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How to improve printing dyeing fastness to meet the increasingly fierce textile market demand, has become a research topic of printing and dyeing industries. In particular, the rectivary dye is sunshire fastness, the wet rub fastation of the deep concentrate fabric; the wet treatment fastness caused by the thermal migration of disperse dyes is decreased; and high-to-chlorine fastness, and sweat-resistant Light fastness, etc.
There are many factors affecting color fastness, and there are many ways to improve color fastness, I have passed many years of production practice. In terms of choosing a suitable dyeing agent, improving the dyeing and finishing process, strengthening process control, explores some methods and measures, has certain improvements and improvements in dyeing fastness, basically meet market demand.
1 Active dye light-colored fabric sun fastness
It is well known that Active dye on cotton fibers, under the sunshine attack, the chromophore or auxiliary group in the dye structure, which will be disrupted to different degrees, and cause color change or color, that is, the sun is fastness problem.
China's national standards have long been stipulated in the light-resistant fastness of the active dyes, such as GB / T411-93 cotton printing dye standard specified that the staining cloth tolerance of active dyes is 4-5 Level, printing cloth to light up 4; GB / T5326 combed polyester cotton mixed printing stamp standard and FZ / T14007-1998 Cotton-mixed printing cloth standfaction stipulates, dispersion / active dyeing cloth tolerance is 4, printing The cloth is also 4.
Active dye is more difficult to achieve this standard to achieve this standard.
The relationship between dyeing parent structure and sunlight
Japanese days of active dyes The sun effusion is mainly related to the parent structure of the dye, 70-75% of the active dye parent structure is azo type, and the rest is a pyroxin type, phthalocyanine type and an A-form.
The azo type light tolerance is poor.
The yellow active dye molecular structure is azo type, the parent chromogen is optimal, the active dye of the blue spectrum and the activated dye of the blue spectrum with pyrazolinone and naphthalene trisullonic acid. With the structure of anthraquinone, phthalocyanine, maternal structure, the sun is very fast, and the red spectrum active dye is azo type.
The sunsian fastness is generally low, especially light colors.
The sunlight fastness of the staining sample changes with the dyeing concentrationDifferent, the same dye is staining on the same fiber, and its sunsia fastness increases with the increase of dyeing concentration, mainly due to the change in the distribution of aggregate particles on the fibers.
The aggregate particles are solarized, and the larger dye is exposed to air-moisture, the smaller, the higher the sunshine.
The increase in dyeing concentration increases the proportion of large particles on the fibers, and the sunshine is also increased accordingly.Low staining concentration of light-colored fabrics, the dye is lower in fibers, and most of the dyes have a single molecular state, that is, the dye is highly decomposed on the fibers. Each molecule has the same chance being affected by light and air, moisture, and the sun is declining.
ISO / 105B02-1994 Standard Day Sunset 1-8 Standard Assessment, China's national standards are also divided into 1-8 standards, AATCC16-1998 or AATCC20AFU standard day Radios 1-5 standard assessment.
Therefore, first, it is necessary to make a clear customer requirement, all dye production enterprises or companies including dye index, the dyeing day, the dyeing day, sunset, The data measured in the case of the dye depth 1/1, that is, the data measured on the Chinese color fabric of about 20-30 g / L, the light-colored fabric is less than this level.
Measures to improve sunlight
1 , The use of dyes affects light-color fabric
The main factor in sunshine is the dye itself, so it is most important to use dyes.When the dye is selected, it is necessary to make the light fastness level of each component dye of the selected amount, as long as any of the components, especially the least amount The lightweight fastness of the division does not reach the light color dyeing, the light fastness of the final dye is not met.
2, other measures
(1) Effect of floating dyes.
Dyeing soap is not thorough, and the unlimated dye and hydrolyzed dye remain on the layout will also affect the light fastness of the pigment, and their light fastness is significantly lower than that Active dye.
The more soap washing, the better the light tolerance.
(2) Effect of Soil and Soft Agent.
Cationic low molecular or polyamine condensation resin forming fixation and cationic softener are applied to the fabric finishing, which will cause the sunlight fastness of the pigment.
Therefore, it is necessary to pay attention to their effects of sunlight sunstrois in the sun.
(3) Effect of ultraviolet absorbers.
Ultraviolet absorbers have recently used for light-colored chromosomes to improve sunlight, but must have a lot of effect, not only increase cost, but also caused fabric yellow and damage. Therefore, it is best not to use this method.
2 Wet treatment of deep concentrate of active dye
In recent years, it has been difficult to use in active dyes and other dyes. The active dye is imparted by a covalent bond to impart excellent dyeing fastness, but the deep concentrated color is often faded and staining phenomenon, and these phenomena have occurred in addition to part of the dye matrix due to light, hot, sweat, acidity. Erosion of gas and oxidant, azo-based decomposition, complex metal ion detach, amino oxidation or the like, or the like, causing the color change and fading.
The breakage of the dye-fiber bond also causes fading and staining. The floating color on the chromosome is to cause water washing fastness of deep concentrated chromosomes.
Floating
Dyes
Some dyes will leave a floating dye on the fabric after dyeing, and the floating dye of the active dye contains some hydrolyzed dyes, adsorbed to the fiber without participating in covalent reactions. Dyes, these floating dye clearance is related to their directness of the fibers, wherein the directness is the highest of the vinyl sulfone group dye, followed by hydrolyzed dyes, unreacted dyes due to a sulfur ester water soluble group, so the smallest fiber It is the easiest floating dye that is the easiest to remove. Practice has proved that even after full water (soap) washing, there is still some residual floating dye on the fibers, the larger the directness of the active dye, the less floating dyes are not easy to be from the fiber. Clear down, and it has water soluble, and it will be dissolved in the water, and the other fabric is contaminated, they are the residual dye depth concentrated fabric wet treatment fast, including water washing, soaphed and wet friction fastness The main reason.
It is necessary to clear the floating dye to consider both dye selection and process rationalization.
The printing dyeing plant selection dye is based on the dye color card Degree performance and sample tests to discriminate the level of fastness of the dye.
Because the fastness provided on the color card is dyed under the depth of 1/1 in the dye, it can only be used as a reference, while the latter is mainly.Therefore, the dye of deep concentrated chromosome must be preferably made, and an inlet active dye having a better cost is better, the solid color rate is high, and the transfection is good.
Process attention
1 Burnt, cooked, silk, etc., and the quality of each process control directly affects the mass and color fastness of the dye.
(1) The dehydride must fully retreat the slurry inside the fiber, refund, will affect the pose and infectation of the dye, hinder the interior of the dye to the fiber. Diffusion, the dye is floated in the fiber surface and affects color fastness.(2) Burnt-burning is clean, and the burning is not net, which directly affects the smoothness and smoothness of the surface of the fiber surface, increasing the coefficient of friction, producing a certain resistance, lowering friction Spend.
(3) Boiled cook and practice bleaching to cook, and reach the requirements of whiteness, remove impurities and cotton seed shells, reach the standard moo, 8-10cm / 30min, more than the moo is not reached The requirements will directly affect the dyeing rate and solid.
The better the gross effect, the better the infectivity and unevenness, the higher the upper dye rate and the fixed rate, the deeper the color, the less floating, the less floats float, friction The better the fastness and water washing, which can save the cost of dyeing, but also improve the dye fastness.
(4) Morality is important for dyeing fabrics, and the filament additionally obtains a stable door size, and can increase the depth of the dye, improve the gloss and sleek of the fabric surface. Improve the wet friction fastness and dressing fastness, especially the deep color fabric, but more important, so it is necessary to control the alkali concentration of silk light to achieve the sufficiently mixed effect. 2, the preferred dyeing method of the dyeing method, the darkness, unevenness, infection, and solid effects of color, the following, the following analysis and discussion .
(1) During the dyeing method of dip, the fabric can have sufficient time at a certain temperature.The reaction is reacted with the dye, through adsorption → diffusion → dyed, reaches the effect of sufficient dye and fiber, and has a higher solid color rate and brightness and color fastness.
(2) Cold rolling, cold rolled stack is stained with fabric by room temperature dip and alkali solution, after a long time to rotate, after room temperature, Wash, soaphed, to achieve sufficient purpose. This method is the best method for energy saving, environmental protection, and small mass production. 
(3) Wet short steamed wet short steaming color is a modular dyeing method, and the fabric is directly steamed with the liquid after dipping, and the solid color is high in high temperature and high humidity. Performing, thereby achieving rapid dyeing, solid color, has good upper dye rate and infection, high color rate, bright color, good tolerance and friction fastness.
(4) There are two process methods for rolling, one is rolling → baking → rolling, the other is rolling → baking → steam, the first It is the first rolled dye and then rolled the solid color, steaming is wet, achieving the purpose of solid color. The second is to rolling solid color after drying, simultaneous steaming,The depth of the latter is 20% more than the former, but the futures is lower than the former, because the former is used, but the depth of the wet movement cannot be achieved, it can be considered With dry steam, it is necessary to improve the dye fastness of the fabric with a solid color.
The solid color reaction is the most important stage of reactive dye staining. The entire process of dyeing must be controlled towards the direction of conducive to the solid color reaction, in order to obtain the highest The solid color rate.
The more dye is used, the more floating dyes, so the dye amount should be appropriate, the amount of dye should be appropriate, and the fiber has one for each dye. The limit value, that is, the saturation of the dye, generally no more than 10% of the saturation value.
When the amount of dye is large, the excess of the dye cannot be stained, which can only be stacked on the surface of the fabric, affecting the friction fastness of the fabric.And the active dye with high promotion should be used, which is high in the case of not much amount.
From the above sever, the fabric was stained with the fabric after testing, the color fastness was found to be: dipping u0026 gt; cold rolled pile u0026 gt; wet short steam u0026 gt; rolling → baking Rolling → steamed u0026 gt; rolling → baking → steam.
1
The method is to rely on water washing, soaphard, and mechanical external force, the object is to remove hydrophilic floating, wash the electrolyte and the alkali agent to reduce the concentration of the electrolyte to increase the floating dye and The electrostatic repulsiveness between the fibers makes the floating dye are easily detached from the fibers; the washing alkali is to prevent the alkali to cause hydrolysis of the solid dye in high temperature soap.
Soap washed after washing is a floating dye that removes a large amount of soap cleaner dispersed.
Water quality during post-treatment is very important. If the water quality hardness is high, there will be more Ca2 +, Mg2 + equal heavy metal ions, which make the sodium sulfonate salt soluble in water to be difficult The calcium sulfonate (magnesium) salts dissolved in water, thereby weakening the hydrophilicity of the floating dye, so the water quality has a significant effect on the post-treatment fastness of the pigment.
4, the post-finishing is insufficient, the day after the day, the dyeing fabric color fastness does not reach the requirements, only after finishing The fixing agent and enhancer are used to make up and improve. Dedicated fixation can increase the deeper thickness of the active dye to increase by 0.5 to 1.0.
3 active dye refinement resistance and anti-light fastness
The active dye is generally poorly poorly resistant, depending on the molecular structure of the chromogen, the ortho position of the dye diazon group, or a carboxylic acid group, or a hydroxyl group of the coupling component. When there is a sulfonic acid group or a carboxylic acid group in an adjacent or a carboxylic acid group, the ability of Ci-off -N-NH- or-N- is reduced due to its spatial stress resistance, thus increasing chlorine fastness.
According to GB / T8433-1998, the hydraulic-resistant tested swimming pool, the effective chlorine concentration is divided into three kinds of 20 mg / l, 50mg / l and 100 mg / l, special requirements. 200 mg / L.
As the effective chlorine concentration increases, chlorine fastness decreases.
Therefore, the dye selection is important, and the method of adopting a solid tank during the post-finishing process, but only 0.5-1.0 levels can be increased.
Active dye is very concerned in recent years, and some active dyes have good fastness, but KhanVery poorlight fastness.Because the fading mechanism is different under the double action of sweat and daylight, the amino acid or related substance in the sweat is cheened from the dye mother. The toner fastness of the dye mother is not good, so it is faded or color change.
4 Fastness caused by heat migration after dyeing dye
The thermal migration phenomenon is a replica phenomenon of disperse dyes in two phase solvents, so all aids that can dissolve disperse dyes can generate thermal migration.
The cause of the thermal migration is due to the dissolution of the dye due to the fiber outer layer, and the dye is widened from the fibers to the fiber surface by fiber. The dye accumulates in the surface of the fiber, causing a series of effects, such as color change, contaminated other fabrics, friction, water resistance, resistant stains, dredging resistance, and weather resistance.
Practice shows that the dye is directly related to the thermal mobility of the fiber to fibers, the deeper depth of the fibers, the more the dye amount of the inner heat transfer, The larger the influence of the pigment; the high temperature treatment after dyeing has a large effect on the heat mobility of the dispersion dye, the higher the temperature, the greater the impact.
Therefore, the mild process is minimized when the dye fabric is finished.The thermal migration of dispersion dye is related to the molecular structure of the dye itself. It is found that the nonionic surfactant widely used in production practice is the main reason for the thermal migration of dispersion dyes.
Amino silicone emulsion as a soft agent is currently using the most softener, because it is necessary to form a microemulsion, a silicone is required to apply a silicone total amount of fat alcohol polyoxyethylene. A nonionic surfactant such as an ether or alkylphenol polyoxyethylene ether as an emulsifier.
As the amino silicone emulsion is widely used, the thermal migration of the dispersion dye is more severe.
The method solved is to select high lift and suction rate, especially a dispersion dye that is good and wet fast after the pigment is hot.
The dye (floating) adhering to the surface of the fiber will increase the effect of thermal migration of dye on the color fastness of dye fabric. Therefore, after dyeing (especially dark) should be reduced by reductant and an alkali agent to completely remove floating.
5 Conclusion
In summary, it is important to increase the color fastness of the pigment, and the dye selection is very important. To choose different dyes for color fastness, Light-color fabrics with high sun effusion should be selected to reduce dyes and reactive dyes with high sun effort; the deep concentrate is only selected to select a solid color rate, and the imported active dye of high-rise is to ensure wet treatment fastness; dispersion Dyes should choose less thermal migration, especially dark, should try to avoid or exceed the dyeing saturation, and should adhere to the use of surfactants. It is not necessary to use it, it can be used less, non-time , Make careful choices.
In the process of production management, it is necessary to enhance process control to ensure that the following process requirements are reached:
(1) The fiber surface is smooth, Happiness is less. (2) The fiber is higher than the mohmer.
(3) The absorbing ability of the fibers is . (4) The dye is good for fibers.
(5) The dye and the fiber bond are solid to be sufficient.
(6) Wash the soap washing is thorough.(7) After the break key of the dye is small.
