Dyeing method of cotton fabric

Abstract

The invention belongs to the technical field of cotton fabrics, and particularly relates to a dyeing method of a cotton fabric, which comprises the following steps: cleaning the cotton fabric by adopting an ethanol aqueous solution and sodium bicarbonate, then forming permeation treatment and expansion treatment by using sodium chloride and sodium bicarbonate, and finally dyeing, fixing and washing in a weak base environment. And drying to obtain the dyed cotton fabric. The problem of poor dyeing stability of the existing cotton fabric is solved, the surface area of the cotton fabric is increased by utilizing the permeability of the sodium chloride alcohol solution and the decomposition and expansion of the ammonium bicarbonate, and the stable dyeing effect is realized by matching with the curing of the weakly alkaline reactive dye.

Description

Technical Field

[0001] The invention belongs to the technical field of cotton fabrics, and particularly relates to a cotton fabric dyeing method. Background Art

[0002] Cotton fabric is a fabric made of cotton and produced by textile technology. This type of fabric has the characteristics of moisture absorption, warmth retention, heat resistance, alkali resistance, and hygiene. Cotton fabric has become one of the representatives of high-end fabrics with its excellent skin-friendliness and good moisture absorption. With the development of clothing technology and the continuous improvement of clothing requirements, the dyeing requirements of cotton fabrics are getting higher and higher. Dip dyeing is a more conventional cotton fabric dyeing method, which is generally dyed through a dye vat. However, this dyeing method is to soak the cotton fabric in the dye solution and achieve excellent dyeing effects through the penetration of the dye solution into the cotton fabric. In the actual processing process, cotton fabrics are very prone to unstable fabric absorption and poor dye penetration, resulting in poor dyeing effects and reduced durability of cotton fabrics, which is not conducive to the promotion and use of cotton fabrics. Summary of the invention

[0003] In view of the problems in the prior art, the present invention provides a method for dyeing cotton fabrics, which solves the problem of poor dyeing stability of the existing cotton fabrics. The permeability of sodium chloride alcohol solution and the decomposition and expansion of ammonium bicarbonate are utilized to increase the surface area of ​​the cotton fabric, and the weakly alkaline active dye is solidified to achieve a stable dyeing effect.

[0004] In order to achieve the above technical objectives, the technical solution of the present invention is:

[0005] A method for dyeing cotton fabrics comprises the following steps:

[0006] Step 1, putting cotton fabric into ethanol aqueous solution and stirring evenly, then adding sodium bicarbonate and stirring until completely dissolved, taking out after ultrasonic treatment for 1-2h, and drying to obtain clean cotton fabric; the volume proportion of ethanol in the ethanol aqueous solution is 20-30%, the mass ratio of cotton fabric to ethanol aqueous solution is 1:10-14, the stirring speed for uniform stirring is 300-600r / min, the concentration of sodium bicarbonate is 10-40g / L, the ultrasonic frequency of the ultrasonic treatment is 70-90kHz, and the temperature is 20-30℃; the drying temperature is 50-70℃; in this step, the ethanol aqueous solution is used to stir and clean the cotton fabric, the surface dust and impurities on the cotton fabric are removed, and the emulsification property of the sodium bicarbonate solution is used to remove the oil agent, so as to achieve the cleaning of the cotton fabric;

[0007] Step 2, adding sodium chloride to ethanol and stirring evenly, adding ammonium bicarbonate and grinding for 10-20min, then adding ethanol to expand the solution, adding cotton fabric to perform low-temperature ultrasonic treatment, taking it out and drying it to obtain the permeated polyester fabric, the mass ratio of sodium chloride to ethanol is 2:0.5-1, the mass ratio of ammonium bicarbonate to sodium chloride is 1:0.2-0.3, the grinding treatment temperature is 5-10°C, the pressure is 0.5-0.7MPa, the sodium chloride concentration after expansion is 50-100g / L, the concentration of the cotton fabric in ethanol is 50-100g / L, and the temperature of the low-temperature ultrasonic treatment is 5-10°C , the ultrasonic frequency is 80-100kHz, and the drying temperature is 10-14°C; this step utilizes the insolubility of sodium chloride in ethanol and converts it into sodium chloride sol. After blending with ammonium bicarbonate, grinding can use the sodium chloride in the form of fine particles as abrasive particles, and the ammonium bicarbonate is miniaturized and gradually converted into fine particles. Finally, under the dissolution effect of ethanol, a suspension of ammonium bicarbonate colloid is obtained. After the cotton fabric is added, low-temperature ultrasonic treatment is performed. Under the action of ethanol permeability and ultrasonic stripping, the ammonium bicarbonate penetrates into the gaps of the cotton fabric, and forms in-situ precipitation during the process of taking it out and drying it; the low temperature condition can ensure that the ammonium bicarbonate remains stable;

[0008] Step 3, after overlapping the permeated cotton fabrics, constant temperature extrusion for 20-30 minutes, and then slowly releasing the pressure to obtain expanded cotton fabrics, the pressure of the constant temperature extrusion is 0.4-0.7MPa, the temperature is 60-70°C; the speed of the slow pressure release is 0.02-0.04MPa / min, and the temperature is 20-30°C; in this step, the permeated cotton fabrics are overlapped to increase the thickness of the fabrics and improve the feasibility. During the constant temperature extrusion process, the temperature drops and the ammonium bicarbonate decomposes to form gas, but the extruded pressure is ground into the gap, and as the slow pressure release proceeds, the gap is continuously opened, thereby forming a puffing effect;

[0009] Step 4, placing the expanded cotton fabric in ethanol for ultrasonic treatment for 5-10 minutes, then adding distilled water and stirring for 1-2 hours, taking it out and airing it to semi-dry, and freeze-drying to obtain the cotton fabric to be dyed, wherein the mass ratio of the expanded cotton fabric to ethanol is 1:5-7, the frequency of the ultrasound is 70-90kHz, and the temperature is 20-30°C; the amount of distilled water added is 10-20% of the volume of ethanol, and the freeze-drying temperature is -20°C; in this step, the expanded cotton fabric is placed in ethanol for ultrasonic treatment to peel off the residual sodium chloride, and at the same time, by adding and stirring distilled water and cooperating with the mutual solubility of distilled water and ethanol, the sodium chloride is completely dissolved to obtain a clean expanded cotton fabric, and in the process of airing it to semi-dry, ethanol can be volatilized in the drying process to form a water-containing cotton fabric, and the expanded cotton fabric is obtained in the freeze drying, and the hydroxyl groups in the cotton fabric are completely exposed;

[0010] Step 5, adding active dye and sodium carbonate into water and stirring evenly to form a dye liquor, then immersing the cotton fabric to be dyed into the dye liquor for dyeing, and drying after fixing, washing and drying to obtain the dyed cotton fabric; in the dye liquor, the concentration of the active dye is 10-50g / L, the concentration of sodium carbonate is 8-30g / L, the active dye is one or more of active yellow O, active red R or active blue B, and the dyeing temperature is 40-50°C; the fixing is carried out in a sodium carbonate solution, and the concentration of the sodium carbonate solution is 5-10g / L, and the temperature is 70-80°C; the drying temperature is 70-90°C; this step utilizes the activity of the active dye in a weak alkaline environment to form a covalent reaction with the hydroxyl group in the cotton dye, thereby achieving a good dyeing effect, and utilizes the curing effect of the weak alkaline environment to improve the overall levelness, thereby achieving the dyeing effect, and cooperates with the shrinkage of cotton fibers under the temperature system to improve the fixation of the active dye, and solves the problem of excessive swelling of the cotton fabric.

[0011] It can be seen from the above description that the present invention has the following advantages:

[0012] 1. The present invention solves the problem of poor dyeing stability of existing cotton fabrics. The permeability of sodium chloride alcohol solution and the decomposition and expansion of ammonium bicarbonate are utilized to increase the surface area of ​​the cotton fabric, and the weakly alkaline reactive dye is solidified to achieve a stable dyeing effect.

[0013] 2. The present invention utilizes sodium carbonate to form a weak alkaline environment to improve the surface activity of the reactive dyes, thereby achieving the fixation of the reactive dyes. At the same time, the high temperature fixation of the weak alkaline environment is utilized to improve the chemical connection stability of the reactive dyes, and the high temperature tightening of the cotton fabric is combined to achieve physical shrinkage fixation of the reactive dyes.

[0014] 3. The present invention utilizes the solubility of ethanol aqueous solution, combined with the emulsification of sodium bicarbonate and the ultrasonic peeling property, to effectively clean cotton fabrics and improve the cleanliness of cotton fabrics. DETAILED DESCRIPTION

[0015] The present invention is described in detail with reference to the embodiments, but no limitation is imposed on the claims of the present invention.

[0016] Example 1

[0017] A method for dyeing cotton fabrics comprises the following steps:

[0018] Step 1, putting cotton fabric into ethanol aqueous solution and stirring evenly, then adding sodium bicarbonate and stirring until completely dissolved, taking it out after ultrasonic treatment for 1 hour, and drying it to obtain clean cotton fabric; the volume proportion of ethanol in the ethanol aqueous solution is 20%, the mass ratio of cotton fabric to ethanol aqueous solution is 1:10, the stirring speed for uniform stirring is 300r / min, the concentration of sodium bicarbonate is 10g / L, the ultrasonic frequency of the ultrasonic treatment is 70kHz, the temperature is 20°C; the drying temperature is 50°C;

[0019] Step 2, adding sodium chloride to ethanol and stirring evenly, adding ammonium bicarbonate and grinding for 10 minutes, then adding ethanol to expand the solution, adding cotton fabric to perform low-temperature ultrasonic treatment, taking it out and drying it to obtain the infiltrated polyester fabric, the mass ratio of sodium chloride to ethanol is 2:0.5, the mass ratio of ammonium bicarbonate to sodium chloride is 1:0.2, the grinding treatment temperature is 5°C, the pressure is 0.5MPa, the sodium chloride concentration after expansion is 50g / L, the concentration of the cotton fabric in ethanol is 50g / L, the temperature of the low-temperature ultrasonic treatment is 5°C, the ultrasonic frequency is 80kHz, and the drying temperature is 10°C;

[0020] Step 3, overlapping the permeated cotton fabrics and extruding them at a constant temperature for 20 minutes, and then slowly releasing the pressure to obtain an expanded cotton fabric, wherein the pressure of the constant temperature extrusion is 0.4 MPa and the temperature is 60° C.; the speed of the slow pressure release is 0.02 MPa / min and the temperature is 20° C.;

[0021] Step 4, placing the expanded cotton fabric in ethanol and ultrasonicating it for 5 minutes, then adding distilled water and stirring it for 1 hour, taking it out and airing it until it is half dry, and freeze-drying it to obtain the cotton fabric to be dyed, wherein the mass ratio of the expanded cotton fabric to ethanol is 1:5, the frequency of the ultrasonication is 70kHz, and the temperature is 20°C; the amount of the distilled water added is 10% of the volume of the ethanol, and the freeze-drying temperature is -20°C;

[0022] Step 5, adding active dye and sodium carbonate into water and stirring evenly to form a dye solution, then immersing the cotton fabric to be dyed into the dye solution for dyeing, fixing, washing and drying to obtain the dyed cotton fabric; in the dye solution, the concentration of the active dye is 10g / L, the concentration of sodium carbonate is 8g / L, the active dye is active yellow O, and the dyeing temperature is 40°C; the fixing is carried out in a sodium carbonate solution, and the concentration of the sodium carbonate solution is 10g / L, and the temperature is 80°C; the drying temperature is 90°C.

[0023] Example 2

[0024] A method for dyeing cotton fabrics comprises the following steps:

[0025] Step 1, putting cotton fabric into ethanol aqueous solution and stirring evenly, then adding sodium bicarbonate and stirring until completely dissolved, taking it out after ultrasonic treatment for 2 hours, and drying it to obtain clean cotton fabric; the volume proportion of ethanol in the ethanol aqueous solution is 30%, the mass ratio of cotton fabric to ethanol aqueous solution is 1:14, the stirring speed for uniform stirring is 600r / min, the concentration of sodium bicarbonate is 20g / L, the ultrasonic frequency of the ultrasonic treatment is 80kHz, the temperature is 25°C; the drying temperature is 70°C;

[0026] Step 2, adding sodium chloride to ethanol and stirring evenly, adding ammonium bicarbonate and grinding for 20 minutes, then adding ethanol to expand the solution, adding cotton fabric to perform low-temperature ultrasonic treatment, taking it out and drying it to obtain a permeated polyester fabric, the mass ratio of sodium chloride to ethanol is 2:1, the mass ratio of ammonium bicarbonate to sodium chloride is 1:0.3, the grinding treatment temperature is 8°C, the pressure is 0.6MPa, the sodium chloride concentration after expansion is 100g / L, the concentration of the cotton fabric in ethanol is 100g / L, the temperature of the low-temperature ultrasonic treatment is 10°C, the ultrasonic frequency is 100kHz, and the drying temperature is 14°C;

[0027] Step 3, overlapping the permeated cotton fabrics and extruding them at a constant temperature for 25 minutes, and then slowly releasing the pressure to obtain an expanded cotton fabric, wherein the pressure of the constant temperature extrusion is 0.6 MPa and the temperature is 65° C.; the speed of the slow pressure release is 0.03 MPa / min and the temperature is 25° C.;

[0028] Step 4, placing the expanded cotton fabric in ethanol and ultrasonicating for 10 minutes, then adding distilled water and stirring for 2 hours, taking it out and airing it until it is half dry, and freeze-drying it to obtain the cotton fabric to be dyed, wherein the mass ratio of the expanded cotton fabric to ethanol is 1:6, the frequency of the ultrasound is 80 kHz, and the temperature is 25° C.; the amount of distilled water added is 15% of the volume of ethanol, and the freeze-drying temperature is -20° C.;

[0029] Step 5, adding active dye and sodium carbonate into water and stirring evenly to form a dye solution, then immersing the cotton fabric to be dyed into the dye solution for dyeing, fixing, washing and then drying to obtain the dyed cotton fabric; in the dye solution, the concentration of the active dye is 50g / L, the concentration of sodium carbonate is 10g / L, the active dye is reactive blue B, and the dyeing temperature is 45°C; the fixing is carried out in a sodium carbonate solution, and the concentration of the sodium carbonate solution is 8g / L, and the temperature is 80°C; the drying temperature is 80°C.

[0030] Example 3

[0031] A method for dyeing cotton fabrics comprises the following steps:

[0032] Step 1, putting cotton fabric into ethanol aqueous solution and stirring evenly, then adding sodium bicarbonate and stirring until completely dissolved, taking it out after ultrasonic treatment for 2 hours, and drying it to obtain clean cotton fabric; the volume proportion of ethanol in the ethanol aqueous solution is 25%, the mass ratio of cotton fabric to ethanol aqueous solution is 1:12, the stirring speed for uniform stirring is 400r / min, the concentration of sodium bicarbonate is 40g / L, the ultrasonic frequency of the ultrasonic treatment is 90kHz, the temperature is 30°C; the drying temperature is 60°C;

[0033] Step 2, adding sodium chloride to ethanol and stirring evenly, adding ammonium bicarbonate and grinding for 15 minutes, then adding ethanol to expand the solution, adding cotton fabric to perform low-temperature ultrasonic treatment, taking it out and drying it to obtain the infiltrated polyester fabric, the mass ratio of sodium chloride to ethanol is 2:1, the mass ratio of ammonium bicarbonate to sodium chloride is 1:0.2, the grinding treatment temperature is 10°C, the pressure is 0.7MPa, the sodium chloride concentration after expansion is 60g / L, the concentration of the cotton fabric in ethanol is 80g / L, the temperature of the low-temperature ultrasonic treatment is 8°C, the ultrasonic frequency is 90kHz, and the drying temperature is 12°C;

[0034] Step 3, overlapping the permeated cotton fabrics and extruding them at a constant temperature for 30 minutes, and then slowly releasing the pressure to obtain an expanded cotton fabric, wherein the pressure of the constant temperature extrusion is 0.7 MPa and the temperature is 70° C.; the speed of the slow pressure release is 0.04 MPa / min and the temperature is 30° C.;

[0035] Step 4, placing the expanded cotton fabric in ethanol and ultrasonically treating it for 8 minutes, then adding distilled water and stirring it for 1 hour, taking it out and airing it until it is half dry, and freeze-drying it to obtain the cotton fabric to be dyed, wherein the mass ratio of the expanded cotton fabric to the ethanol is 1:7, the frequency of the ultrasonic treatment is 90 kHz, and the temperature is 30° C.; the amount of the distilled water added is 20% of the volume of the ethanol, and the freeze-drying temperature is -20° C.;

[0036] Step 5, adding active dye and sodium carbonate into water and stirring evenly to form a dye solution, then immersing the cotton fabric to be dyed into the dye solution for dyeing, fixing, washing and then drying to obtain the dyed cotton fabric; in the dye solution, the concentration of the active dye is 30g / L, the concentration of sodium carbonate is 30g / L, the active dye is reactive red R, and the dyeing temperature is 50°C; the fixing is carried out in a sodium carbonate solution, and the concentration of the sodium carbonate solution is 10g / L, and the temperature is 75°C; the drying temperature is 90°C.

[0037] Comparative Example 1

[0038] A method for dyeing cotton fabrics comprises the following steps:

[0039] Step 1, putting cotton fabric into ethanol aqueous solution and stirring evenly, then adding sodium bicarbonate and stirring until completely dissolved, taking it out after ultrasonic treatment for 2 hours, and drying it to obtain clean cotton fabric; the volume proportion of ethanol in the ethanol aqueous solution is 25%, the mass ratio of cotton fabric to ethanol aqueous solution is 1:12, the stirring speed for uniform stirring is 400r / min, the concentration of sodium bicarbonate is 40g / L, the ultrasonic frequency of the ultrasonic treatment is 90kHz, the temperature is 30°C; the drying temperature is 60°C;

[0040] Step 2, placing the clean cotton fabric in ethanol and ultrasonically treating it for 8 minutes, then adding distilled water and stirring it for 1 hour, taking it out and airing it until it is half dry, and freeze-drying it to obtain the cotton fabric to be dyed, wherein the mass ratio of the clean cotton fabric to ethanol is 1:7, the frequency of the ultrasonic treatment is 90kHz, and the temperature is 30°C; the amount of distilled water added is 20% of the volume of ethanol, and the freeze-drying temperature is -20°C;

[0041] Step 3, adding active dye and sodium carbonate into water and stirring evenly to form a dye solution, then immersing the cotton fabric to be dyed into the dye solution for dyeing, fixing, washing and then drying to obtain the dyed cotton fabric; in the dye solution, the concentration of the active dye is 30g / L, the concentration of sodium carbonate is 30g / L, the active dye is reactive red R, and the dyeing temperature is 50°C; the fixing is carried out in a sodium carbonate solution, and the concentration of the sodium carbonate solution is 10g / L, and the temperature is 75°C; the drying temperature is 90°C.

[0042] Comparative Example 2

[0043] A method for dyeing cotton fabrics comprises the following steps:

[0044] Step 1, placing cotton fabric in ethanol and ultrasonicating for 8 minutes, then adding distilled water and stirring for 1 hour, taking it out and drying it to obtain the cotton fabric to be dyed, wherein the mass ratio of the cotton fabric to the ethanol is 1:7, the frequency of the ultrasonication is 90kHz, and the temperature is 30°C; the amount of the distilled water added is 20% of the volume of the ethanol;

[0045] Step 2, adding active dye and sodium carbonate into water and stirring evenly to form a dye solution, then immersing the cotton fabric to be dyed into the dye solution for dyeing, fixing, washing and then drying to obtain the dyed cotton fabric; in the dye solution, the concentration of the active dye is 30g / L, the concentration of sodium carbonate is 30g / L, the active dye is reactive red R, and the dyeing temperature is 50°C; the fixing is carried out in a sodium carbonate solution, and the concentration of the sodium carbonate solution is 10g / L, and the temperature is 75°C; the drying temperature is 90°C.

[0046] Performance Testing

[0047] The dyed cotton fabrics of Examples 1-3 and Comparative Examples 1-2 were used as test samples for performance testing, and the results are as follows:

[0048]

[0049] From the data comparison of the above-mentioned Examples 1-3 and Comparative Examples 1-3, it can be seen that the dyeing effect and color fastness of Examples 1-3 are significantly better than those of Comparative Examples 1-2, indicating that the technical solution using ethanol aqueous solution combined with sodium bicarbonate emulsification can effectively improve the cleanliness of cotton fabrics and reduce the influence of surface impurities on reactive dye dyeing. At the same time, the synergistic effect of sodium chloride alcohol solution and ammonium bicarbonate effectively increases the puffed exposed area of ​​cotton fabrics, provides a large number of reactive dye connection points, improves the covalent connection and leveling effect of reactive dyes, and cooperates with subsequent high-temperature shrinkage to improve the color fastness of reactive dyes on cotton fabrics.

[0050] It is understood that the above specific description of the present invention is only used to illustrate the present invention and is not limited to the technical solutions described in the embodiments of the present invention. Those skilled in the art should understand that the present invention can still be modified or replaced by equivalents to achieve the same technical effects; as long as the use requirements are met, they are within the protection scope of the present invention.

Claims

1. A method for dyeing cotton fabric, characterized in that: The steps include: Step 1, putting cotton fabric into ethanol aqueous solution and stirring evenly, then adding sodium bicarbonate and stirring until completely dissolved, taking out after ultrasonic treatment for 1-2 hours, and drying to obtain clean cotton fabric; Step 2, adding sodium chloride to ethanol and stirring evenly, adding ammonium bicarbonate and grinding for 10-20 minutes, then adding ethanol to dissolve, adding cotton fabric to perform low-temperature ultrasonic treatment, taking out and drying to obtain a permeated polyester fabric; Step 3, overlapping the permeated cotton fabrics and extruding them at a constant temperature for 20-30 minutes, and then slowly releasing the pressure to obtain an expanded cotton fabric; Step 4, placing the expanded cotton fabric in ethanol and ultrasonicating it for 5-10 minutes, then adding distilled water and stirring it for 1-2 hours, taking it out and airing it until it is half dry, and freeze-drying it to obtain the cotton fabric to be dyed; Step 5, adding active dye and sodium carbonate into water and stirring evenly to form a dye solution, then immersing the cotton fabric to be dyed into the dye solution for dyeing, fixing the color, washing with water and then drying to obtain the dyed cotton fabric.

2. The method for dyeing cotton fabric according to claim 1, characterized in that: The volume proportion of ethanol in the ethanol aqueous solution in step 1 is 20-30%, the mass ratio of cotton fabric to ethanol aqueous solution is 1:10-14, and the stirring speed for uniform stirring is 300-600r / min.

3. The method for dyeing cotton fabric according to claim 1, characterized in that: The concentration of sodium bicarbonate in step 1 is 10-40 g / L, the ultrasonic frequency of the ultrasonic treatment is 70-90 kHz, and the temperature is 20-30° C.; the drying temperature is 50-70° C.

4. The method for dyeing cotton fabric according to claim 1, characterized in that: The mass ratio of sodium chloride to ethanol in step 2 is 2:0.5-1, the mass ratio of ammonium bicarbonate to sodium chloride is 1:0.2-0.3, the grinding temperature is 5-10°C, the pressure is 0.5-0.7MPa, and the concentration of sodium chloride after expansion is 50-100g / L.

5. The method for dyeing cotton fabric according to claim 1, characterized in that: The concentration of the cotton fabric in the ethanol in step 2 is 50-100 g / L, the temperature of the low-temperature ultrasonic treatment is 5-10° C., the ultrasonic frequency is 80-100 kHz, and the drying temperature is 10-14° C.

6. The method for dyeing cotton fabric according to claim 1, characterized in that: The pressure of the constant temperature extrusion in step 3 is 0.4-0.7 MPa, and the temperature is 60-70°C; the speed of the slow pressure release is 0.02-0.04 MPa / min, and the temperature is 20-30°C.

7. The method for dyeing cotton fabric according to claim 1, characterized in that: The mass ratio of the expanded cotton fabric to ethanol in step 4 is 1:5-7, the frequency of ultrasound is 70-90kHz, and the temperature is 20-30°C; the amount of distilled water added is 10-20% of the volume of ethanol, and the freeze-drying temperature is -20°C.

8. The method for dyeing cotton fabric according to claim 1, characterized in that: In the dye solution in step 5, the concentration of the reactive dye is 10-50 g / L, the concentration of sodium carbonate is 8-30 g / L, and the reactive dye is one or more of reactive yellow O, reactive red R or reactive blue B.

9. The method for dyeing cotton fabric according to claim 1, characterized in that: The dyeing temperature in step 5 is 40-50°C; the fixing is carried out in a sodium carbonate solution with a concentration of 5-10 g / L and a temperature of 70-80°C; the drying temperature is 70-90°C.

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