Wool fiber dyeing method based on electrostatic spraying technology

Abstract

The invention discloses a wool fiber dyeing method based on an electrostatic spraying technology, and belongs to the field of spinning. The method comprises the following steps: firstly, preparing electrostatic dye liquor containing acid dye; then, the wool fabric is subjected to wetting pretreatment with water; fixing the pretreated wool fabric on a collecting device, and uniformly spraying the dye liquor onto the wool fabric through an electrostatic spraying technology; and finally, carrying out color fixation treatment through open-width steaming to obtain the wool fiber material dyed by the acid dye. The dyeing method greatly reduces the use of water resources and dyeing assistants, greatly reduces the generation of printing and dyeing wastewater, is a green and environment-friendly wool fiber dyeing technology, and has huge application potential in the textile printing and dyeing industry.

Description

Technical Field

[0001] The invention relates to a wool fiber dyeing method based on electrostatic spraying technology, belonging to the field of textiles. Background Art

[0002] As a natural protein fiber, wool fiber occupies an important position in the textile industry due to its excellent warmth retention, moisture absorption and biodegradability. With the increasing market demand for diversified and personalized wool products, dyeing technology has become a key link in determining product quality and added value. However, traditional dyeing processes generally use water-bath immersion dyeing, which requires the use of large amounts of water media and chemical auxiliaries (such as leveling agents, dispersants, etc.), thereby consuming a large amount of water resources and generating a large amount of printing and dyeing wastewater containing heavy metals, dyes and organic pollutants. Therefore, there is an urgent need to develop a new "dye-free, low-dye" wool fiber dyeing and finishing technology.

[0003] At present, the green dyeing and finishing technologies that have been formed and promoted mainly include supercritical carbon dioxide dyeing, organic solvent dyeing, foam dyeing and electrochemical dyeing. Carbon dioxide dyeing technology in a supercritical state uses liquefied carbon dioxide as a dyeing medium. This process involves liquefying carbon dioxide under extreme conditions far exceeding the critical pressure of carbon dioxide, during which the dye is dissolved and the textile fibers undergo expansion, thereby promoting the rapid and uniform penetration of dye molecules. Organic solvent dyeing usually dissolves the dye in an organic solvent and then allows the organic solvent to penetrate into the interior of the dyed material. At the same time, the dye molecules also enter and attach to the molecular structure of the dyed material, thereby achieving the dyeing effect. Foam dyeing replaces the water in the dyeing and finishing solution with as much air as possible, and the concentrated dyeing solution or suspension is expanded and converted into foam by air. The foam is then forced to spread evenly on the fabric surface through a certain device, thereby achieving the dyeing or finishing effect under the condition of minimum moisture supply. Electrochemical dyeing is a new dyeing technology. It is a method of dyeing by causing the dye to undergo redox reaction on the fabric surface through electrode reaction in an electrolyte solution.

[0004] Although the above technologies have reduced water waste and the generation of dye wastewater to a certain extent, there are still problems such as poor dyeing effect, difficulty in solvent recovery, poor dyeing depth and uniformity. Summary of the Invention

[0005] [Technical Issues]

[0006] The technical problem to be solved by the present invention is that the existing wool fiber material dyeing technology process produces a large amount of dye wastewater, and has problems such as poor dyeing effect, difficult solvent recovery, poor dyeing depth and uniformity.

[0007] [Technical solution]

[0008] To solve the above problems, the present invention provides a method for dyeing wool fibers based on electrostatic spraying technology. First, prepare an electrostatic spraying dye solution containing acid dyes; then pre-wet the wool fabric with water; then fix the pre-treated wool fabric on a collection device, and evenly spray the dye solution onto the wool fabric through electrostatic spraying technology; finally, perform a fixation treatment through flat-screen steam heating to obtain a wool fiber material dyed with acid dyes.

[0009] The present invention provides a method for dyeing wool fibers based on electrostatic spraying technology, including the following steps:

[0010] (1) Preparation of the electrostatic spraying dye solution:

[0011] First, add polyvinyl alcohol powder to deionized water or N,N-dimethylformamide and stir to dissolve to obtain a polyvinyl alcohol solution; then add acid dyes to the polyvinyl alcohol solution, and dropwise add an acetic acid solution to adjust the pH value of the solution. After stirring evenly, an electrostatic spraying dye solution containing acid dyes is obtained;

[0012] (2) Pretreatment of the wool fiber material:

[0013] Immerse the wool fiber material in water, take it out after complete wetting, and obtain the pre-treated wool fiber material; at this time, the wool fibers are completely wet;

[0014] (3) Electrostatic spraying dyeing treatment:

[0015] Fix the completely infiltrated wool fiber material on a receiving device, and evenly spray the dye solution containing acid dyes onto the fabric surface through electrostatic spraying technology to obtain a dyed wool fiber material;

[0016] (4) Fixation treatment:

[0017] Perform a fixation treatment on the dyed wool fiber material through a flat-screen steam heating process, and then wash and dry to obtain a wool fiber material dyed with acid dyes.

[0018] In one embodiment of the present invention, in the electrostatic spraying dye solution containing acid dyes in step (1), the mass fraction of polyvinyl alcohol is 0.5-2%; the dissolution condition is stirring at 60°C for 6-24 h.

[0019] In one embodiment of the present invention, the acid dyes in step (1) are one or more of acid orange 7, acid red 2, acid green A, acid blue 1, acid anthracene brown PG, β-naphthol purple, acid fuchsin, Coomassie brilliant blue R250, xylene cyanol FF, orange yellow Ⅳ, acid violet 49, quinoline yellow, saffron orange G, xylene fast yellow 2G, soap yellow, and naphthol yellow S.

[0020] In one embodiment of the present invention, in the electrostatic spray dyeing solution containing acid dyes in step (1), the mass fraction of the acid dyes is 1-10%.

[0021] In one embodiment of the present invention, in the electrostatic spray dyeing solution containing acid dyes in step (1), the mass fraction of the acid dyes is 3-5%.

[0022] In one embodiment of the present invention, the acetic acid solution in step (1) can be replaced by one or several of sulfuric acid, hydrochloric acid, phosphoric acid, citric acid solution and its buffer solution.

[0023] In one embodiment of the present invention, the pH of the electrostatic spray dyeing solution in step (1) is 1-5.

[0024] In one embodiment of the present invention, the pH of the electrostatic spray dyeing solution in step (1) is 1-4.

[0025] In one embodiment of the present invention, the wool fiber material in step (2) is a wool fiber web, wool yarn or wool fabric.

[0026] In one embodiment of the present invention, the wool fiber material in step (2) can also be an untreated wool fiber material.

[0027] In one embodiment of the present invention, the complete wetting time in step (2) is 1-12 h, and the bath ratio is 1:20-30.

[0028] In one embodiment of the present invention, the electrostatic spray process parameters in step (3) are: temperature is 20-40 °C, humidity is 30-80%, positive voltage is 15-50 kV, negative voltage is -10-0 kV, feed rate is 1-10 mL / h, the distance between the needle and the collection device is 10-20 cm, and the mass ratio of the dry weight of the wool fiber material to the amount of the electrostatic spray dyeing solution used is 1:0.2-1.

[0029] In one embodiment of the present invention, in step (3), the mass ratio of the dry weight of the wool fiber material to the amount of the electrostatic spray dyeing solution used is 1:0.4-0.6, and further preferably 1:0.4.

[0030] In one embodiment of the present invention, the steam heating process parameters in step (4) are: temperature is 100-120 °C, and time is 30-90 min.

[0031] The present invention also provides a wool fiber material dyed with acid dyes prepared by the above-mentioned method.

[0032] [Beneficial effects]

[0033] The present invention first proposes a dyeing method for wool fiber materials based on electrostatic spraying technology. By spraying submicron droplets containing acid dyes onto the surface of the wetted wool fabric and then immediately performing steam fixation, the use of water resources and dyeing auxiliaries is minimized to the greatest extent, establishing a new type of "non-dyeing, low-dyeing" green dyeing and finishing technology, which is of great significance for promoting the green and high-quality development of the textile and printing industry. Specific Embodiments

[0034] The following are descriptions of the preferred embodiments of the present invention. It should be understood that the embodiments are for better explaining the present invention and are not used to limit the present invention.

[0035] Testing Methods:

[0036] 1. Testing of Dye Uptake Rate:

[0037] Use a Datacolor 800 colorimeter to measure the K / S value of the dyed polyester fabric sample. Measure 4 times at different positions and take the average value. The K / S value is used to evaluate the color depth of the fabric. The larger the K / S value, the darker the fabric color.

[0038] The standard curve of the acid orange 7 solution (solvent is water) measured by an ultraviolet-visible spectrophotometer is y = 0.06065x + 0.0011. Here, x is the dye concentration (g / L), and y is the absorbance. Soak and wash the dyed polyester fabric repeatedly with deionized water until the filtrate is clear. Collect the filtrate throughout the process, weigh the volume of the filtrate (V), and measure the absorbance of the filtrate (A). Calculate the mass of the undyed dye (m1) through formula (1) and calculate the dye uptake rate (e) through formula (2).

[0039]

[0040] In the formula: m0 is the mass of the dye in the dye solution (g); m1 is the mass of the undyed dye (g).

[0041] 2. Testing of Color Fastness:

[0042] Test the color fastness to soaping according to GB3921—2008 "Textiles - Tests for color fastness - Color fastness to soaping".

[0043] Test the color fastness to rubbing according to GB3920—2008 "Textiles - Tests for color fastness - Color fastness to rubbing".

[0044] Example 1

[0045] A wool fiber dyeing method based on electrostatic spraying technology includes the following steps:

[0046] (1) Preparation of Electrostatic Spraying Dye Solution:

[0047] First, add polyvinyl alcohol powder to deionized water and stir for 12 h at a temperature of 60 °C to obtain a polyvinyl alcohol solution. Then, add Acid Orange 7 dye to the polyvinyl alcohol solution and dropwise add an acetic acid solution to adjust the pH value of the solution. After stirring at room temperature for 6 h, an electrostatic spray dyeing solution containing acidic dye is obtained. Among them, the mass fraction of polyvinyl alcohol is 1%; the mass fractions of Acid Orange 7 are 1, 3, 5, 7, and 9% respectively; the pH of the dyeing solution is 4.

[0048] (2) Pretreatment of wool fiber materials:

[0049] Soak 20 g of wool fabric in water for 2 h, take it out after complete wetting, and obtain the pretreated wool fiber material; the bath ratio is 1:25.

[0050] (3) Electrostatic spray dyeing treatment:

[0051] Fix the completely wetted wool fabric on an electrostatic spray receiving device, and uniformly spray the dyeing solution containing acidic dye onto the fabric surface through electrostatic spray technology to obtain the dyed wool fabric. Among them, the electrostatic spray process parameters are: temperature is 25 °C, humidity is 40%, positive voltage is 30 kV, negative voltage is 0 kV, feeding speed is 8 mL / h, the distance between the spinneret and the collection device is 15 cm, and the mass ratio of the dry weight of the wool fabric to the amount of dyeing solution used is 1:0.4.

[0052] (4) Fixing treatment:

[0053] Carry out fixing treatment on the dyed wool fabric by flat-screen steam heating at 105 °C for 60 min, then wash and dry to obtain the wool fiber material dyed with Acid Orange 7.

[0054] Carry out performance tests on the obtained dyed wool fabric, and the test results are shown in Table 1:

[0055] Table 1 Dyeing performance of fabrics with different dye mass fractions

[0056]

[0057] Example 2

[0058] A method for dyeing wool fibers based on electrostatic spray technology, comprising the following steps:

[0059] (1) Preparation of electrostatic spray dyeing solution:

[0060] First, add polyvinyl alcohol powder to deionized water and stir for 12 h at 60 °C to obtain a polyvinyl alcohol solution. Then, add Acid Orange 7 dye to the polyvinyl alcohol solution and dropwise add acetic acid solution to adjust the pH value of the solution. After stirring at room temperature for 6 h, an electrostatic spray dyeing solution containing acid dye is obtained. Among them, the mass fractions of polyvinyl alcohol are 0.5%, 1%, 1.5%, and 2% respectively; the mass fraction of Acid Orange 7 is 3%; the pH of the dyeing solution is 4.

[0061] (2) Pretreatment of wool fiber materials:

[0062] Soak 20 g of wool fabric in water for 2 h, take it out after complete wetting, and obtain the pretreated wool fiber material. Among them, the bath ratio is 1:25.

[0063] (3) Electrostatic spray dyeing treatment:

[0064] Fix the completely infiltrated wool fabric on an electrostatic spray receiving device, and evenly spray the spray solution containing acid dye onto the fabric surface through electrostatic spray technology to obtain a dyed wool fabric. Among them, the electrostatic spray process parameters are: temperature is 25 °C, humidity is 40%, positive voltage is 30 kV, negative voltage is 0 kV, feeding speed is 8 mL / h, the distance between the spinneret and the collection device is 15 cm, and the mass ratio of the dry weight of the wool fabric to the amount of dyeing solution used is 1:0.4.

[0065] (4) Fixing treatment:

[0066] Carry out fixing treatment on the dyed wool fabric by flat-screen steam heating at 105 °C for 60 min, then wash and dry to obtain the wool fiber material dyed with Acid Orange 7.

[0067] Carry out performance tests on the obtained dyed wool fabric, and the test results are shown in Table 2:

[0068] Table 2 Dyeing performance of fabrics with different mass fractions of polyvinyl alcohol

[0069]

[0070] Example 3

[0071] A method for dyeing wool fibers based on electrostatic spray technology, comprising the following steps:

[0072] (1) Preparation of electrostatic spray dyeing solution:

[0073] First, add polyvinyl alcohol powder to deionized water and stir for 12 h at a temperature of 60 °C to obtain a polyvinyl alcohol solution; then add Acid Orange 7 dye to the polyvinyl alcohol solution and dropwise add acetic acid solution to adjust the pH value of the solution. After stirring at room temperature for 6 h, an electrostatic spray dyeing solution containing acid dye is obtained; among them, the mass fraction of polyvinyl alcohol is 1%; the mass fraction of Acid Orange 7 is 3%; the pH values of the dyeing solution are 1, 2, 3, 4, and 5 respectively.

[0074] (2) Pretreatment of wool fiber materials:

[0075] Soak 20 g of wool fabric in water for 2 h, and take it out after complete wetting to obtain the pretreated wool fiber material; the bath ratio is 1:25.

[0076] (3) Electrostatic spray dyeing treatment:

[0077] Fix the completely wetted wool fabric on an electrostatic spray receiving device, and evenly spray the dyeing solution containing acid dye onto the fabric surface through electrostatic spray technology to obtain the dyed wool fabric; among them, the electrostatic spray process parameters are: temperature is 25 °C, humidity is 40%, positive voltage is 30 kV, negative voltage is 0 kV, feeding speed is 8 mL / h, the distance between the spinneret and the collection device is 15 cm, and the mass ratio of the dry weight of the wool fabric to the amount of dyeing solution used is 1:0.4.

[0078] (4) Fixing treatment:

[0079] Carry out fixing treatment on the dyed wool fabric by flat-screen steam heating at 105 °C for 60 min, and then wash and dry to obtain the wool fiber material dyed with Acid Orange 7.

[0080] Perform performance tests on the obtained dyed wool fabric, and the test results are shown in Table 3:

[0081] Table 3 Dyeing performance of fabrics with different pH values of electrostatic spray dyeing solutions

[0082]

[0083] Example 4

[0084] A method for dyeing wool fibers based on electrostatic spray technology, comprising the following steps:

[0085] (1) Preparation of electrostatic spray dyeing solution:

[0086] First, add polyvinyl alcohol powder to deionized water and stir for 12 h at a temperature of 60 °C to obtain a polyvinyl alcohol solution. Then, add Acid Orange 7 dye to the polyvinyl alcohol solution and dropwise add acetic acid solution to adjust the pH value of the solution. After stirring at room temperature for 6 h, an electrostatic spraying dyeing solution containing acid dye is obtained. Among them, the mass fraction of polyvinyl alcohol is 1%; the mass fraction of Acid Orange 7 is 3%; the pH of the dyeing solution is 4.

[0087] (2) Pretreatment of wool fiber materials:

[0088] Soak 20 g of wool fabric in water for 2 h, take it out after complete wetting, and obtain the pretreated wool fiber material; the bath ratio is 1:25.

[0089] (3) Electrostatic spraying dyeing treatment:

[0090] Fix the fully wetted wool fabric on the electrostatic spraying receiving device, and evenly spray the dyeing solution containing acid dye onto the fabric surface through electrostatic spraying technology to obtain the dyed wool fabric. Among them, the electrostatic spraying process parameters are: temperature is 25 °C, humidity is 40%, positive voltage is 30 kV, negative voltage is 0 kV, feeding speed is 8 mL / h, the distance between the spinneret and the collecting device is 15 cm, and the mass ratios of the dry weight of the wool fabric to the amount of the dyeing solution used are 1:0.2, 0.4, 0.6, 0.8, 1.

[0091] (4) Fixing treatment:

[0092] Carry out fixing treatment on the dyed wool fabric by flat-screen steam heating at 105 °C for 60 min, then wash and dry to obtain the wool fiber material dyed with Acid Orange 7.

[0093] Carry out performance tests on the obtained dyed wool fabric, and the test results are shown in Table 4:

[0094] Table 4 Dyeing performance of different fabrics and mass ratios of the amount of dyeing solution used

[0095]

[0096] Example 5

[0097] A method for dyeing wool fibers based on electrostatic spraying technology, comprising the following steps:

[0098] (1) Preparation of electrostatic spraying solution:

[0099] First, add polyvinyl alcohol powder to deionized water and stir for 12 h at 60 °C to obtain a polyvinyl alcohol solution. Then, add Acid Orange 7 dye to the polyvinyl alcohol solution and dropwise add acetic acid solution to adjust the pH value of the solution. After stirring at room temperature for 6 h, an electrostatic spraying liquid containing acid dye is obtained. Among them, the mass fraction of polyvinyl alcohol is 1%; the mass fraction of Acid Orange 7 is 3%; the pH of the spraying liquid is 4.

[0100] (2) Pretreatment of wool fiber material:

[0101] Soak 20 g of wool fabric in water for 2 h, take it out after complete wetting, and obtain the pretreated wool fiber material; the bath ratio is 1:25.

[0102] (3) Electrostatic spraying dyeing treatment:

[0103] Fix the fully infiltrated wool fabric on the electrostatic spraying receiving device, and evenly spray the dye solution containing acid dye onto the fabric surface through electrostatic spraying technology to obtain the dyed wool fabric. Among them, the electrostatic spraying process parameters are: temperature is 25 °C, humidity is 40%, positive voltage is 30 kV, negative voltage is 0 kV, feeding speed is 8 mL / h, the distance between the spinneret and the collection device is 15 cm, and the mass ratio of the dry weight of the wool fabric to the amount of dye solution used is 1:0.4.

[0104] (4) Fixing treatment:

[0105] Carry out fixing treatment on the dyed wool fabric by flat-screen steam heating at 105 °C for 30, 60, 90 min, then wash and dry to obtain the wool fiber material dyed with Acid Orange 7.

[0106] Carry out performance testing on the obtained dyed wool fabric, and the test results are shown in Table 5:

[0107] Table 5 Dyeing performance of fabrics with different steaming times

[0108]

[0109] Example 6

[0110] Replace the solvent water in the electrostatic spraying dye solution in Example 1 with N,N-dimethylformamide, and the mass fraction of Acid Orange 7 is 3%; keep the others the same as in Example 1 to obtain the wool fabric dyed with acid dye.

[0111] Example 7

[0112] Replace the pretreated wool fabric in Example 1 with an untreated wool fabric, and the mass fraction of Acid Orange 7 is 3%; keep the others the same as in Example 1 to obtain the wool fabric dyed with acid dye.

[0113] Example 8

[0114] Replace the acetic acid solution in Example 1 with sulfuric acid solution, and the mass fraction of Acid Orange 7 is 3%; keep the others the same as in Example 1 to obtain a wool fabric dyed with acid dye.

[0115] Comparative Example 1

[0116] Replace the mass fraction of polyvinyl alcohol in the dyeing solution in Example 1 with 10%, and the mass fraction of Acid Orange 7 is 3%. Set the process parameters of electrospinning as follows: temperature is 25 °C, humidity is 40%, positive voltage is 12 kV, negative voltage is 0 kV, feeding speed is 0.5 mL / h, the distance between the spinneret and the collection device is 15 cm, and the mass ratio of the dry weight of the wool fabric to the amount of the dyeing solution is 1:0.4. Under this process, the dyeing solution is sprayed onto the fabric surface in the form of a fiber membrane; keep the others the same as in Example 1 to obtain a wool fabric dyed with acid dye.

[0117] Perform performance tests on the obtained dyed wool fabric, and the test results are shown in Table 6:

[0118] Table 6 Properties of the wool fabrics prepared in Examples 6 - 8 and Comparative Example 1

[0119]

[0120]

[0121] The examples provided above are not intended to limit the scope covered by the present invention, nor are the described steps intended to limit the order of their execution. Obvious improvements made by those skilled in the art in combination with the existing well-known common sense also fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for dyeing wool fibers, characterized in that, It includes the following steps: adding an acid dye into a polyvinyl alcohol solution and adjusting the pH to obtain an electrostatic spraying dyeing solution containing the acid dye, spraying the electrostatic spraying dyeing solution containing the acid dye onto the surface of a wool fiber material through an electrostatic spraying technique, performing a fixing treatment through a stentering and steaming process, and finally washing and drying to obtain a wool fiber material dyed with the acid dye.

2. The method according to claim 1, wherein The polyvinyl alcohol powder is added to deionized water or N,N-dimethylformamide and stirred to dissolve to obtain a polyvinyl alcohol solution.

3. The method according to claim 1, wherein The acid dye is one or more of acid orange 7, acid red 2, acid green A, acid blue 1, acid anthracene brown PG, β-naphthol purple, acid magenta, Coomassie brilliant blue R250, xylene cyanol FF, orange yellow Ⅳ, acid violet 49, quinoline yellow, saffron orange G, xylene fast yellow 2G, soap yellow, and naphthol yellow S.

4. The method according to claim 1, wherein In the electrostatic spraying dyeing solution containing the acid dye, the mass fraction of polyvinyl alcohol is 0.5-2%, and the mass fraction of the acid dye is 1-10%.

5. The method according to claim 1, characterized in that, The pH of the electrostatic spraying dyeing solution containing the acid dye is 1-5.

6. The method according to claim 1, wherein The wool fiber material is a wool fiber web, wool yarn, or wool fabric.

7. The method according to claim 1, characterized in that The electrostatic spraying process parameters are: temperature is 20-40°C, humidity is 30-80%, positive voltage is 15-50 kV, negative voltage is -10-0 kV, feed rate is 1-10 mL / h, and the distance between the needle and the collecting device is 10-20 cm.

8. The method according to claim 1, characterized in that, The mass ratio of the dry weight of the wool fiber material to the mass of the electrostatic spraying dyeing solution is 1:0.2-1.

9. The method according to claim 1, characterized in that, The steaming process parameters are: temperature is 100-120°C, and time is 30-90 min.

10. A wool fiber material dyed with an acid dye prepared by the method according to any one of claims 1-9.

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