阅读说明：本技术 一种提高深色羊绒织物耐摩擦牢度的方法 (Method for improving rubbing fastness of dark cashmere fabric ) 是由 蒋庆云 许永仙 俞建丰 于 2020-12-02 设计创作，主要内容包括：本发明涉及一种提高深色羊绒织物耐摩擦牢度的方法,包括预处理,染色,碱洗和中和,其中碱洗分为2次碱洗,纯碱的用量第一次小于第二次,当甲酸的量为A摩尔,碱洗第一次加入0.4～0.6A摩尔纯碱,温度升到80～85℃,运行20～25min,降温后将液体排空,再加入0.5～1g/L润湿剂,升温到45～50℃,运行20～40分钟,排空后进行第二次碱洗,第二次纯碱量为0.2～0.5A摩尔,温度升到80～85℃,运行20～25min,之后降温至30～35℃冲洗一次；本方法在工业化生产的羊绒染色过程中,一方面通过改进染色工艺和选用合适的助染剂,提高染料的牢固度,另一方面,在后处理中,在去除浮色时,尽可能减少对羊绒纤维的损失,以提高染色后羊绒的耐磨色牢度。(The invention relates to a method for improving the rubbing fastness of dark cashmere fabric, which comprises the steps of pretreatment, dyeing, alkali washing and neutralization, wherein the alkali washing is 2 times of alkali washing, the amount of soda is less than that of the second time for the first time, when the amount of formic acid is A mol, 0.4-0.6A mol of soda is added in the alkali washing for the first time, the temperature is increased to 80-85 ℃, the operation is 20-25 min, the liquid is emptied after the temperature is reduced, 0.5-1 g/L wetting agent is added, the temperature is increased to 45-50 ℃, the operation is 20-40 min, the second time of alkali washing is carried out after the emptying, the amount of soda for the second time is 0.2-0.5A mol, the temperature is increased to 80-85 ℃, the operation is 20-25 min, and then the temperature is reduced to 30-35 ℃ for washing once; in the industrial cashmere dyeing process, the method improves the fastness of the dye by improving the dyeing process and selecting a proper dyeing assistant, and reduces the loss of cashmere fibers as much as possible when removing the floating color in the post-treatment so as to improve the wear-resistant color fastness of the dyed cashmere.)

1. A method for improving the rubbing fastness of dark cashmere fabric is characterized by comprising the following steps:

pretreatment: adding a wetting agent into a dye vat with a bath ratio of 1: 5-10, wherein the adding amount is 0.5-1 g/L, heating to 45-50 ℃, running for 20-40 minutes, emptying, and then cleaning with clear water once;

the dyeing process comprises the following steps: adding 0.5-1.0 g/L defoaming agent into a dye vat with a bath ratio of 1: 5-10, adjusting the pH value of bath liquid to be 4-4.3 by adding formic acid, adding formic acid A in a molar ratio, stirring for 10-15 min, continuously adding 2-3% low-temperature dyeing auxiliary agent and 3% lanonine dye, operating for 10-15 min, heating to 85-90 ℃ at a speed of 1.5 ℃/min, and operating for 60-75 min;

alkali washing: emptying liquid of the dyed cashmere obtained in the step (2), adding clear water at a bath ratio of 1: 5-10, adding 0.4-0.6A mol of soda ash, heating to 80-85 ℃, running for 20-25 min, emptying the liquid after cooling, adding 0.5-1 g/L of wetting agent for washing, carrying out secondary alkali washing after emptying, adding 0.2-0.4A mol of soda ash, heating to 80-85 ℃, running for 20-25 min, cooling to 30-35 ℃, and washing for once;

neutralizing: adjusting pH to 7 with formic acid, heating to 40 deg.C, running for 10min, draining, and washing again.

2. The method for improving the rubbing fastness of the dark cashmere fabric according to claim 1, characterized in that in the alkali washing process in the step (2), A mol of soda is dissolved in water at a temperature of 35-45 ℃, a 40-50% by mass of soda aqueous solution is prepared, and the soda aqueous solution is added into a dye vat in a dropping manner within 30-40 min.

3. The method for improving the crockfastness of dark cashmere fabrics according to claim 1, wherein said wetting agent is ULTRAVON CN.

4. The method for improving the rubbing fastness of dark cashmere fabric according to claim 1, characterized in that the low temperature dyeing assistant is MIRALAN LTD.

5. The method of claim 1, wherein the defoamer is ALBAFLOW CIR.

6. The method for improving the rubbing fastness of dark cashmere fabrics according to claim 1, characterized in that the dyeing process comprises: adding 1.0g/L of defoaming agent into a dye vat with a bath ratio of 1:6, adjusting the pH value of the solution to 4 by adding formic acid, adding formic acid A in a molar ratio, stirring for 10-15 min, continuously adding 3% of low-temperature dyeing auxiliary agent and 3% of lanatin dye, operating for 15min, heating to 85-90 ℃ at a speed of 1.5 ℃/min, and operating for 75 min.

7. The method for improving the rubbing fastness of the dark cashmere fabric according to claim 1, wherein the alkali washing process comprises the following steps: after liquid of dyed cashmere is emptied, clear water is added, the bath ratio is 1:6, 0.5A mol of soda ash is added, the temperature is increased to 80 ℃, the operation is carried out for 20min, the liquid is emptied after the temperature is reduced, 1g/L of wetting agent is added, the temperature is increased to 45-50 ℃, the operation is carried out for 20-40 min, the second alkali washing is carried out after the emptying, 0.2A mol of soda ash is added, the temperature is increased to 80-85 ℃, the operation is carried out for 20-25 min, and then the temperature is reduced to 30-35 ℃ for washing once.

Technical Field

The invention relates to the field of cashmere processing, in particular to a method for improving the rubbing fastness of dark cashmere fabric.

Background

The cashmere fiber is the finest of animal fibers, has uniform fineness and small density, has the average fineness of 15-16 mu m, is closely arranged in spinning and weaving, has good cohesive force and good heat retention property. The cross section of cashmere fiber is mostly regular round, and compared with other fibers, cashmere has the advantages of natural luster, softness, purity, gorgeous appearance and the like. The cashmere fiber is suitable for being processed into knitwear with plump hand feeling, softness and good elasticity because of large crimp number, crimp rate and crimp recovery rate. The cashmere fabric has the characteristics of soft hand feeling, plump suede, good heat retention, strong moisture absorption, natural and soft luster, comfortable wearing and the like, and is an ideal and good product for pursuing high-grade and perfect clothes.

However, the dye concentration of the cashmere dark products is high and exceeds the color absorption amount of the fibers, so that the oversaturation phenomenon is generated to generate loose color, the cashmere dark products are easy to loosen under the action of external force (by friction or pressure), the color fastness index cannot meet the requirement, and the quality of the cashmere dark products is influenced. Therefore, many dyeing manufacturers are eagerly seeking a technology for improving the deep color fastness of cashmere for many years.

In the prior art, part of methods for improving the rubbing fastness of dark cashmere fabrics are as follows:

CN103952926A discloses a dyeing formula and a process for improving the color fastness of dark cashmere products, which adopts a microwave pretreatment and an auxiliary agent addition method to improve the color fastness. After microwave treatment, the scale layer on the surface of the cashmere fiber is etched, so that the main barrier for preventing the dye from entering the fiber is damaged, and the dye can enter the fiber more easily and more. Therefore, the dye remained on the surface of the fiber is relatively reduced, the washing fastness and the rubbing fastness of the cashmere fabric are improved to a certain extent, and the dry grinding and the wet grinding can reach more than level 4. Although the method can effectively improve the rubbing fastness, the pretreatment is carried out by a microwave method before dyeing, and because cashmere needs to be produced in large scale in industrial production and the existing microwave device cannot meet the continuous production process in large scale, the microwave pretreatment mode is not suitable for industrial cashmere dyeing.

CN1607294 discloses a dyeing technology for improving the color fastness of cashmere fiber and products thereof, and the technological process of the disperse dyeing is as follows: firstly, pretreating cashmere by using a low-temperature assistant, then adding a dyeing assistant, finishing a dyeing process, and then carrying out post-treatment by adopting a mode of alkali washing twice, wherein the first time is as follows: adjusting the pH value to 8.0-8.5 by ammonia water or soda ash at the temperature of 40 ℃, running for 10 minutes, heating at the speed of 5 ℃/min, raising the temperature to 80 ℃, treating for 20 minutes at constant temperature, and then cooling to 30 ℃ for washing; and (3) for the second time: adjusting the pH value to 8.0-8.5 by using sodium carbonate, operating for 10 minutes, adding a soaping agent, heating at 5 ℃/min, raising the temperature to 85 ℃, carrying out constant-temperature treatment for 20 minutes, and then cooling to 30 ℃ for washing. And finally neutralizing with acetic acid. The cashmere obtained by the scheme has the wash fastness of more than 3 grade and the water fastness of more than 4 grade, but the wear fastness is still obviously lower, and the cashmere is subjected to dry grinding of 3-4 grade and wet grinding of 2-3 grade. More than 3 grades are required for wet grinding to be qualified products, and more than 4 grades are required for dry grinding and wet grinding to be excellent products. Therefore, the wear resistance fastness of the cashmere obtained by the dyeing process needs to be further improved.

Pom winter et al in "dyeing process for improving color fastness of dark cashmere products" point out that "dyeing of fibers with dyes can generally be divided into three processes: (1) the dye diffuses from the liquor to the surface of the fibre and dyes the surface of the fibre, a process known as adsorption. (2) The dye adsorbed on the surface of the fiber diffuses into the fiber until the dyeing equilibrium or substantial equilibrium, a process known as dye diffusion in the fiber. (3) The dye and the fiber are fixed on the fiber through chemical reaction. The absorption and diffusion of the dye are mainly determined by the structure of the dye and the structure and performance of the surface of the fiber, and are influenced by a plurality of factors including equipment, the dye, dyeing auxiliaries, dyeing processes (including pH value, temperature, heating rate, holding time and the like) and fiber performance, and if the factors cannot be scientifically controlled, the appearance quality (color, leveling property) and the inherent quality (permeability and color fastness) of the product are directly influenced. Therefore, only by scientifically and reasonably testing the factors, the dyeing quality can be ensured, and the product grade can be improved. According to the principle, the low-temperature surfactant is added in the cashmere dyeing process to improve the wettability of cashmere fibers, so that scale layers are swelled, the fiber structure becomes loose, the surface tension of a dye bath is reduced, dyes are adsorbed by cashmere as soon as possible and are diffused and permeated into the fibers, meanwhile, the dyes and the fibers have sufficient reaction fixation time by adjusting the dyeing process, the dye uptake is increased, meanwhile, the after-finishing process is added, so that the dyes which are not fixed are thoroughly removed, the combination of the fixed dyes and the fibers is firmer, and the color fastness of the cashmere fibers and products thereof is improved. "

The data show that the improvement of the wear-resistant color fastness of cashmere from the perspective of the dyeing process mainly comprises two aspects, namely a dyeing process and a post-treatment process. Improved dyeing processes and auxiliaries to make the bond of the fixed dye to the fiber more robust, the post-treatment enables the unfixed dye to be completely removed. In the dyeing process, the dye, the dyeing assistant and the low-temperature dyeing process play main roles, and the currently widely used reactive dye lanatin has good dyeing performance. Zeli et al, in the research on the fastness to perspiration of cashmere dyed with Lannasu red series dyes, used in the low temperature dyeing process, effectively improved the fastness to perspiration of cashmere. Therefore, in the existing process, the post-treatment is very important to improve the abrasion-resistant color fastness of cashmere.

Disclosure of Invention

The invention provides a method for improving the rubbing fastness of dark cashmere fabric, which improves the fastness of dye by improving the dyeing process and selecting a proper dyeing assistant in the cashmere dyeing process of industrial production, and reduces the loss of cashmere fiber as much as possible during removing floating color in post-treatment so as to improve the wear-resistant color fastness of dyed cashmere.

The invention realizes the purpose through the following technical scheme:

a method of improving the crockfastness of dark cashmere fabrics, said method comprising the steps of:

(1) pretreatment: adding a wetting agent into a dye vat with a bath ratio of 1: 5-10, wherein the adding amount is 0.5-1 g/L, heating to 45-50 ℃, running for 20-40 minutes, emptying, and then cleaning with clear water once;

(2) the dyeing process comprises the following steps: adding 0.5-1.0 g/L of defoaming agent into a dye vat with a bath ratio of 1: 5-10, adjusting the pH value of the solution to 4-4.3 by adding formic acid, adding formic acid A in a molar ratio, stirring for 10-15 min, continuously adding 2-3% of low-temperature dyeing auxiliary agent and 3% of lanatine dye, operating for 10-15 min, heating to 85-90 ℃ at a speed of 1.5 ℃/min, and operating for 60-75 min;

(3) alkali washing: emptying liquid of the dyed cashmere obtained in the step (2), adding clear water at a bath ratio of 1: 5-10, adding 0.4-0.6A mol of soda ash, heating to 80-85 ℃, running for 20-25 min, emptying the liquid after cooling, adding 0.5-1 g/L wetting agent for washing, carrying out secondary alkali washing after emptying, adding 0.2-0.4A times of soda ash, heating to 80-85 ℃, running for 20-25 min, cooling to 30-35 ℃, and washing for once;

(4) neutralizing: adjusting pH to 7 with formic acid, heating to 40 deg.C, running for 10min, draining, and washing again.

Further, in the alkali washing process in the step (2), 0.3A mol of soda ash is dissolved in water at the temperature of 35-45 ℃, a soda ash aqueous solution with the mass fraction of 40-50% is prepared, and the soda ash aqueous solution is added into a dye vat in a dropwise adding mode within 30-40 min.

Further, the wetting agent is ULTRAVON CN.

Further, the low-temperature dyeing auxiliary agent is MIRALAN LTD.

Further, the defoamer is ALBAFLOW CIR.

Further, the dyeing process comprises the following steps: adding 1.0g/L of defoaming agent into a dye vat with a bath ratio of 1:6, adjusting the pH value of the solution to 4 by adding formic acid, adding formic acid A in a molar ratio, stirring for 10-15 min, continuously adding 3% of low-temperature dyeing auxiliary agent and 3% of lanatin dye, operating for 15min, heating to 85-90 ℃ at a speed of 1.5 ℃/min, and operating for 75 min.

Further, the alkali washing process comprises the following steps: after liquid of dyed cashmere is emptied, clear water is added, the bath ratio is 1:6, 0.5A mol of soda ash is added, the temperature is increased to 80 ℃, the operation is carried out for 20min, the liquid is emptied after the temperature is reduced, 1g/L of wetting agent is added, the temperature is increased to 45-50 ℃, the operation is carried out for 20-40 min, the second alkali washing is carried out after the emptying, 0.2A mol of soda ash is added, the temperature is increased to 80-85 ℃, the operation is carried out for 20-25 min, and then the temperature is reduced to 30-35 ℃ for washing once.

In the present application, the wetting agent ULTRAVON CN, which is a highly efficient wetting agent, has a strong wetting efficiency, and has low foam, is added during dyeing. After the cashmere is treated by the wetting agent, the scale layer can be swelled, so that the dye can enter the fiber, and the low-foam wetting agent can reduce the surface tension of the liquid, so that the dye can be adsorbed by the cashmere and diffused into the fiber as soon as possible.

In the dyeing process, a defoaming agent ALBAFLOW CIR is added for removing air in bath liquid, and has the functions of wetting and penetration, so that the dye is uniformly distributed on the cashmere fiber and further penetrates into the fiber. During the dyeing process, the defoaming agent is added to ensure that the dyeing is uniform. If the dye is not uniformly adsorbed on the surface of the fiber, partial flooding with high dye concentration is serious, and when the flooding is removed by washing with alkali, the added alkali is excessive for the fiber with low dye concentration. At this time, in the portion where the dye concentration is low, the excessive alkali fineness may cause damage to the fiber, resulting in a decrease in abrasion resistance. Therefore, the addition of the defoaming agent during dyeing is very helpful for uniform dyeing and improvement of abrasion resistance fastness.

During dyeing, formic acid is added to adjust the pH value of the bath liquid to be 4-4.3, and too low or too high pH value can reduce the fixation rate of the dye, so that the wear resistance fastness is reduced.

In the alkaline cleaning process, alkaline cleaning is carried out twice, and the purpose of the alkaline cleaning is to remove formic acid in the bath solution on one hand and remove flooding on the other hand. During the alkaline washing process, it is important to add a proper amount of soda ash. In the prior art, in order to completely remove the flooding, the pH value of the bath liquid is controlled to be 8.0-8.5 when the soda ash is added. However, in the range of the pH value of 8.0-8.5, excessive soda is easily caused, and the cashmere fibers are damaged by the excessive soda, so that the wear-resistant color fastness is reduced. When pH valueWhen the concentration is 8.0, that is, the concentration of hydrogen ions [ H ]⁺]＝10^-8mol/L, thus [ OH⁺]＝10^-6mol/L, sodium carbonate dissociation constant of 1.78X 10^-4Thus, sodium carbonate was added at a concentration of 10^-6/(1.78×10^-4)＝0.56×10^-2The mass of soda ash added to a bath of mol/L, for example 100L, is 0.56X 10^-2mol/L × 106 × 100 ═ 59.36 g. When the pH is 8.5, [ OH ]⁺]＝3.2×10^-6mol/L, sodium carbonate dissociation constant of 1.78X 10^-4Thus, the concentration of sodium carbonate added was (3.2X 10)^-6)/(1.78×10^-4)＝1.79×10^-2mol/L, the mass of soda added in 100L bath is 1.79 multiplied by 10^-2mol/L×106×100＝189.74g。

Therefore, in the actual production, the pH value is controlled to be 8.0-8.5, the soda ash is added into 100L of bath liquid in an amount of 59.36-189.74 g, and the amount difference of the added soda ash is very large. Different workers or different production batches can therefore cause the cashmere to have completely different wear-resistance.

In the application, the amount of the soda ash is determined by the amount of formic acid, and when A mol of formic acid is added in the first alkali washing, the amount of the soda ash is 0.4-0.6A mol, and the first alkali washing is mainly used for neutralizing the formic acid in the bath liquid. And during the second step of alkaline washing, adding 0.2-0.5A mol of soda ash and adding a wetting agent. This is done to neutralize formic acid floating on the fibers, on the one hand, and to remove the floating color, on the other hand. And the mode of dropwise adding the soda solution is adopted, so that the problems that the excessive part of soda causes large layout floating amount and the reduction of the wear-resistant color fastness can be avoided. Meanwhile, the pH value of the solution after adding the sodium carbonate twice is also between 8.0 and 8.5.

Compared with the prior art, the invention has the following beneficial effects:

1. the color fixation is firmer by improving the formula of the auxiliary agent in the dyeing process.

2. And the addition of the soda twice is adopted, and the amount of the added soda is accurately calculated, so that the excessive soda is prevented from being added, and the damage to the fibers is reduced. Not only the color fastness to abrasion is improved from the viewpoint of removing the flooding, but also the color fastness to abrasion is improved by reducing the damage of the fiber by controlling the using amount of the soda ash.

Detailed Description

Example 1

A method for improving the rubbing fastness of dark cashmere fabric comprises the steps of dyeing cashmere into black, pretreating loose cashmere in the first step, adding 100kg of cashmere and 600L of clear water into a dye vat, adding 300g of wetting agent ULTRAVON CN, heating to 45-50 ℃, running for 40 minutes, emptying, and cleaning once with clear water; adding 600L of clear water into a dye vat, adding 300g of defoaming agent ALBAFLOW CIR, adjusting the pH value of bath liquid to be 4-4.3 by adding formic acid, adding 1.3kg of formic acid (26.26 mol) at the moment, stirring for 15min, continuously adding 2kg of low-temperature dyeing auxiliary agent MIRALAN LTD and 3kg of black lanner dye, heating to 85 ℃ at the speed of 1.5 ℃/min after running for 15min, and running for 75 min; the third step is alkaline washing, wherein after the dyed cashmere is emptied, 800L of clear water is added, 12.26 moles of soda are added, namely 1.3kg of soda is added, 1.3kg of soda is dissolved in water, a soda water solution with the mass fraction of 40-50% is prepared, the soda water solution is added into a dye vat in a dropping mode within 30-40 min, the temperature is increased to 80 ℃, the operation is carried out for 25min, the liquid is emptied after the temperature is reduced, then 500g/L of wetting agent is added, the temperature is increased to 45-50 ℃, the operation is carried out for 20-40 min, the secondary alkaline washing is carried out after the emptying, 0.65kg of soda is added, the temperature is increased to 80 ℃, the operation is carried out for 25min, and then the temperature is reduced to 30-35 ℃ for washing once; and the fourth step is neutralization, the pH value is adjusted to 7 by formic acid, the temperature is raised to 40 ℃, after 10min of operation, the liquid is emptied, washed once again, and dried to obtain black cashmere.

After the dyeing and finishing by the process, the friction color fastness of the cashmere is tested by the method in GB/T3920. The resulting crocking fastness was grade 4.

Comparative example 2

The same parameters and procedures as in example 1 except for the components in the table give the following crockfastness:

the foregoing illustrates and describes the principles, general features, and advantages of the present invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed.