and auxiliaries used, which can be washed at 40°C to facilitate the dissolution of the residue contaminated on the fabric. Cellulose fibers are dyed with direct blending dyes. If the overall color of the sample is larger than that of the sample, the color obtained after washing with warm water can be similar, and the color fastness can be improved to some extent.

3. Hot water cleaning

Hot water cleaning is mostly used for silk, synthetic fabrics and their fabrics that are dyed with acidic, direct and basic dyes. If the color is darker, dyes with 1-2 dyes need to be removed, and hot water at 70-80°C may be used. Silk fabrics can be added to the hot water bath with 0.3 to 0.5L of flat and 0 (leveling agent); polyester, nylon and other synthetic fiber blended fabrics, can add 0.5 ~ 1.0L repair agent or Staining carrier. Due to the small amount of additives added in the hot bath, the fabric only needs to be flushed with water to room temperature. If dyed fabrics are treated with cationic fixing agents, softeners, etc., it is best to add 2 to 4 L of dispersant DAM to the hot bath. Hot water washing (repair) is carried out on the original dyeing equipment in principle. For example, after Nilesi spinning, acetate fiber and interlaced silk are dyed and dyed, if the hot water is washed with an overflow machine (rope), the fabric will have permanent wrinkles.

Second, additive method

1. Add electrolyte

(1) Dyeing cellulosic fibers with direct dyes, the depth of the dye sample is often insufficient. If there is dye in the dye bath, add 1.5-5. Og/L electrolyte (NaCl, Na2SO4) promotes staining. This pair of salt effect direct dyes, such as Direct Fast Yellow 3RLL, Orange (L, Sapphire BNL, Red 4BL, Red Jade RNLL, Violet BL, Blue BL, B2RL, Sky Blue G, Turquoise Blue GL, Green 5GLL, Green GL, Gray 4GL, ash GB, etc. are very effective, and for temperature effect direct dyes, it is necessary to maintain a certain temperature.

(2) Dyeing protein fibers with acid dyes, or dyeing acrylic fibers with basic dyes or cationic dyes. When coloring is too dark or colored, add 3 to 6 g/L Na2SO4 to discolor or level dye.

2. Acetic acid

(1) dyeing silk, wool, and other protein fibers with acid dyes. If there is more color in the dyeing solution than in the dyeing solution, add O. 5-2mL/L of 98% acetic acid promoted. Before adding, steam valve must be closed, diluted with 10 times cold water, and slowly added when the dye is running, to avoid creating new color flowers.

(2) Use K-type and KN-type reactive dyes to dye cellulose fibers. If the sample is too dark, add 2-3 mL/L of 98% acetic acid, treat it at 90-95°C for 3Omin, and push the dye partially to break the bond and achromatize. , generally reduced by 20%.

(3) When dyeing silk with basic dyes or acrylic dyes with cationic dyes, if the sample is too dark, 2~3mI/L acetic acid can be used to treat 2O~30min in a 4JD-60C warm water bath to dissolve the dyes. Reduce 20% to 30%.

3 additional levelling agent

(1) dyeing polyester and blended fabrics with disperse dyes. When the color of the sample is darker than that of the sample, a high temperature leveler or repair agent can be added. If the color of the sample is small, the corresponding dye should be added. However, it should be noted that the steam valve should be closed when it is added to avoid coloring. Add the proper leveling agent first. In addition, when the disperse dyes are additionally dyed, they must be warmed up to a certain dyeing temperature, incubated for 15-20 minutes, and then reduced in temperature and pressure.

(2) When dyeing cellulose fibers, silk, wool, and nylon fabrics with direct, acidic, neutral dyes, in principle, all can be used to remove the migration dye by leveling and O to achieve level dyeing. The amount of O added to wool fabrics should not exceed 0.3 g/L. In order to prevent wool felting, wool protector Wool20%-3% (Dys-tar) can also be added. When nylon is dyed with neutral dyes, if the color is too deep or there is a crossover, etc. to be covered, the use of color Lego N-ER3% ~ 5% (D'ystar) has an excellent effect.

(3) When dyeing acrylonitrile, alkali-modified polyester and silk with alkaline and cationic dyes, if the color of the dyed sample is slightly darker, hot water may be used for cleaning; if the color of the sample is about 20% deeper, the dyeing residue can be basically At the end of the wash, 2 to 4 L of surfactant 1227 was added to achieve discoloration through competition dyeing.

4. Add brightener

When dyeing red jade, rose red, violet blue, snow blue, sky blue and brilliant purple and other bright colors, if you feel the sample is not bright enough, you can generally add 0.0015% to 0.0025% (owf) fluorescent brightener, the more light the amount of more less. The effect of fluorescent whitening agent 4BK on cotton textiles is better, and its fluorescence is weak, the brilliance is strong, the amount is small, the adjustability is good, and the adaptability to the color is wide, and it is not easy to “jump lights”. "Hit jump" caused by fluorescent whitening agents can be removed with fluorescent stain removal agents that do not affect the vividness of color.

5. Additional dyeing carrier

For polyester-cotton (viscose) and nylon-cotton (viscose), because polyester and nylon are hydrophobic fibers, their color development is deeper than hydrophilic fibers such as cotton and viscose, and 2-4 mL can be added to a 60°C water bath. The carrier was dyed with L/L and then gradually heated to 80-9O°C to slowly desorb the dye on the hydrophobic fiber to achieve the same color as the two phases. Practice has proved that dyeing carriers not only dissolve disperse dyes on hydrophobic fibers, but also have dissolution effects on other dyes. When the temperature rose to 80 °C, the operator must continue to sample the sample, generally kept to the size of the sample match.

Third, dye (Yan) material addition method

1. When adding additional disperse dyes to polyester, it is best to lower the temperature of the dye bath to below 80°C, dilute the pre-dissolved dye sufficiently, add it within 5-8 minutes, then continue to increase the temperature to the original dyeing. Temperature, insulation dyeing more than 15rnin, to ensure uniform color before and after the dye, to reduce the impact of heat setting.

2. If a dye sample is found in the cylinder and a color difference is found in the sample size, add a dye or adjust the color shade on the large sample. When adjusting, in addition to calculating the type and amount of dyes needed on large samples, the original prescription should be supplemented with 15% to 20% of the dye.

3. For colors with 3 to 4 dyes, such as rice ash, tile ash, incense ash, silver ash and ivory, etc., can not be used to repair the color difference between the size of the sample.