A supercritical CO2 fluid dyeing method for precisely controlling the mixing of dyes

Abstract

This invention relates to a supercritical CO2 fluid dyeing method for precisely controlling the mixing of dyes. The method involves injecting molten dyes with different molecular structures in small batches into a pipeline using a high-temperature injector. These dyes mix with supercritical CO2 fluid circulating within the pipeline at a specific temperature and pressure, and then dye the fibers in the dyeing vessel. The dyes with different molecular structures are prioritized according to their solubility in the supercritical CO2 fluid. The "small batches" refers to adding the dyes sequentially from highest to lowest priority, precisely controlling the injection rate and time for each dye. After dyeing according to this invention, a reduction cleaning process is performed. After reduction cleaning, the CIELAB color difference of the dyed product relative to the dyed standard sample is <0.5, and the dyeing uniformity assessment reaches level 4-5, meeting the standard for superior grade synthetic fiber fabrics in GB / T 17253-2018.

Description

Technical Field

[0001] The invention belongs to the technical field of dyeing and finishing and relates to a supercritical CO 2 Fluid dyeing method. Background Art

[0002] Disperse dyes reported in the prior art in supercritical CO 2 The solubility in the fluid is 10 -8 ~10 -5 mol·mol -1 When the fluid flows through the disperse dye, the single dissolution amount is low, so the disperse dye is 2 The dyeing of polyester fibers in fluid needs to go through a continuous cycle of "dissolution-adsorption-diffusion-microanalysis" to achieve the purpose of dyeing a certain amount of polyester fibers.

[0003] In the actual production process, most colors are obtained by mixing dyes with different molecular structures. However, dyes with different molecular structures 2 The solubility in the fluid varies greatly. 2 There is a competitive dissolution effect in the fluid. Dyes with high solubility dissolve quickly in a short period of time, and the large aggregates formed easily block the pores of polyester fibers, affecting their diffusion inside the polyester fibers and reducing the dyeing efficiency. Dyes with low solubility can only begin to dissolve in the middle and late stages of dyeing due to the competitive dissolution effect. At this time, dyes with high solubility have already occupied most of the dyeing sites on the polyester fibers. The small amount of dissolution and the number of dyeing sites cause the low-solubility dyes to dye very little or even not dye the fibers, resulting in the color of the dyed products failing to meet production requirements.

[0004] Supercritical CO 2 Fluid dyeing technology currently mainly adopts the immersion dyeing method and the spray dyeing method, in which all dyes are added at one time. The immersion dyeing method refers to adding all dyes into the dye kettle at one time and dyeing is achieved through the above dyeing process (most people's work); the spray dyeing method refers to using a nozzle to spray a supercritical CO2 solution containing dissolved or partially dissolved dyes. 2 The fluid is sprayed directly onto the surface of the fiber or fabric, and the temperature and pressure conditions are used to make the dye adsorb and diffuse into the fiber (such as patent CN110904599B, ​​etc.). 2The fluid impregnation method cannot solve the problem that the dyeing color does not meet the production requirements due to the competitive dissolution effect of dyes. Although the spray dyeing method can spray soluble dyes and insoluble dyes onto the fiber surface through the nozzle, the rate and quality of their diffusion into the fiber will be significantly different due to the difference in solubility, which will lead to uneven dyeing. In addition, dyes with low solubility are prone to floating colors on the fiber surface and are easily washed away during cleaning, and the color of the dyed product still does not meet the requirements.

[0005] Patent application CN112458672A, an immersion dyeing device and dyeing method capable of maintaining a stable dye liquor concentration, maintains the dye concentration in the dyeing kettle within a certain range through a metering pump, a dye liquor concentration data acquisition device and an automatic feeding device, so that the dyeing rate is controlled within the optimal range, solves the problems of color spots caused by high-concentration dye agglomeration, and improves dyeing uniformity and quality. This method is based on the water dyeing system setting. Under the dyeing temperature and pressure conditions, most dyes have a high solubility in water, and dyes with low water solubility such as disperse dyes can also rely on dispersants to maintain a high concentration in water. Therefore, under water dyeing conditions, there is no problem of competitive dissolution of dyes. Therefore, this invention method does not take into account the supercritical CO 2 Some key points in fluid dyeing.

[0006] Through organic solvents and supercritical CO 2 Fluids form co-solvents, which can increase the solubility of some poorly soluble dyes, thereby reducing the color problem caused by competitive dissolution effects. However, organic solvents have the defects of toxicity and difficulty in separation and recovery, and cannot be applied on a large scale in industry. Summary of the invention

[0007] The purpose of the present invention is to solve the above problems existing in the prior art and provide a supercritical CO 2 Fluid dyeing method.

[0008] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0009] A supercritical CO system for precisely controlling dye mixing 2 Fluid dyeing method, through the high temperature grouting device, the molten dyes with different molecular structures are injected into the pipeline in batches, and the supercritical CO2 with a certain temperature and pressure circulating in the pipeline is 2 The fluids are mixed and then dyed to the fibers in the dye kettle;

[0010] Dyes with different molecular structures were subjected to supercritical CO 2 The injection priority is divided according to the solubility in the fluid. -8 mol·mol -1The highest priority, solubility is 10 -8 ~10 -7 mol·mol -1 High priority, solubility in 10 -7 ~10 -6 mol·mol -1 It is a general priority, with a solubility of 10 -6 ~10 -5 mol·mol -1 Low priority, solubility>10 -5 mol·mol -1 The low priority is the lowest priority; the small batches are added in order from high to low according to the injection priority (the dyes with the same priority can be injected at the same time), and the injection time of each batch of dyes is The injection rates of dyes with different priority levels are as follows:

[0011]

[0012]

[0013]

[0014]

[0015]

[0016] Among them, m fiber is the mass of the dyed fiber (g), w is the weight of the dye on the fiber (omf), M dye is the molecular weight of the dye, V x is the dye injection rate (mol·min -1 ), t x is the injection time of the dye (min), For dyes in supercritical CO 2 Solubility in fluid (mol·mol -1 ),u x For supercritical CO 2 Fluid flow rate (g·min -1 ), M CO2 For CO 2 Molecular weight (44 g·mol -1 ), x=A, B, C, D, E, representing the dyes with the highest, high, normal, low and lowest injection priority, respectively.

[0017] For the above V C 、V D and V E The selection of coefficients in the calculation formula is to select appropriate coefficients so that tC Try to keep it between 20 and 30 minutes. D Try to keep it between 15 and 20 minutes. E Try to keep it between 10 and 15 minutes, and at the same time ensure that the injection time of the dye with higher solubility is longer than that of the dye with lower solubility for the same total injection amount of dye.

[0018]

[0019] As the preferred technical solution:

[0020] As described above, a supercritical CO 2 The fluid dyeing method comprises the following steps: the number of the high-temperature grouting devices is multiple, which is the same as the number of types of the mixed dyes, and one type of dye is placed in each high-temperature grouting device.

[0021] As described above, a supercritical CO 2 Fluid dyeing method, the melting point of the dye is set to M°C, and the value range of M is 60-230°C.

[0022] As described above, a supercritical CO 2 The fluid dyeing method, the high-temperature grouting device, has an internal temperature of M°C to (M+20)°C.

[0023] As described above, a supercritical CO 2 Fluid dyeing method, the dye is in supercritical CO 2 The solubility in the fluid is N mol·mol -1 , the value range of N is 10 -9 ~10 -3 .

[0024] As described above, a supercritical CO 2 Fluid dyeing method, the injection rate of the dye is set to P mol·min -1 , the value range of P is 10 -6 ~0.1, the injection rate of each dye is set according to the solubility of the dye.

[0025] As described above, a supercritical CO 2 Fluid dyeing method, the dye weight to fiber is set as Q% omf, Q value range is 0-10, and the total amount of each dye injected is set according to the target color.

[0026] As described above, a supercritical CO 2Fluid dyeing method, the target color is one of the Pantone color cards.

[0027] As described above, a supercritical CO 2 The fluid dyeing method comprises the certain temperature and pressure, the temperature being greater than 31.1°C and the pressure being greater than 7.38MPa.

[0028] As described above, a supercritical CO 2 The fluid dyeing method, the dye is a non-ionic dye.

[0029] As described above, a supercritical CO 2 The fluid dyeing method, the non-ionic dye is one or more of disperse dyes, disperse reactive dyes, solvent dyes, non-ionic food dyes, organic pigments and non-ionic natural dyes.

[0030] As described above, a supercritical CO 2 Fluid dyeing method, the supercritical CO 2 The flow rate of the fluid is 1.667×10 4 ~200.040×10 4 g·min -1 .

[0031] As described above, a supercritical CO 2 Fluid dyeing method, injecting the highest priority dye, controlling supercritical CO 2 The flow rate of the fluid is 200.040×10 4 g·min -1 ;

[0032] When injecting high priority dyes, control supercritical CO 2 The flow rate of the fluid is 25.005×10 4 g·min -1 ;

[0033] Control of supercritical CO when injecting normal priority, low priority, and lowest priority dyes 2 The flow rate of the fluid is 1.667×10 4 g·min -1 .

[0034] As described above, a supercritical CO 2 In the fluid dyeing method, the process of dyeing the fibers in the dyeing kettle is as follows: keeping the temperature and pressure for a certain period of time, then cooling and releasing the pressure;

[0035] The insulation time is 10 to 40 minutes;

[0036] The cooling rate is 1-20℃ / min, and the pressure reduction rate is greater than 1MPa / min. If the cooling rate is too slow, it will take longer and the efficiency of the whole dyeing process will decrease; if the cooling rate is too fast, CO 2 The increased density makes it easier to strip the dye from the fiber, reducing the dye uptake rate.

[0037] Invention mechanism:

[0038] Supercritical CO 2 During fluid dyeing, dyes with high solubility in the fluid will preferentially dissolve in the fluid and first occupy the pores of the dyed fiber. If (1) the amount of dye with low solubility is never dissolved during the dyeing time, the color yield and chromaticity of the final dyed product will not meet production requirements. If (2) the dye with low solubility becomes soluble at the end of dyeing, the pores of the fiber may have been filled with the dye with high solubility, which can only be adsorbed on the fiber surface, resulting in floating color or uneven dyeing of the dyed product.

[0039] The present invention comprises the following steps: (1) melting a dye with high solubility to make it liquid and then controlling the liquid to enter a supercritical CO 2 The amount of the fluid in which it is dissolved in supercritical CO in the form of single molecules or small aggregates 2 In the fluid, they can quickly diffuse into the pores of the polyester fiber, improving the dyeing efficiency; (2) melting the low-solubility dye to break up the interaction between the dye molecules. When the molten dye is injected into the fluid, the local working conditions around the dye quickly change from high temperature and high pressure to low temperature and high pressure. 2 The solubility of the fluid for the insoluble dye is improved, and the insoluble dye can be dissolved quickly in the supercritical CO in the form of single molecules or small aggregates. 2 (3) Since the injection rate of the high-temperature slurry injector is controllable, the method of adding small amounts in batches can ensure that dyes of different solubility enter the pores of the fiber according to the injection ratio, so that the uniformity of dyeing and the amount of color obtained meet the production requirements.

[0040] For dyes with poor solubility or very poor solubility, due to the competitive solubility effect, if they are added together with dyes with other solubility for dyeing at the same time, they will dissolve very little or not at all during the dyeing time. The present invention proposes to add dyes with poor solubility or very poor solubility first, so that they are dyed first, thereby avoiding the competitive solubility effect; at the same time, since dyes with poor solubility or very poor solubility are generally not very soluble in supercritical CO 2 Fluid flow rate (1.667×10 4 g·min -1 )The addition of these two types of dyes takes a long time, which affects the dyeing efficiency. Therefore, when adding these two types of dyes, the fluid flow rate is accelerated to reduce the overall dyeing time.

[0041] For dyes with good solubility and excellent solubility, most dyes can be dissolved in supercritical CO due to their fast dissolution rate. 2 The dye aggregates into large clusters in the fluid, which affects the rate at which the dye diffuses into the fiber, resulting in reduced dyeing uniformity and efficiency. The present invention proposes to use a high-temperature slurry injector to slowly and uniformly add a small amount of dye to prevent aggregation between dye molecules, so that the dye in the form of single molecules or small clusters can diffuse into the fiber as soon as possible. In particular, for the supercritical CO 2 Fluid dyeing, dyes in the form of single molecules or small clusters are also more conducive to their diffusion between fibers and yarns.

[0042] At the same time, for dye mixing systems with large differences in solubility, they are injected in batches according to their solubility, and dyes with lower solubility are added first. This can ensure that dyes with different solubilities enter the pores of the fiber according to the injection ratio, so that the dyeing uniformity and color yield meet production requirements.

[0043] Beneficial effects:

[0044] In the prior art, there are mainly two methods for dyeing with multiple dyes:

[0045] 1. One-bath dyeing: Mix different dyes in a certain proportion and add them all at once for dyeing.

[0046] 2. Two-bath dyeing: The fabric to be dyed is placed in the dyeing system of the first dye for the first dyeing. After the first dyeing is completed, the dyed fabric is placed in the dyeing system of the second dye for the second dyeing to obtain a color-matching dyed fabric.

[0047] The existing two-bath color matching and one-bath color matching, and the color matching in supercritical dyeing are greatly affected by the solubility of the dye itself. For the color difference of dyes with poor solubility and very poor solubility mixed with dyes of other solubility grades, it cannot meet the requirements of national standards; the color difference of dyes with average solubility and very good solubility mixed can only meet the requirements of national standards for second-class products; the color difference of dyes with good solubility and very good solubility mixed can only meet the requirements of national standards for first-class products; only when dyes with average solubility and dyes with average solubility and dyes with good solubility are mixed, the color difference can meet the requirements of national standards for excellent products.

[0048] A supercritical CO2 for accurately controlling the mixing of dyes of the present invention 2 Fluid dyeing method, according to the target color, select the disperse dyes used for mixing and determine the dosage and proportion of different dyes, according to the dye in supercritical CO 2The solubility in the fluid determines its injection sequence and injection rate for dyeing. After dyeing, reduction cleaning is carried out. After reduction cleaning, the CIELAB color difference between the dyed product and the dyed standard sample is <0.5. The dyeing uniformity can reach level 4-5 according to the "GBT 250-2008 Textiles - Tests for colour fastness - Grey scale for assessing change in colour". It meets the standard of first-class products for synthetic fiber silk fabrics in GB / T 17253-2018 (in GB / T 17253-2018, the requirements for first-class products: CIELAB color difference <1.7, dyeing uniformity ≥4 levels; requirements for first-class and second-class products: 1.7 < CIELAB color difference <2.5, dyeing uniformity 3-4 levels). Description of the Drawings

[0049] Figure 1 It is a schematic diagram of the equipment structure adopted by the present invention;

[0050] Among them, 1 - CO 2 Storage tank, 2 - Valve, 3 - Condensation device, 4 - Filtration device, 5 - Separation device, 6 - Heat tracing heating tape, 7 - Dyeing kettle, 8 - Fiber, 9 - Temperature and pressure sensor, 10 - High-temperature grouting injector, 11 - Circulation pump, 12 - Pressure pump, 13 - Preheating device, 14 - CO 2 Input pipeline, 15 - CO 2 Output pipeline. Detailed Embodiments

[0051] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

[0052] As Figure 1 shown, the equipment adopted by the present invention includes a CO 2 storage tank 1, a CO 2 input pipeline 14 and a CO 2 output pipeline 15; a preheating device 13, a pressure pump 12, a circulation pump 11, a high-temperature grouting injector 10 equipped with a temperature and pressure sensor 9 and a dyeing kettle 7 equipped with a fiber 8 are successively arranged on the CO 2 input pipeline 14, and a separation device 5, a filtration device 4 and a condensation device 3 are successively arranged on the CO 2 output pipeline 15; an additional pipeline and a valve 2 are arranged between the pressure pump 12 and the circulation pump 11; an additional pipeline and a valve 2 are arranged on the pipeline after the dyeing kettle 7 to form a closed loop, and the above pipelines are covered by a heat tracing heating tape 6.

[0053] In the embodiments of the present invention, the dyeing uniformity is evaluated according to "GBT 250-2008 Grey Scale for Colour Change of Textiles - Colour Fastness Tests"; in GB / T 17253-2018, for first-class products, the requirements are: CIELAB colour difference < 1.7, and dyeing uniformity ≥ 4 levels; for first-grade and second-grade products, the requirements are: 1.7 < CIELAB colour difference < 2.5, and dyeing uniformity 3-4 levels.

[0054] A supercritical CO2 fluid dyeing method for precisely controlling blended dyes, using the above equipment, injecting small batches of molten non-ionic dyes with different molecular structures into the pipeline respectively through the high-temperature grouting device 10, and mixing with the supercritical CO2 fluid circulating in the pipeline with a temperature greater than 31.1 °C and a pressure greater than 7.38 MPa, and then keeping the temperature and pressure of the fibers in the dyeing kettle for 10-40 minutes and then cooling and depressurizing (the cooling rate is 1-20 °C / min, and the depressurization rate is greater than 1 MPa / min), so that the fibers in the dyeing kettle are dyed with one color in the Pantone color card; 2 Among them, the non-ionic dyes are one or more of disperse dyes, disperse reactive dyes, solvent dyes, non-ionic food dyes, organic pigments and non-ionic natural dyes; the number of high-temperature grouting devices is the same as the number of types of blended dyes, and one dye is placed in each high-temperature grouting device; the melting point of the dye is set as M °C, and the value range of M is 60-230; the internal temperature of the high-temperature grouting device is M °C to (M + 20) °C; 2 The solubility of the dye in the supercritical CO2 fluid is set as N mol·mol-1, and the value range of N is 10-10; the dyes with different molecular structures are divided into injection priority levels according to the solubility in the supercritical CO2 fluid, solubility < 10 mol·mol-1 is the highest priority, solubility between 10-10 mol·mol-1 is high priority, solubility between 10-10 mol·mol-1 is general priority, solubility between 10-10 mol·mol-1 is low priority, solubility > 10 mol·mol-1

[0055] ;

[0056] 2 -1 -1 -9 -1 -3 -1 2 -8 -1 -1 -8 -7 -1 -1 -7 -1 -6 -1 -6 -5 -1 - 5 -1 ​​​​​​​​​​​​is the lowest priority;

[0057] Supercritical CO 2 The flow rate of the fluid is 1.667×10 4 ~200.040×10 4 g·min -1 ; When injecting the highest priority dye, control the supercritical CO 2 The flow rate of the fluid is 200.040×10 4 g·min -1 ; When injecting high priority dyes, control supercritical CO 2 The flow rate of the fluid is 25.005×10 4 g·min -1 ; Control supercritical CO when injecting normal priority, low priority and lowest priority dyes 2 The flow rate of the fluid is 1.667×10 4 g·min -1 ;

[0058] Small batches refer to adding dyes in descending order according to the injection priority. Dyes with the same priority can be injected at the same time. The weight of dye on fiber is set to Q% omf, and the value range of Q is 0 to 10. The injection time of each batch of dye is The dye injection rate was set to P mol·min -1 , the value range of P is 10 -6 ~0.1, the injection rates of dyes with different priority levels are as follows:

[0059]

[0060]

[0061]

[0062]

[0063]

[0064] Among them, m fiber is the mass of the dyed fiber (g), w is the weight of the dye on the fiber (omf), M dye is the molecular weight of the dye, V x is the dye injection rate (mol·min -1 ), t x is the injection time of the dye (min), For dyes in supercritical CO 2 Solubility in fluid (mol·mol -1 ),ux For supercritical CO 2 Fluid flow rate (g·min -1 ), M CO2 For CO 2 Molecular weight (44 g·mol -1 ), x = A, B, C, D, E, representing the dyes with the highest, high, normal, low and lowest injection priority, respectively;

[0065] For the above V C 、V D and V E The selection of coefficients in the calculation formula is to select appropriate coefficients so that t C Try to keep it between 20 and 30 minutes. D Try to keep it between 15 and 20 minutes. E Try to keep it between 10 and 15 minutes, and at the same time ensure that the injection time of the dye with higher solubility is longer than that of the dye with lower solubility for the same total injection amount of dye.

[0066] The dyed fibers are reduction cleaned (the specific steps of reduction cleaning are: place the dyed fibers in a beaker, add hydrosulfite, soda ash and water, the bath ratio is 1:40, heat to 80°C, stir with a glass rod for 15 minutes, take out, and then wash and dry). After reduction cleaning, the CIELAB color difference of the dyed product relative to the dyed standard is <0.5, and the dyeing uniformity can reach level 4-5, which meets the standard of superior synthetic fiber silk fabrics in GB / T 17253-2018.

[0067] Example 1

[0068] A supercritical CO system for precisely controlling dye mixing 2 The fluid dyeing method uses the above equipment and the specific steps are as follows:

[0069] (1) Determine the fiber to be dyed and the target color: the fiber to be dyed is polyester fiber with a mass of 300g; the target color is 19-40005TPG (Stretch Limo) in the Pantone color card;

[0070] (2) Determine the injection order, injection rate, injection time and fiber weight of each dye:

[0071] There are three kinds of dyes, namely Disperse Orange 25, Disperse Blue 60, and Disperse Red 60;

[0072] The melting point of the dye Disperse Orange 25 is 170°C, the corresponding internal temperature of the high-temperature grouting machine is 175°C, the molecular weight is 323.3492, and the 2 The solubility in the fluid is 6.41×10 -6 mol·mol-1 , the priority level is general; when the dye is injected, supercritical CO 2 The flow rate of the fluid is 1.667×10 4 g·min -1 ; The dye injected is 1% omf on the fiber weight; by the formula (coefficient is 0.3), the injection rate of the dye is 0.000728 mol min -1 , and then the injection time is calculated to be 12.74min;

[0073] The melting point of the dye disperse blue 60 is 191°C, the corresponding internal temperature of the high-temperature grouting machine is 205°C, the molecular weight is 379.3661, and the 2 The solubility in the fluid is 4.21×10 -6 mol·mol -1 , the priority level is general; when the dye is injected, supercritical CO 2 The flow rate of the fluid is 1.667×10 4 g·min -1 ; The dye injected is 1% omf on the fiber weight; by the formula (coefficient is 0.4), the injection rate of the dye is 0.000638 mol·min -1 , and then the injection time is calculated to be 12.40min;

[0074] The melting point of the dye disperse red 60 is 185℃, the corresponding internal temperature of the high temperature grouting machine is 195℃, the molecular weight is 331.3215, and the 2 The solubility in the fluid is 2.23×10 -5 mol·mol -1 , the priority is low; when the dye is injected, supercritical CO 2 The flow rate of the fluid is 1.667×10 4 g·min -1 ; The dye injected is 1% omf on the fiber weight; by the formula (coefficient is 0.05), the injection rate of the dye is 0.000422 mol·min -1 , and then the injection time is calculated to be 21.44min;

[0075] (3) The dyes in step (2) are injected into the pipeline in descending order of injection priority through a high-temperature grouting device, and the supercritical CO2 at a temperature of 120°C and a pressure of 25 MPa circulating in the pipeline is 2The fluids are mixed, and then the fibers in the dyeing kettle are kept warm and pressurized for 30 minutes, then cooled and depressurized (the cooling rate is 1°C / min, and the pressure reduction rate is 2MPa / min), so that the fibers in the dyeing kettle are dyed with the target color.

[0076] The dyed fibers were reduction-cleaned. After reduction-cleaning, the CIELAB color difference of the dyed product relative to the dyed standard was 0.48, and the dyeing uniformity was level 4-5.

[0077] Example 2

[0078] A supercritical CO system for precisely controlling dye mixing 2 The fluid dyeing method uses the above equipment and the specific steps are as follows:

[0079] (1) Determine the fiber to be dyed and the target color: the fiber to be dyed is polyester fiber with a mass of 300 g; the target color is 18-1453TPG (Fire Whirl) in the Pantone color card;

[0080] (2) Determine the injection order, injection rate, injection time and fiber weight of each dye:

[0081] There are two kinds of dyes, namely disperse red 13 and disperse orange 3;

[0082] The melting point of the dye disperse red 13 is 129°C, the corresponding internal temperature of the high-temperature grouting machine is 143°C, the molecular weight is 348.7842, and the 2 The solubility in the fluid is 5.42×10 -6 mol·mol -1 , the priority level is general; when the dye is injected, supercritical CO 2 The flow rate of the fluid is 1.667×10 4 g·min -1 ; The dye injected is 1% omf on the fiber weight; by the formula (coefficient is 0.3), the injection rate of the dye is 0.000616 mol min -1 , and then the injection time is calculated to be 13.97min;

[0083] The melting point of the dye Disperse Orange 3 is 200°C, the corresponding internal temperature of the high-temperature slurry injection machine is 220°C, and the molecular weight is 242.2334. 2 The solubility in the fluid is 4.95×10 -6 mol·mol -1 , the priority level is general; when the dye is injected, supercritical CO 2 The flow rate of the fluid is 1.667×10 4g·min -1 ; The dye injected is 1% omf on the fiber weight; by the formula (coefficient is 0.5), the injection rate of the dye is 0.00938 mol·min -1 , and then the injection time is calculated to be 13.21min;

[0084] (3) The dyes in step (2) are injected into the pipeline in descending order of injection priority through a high-temperature grouting device, and the supercritical CO2 at a temperature of 120°C and a pressure of 20 MPa circulating in the pipeline is 2 The fluids are mixed, and then the fibers in the dyeing kettle are kept warm and pressurized for 30 minutes, then cooled and depressurized (the cooling rate is 1°C / min, and the pressure reduction rate is 1MPa / min), so that the fibers in the dyeing kettle are dyed with the target color.

[0085] The dyed fibers were reduction-cleaned. After reduction-cleaning, the CIELAB color difference of the dyed product relative to the dyed standard was 0.43, and the dyeing uniformity was level 4-5.

[0086] Example 3

[0087] A supercritical CO system for precisely controlling dye mixing 2 The fluid dyeing method uses the above equipment and the specific steps are as follows:

[0088] (1) Determine the fiber to be dyed and the target color: the fiber to be dyed is polyester fiber with a mass of 300g; the target color is 19-2430TPG (Purple Potion) in the Pantone color card;

[0089] (2) Determine the injection order, injection rate, injection time and fiber weight of each dye:

[0090] There are two dyes, disperse blue 79 and disperse red 1;

[0091] The melting point of the dye disperse blue 79 is 146°C, the corresponding internal temperature of the high-temperature slurry injection device is 153°C, and the molecular weight is 639.4094. 2 The solubility in the fluid is 5.83×10 -8 mol·mol -1 , with the highest priority; when the dye is injected, supercritical CO 2 The flow rate of the fluid is 200.040×10 4 g·min -1 ; The dye injected is 1% omf on the fiber weight; by the formula The injection rate of the dye was calculated to be 0.00265 mol·min-1 , and then the injection time is calculated to be 1.77min;

[0092] The melting point of the dye disperse red 1 is 160℃, the corresponding internal temperature of the high temperature slurry injection machine is 183℃, the molecular weight is 314.3391, and the 2 The solubility in the fluid is 4.89×10 -7 mol·mol -1 , the priority is high; when the dye is injected, supercritical CO 2 The flow rate of the fluid is 25.005×10 4 g·min -1 ; The dye injected is 1% omf on the fiber weight; by the formula The injection rate of the dye was calculated to be 0.00278 mol·min -1 , and then the injection time is calculated to be 3.43min;

[0093] (3) The dyes in step (2) are injected into the pipeline in descending order of injection priority through a high-temperature grouting device, and the supercritical CO2 at a temperature of 120°C and a pressure of 15 MPa circulating in the pipeline is 2 The fluids are mixed, and then the fibers in the dyeing kettle are kept warm and pressurized for 40 minutes, then cooled and depressurized (the cooling rate is 1°C / min, and the pressure reduction rate is 1.5MPa / min), so that the fibers in the dyeing kettle are dyed with the target color.

[0094] The dyed fibers were reduction-cleaned. After reduction-cleaning, the CIELAB color difference of the dyed product relative to the dyed standard was 0.49, and the dyeing uniformity was level 4-5.

[0095] Example 4

[0096] A supercritical CO system for precisely controlling dye mixing 2 The fluid dyeing method uses the above equipment and the specific steps are as follows:

[0097] (1) Determine the fiber to be dyed and the target color: the fiber to be dyed is polyester fiber with a mass of 300g; the target color is 18-6026TPG (Abundant Green) in the Pantone color card;

[0098] (2) Determine the injection order, injection rate, injection time and fiber weight of each dye:

[0099] There are two dyes, solvent blue 63 and pigment yellow 5;

[0100] The melting point of the dye solvent blue 63 is 118°C, the corresponding internal temperature of the high-temperature slurry injection device is 120°C, the molecular weight is 342.3905, and the 2 The solubility in the fluid is 8.9×10 -4 mol·mol -1 , with the lowest priority; when the dye is injected, supercritical CO 2 The flow rate of the fluid is 1.667×10 4 g·min -1 ; The dye injected is 1% omf on the fiber weight; by the formula (coefficient is 0.001), the injection rate of the dye is 0.000337 mol·min -1 , and then the injection time is calculated to be 25.99min;

[0101] The melting point of the dye pigment yellow 5 is 206°C, the corresponding internal temperature of the high-temperature grouting machine is 210°C, the molecular weight is 326.31, and the 2 The solubility in the fluid is 1.8×10 -5 mol·mol -1 , the priority is low; when the dye is injected, supercritical CO 2 The flow rate of the fluid is 1.667×10 4 g·min -1 ; The dye injected is 1% omf on the fiber weight; by the formula (coefficient is 0.07), the injection rate of the dye is 0.000477 mol min -1 , and then the injection time is calculated to be 19.26min;

[0102] (3) The dyes in step (2) are injected into the pipeline in descending order of injection priority through a high-temperature grouting device, and the supercritical CO2 at a temperature of 120°C and a pressure of 20 MPa circulating in the pipeline is 2 The fluids are mixed, and then the fibers in the dyeing kettle are kept warm and pressurized for 30 minutes, then cooled and depressurized (the cooling rate is 1°C / min, and the pressure reduction rate is 1.5MPa / min), so that the fibers in the dyeing kettle are dyed with the target color.

[0103] The dyed fibers were reduction-cleaned. After reduction-cleaning, the CIELAB color difference of the dyed product relative to the dyed standard was 0.42, and the dyeing uniformity was level 4-5.

[0104] Example 5

[0105] A supercritical CO system for precisely controlling dye mixing 2The fluid dyeing method uses the above equipment and the specific steps are as follows:

[0106] (1) Determine the fiber to be dyed and the target color: the fiber to be dyed is polyester fiber) with a mass of 300 g; the target color is 18-1553TPG (Abundant Rush) in the Pantone color card;

[0107] (2) Determine the injection order, injection rate, injection time and fiber weight of each dye:

[0108] There are two kinds of dyes, namely cochineal red and food orange 3;

[0109] The melting point of the dye cochineal red is 136°C, the corresponding internal temperature of the high-temperature slurry injection device is 140°C, and the molecular weight is 492.39. 2 The solubility in the fluid is 5.1×10 -4 mol·mol -1 , with the lowest priority; when the dye is injected, supercritical CO 2 The flow rate of the fluid is 1.667×10 4 g·min -1 ; The dye injected is 1% omf on the fiber weight; by the formula (coefficient is 0.001), the injection rate of the dye is 0.000193 mol·min -1 , and then the injection time is calculated to be 31.54min;

[0110] The melting point of the dye Food Orange 3 is 160°C, the corresponding internal temperature of the high-temperature slurry injector is 165°C, the molecular weight is 248.29, and the 2 The solubility in the fluid is 9.8×10 -5 mol·mol -1 , the priority is low; when the dye is injected, supercritical CO 2 The flow rate of the fluid is 1.667×10 4 g·min -1 ; The dye injected is 1% omf on the fiber weight; by the formula (coefficient is 0.02), the injection rate of the dye is 0.000742 mol·min -1 , and then the injection time is calculated to be 16.27min;

[0111] (3) The dyes in step (2) are injected into the pipeline in descending order of injection priority through a high-temperature grouting device, and the supercritical CO2 at a temperature of 120°C and a pressure of 25 MPa circulating in the pipeline is 2The fluids are mixed, and then the fibers in the dyeing kettle are kept warm and pressurized for 30 minutes, then cooled and depressurized (the cooling rate is 1°C / min, and the pressure reduction rate is 1.5MPa / min), so that the fibers in the dyeing kettle are dyed with the target color.

[0112] The dyed fibers were reduction-cleaned. After reduction-cleaning, the CIELAB color difference of the dyed product relative to the dyed standard was 0.45, and the dyeing uniformity was level 4-5.

[0113] Example 6

[0114] A supercritical CO system for precisely controlling dye mixing 2 The fluid dyeing method uses the above equipment and the specific steps are as follows:

[0115] (1) Determine the fiber to be dyed and the target color: the fiber to be dyed is polyester fiber with a mass of 300 g; the target color is 18-1659TPG (Goji Berry) in the Pantone color card;

[0116] (2) Determine the injection order, injection rate, injection time and fiber weight of each dye:

[0117] There are two kinds of dyes, namely, azo-vinyl sulfone type reactive disperse orange dye and azo-s-triazine type reactive disperse red dye;

[0118] The melting point of the dye azo-vinyl sulfone type active disperse orange dye is 143°C, the corresponding internal temperature of the high-temperature grouting machine is 150°C, the molecular weight is 441.52, and the 2 The solubility in the fluid is 4.9×10 -4 mol·mol -1 , with the lowest priority; when the dye is injected, supercritical CO 2 The flow rate of the fluid is 1.667×10 4 g·min -1 ; The dye injected is 1% omf on the fiber weight; by the formula (coefficient is 0.002), the injection rate of the dye is 0.000371 mol·min -1 , and then the injection time is calculated to be 18.30min;

[0119] The melting point of the dye azo-s-triazine type active disperse red dye is 128°C, the corresponding internal temperature of the high-temperature grouting machine is 135°C, the molecular weight is 577.33, and the 2 The solubility in the fluid is 7.3×10 -4 mol·mol -1 , with the lowest priority; when the dye is injected, supercritical CO2 The flow rate of the fluid is 1.667×10 4 g·min -1 ; The dye injected is 1% omf on the fiber weight; by the formula (coefficient is 0.001), the injection rate of the dye is 0.000277 mol min -1 , and then the injection time is calculated to be 18.79min;

[0120] (3) The dyes in step (2) are injected into the pipeline in descending order of injection priority through a high-temperature grouting device, and the supercritical CO2 at a temperature of 120°C and a pressure of 25 MPa circulating in the pipeline is 2 The fluids are mixed, and then the fibers in the dyeing kettle are kept warm and pressurized for 30 minutes, then cooled and depressurized (the cooling rate is 1°C / min, and the pressure reduction rate is 1MPa / min), so that the fibers in the dyeing kettle are dyed with the target color.

[0121] The fibers after dyeing are reduction cleaned. After reduction cleaning, the CIELAB color difference of the dyed product relative to the dyed standard is 0.40, and the dyeing uniformity is level 4-5, which meets the standards for superior synthetic fiber silk fabrics in GB / T 17253-2018.

Claims

1. A supercritical CO2 fluid dyeing method for accurately controlling the mixing of dyes, characterized in that: The molten dyes with different molecular structures are injected into the pipeline in small batches through a high-temperature grouting device, mixed with the supercritical CO2 fluid circulating in the pipeline with a certain temperature and pressure, and then the fibers in the dyeing kettle are dyed; The number of the high-temperature grouting machines is the same as the number of types of the mixed dyes, and one type of dye is placed in each high-temperature grouting machine; The dye is a nonionic dye, and the nonionic dye is one or more of disperse dyes, disperse reactive dyes, solvent dyes, nonionic food dyes, organic pigments and nonionic natural dyes; The melting point of the dye is set to M°C, the value range of M is 60-230°C, and the solubility of the dye in the supercritical CO2 fluid is set to N mol·mol -1 , the value range of N is 10 -9 ~10 -3 ; The internal temperature of the high temperature grouting device is M°C to (M+20)°C; The target color is one of the Pantone color cards; The flow rate of the supercritical CO2 fluid is 1.667×10 4 ~200.040×10 4 g·min -1 ; The injection rate of the dye was set to P mol·min -1 , the value range of P is 10 -6 ~0.1, the fiber weight is set to Q%omf, and the value range of Q is 0~10; The certain temperature and pressure are as follows: the temperature is greater than 31.1°C and the pressure is greater than 7.38MPa The process of dyeing the fiber in the dyeing kettle is: keep the temperature and pressure for a certain period of time, then cool down and reduce the pressure; the heat preservation time is 10 to 40 minutes; the cooling rate is 1 to 20°C / min, and the pressure reduction rate is greater than 1MPa / min; The dyes with different molecular structures are divided into injection priorities according to their solubility in supercritical CO2 fluid. -8 mol·mol -1 The highest priority, solubility is 10 -8 ~10 -7 mol·mol -1 High priority, solubility in 10 -7 ~10 -6 mol·mol -1 It is a general priority, with a solubility of 10 -6 ~10 -5 mol·mol -1 Low priority, solubility>10 -5 mol·mol -1 The lowest priority is the small batches; the small batches are added in order from high to low injection priority, and the injection time of each batch of dye is The injection rates of dyes with different priority levels are as follows: Among them, m fiber is the mass of the dyed fiber, w is the weight of the dye to the fiber, M dye is the molecular weight of the dye, V x is the injection rate of dye, t x is the injection time of the dye, is the solubility of the dye in supercritical CO2 fluid, u x is the flow rate of supercritical CO2 fluid, M CO2 is the molecular weight of CO2, and x = A, B, C, D, E, representing the dyes with the highest, high, normal, low and lowest injection priority, respectively.

2. A supercritical CO2 fluid dyeing method for accurately controlling the mixing of dyes according to claim 1, characterized in that: When injecting the highest priority dye, the flow rate of supercritical CO2 fluid is controlled to be 200.040×10 4 g·min -1 ; When injecting high priority dye, the flow rate of supercritical CO2 fluid is controlled to be 25.005×10 4 g·min -1 ; When injecting the dyes of general priority, low priority and lowest priority, the flow rate of supercritical CO2 fluid is controlled to be 1.667×10 4 g·min -1 .

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