阅读说明：本技术 一种棉针织物高效染色方法 (Efficient dyeing method for cotton knitted fabric ) 是由 左凯杰 何瑾馨 张东润 王存山 王碧华 黄庄芳容 于 2021-03-12 设计创作，主要内容包括：本发明提供了一种棉针织物高效染色方法,涉及织物染色技术领域。本发明对棉针织物进行染色的方法是利用活性染料和元明粉对织物进行染色,染色后再浸轧碱液,并快速降低织物中的带水率,再对织物进行密封固色,大幅降低了活性染料的水解,提高了染色固色率。(The invention provides a high-efficiency dyeing method for cotton knitted fabrics, and relates to the technical field of fabric dyeing. The method for dyeing the cotton knitted fabric comprises the steps of dyeing the fabric by using the reactive dye and the anhydrous sodium sulphate, padding the fabric with alkali liquor after dyeing, rapidly reducing the water carrying rate in the fabric, and performing sealed color fixation on the fabric, so that the hydrolysis of the reactive dye is greatly reduced, and the dyeing color fixation rate is improved.)

1. The efficient dyeing method for the cotton knitted fabric is characterized by comprising the following steps of:

(1) pretreatment, namely pretreating the cotton knitted fabric;

(2) dyeing, namely soaking the pretreated fabric in a dye solution containing reactive dye and anhydrous sodium sulphate for dyeing;

(3) padding with alkali liquor, taking out the dyed fabric, squeezing, padding the fabric in 10-20g/L of soda solution with the residual rate of 70-80%, wherein the dyeing residual liquid after dyeing is left for standby;

(4) and (3) quick drying, namely taking out the fabric treated in the step (3), and quickly drying the fabric for 1-3min until the liquid carrying rate of the fabric is reduced to 30% -40%;

(5) sealing and baking, namely filling the quickly dried fabric into a sealing bag for sealing, and putting the sealing bag into a baking box for baking, wherein the baking temperature is 70-100 ℃, and the baking time is 10-60 min;

(6) and (3) washing and drying, taking out the sealed and baked fabric, washing with water and neutralizing with acid in sequence, soaping for 5-20min at 95 ℃ by using a soaping agent with the concentration of 1-5g/L, washing with water again, and drying to obtain the dyed cotton knitted fabric.

2. The efficient dyeing method of the cotton knitted fabric according to claim 1, characterized in that the pretreatment of the cotton knitted fabric in the step (1) is to treat the cotton knitted fabric by adopting a traditional alkaline-oxygen process, a tea saponin ecological bleaching process, a low-temperature activated bleaching process or a low-alkali catalytic bleaching process so as to obtain the fabric with the whiteness of 65-75 and the capillary effect of 8-18cm/30 min.

3. The efficient dyeing method for the cotton knitted fabric according to claim 1, characterized in that the concentration of the reactive dye in the dyeing solution in the step (2) is 0.1-10g/L, and the concentration of the anhydrous sodium sulphate is 20-80 g/L.

4. The efficient dyeing method for the cotton knitted fabric according to claim 1, characterized in that the dyeing process in the step (2) is to run the fabric in the dye solution for 5-10min, then to heat up to 60-80 ℃ at a heating rate of 1-2 ℃/min, then to maintain the temperature for 20-40min, and finally to run for 10-20min after cooling to 30 ℃.

5. The efficient dyeing method for the cotton knitted fabric according to claim 1, characterized in that the dyeing residual liquid after dyeing treatment is supplemented with reactive dyes and anhydrous sodium sulphate to reach the concentration before dyeing and is recycled.

6. The method for efficiently dyeing the cotton knitted fabric according to claim 1, wherein the step (4) is to rapidly dry the fabric by non-direct contact heating.

7. The method for efficiently dyeing the cotton knitted fabric according to claim 1, wherein the soaping agent in the step (6) is an anionic soaping agent for cotton.

8. The efficient dyeing method for cotton knitted fabric according to claim 1, characterized in that the drying temperature in step (6) is 130-160 ℃ and the drying time is 1.5-3 min.

Technical Field

The invention relates to the technical field of fabric printing and dyeing, in particular to a high-efficiency dyeing method for cotton knitted fabrics.

Background

Most of the traditional cotton knitted fabrics are dyed by dip dyeing with reactive dyes in an overflow dyeing machine or an airflow dyeing machine, a large amount of inorganic salt (anhydrous sodium sulphate or salt) is consumed to accelerate dyeing in the dip dyeing process, and then the reactive dyes are subjected to color fixing reaction by using soda ash to ensure that the reactive dyes are combined with primary hydroxyl groups on cotton fibers by covalent bonds; after dyeing, still need carry out washing, acid neutralization repeatedly, get rid of most saline and alkaline on the fabric, carry out high temperature soaping again, will adsorb the loose color dyestuff or the hydrolysis dyestuff on the fibre thoroughly and get rid of to guarantee that the fastness of fabric reaches customer's demand. However, the conventional dip dyeing technique causes the following problems to the printed and dyed cotton knitted fabric:

the reactive dye has the advantages that the color fixing rate is not high, only about 60-70%, and the reason is that the reactive dye can be subjected to hydrolysis reaction with water under an alkaline condition while being fixed, the hydrolyzed dye can not react with fibers any more, the wastewater treatment difficulty is increased along with the discharge of dyeing wastewater, and the resource waste is caused;

in the dyeing process, a large amount of salt and alkali electrolytes are used, so that the printing and dyeing wastewater has high salinity and is easy to cause salinization of the land.

Therefore, how to reduce the hydrolysis of the dye in the dyeing process of the cotton knitted fabric and improve the fixation rate and the dyeing stability of the cotton knitted fabric is a problem to be solved by the industry at present.

Disclosure of Invention

In view of the above, the invention provides an efficient dyeing method for cotton knitted fabrics, which is characterized in that reactive dyes and anhydrous sodium sulphate are used for dyeing fabrics, alkali liquor is padded after dyeing, the water carrying rate of the fabrics is rapidly reduced, and then the fabrics are sealed and fixed, so that the hydrolysis of the dyes is greatly reduced, and the color fixing rate is improved.

The efficient dyeing method of the cotton knitted fabric comprises the following steps:

(1) pretreatment, namely pretreating the cotton knitted fabric;

(2) dyeing, namely soaking the pretreated fabric in a dye solution containing reactive dye and anhydrous sodium sulphate for dyeing;

(3) padding with alkali liquor, taking out the dyed fabric, squeezing, padding the fabric in 10-20g/L sodium carbonate solution with the residual rate of 70-80%, wherein the dyeing residual liquid after dyeing is left for standby;

(4) and (3) quick drying, namely taking out the fabric treated in the step (3), and quickly drying the fabric for 1-3min until the liquid carrying rate of the fabric is reduced to 30% -40%;

(5) sealing and baking, namely filling the quickly dried fabric into a sealing bag for sealing, and putting the sealing bag into a baking box for baking, wherein the baking temperature is 70-100 ℃, and the baking time is 10-60 min;

(6) and (3) washing and drying, taking out the sealed and baked fabric, washing with water and neutralizing with acid in sequence, soaping for 5-20min at 95 ℃ by using a soaping agent with the concentration of 1-5g/L, washing with water again, and drying to obtain the dyed cotton knitted fabric.

Preferably, the pretreatment of the cotton knitted fabric in the step (1) of the invention is to treat the cotton knitted fabric by adopting a traditional alkaline-oxygen process, a tea saponin ecological bleaching process, a low-temperature activation bleaching process or a low-alkali catalytic bleaching process so as to obtain the fabric with the whiteness of 65-75 and the capillary effect of 8-18cm/30 min.

Preferably, the concentration of the reactive dye in the dye liquor in the step (2) of the invention is 0.1-10g/L, and the concentration of the anhydrous sodium sulphate is 20-80 g/L.

Preferably, the dyeing process in the step (2) of the invention is to run the fabric in the dye solution for 5-10min, then heat up to 60-80 ℃ at a heating rate of 1-2 ℃/min, then hold the temperature for 20-40min, finally cool down to 30 ℃ and run for 10-20 min.

Preferably, the reactive dye and the anhydrous sodium sulphate are supplemented to the dyeing residual liquid after the dyeing treatment so as to reach the concentration before dyeing, and the dyeing residual liquid is recycled.

Preferably, step (4) of the present invention is to rapidly dry the fabric by indirect contact heating.

Preferably, the soaping agent in the step (6) of the invention is an anionic soaping agent for cotton.

Preferably, the drying temperature in step (6) of the present invention is 130-.

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

1) according to the invention, the fabric is dyed only by using the reactive dye and the anhydrous sodium sulphate as the dye solution, and the soda ash is not used in the dye solution, so that the dye is prevented from being hydrolyzed under the alkaline condition, compared with the existing continuous vat dyeing technology, the utilization rate of the dye is higher, and the dye and the anhydrous sodium sulphate can be recycled after being supplemented;

2) after the dyed fabric is quickly dried, the fabric is hermetically dried under the condition that the water carrying rate is 30-40%, so that the hydrolysis of the dye is further reduced, the color fixing rate of the dye is improved, and the color fixing rate is improved by over 10%;

3) after the fabric is dyed, the color fastness of the dye is stable, and the risk of fastness reduction is avoided.

Drawings

FIG. 1 is a graph of the linear relationship between conductivity and concentration of anhydrous sodium sulfate.

Detailed Description

The present invention will be further described with reference to the following examples.

Example 1

A high-efficiency dyeing method for cotton knitted fabrics comprises the following steps:

(1) pretreatment, namely pretreating cotton single-sided cloth (cotton 26S, 100%) by adopting a traditional alkaline oxidation process: cotton single-side cloth is placed in a solution containing the following raw materials: 0.4g/L of penetrating agent, 1g/L of emulsifier, 0.56g/L of hydrogen peroxide stabilizer, 2.5g/L of caustic soda and 7g/L of hydrogen peroxide; soaking at 98 deg.C for 45min, and pre-treating to obtain fabric with whiteness of 74.56 and capillary effect of 15.9cm/30 min;

(2) dyeing treatment, namely soaking 3g of the pretreated fabric in 0.06L of dye liquor for dyeing, wherein the dye liquor is formed by mixing reactive dye, anhydrous sodium sulphate and water, the reactive dye in the dye liquor is H-E3B red dye and has the concentration of 1g/L, and the concentration of the anhydrous sodium sulphate is 60 g/L;

the dyeing process is that the fabric is run in dye liquor for 10min, then the temperature is raised to 80 ℃ at the temperature raising rate of 2 ℃/min, the temperature is maintained for 30min, then the temperature is lowered to 30 ℃ at the temperature lowering rate of 2 ℃/min, and the fabric is run for 20 min;

(3) padding with alkali liquor, taking out the dyed fabric, squeezing, and padding the fabric in 20g/L sodium carbonate solution with the rolling residual rate of 75%;

(4) quick drying, namely taking out the fabric treated in the step (3), and quickly drying by adopting hot air at the temperature of 80 ℃, wherein the drying time is 2min, and the liquid carrying rate of the fabric is reduced to 30%;

(5) sealing and baking, namely filling the quickly dried fabric into a sealing bag for sealing, and putting the sealing bag into a baking box for baking treatment, wherein the baking temperature is 90 ℃, and the baking time is 50 min;

(6) washing with water, drying, taking out the sealed and baked fabric, washing with water and neutralizing with acid in sequence, soaping with 2g/L FW-A06 soaping agent at 95 ℃ for 15min, washing with water again, and drying at 150 ℃ for 1.5min to obtain dyed cotton knitted fabric;

(7) and (3) supplementing reactive dye and anhydrous sodium sulphate to the dyeing residual liquid after dyeing treatment to reach the concentration before dyeing, and recycling, namely repeating the steps (1) - (6) to carry out continuous vat dyeing for 5 times.

Wherein the dye raffinate after the dyeing treatment is supplemented with water to 0.06L, the absorbance of the dye raffinate is respectively measured to be 0.0318, the conductivity is 109.7us/cm (both measured after being diluted by 100 times, the same is applied below), the absorbance of the dyeing solution in the step (2) is 0.2420, and the conductivity is 128.2 us/cm.

a. Calculation of dye addition

Calculating the amount of the dye to be added for continuous cup dyeing (1-0.0318/0.2420) multiplied by 1 multiplied by 0.06 to 0.0521g by utilizing the direct proportion relation between the absorbance of the dye and the concentration under low concentration;

b. calculation of sodium sulfate supplement

The conductivity of the anhydrous sodium sulfate at low concentration is in a linear relation with the concentration, as shown in figure 1; the relationship between conductivity y and anhydrous sodium sulphate concentration x can be found as follows: y 148.1x + 43.867.

Substituting the formula can obtain that the anhydrous sodium sulphate concentration of the dyeing standard solution in the step (2) is 56.94g/L, and the anhydrous sodium sulphate concentration of the dyeing residual solution is 44.45g/L, so that the mass of the anhydrous sodium sulphate to be supplemented is 0.7896 g.

Example 2

A high-efficiency dyeing method for cotton knitted fabrics comprises the following steps:

(1) pretreatment, namely adopting a tea saponin pretreatment process to cotton single-sided cloth (cotton 26S, 100%): cotton single-side cloth is placed in a solution containing the following raw materials:

refining penetrant AP8000.5g/L, tea saponin HD-1907 g/L; soaking at 98 deg.C for 50 min. The whiteness of the treated fabric is 75.65, and the capillary effect is 14.6 cm;

(2) dyeing treatment, namely soaking 3g of the pretreated fabric in 0.06L of dye liquor for dyeing, wherein the dye liquor is formed by mixing reactive dye, anhydrous sodium sulphate and water, the reactive dye in the dye liquor is reactive brilliant blue KN-R, the concentration of the reactive dye is 1g/L, and the concentration of the anhydrous sodium sulphate is 60 g/L;

the dyeing process is that the fabric is run in dye liquor for 10min, then the temperature is raised to 80 ℃ at the temperature raising rate of 2 ℃/min, the temperature is maintained for 30min, then the temperature is lowered to 30 ℃ at the temperature lowering rate of 2 ℃/min, and the fabric is run for 20 min;

(3) padding with alkali liquor, taking out the dyed fabric, squeezing, and padding the fabric in 20g/L sodium carbonate solution with the rolling residual rate of 75%;

(4) quick drying, namely taking out the fabric treated in the step (3), and quickly drying by adopting hot air at the temperature of 80 ℃, wherein the drying time is 2min, and the liquid carrying rate of the fabric is reduced to 30%;

(5) sealing and baking, namely filling the quickly dried fabric into a sealing bag for sealing, and putting the sealing bag into a baking box for baking treatment, wherein the baking temperature is 80 ℃, and the baking time is 20 min;

(6) washing, drying, taking out the sealed and baked fabric, washing with water and neutralizing with acid in sequence, soaping with 2g/L FW-A06 soaping agent at 95 ℃ for 5-20min, washing with water again, and drying at 150 ℃ for 1.5min to obtain dyed cotton knitted fabric;

(7) and (3) supplementing the dyeing residual liquid after the dyeing treatment with reactive dye and anhydrous sodium sulphate according to the mode of the example 1 to reach the concentration before dyeing, and recycling the dyeing residual liquid, namely repeating the steps (1) to (6) to perform continuous vat dyeing for 5 times.

Example 3

A high-efficiency dyeing method for cotton knitted fabrics comprises the following steps:

(1) pretreating cotton single-sided cloth (cotton 26S, 100%) by adopting a low-alkali catalytic bleaching process; namely, the cotton single side is arranged in a solution containing the following raw materials:

oenolan SuperBLUE 1g/L, NaOH 1.1g/L, H₂O₂7g/L；

Soaking at 98 deg.C for 45 min; the whiteness of the pretreated fabric is 75.24, and the capillary effect is 17.2 cm;

(2) dyeing treatment, namely soaking 3g of the pretreated fabric in 0.06L of dye liquor for dyeing, wherein the dye liquor is formed by mixing reactive dye, anhydrous sodium sulphate and water, the reactive dye in the dye liquor is reactive red R-3BS, the concentration of the reactive dye is 1g/L, and the concentration of the anhydrous sodium sulphate is 60 g/L;

the dyeing process is that the fabric is run in dye liquor for 10min, then the temperature is raised to 80 ℃ at the temperature raising rate of 2 ℃/min, the temperature is maintained for 30min, then the temperature is lowered to 30 ℃ at the temperature lowering rate of 2 ℃/min, and the fabric is run for 20 min;

(3) padding with alkali liquor, taking out the dyed fabric, squeezing, and padding the fabric in 20g/L sodium carbonate solution with the rolling residual rate of 75%;

(4) fast drying, namely taking out the fabric treated in the step (3), and fast drying by adopting hot air with the temperature of 80 ℃ for 2min, wherein the liquid carrying rate of the fabric is reduced to 30%;

(5) sealing and baking, namely filling the quickly dried fabric into a sealing bag for sealing, and putting the sealing bag into a baking box for baking treatment, wherein the baking temperature is 80 ℃, and the baking time is 25 min;

(6) washing, drying, taking out the sealed and baked fabric, washing with water and neutralizing with acid in sequence, soaping with FW-A06 soaping agent with the concentration of 5g/L at 95 ℃ for 5-20min, washing with water again, and drying at 150 ℃ for 1.5min to obtain dyed cotton knitted fabric;

(7) and (3) supplementing the dyeing residual liquid after the dyeing treatment with reactive dye and anhydrous sodium sulphate according to the mode of the example 1 to reach the concentration before dyeing, and recycling the dyeing residual liquid, namely repeating the steps (1) to (6) to perform continuous vat dyeing for 5 times.

Example 4

A high-efficiency dyeing method for cotton knitted fabrics comprises the following steps:

(1) pretreatment, namely, adopting a low-temperature activation bleaching process to the cotton single-sided cloth (26S cotton, 100%), namely placing the cotton single-sided cloth in a solution containing the following raw materials:

refining penetrant AP8000.8g/L, refining emulsifier SEN 1g/L, TAED 3g/L, NaOH 1g/L, H₂O₂7g/L；

Then soaking for 60min at 80 ℃; the whiteness of the treated fabric is 64.74, and the capillary effect is 9.1 cm;

(2) dyeing, namely soaking 3g of the pretreated fabric in 0.06L of dye liquor for dyeing, wherein the dye liquor is formed by mixing reactive dye, anhydrous sodium sulphate and water, the reactive dye in the dye liquor is reactive Black RGB and has the concentration of 2g/L, and the concentration of the anhydrous sodium sulphate is 60 g/L;

the dyeing process is that the fabric is run in dye liquor for 10min, then the temperature is raised to 80 ℃ at the temperature raising rate of 2 ℃/min, the temperature is maintained for 30min, then the temperature is lowered to 30 ℃ at the temperature lowering rate of 2 ℃/min, and the fabric is run for 20 min;

(3) padding with alkali liquor, taking out the dyed fabric, squeezing, and padding the fabric in 20g/L sodium carbonate solution with the rolling residual rate of 75%;

(4) fast drying, namely taking out the fabric treated in the step (3), and fast drying by adopting hot air with the temperature of 80 ℃ for 2min, wherein the liquid carrying rate of the fabric is reduced to 30%;

(5) sealing and baking, namely filling the quickly dried fabric into a sealing bag for sealing, and putting the sealing bag into a baking box for baking treatment, wherein the baking temperature is 80 ℃, and the baking time is 10 min;

(6) washing with water, drying, taking out the sealed and baked fabric, washing with water and neutralizing with acid in sequence, soaping with FW-A06 soaping agent with concentration of 5g/L at 95 ℃ for 5-20min, washing with water again, and drying at 150 ℃ for 1.5min to obtain dyed cotton knitted fabric;

(7) and (3) supplementing the dyeing residual liquid after the dyeing treatment with reactive dye and anhydrous sodium sulphate according to the mode of the example 1 to reach the concentration before dyeing, and recycling the dyeing residual liquid, namely repeating the steps (1) to (6) to perform continuous vat dyeing for 5 times.

Comparative example 1

The cotton single-faced fabric of example 1 was treated with H-E3B red dye using a conventional dyeing process, the steps of which were as follows:

(1) the pretreatment of the cotton fabric was the same as in example 1;

(2) immersing 3g of pretreated fabric in 0.06L of dye liquor for dyeing, wherein the dye liquor is formed by mixing reactive dye, anhydrous sodium sulphate and water, the reactive dye in the dye liquor is H-E3B red dye and has the concentration of 1g/L, the concentration of the anhydrous sodium sulphate is 60g/L, after 10min of operation, heating to 80 ℃ according to the heating rate of 1 ℃/min, adding 1.2g of soda ash, preserving heat for 45min, and finishing dyeing;

(3) and (3) washing the dyed fabric with water and neutralizing the dyed fabric with acid, soaping the dyed fabric for 15min at 95 ℃ by using a soaping agent FW-A06 with the concentration of 2g/L, and drying the dyed fabric for 1.5min at 150 ℃ after washing again to obtain the dyed cotton knitted fabric.

Comparative example 2

The cotton fabric is pretreated in the same way as in example 2, the cotton single-sided cloth in example 2 is treated by using reactive brilliant blue KN-R according to the traditional dyeing process of comparative example 1, and only the dyeing temperature is changed from 80 ℃ to 60 ℃.

Comparative example 3

Pretreatment of Cotton Fabric As in example 3, the cotton single-faced fabric of example 3 was treated with reactive Red R-3BS according to the conventional dyeing method of comparative example 2

Comparative example 4

Pretreatment of cotton fabric the same as in example 4, the cotton single-faced fabric of example 4 was treated with reactive Black RGB according to the conventional dyeing process of comparative example 2.

Cotton single-side cloths were cup dyed according to the procedure of examples 1-4 and their stability was determined as shown in table 1.

TABLE 1 continuous cup dyeing stability

The fixation degrees of the dyed fabrics obtained in examples 1 to 4 and comparative documents 1 to 4 were measured as shown in table 2.

TABLE 2

It can be seen from table 2 that the dye fixation rate of the dye in the fabric can be improved by more than 10% by adopting the dyeing process of the invention.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.