Method for improving brightness of dope-dyed viscose

Abstract

The invention relates to the technical field of fiber coloring, and particularly discloses a method for improving the brightness of dope-colored viscose fibers, which comprises the following steps: preparing a brightening agent by using solid acrylic resin with the molecular weight of 3000-8000, zirconium dioxide, a surfactant, a thickener and deionized water as raw materials, then uniformly mixing the brightening agent with color paste slurry, and then uniformly mixing to obtain the dope-colored viscose fibers. Continuously blending the mixed solution and a spinning viscose stock solution in pre-spinning injection equipment according to the injection amount of 3.5-4%, uniformly mixing the spinning solution in a static mixer, metering by using a metering pump, flowing through a spinning nozzle, entering a coagulating bath for spinning, and carrying out spinning to obtain a spinning viscose spinning solution; the colored viscose staple fibers with the fineness being 2.2 dtex or below are prepared through the procedures of drafting, cutting, primary washing, desulfuration, secondary washing, acid pickling, final washing, oiling, dewatering and drying in sequence, the strength of the colored viscose staple fibers prepared through the mode is similar to that of colored fibers prepared through a conventional pre-spinning injection technology, and the color degree is obviously improved; the market demand of the colored fiber is widened.

Description

Technical Field

[0001] The invention belongs to the technical field of fiber coloring, and in particular relates to a method for improving the brightness of liquid-dyed viscose fibers. Background Art

[0002] At present, the mainstream fiber coloring method is still through fiber or yarn dyeing. Although traditional dyeing has many processes, high water and electricity consumption, and the color difference of the product is difficult to control, the color fastness deviation, etc. In this context, colored fibers dyed with stock solution have been vigorously promoted.

[0003] In the prior art, the solution dyeing method usually adopts acid etching technology, that is, the black solution-dyed fiber is placed in an acid solution and immersed to etch the surface of the fiber, so that the originally regular surface of the fiber becomes pitted, reducing the reflection of light and increasing the blackness of the black viscose fiber.

[0004] However, although the colored viscose fiber produced by the solution dyeing method has great advantages in energy consumption and cost, the brightness of the current solution-dyed colored viscose fiber cannot be further improved by increasing the amount of pigment added or optimizing the pigment quality. It is difficult to achieve an effect similar to that of dyed fibers in color, which affects the quality of the brightness of the solution-dyed viscose fiber and fails to meet market demand. Therefore, we need to propose a method for improving the brightness of solution-dyed viscose fiber to solve the above-mentioned problems, so that it can effectively improve the brightness of the solution-dyed viscose fiber and meet market demand. Summary of the invention

[0005] The object of the present invention is to provide a method for improving the brightness of solution-dyed viscose fibers, which can effectively improve the brightness of solution-dyed viscose fibers and meet market demand, so as to solve the problems raised in the above-mentioned background technology.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A method for improving the brightness of liquid-dyed viscose fibers, comprising the following steps:

[0008] S1. Prepare a brightener using solid acrylic resin with a molecular weight of 3000-8000, zirconium dioxide, a surfactant, a thickener, and deionized water as raw materials;

[0009] S2, mixing the brightener and the color paste slurry evenly to obtain a mixed solution;

[0010] S3, continuously blending the mixed solution with the spinning viscose stock solution in a pre-spinning injection device, with the injection amount being 3.5-4% to the methyl cellulose to obtain a spinning solution;

[0011] S4. After the spinning liquid is evenly mixed in a static mixer, it is measured by a metering pump and flows through a spinneret, and enters a coagulation bath for spinning, and then sequentially undergoes the steps of drawing, cutting, first water washing, desulfurization, second water washing, acid washing, final water washing, oiling, dehydration, and drying to obtain colored viscose staple fibers with a fineness of less than 2.2 dtex, wherein a brightener with a concentration of 1-2 g / L needs to be added to the oil during oiling.

[0012] Preferably, the raw materials used in the preparation of the brightener include the following raw materials by mass: 100-120 parts of solid acrylic resin, 50-60 parts of zirconium dioxide, 2-5 parts of surfactant, 1-2 parts of thickener, and 33-47 parts of deionized water.

[0013] Preferably, when preparing the brightener, solid acrylic resin, surfactant and thickener are added to deionized water in a mixing tank, mixed and stirred to form a dissolved solution, and then the dissolved solution is sent to a sand mill for grinding to obtain the brightener.

[0014] Preferably, in step S2, the brightener and the color paste slurry are mixed in a ratio of 1-3:20, the average particle size of the pigment of the color paste slurry is below 300 nm, and the color paste slurry is set to be carbon black slurry or blue pigment slurry.

[0015] Preferably, in step S3, the injection amount of 3.5-4% to the methyl fiber refers to the amount of the mixed color paste and brightener added to the viscose stock solution during the spinning process, and the added amount is calculated based on 3.5% to 4% of the methyl fiber content in the viscose stock solution.

[0016] Preferably, in step S4, the coagulation bath is composed of sulfuric acid, sodium sulfate and zinc sulfate, and the raw materials used in the coagulation bath are as follows: 110-130 g / L sulfuric acid, 330-350 g / L sodium sulfate, and 11-12 g / L zinc sulfate.

[0017] Preferably, the spinning speed is 55-65 m / min, and the sulfuric acid used in the coagulation bath is set to have a concentration of 75%.

[0018] Preferably, the desulfurizing agent used in the desulfurization process is a sodium hydroxide solution with a mass concentration of 6-8 g / L, and the acid solution used in the pickling is sulfuric acid with a concentration of 75%.

[0019] Preferably, the oil used during oiling is set to be a special oil for colored viscose spinning, and the concentration of the oil is 8-9g / L.

[0020] Preferably, the quality indicators met by the prepared colored viscose staple fiber are: fineness of 1.33-1.67 dtex; length of 32-38 mm; dry breaking strength of ≥2.3 cN / dtex, dry breaking elongation of 21±2%; oil content of 0.35%-0.45%; product regain is controlled at 13%; defect content ≤1.5 mg / 100 g; residual sulfur content ≤8 mg / 100 g; whiteness ≤2%, and color fastness ≥level 4.

[0021] The method for improving the brightness of liquid-dyed viscose fiber proposed by the present invention has the following advantages compared with the prior art:

[0022] 1. The present invention prepares a brightener by using solid acrylic resin with a molecular weight of 3000-8000, zirconium dioxide, a surfactant, a thickener, and deionized water as raw materials, and then mixes the brightener with a color paste slurry evenly, and then continuously blends the mixed solution with a spinning viscose stock solution in a pre-spinning injection device, and the injection amount is 3.5-4% to the first fiber, and then the spinning liquid is mixed evenly in a static mixer, and then it flows through a spinneret after being metered by a metering pump, and enters a coagulation bath for spinning, and then sequentially through the steps of drawing, cutting, first washing, desulfurization, second washing, acid washing, final washing, oiling, dehydration, and drying to obtain a colored viscose staple fiber with a fineness of less than 2.2 dtex. The strength of the colored viscose staple fiber prepared in this way is similar to that of the colored fiber prepared by conventional pre-spinning injection technology, and the color is significantly improved, which expands the market demand for colored fibers. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a flowchart of the present invention. DETAILED DESCRIPTION

[0024] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0025] The present invention provides Figure 1 A method for improving the brightness of liquid-dyed viscose fibers is shown, comprising the following steps:

[0026] S1. Prepare a brightener using solid acrylic resin with a molecular weight of 3000-8000, zirconium dioxide, a surfactant, a thickener, and deionized water as raw materials;

[0027] The raw materials used in the preparation of the brightener include the following raw materials by mass: 100-120 parts of solid acrylic resin, 50-60 parts of zirconium dioxide, 2-5 parts of surfactant, 1-2 parts of thickener, and 33-47 parts of deionized water. The brightener prepared by the above raw materials is acid- and alkali-resistant, has little effect on color, and has certain film-forming properties.

[0028] When preparing the brightener, solid acrylic resin, surfactant and thickener are added to deionized water in a mixing tank, mixed and stirred to form a dissolved solution, and then the dissolved solution is sent to a sand mill for grinding to obtain the brightener, so that the brightener is a resin, which is coated on the fiber surface to reduce the roughness of the fiber, increase the reflection of light, and improve the brightness.

[0029] S2, mixing the brightener and the color paste slurry evenly to obtain a mixed solution;

[0030] The brightener and the color paste slurry are mixed in a ratio of 1-3:20, the average particle size of the pigment of the color paste slurry is below 300nm, the color paste slurry is set to be carbon black slurry or blue pigment slurry, and this color paste slurry is generally purchased from outside.

[0031] S3, continuously blending the mixed solution with the spinning viscose stock solution in a pre-spinning injection device, with the injection amount being 3.5-4% to the methyl cellulose to obtain a spinning solution;

[0032] The injection amount of 3.5-4% for acetone refers to the amount of the mixed color paste and brightener added to the viscose stock solution during the spinning process. This added amount is calculated based on the 3.5% to 4% acetone content in the viscose stock solution.

[0033] S4. After the spinning liquid is evenly mixed in a static mixer, it is measured by a metering pump and flows through a spinneret, and enters a coagulation bath for spinning, and then sequentially undergoes the steps of drawing, cutting, first water washing, desulfurization, second water washing, acid washing, final water washing, oiling, dehydration, and drying to obtain colored viscose staple fibers with a fineness of less than 2.2 dtex, wherein a brightener with a concentration of 1-2 g / L needs to be added to the oil during oiling.

[0034] The coagulation bath is composed of sulfuric acid, sodium sulfate and zinc sulfate. The raw materials used in the coagulation bath are as follows: 110-130 g / L sulfuric acid, 330-350 g / L sodium sulfate and 11-12 g / L zinc sulfate.

[0035] During spinning, the spinning speed is 55-65 m / min, and the sulfuric acid used in the coagulation bath is set to have a concentration of 75%.

[0036] The desulfurization agent used in the desulfurization process is a sodium hydroxide solution with a mass concentration of 6-8g / L, and the acid solution used in the pickling is sulfuric acid with a concentration of 75%.

[0037] The oil used during oiling is set to be a special oil for colored viscose spinning, and the concentration of the oil is 8-9g / L.

[0038] The quality indicators met by the prepared colored viscose staple fiber are: fineness of 1.33-1.67 dtex; length of 32-38 mm; dry breaking strength of ≥2.3 cN / dtex, dry breaking elongation of 21±2%; oil content of 0.35%-0.45%; product regain is controlled at 13%; defect content ≤1.5 mg / 100 g; residual sulfur content ≤8 mg / 100 g; whiteness ≤2%, and color fastness ≥level 4.

[0039] Example 1

[0040] According to the method provided above, a specific implementation scheme is proposed, and the specific operations are as follows:

[0041] S1, preparing a brightener with 100 parts of solid acrylic resin with a molecular weight of 3000-8000, 50 parts of zirconium dioxide, 2 parts of surfactant, 1 part of thickener and 33 parts of deionized water as raw materials;

[0042] S2, mixing the brightener and the color paste slurry evenly, the mixing ratio of the brightener and the color paste slurry is 1:20, and the color paste slurry is set to carbon black slurry to obtain a mixed solution;

[0043] S3, continuously blending the mixed solution with the spinning viscose stock solution in a pre-spinning injection device, with the injection amount being 4% to the methyl cellulose to obtain a spinning solution;

[0044] S4, after the spinning liquid is evenly mixed in a static mixer, it is metered by a metering pump and then flows through a spinneret, and enters a coagulation bath for spinning, and then sequentially through the steps of drawing, cutting, first water washing, desulfurization, second water washing, pickling, final water washing, oiling, dehydration, and drying to obtain black viscose staple fibers with a fineness of less than 2.2 dtex, wherein the raw materials used in the coagulation bath are: 110 g / L sulfuric acid, 330 g / L sodium sulfate, and 11 g / L zinc sulfate. The spinning speed is 55 m / min, and the oil used in the oiling is set to a special oil for colored viscose spinning, and the concentration of the oil is 8 g / L. In addition, a brightener with a concentration of 1 g / L is added to the oil.

[0045] Example 2

[0046] According to the method provided above, another specific implementation scheme is proposed, and the specific operations are as follows:

[0047] S1, preparing a brightener with 110 parts of solid acrylic resin with a molecular weight of 3000-8000, 55 parts of zirconium dioxide, 3.5 parts of a surfactant, 1.5 parts of a thickener, and 40 parts of deionized water as raw materials;

[0048] S2, mixing the brightener and the color paste slurry evenly, the mixing ratio of the brightener and the color paste slurry is 2:20, and the color paste slurry is set to carbon black slurry to obtain a mixed solution;

[0049] S3, continuously blending the mixed solution with the spinning viscose stock solution in a pre-spinning injection device, with the injection amount being 4% to the methyl cellulose to obtain a spinning solution;

[0050] S4, after the spinning liquid is evenly mixed in a static mixer, it is metered by a metering pump and then flows through a spinneret, and enters a coagulation bath for spinning, and then sequentially through the steps of drawing, cutting, first water washing, desulfurization, second water washing, pickling, final water washing, oiling, dehydration, and drying to obtain black viscose staple fibers with a fineness of less than 2.2 dtex, wherein the raw materials used in the coagulation bath are: 120 g / L sulfuric acid, 340 g / L sodium sulfate, and 11.5 g / L zinc sulfate, the spinning speed during spinning is 60 m / min, the oil agent used during oiling is set to a special oil agent for colored viscose spinning, the concentration of the oil agent is 8.5 g / L, and a brightener with a concentration of 1.5 g / L is added to the oil agent.

[0051] Example 3

[0052] According to the method provided above, another specific implementation scheme is proposed, and the specific operations are as follows:

[0053] S1, preparing a brightener with 120 parts of solid acrylic resin with a molecular weight of 3000-8000, 60 parts of zirconium dioxide, 5 parts of a surfactant, 2 parts of a thickener, and 47 parts of deionized water as raw materials;

[0054] S2, mixing the brightener and the color paste slurry evenly, the mixing ratio of the brightener and the color paste slurry is 3:20, and the color paste slurry is set to carbon black slurry to obtain a mixed solution;

[0055] S3, continuously blending the mixed solution with the spinning viscose stock solution in a pre-spinning injection device, with the injection amount being 4% to the methyl cellulose to obtain a spinning solution;

[0056] S4, after the spinning liquid is evenly mixed in a static mixer, it is metered by a metering pump and flows through a spinneret, and enters a coagulation bath for spinning, and then sequentially through the steps of drawing, cutting, first water washing, desulfurization, second water washing, pickling, final water washing, oiling, dehydration, and drying to obtain black viscose staple fibers with a fineness of less than 2.2 dtex, wherein the raw materials used in the coagulation bath are: 130 g / L sulfuric acid, 350 g / L sodium sulfate, and 12 g / L zinc sulfate, the spinning speed during spinning is 65 m / min, the oil agent used during oiling is set to a special oil agent for colored viscose spinning, the concentration of the oil agent is 9 g / L, and a brightener with a concentration of 2 g / L is added to the oil agent.

[0057] Example 4

[0058] According to the above method, the brightness effect is verified, and the verification results are as follows:

[0059] Experiment 1:

[0060] The strength of the black viscose staple fiber prepared by the method provided in Example 1 was compared with the strength of the black fiber prepared by conventional pre-spinning injection technology to confirm the effect of different amounts of brightener added on the improvement of fiber brightness. The test results are as follows:

[0061]

[0062] From the results in the above table, it can be concluded that in Example 1, as the amount of brightener increases, the red-green degree, yellow-blue degree and brightness are all improved to a certain extent, and when 1-2 g / L of brightener is added to the oil bath, the brightness is similar to the brightness of black dyeing using conventional pre-spinning injection technology, and its fiber strength is not affected by the addition of brightener, which expands the market demand for black fibers.

[0063] Experiment 2:

[0064] According to the method provided in Example 2, the carbon black slurry was replaced with a blue pigment slurry to prepare blue viscose staple fibers, and then the strength of the blue viscose staple fibers was compared with the strength of blue fibers prepared by conventional pre-spinning injection technology. The results are shown in the following table:

[0065]

[0066] From the results in the above table, it can be concluded that in Example 2, as the amount of brightener increases, the brightness is similar to that of blue dyeing using conventional pre-spinning injection technology, and when 1-3 g / L of brightener is added to the oil bath, the yellow-blue degree is similar to that of blue dyeing using conventional pre-spinning injection technology, and its fiber strength is not affected by the addition of the brightener.

[0067] In summary, a brightener is prepared by using solid acrylic resin with a molecular weight of 3000-8000, zirconium dioxide, a surfactant, a thickener, and deionized water as raw materials, and then the brightener is mixed evenly with a color paste slurry, and then the mixed solution is continuously blended with a spinning viscose stock solution in a pre-spinning injection device, and the injection amount is 3.5-4% to the methyl cellulose, and then the spinning liquid is mixed evenly in a static mixer, and then it is metered by a metering pump and flows through a spinneret, and enters a coagulation bath for spinning, and then sequentially subjected to drawing, cutting, and a After washing, desulfurization, double washing, acid washing, final washing, oiling, dehydration and drying processes, colored viscose staple fibers with a fineness of less than 2.2dtex are obtained, and brighteners need to be added to the oil when oiling. By covering the fiber surface with a layer of high-brightness resin, the absorption of light is changed and the reflection of light is increased, so as to further optimize the color brightness, make the strength of colored viscose staple fibers similar to that of colored fibers prepared by conventional pre-spinning injection technology, and significantly improve the color, thereby expanding the market demand for colored fibers.

[0068] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for improving the brightness of liquid-dyed viscose fibers, characterized in that: The steps include: S1. Prepare a brightener using solid acrylic resin with a molecular weight of 3000-8000, zirconium dioxide, a surfactant, a thickener, and deionized water as raw materials; S2, mixing the brightener and the color paste slurry evenly to obtain a mixed solution; S3, continuously blending the mixed solution with the spinning viscose stock solution in a pre-spinning injection device, with the injection amount being 3.5-4% to the methyl cellulose to obtain a spinning solution; S4. After the spinning liquid is evenly mixed in a static mixer, it is measured by a metering pump and flows through a spinneret, and enters a coagulation bath for spinning, and then sequentially undergoes the steps of drawing, cutting, first water washing, desulfurization, second water washing, acid washing, final water washing, oiling, dehydration, and drying to obtain colored viscose staple fibers with a fineness of less than 2.2 dtex, wherein a brightener with a concentration of 1-2 g / L needs to be added to the oil during oiling.

2. A method for improving the brightness of liquid-dyed viscose fibers according to claim 1, characterized in that: The raw materials used in the preparation of the brightener include the following raw materials by mass: 100-120 parts of solid acrylic resin, 50-60 parts of zirconium dioxide, 2-5 parts of surfactant, 1-2 parts of thickener, and 33-47 parts of deionized water.

3. A method for improving the brightness of liquid-dyed viscose fibers according to claim 2, characterized in that: When preparing the brightener, solid acrylic resin, surfactant and thickener are added to deionized water in a mixing tank, mixed and stirred evenly to form a dissolved solution, and then the dissolved solution is sent to a sand mill for grinding to obtain the brightener.

4. A method for improving the brightness of solution-dyed viscose fibers according to claim 3, characterized in that: In step S2, the brightener and the color paste slurry are mixed in a ratio of 1-3:20, the average particle size of the pigment of the color paste slurry is below 300 nm, and the color paste slurry is set to be carbon black slurry or blue pigment slurry.

5. A method for improving the brightness of solution-dyed viscose fibers according to claim 4, characterized in that: In step S3, the injection amount of 3.5-4% for methyl cellulose refers to the amount of the mixed color paste and brightener added to the viscose stock solution during the spinning process. This added amount is calculated based on 3.5% to 4% of the methyl cellulose content in the viscose stock solution.

6. A method for improving the brightness of solution-dyed viscose fibers according to claim 5, characterized in that: In step S4, the coagulation bath is composed of sulfuric acid, sodium sulfate and zinc sulfate, and the raw materials used in the coagulation bath are as follows: 110-130 g / L sulfuric acid, 330-350 g / L sodium sulfate, and 11-12 g / L zinc sulfate.

7. A method for improving the brightness of solution-dyed viscose fibers according to claim 6, characterized in that: During spinning, the spinning speed is 55-65 m / min, and the sulfuric acid used in the coagulation bath is set to have a concentration of 75%.

8. A method for improving the brightness of solution-dyed viscose fibers according to claim 7, characterized in that: The desulfurization agent used in the desulfurization process is a sodium hydroxide solution with a mass concentration of 6-8g / L, and the acid solution used in the pickling is sulfuric acid with a concentration of 75%.

9. A method for improving the brightness of solution-dyed viscose fibers according to claim 8, characterized in that: The oil used during oiling is set to be a special oil for colored viscose spinning, and the concentration of the oil is 8-9g / L.

10. A method for improving the brightness of solution-dyed viscose fibers according to claim 9, characterized in that: The quality indicators met by the prepared colored viscose staple fiber are: fineness of 1.33-1.67 dtex; length of 32-38 mm; dry breaking strength of ≥2.3 cN / dtex, dry breaking elongation of 21±2%; oil content of 0.35%-0.45%; product regain is controlled at 13%; defect content ≤1.5 mg / 100 g; residual sulfur content ≤8 mg / 100 g; whiteness ≤2%, and color fastness ≥level 4.

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