Environment-friendly double-effect dyeing and finishing process for cellulosic fiber fabric

Abstract

The invention relates to an environment-friendly double-effect dyeing and finishing process for a cellulosic fiber fabric, and relates to the technical field of textile dyeing and finishing, and the process comprises the step of adding a fabric, water, a biological enzyme, a dye and a multifunctional microcapsule into a treatment bath at one time. Enzyme treatment is firstly carried out at low temperature, then heating is carried out, the temperature is utilized to trigger the microcapsule to release the alkaline agent in the inner core, the dye bath is automatically changed from acidity to alkalinity, and thus color fixation is continuously completed in the same bath. The microcapsule is characterized in that an inner core is a compound of an alkaline agent and a buffering agent, stable rising of the pH value is ensured, and the leveling property is improved; the temperature-sensitive phase-change polymer shell layer stabilizes the temperature through phase-change heat absorption during heating, dye hydrolysis is reduced, and the temperature-sensitive phase-change polymer shell layer serves as a dispersing agent after being dissolved to improve the soaping effect and the color fastness. The two core steps of biological enzyme treatment and reactive dye fixation with repellent chemical environments are integrated in the same treatment bath, so that the production cycle is greatly shortened.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of textile dyeing and finishing, and particularly relates to an environment-friendly double-effect dyeing and finishing process for cellulose fiber fabrics. BACKGROUND

[0002] Cellulose fiber fabrics are widely used due to their excellent wearing performance, and reactive dyes are the most important dye type thereof. Under the industry trend of pursuing higher product quality and more environmentally friendly production methods, pretreatment with biological enzymes before dyeing and finishing has become a mainstream green process. However, the existing technology faces a deep-rooted process contradiction when combining biological enzyme treatment and reactive dyeing. The biological enzyme needs a weakly acidic or neutral environment to exert its best activity, while the fixing reaction of reactive dyes with cellulose fibers must be carried out in a strongly alkaline environment. This completely opposite chemical environment requirement makes the two processes unable to be continuously carried out in the same treatment bath, and the industry generally adopts a split-bath process route. This mode inevitably leads to a long production process, low equipment turnover rate, and involves a large amount of wastewater discharge, water replenishment, and repeated heating and cooling processes between processes, resulting in a huge waste of water resources and energy.

[0003] In the traditional reactive dye fixing process, the quality of the dyed product, especially the color uniformity, is often challenged. The fixing stage usually quickly raises the pH value by directly adding a strong alkali agent (such as soda ash) to the dye bath to promote the dye reaction. However, this direct and rapid alkali addition method causes local and instantaneous pH value fluctuations in the dye bath. This uneven alkaline environment causes unbalanced and explosive fixing reactions of the dye on the fabric surface, making the dye molecules unable to fully migrate and level dye, and easily producing dyeing defects such as color spots, color patches, and color differences, which seriously affect the appearance and first-grade product rate of the final product.

[0004] In addition, the chemical instability of reactive dyes under high-temperature and strong-alkali fixing conditions also brings another technical challenge. Dye molecules not only react with fibers, but also inevitably undergo hydrolysis reactions with water molecules, forming inactive dyes that cannot be dyed. This side reaction directly reduces the effective utilization rate of the dye, i.e., the fixing rate. These hydrolyzed and unfixed dyes, as colored impurities (floats), must be completely removed in the subsequent soaping process. However, in the soaping process, these floats washed off the fabric can easily re-aggregate in the treatment bath and adhere to the fabric surface, i.e., the so-called re-staining phenomenon. This re-staining seriously reduces the key color fastness indicators such as wash fastness and rubbing fastness, greatly reducing the quality of the final product. SUMMARY

[0005] The application aims to provide an environmentally friendly double-effect dyeing and finishing process for cellulose fiber fabrics, which solves the technical problem of long process, high energy and water consumption and low production efficiency caused by the conflict between the weak acidic environment of biological enzyme treatment and the strong alkaline environment of active dye fixation in the prior art.

[0006] In a first aspect, the application provides an environmentally friendly double-effect dyeing and finishing process for cellulose fiber fabrics, which comprises the following steps: S1, feeding and environment establishing step: cellulose fiber fabrics, water, biological enzymes, dyes and microcapsules containing alkali agents in the core are added into the treatment bath at one time, and the environment of the treatment bath is adjusted to be weakly acidic or neutral; S2, biological enzyme treatment step: the temperature of the treatment bath is raised to and maintained at a first preset temperature, so that the biological enzyme treats the fabric; S3, temperature control fixation step: the temperature of the treatment bath is raised from the first preset temperature to and maintained at a second preset temperature, in the process, the microcapsules release the alkali agents in the core, so that the environment of the treatment bath changes to alkaline, thereby the dye fixation is carried out; S4, post-treatment step: after the fixation is completed, the fabric is washed.

[0007] Preferably, in the biological enzyme treatment step S2, the first preset temperature is 50-55℃, the pH value of the treatment bath is maintained at 5.0-6.0, and the duration of this step is 35-50 minutes. This combination of conditions aims to provide the best active environment for the selected biological enzyme.

[0008] Preferably, in the temperature control fixation step S3, the second preset temperature is 60-65℃, the pH range of the alkaline environment is 10.5-11.5, and the holding time at this temperature is 45-60 minutes. This combination of conditions aims to provide an efficient fixation environment for the selected active dye.

[0009] Preferably, in order to ensure the controllable rupture of the microcapsule shell layer, the temperature rising rate in the process of raising the temperature from the first preset temperature to the second preset temperature in step S3 is controlled in the range of 0.8℃ / min-1.5℃ / min.

[0010] In a second aspect, the application provides a preparation method of multifunctional synergistic microcapsules in an environmentally friendly double-effect dyeing and finishing process for cellulose fiber fabrics, which comprises the following steps: Core preparation: mechanically mix and dry the powders of the main alkali agent and the latent buffer agent at a molar ratio of 3:1-5:1 to prepare a core compound.

[0011] Oil phase preparation: the temperature-sensitive phase change copolymer synthesized in the core preparation step was dissolved in the oil phase solvent, and the core composite powder prepared in the core preparation step was dispersed in the oil phase solution to form a uniform oil phase suspension.

[0012] Emulsification encapsulation: the oil phase suspension was slowly added to the water phase solution containing emulsifier under high-speed shearing conditions to form a water-in-oil emulsion.

[0013] Solidification and collection: the oil phase solvent was removed by methods such as reduced pressure distillation, so that the shell polymer was solidified into a film on the surface of the core composite to form microcapsules. Subsequently, after filtration, washing and freeze-drying, the final microcapsule product was obtained.

[0014] Preferably, the microcapsule is a core-shell structure with multiple synergistic functions, which is prepared by the method of the second aspect.

[0015] The core thereof is a composite composed of a main alkali agent (preferably sodium carbonate) and a latent buffer (preferably sodium bicarbonate).

[0016] The shell thereof is the temperature-sensitive phase change polymer.

[0017] The microcapsule is that in step S3, the shell ruptures or changes permeability in response to temperature rise, and the latent heat of phase change can form a short constant temperature platform; at the same time, the released core composite can smoothly increase the pH value; and the dissolved shell molecules can play a role as chelating agents or dispersants in the treatment bath.

[0018] In summary, the present application includes at least one of the following beneficial technical effects: 1. The present application successfully integrates the two core steps of biological enzyme treatment and active dye fixing, which are repulsive in chemical environment, into the same treatment bath through multifunctional microcapsules, completely cancels the redundant steps of intermediate drainage, cleaning and rewatering required in traditional process, thereby greatly shortening the production cycle, significantly reducing the water resource and heat energy consumption in the production process, and realizing the greenization and high efficiency of the dyeing and finishing process; 2. The core of the microcapsule of the present application adopts a composite design of main alkali agent and latent buffer. When the microcapsule is triggered to release its core by temperature, the composite can establish a dynamic buffer system in the treatment bath, realize the smooth and controllable transition of pH value from weak acid to strong alkali, control the pH jump, avoid the instantaneous and too fast dyeing of dyes due to the drastic change of local alkali concentration, and ensure the uniform and smooth fixing of dyes on the fabric fibers, thereby effectively preventing the occurrence of defects such as color spots and color difference; 3. The unique phase change characteristics of the shell material in this application can form a short-term isothermal plateau during the color fixing and heating stage, which effectively inhibits the hydrolysis side reaction of the dye, improves the utilization rate of the dye and the final color yield. On the other hand, after the shell completes its release mission and dissolves, its molecular chains are transformed into highly efficient dispersants and chelating agents in the treatment bath, which can effectively prevent the floating color from re-contaminating in the subsequent soaping process, thereby ensuring that the final product has excellent wash resistance and abrasion resistance. Detailed Implementation

[0019] This application will be further described in detail below.

[0020] Example 1 This embodiment provides an environmentally friendly dual-effect dyeing and finishing process for cellulose fiber fabrics, including the following steps: Preparation of multifunctional synergistic microcapsules Step 1: Synthesis of the shell material (octadecyl methacrylate-N-isopropylacrylamide copolymer): 90 mmol of N-isopropylacrylamide, 10 mmol of octadecyl methacrylate monomer, and 0.5 mmol of azobisisobutyronitrile initiator were dissolved in 200 mL of tetrahydrofuran solvent. Under nitrogen protection, the mixture was polymerized at 70 °C for 6 hours. After the reaction, the product was precipitated in excess cold diethyl ether, filtered, washed, and vacuum dried to obtain a white powdery shell material.

[0021] Step 2, Preparation of the core complex: 4 mol of anhydrous sodium carbonate powder and 1 mol of sodium bicarbonate powder were placed in a ball mill and mechanically mixed for 30 minutes, and then dried at 110°C for 3 hours to obtain the core complex.

[0022] Step 3: Microcapsule encapsulation: Dissolve 10g of the shell material obtained in Step 1 in 100mL of cyclohexane, then add 20g of the core complex powder obtained in Step 2, and stir to disperse evenly, forming an oil phase suspension. In another container, dissolve 1.0g of sodium dodecyl sulfate in 400mL of deionized water to form an aqueous phase. Under high-speed shear at 6000rpm, slowly add the oil phase suspension dropwise to the aqueous phase over 30 minutes, and continue emulsification for 25 minutes. Finally, perform rotary evaporation at 40℃ and -0.09MPa to remove cyclohexane, and after washing and freeze-drying, obtain the final microcapsule product.

[0023] 2. Dyeing and finishing process (1) S1 : Take 100 g of pure cotton knitted fabric and place it in a dyeing and finishing equipment. Set the bath ratio to 1 : 12 and add 1200 mL of water. Then add the following all at once: 12 g / L of the above-mentioned microcapsules, 2% of ethylene sulfone type reactive dye, and 1.5% of a complex of acid-stable cellulase and pectinase. Adjust the pH of the dye bath to 5.5 with glacial acetic acid.

[0024] (2) S2: Increase the temperature of the dye bath to 52°C at a rate of 2.0°C / min and maintain it at this temperature for 40 minutes.

[0025] (3) S3: Increase the temperature of the dye bath from 52°C to 62°C at a rate of 1.2°C / min and maintain it at this temperature for 50 minutes. At this time, the pH of the dye bath is measured to be 11.0.

[0026] (4) S4: After completing the fixation, cool down and drain the water. Then perform post-treatment: soaping at 92°C for 15 minutes with a soaping agent, followed by one hot water wash and one warm water wash. Finally, dehydrate and dry the fabric.

[0027] Example 2 This example provides an environmentally friendly double-effect dyeing and finishing process for cellulose fiber fabric, comprising the following steps: 1. Preparation of multifunctional synergistic microcapsules Prepared in a similar manner to Example 1, except that: Step one, preparation of the core complex: mix 3 mol of anhydrous sodium carbonate powder with 1 mol of sodium bicarbonate powder.

[0028] Step two, all other preparation parameters use the lower limit values disclosed in Example 1 or corresponding adjustments.

[0029] 2. Dyeing and finishing process (1) S1 : Set the bath ratio to 1 : 10. Add: 8 g / L of the above-mentioned microcapsules, 0.5% of ethylene sulfone type reactive dye, and 0.8% of enzyme complex. Adjust the pH of the dye bath to 5.0.

[0030] (2) S2: Increase the temperature of the dye bath to 50°C and maintain it at this temperature for 35 minutes.

[0031] (3) S3: Increase the temperature of the dye bath from 50°C to 60°C at a rate of 0.8°C / min and maintain it at this temperature for 45 minutes. At this time, the pH of the dye bath is measured to be 10.5.

[0032] (4) S4: After completing the fixation, soaping is performed at 90°C, followed by washing and finishing.

[0033] Example 3 The embodiment provides an environmentally-friendly double-effect dyeing and finishing process for cellulose fiber fabrics, and specifically comprises the following steps. 1. Preparation of multifunctional synergistic microcapsules The preparation is performed by using a method similar to that in Embodiment 1, except that: Step one, preparation of the inner core complex: 5 mol of anhydrous sodium carbonate powder is mixed with 1 mol of sodium bicarbonate powder.

[0034] Step two, other preparation parameters are all upper limit values disclosed in Embodiment 1 or corresponding adjustments.

[0035] 2. Dyeing and finishing process (1) S1: Set the bath ratio to 1:15. Add: 18 g / L of the above microcapsules, 5% of ethylene sulfone type reactive dyes, and 2.5% of enzyme complex. Adjust the dye bath pH value to 6.0.

[0036] (2) S2: The dye bath temperature is raised to 55°C, and the temperature is kept at this temperature for 50 minutes.

[0037] (3) S3: The dye bath temperature is raised from 55°C to 65°C at a rate of 1.5°C / min, and the temperature is kept at this temperature for 60 minutes. At this time, the dye bath pH value is measured to be 11.5.

[0038] (4) S4: After fixing the color, soaping is performed at 95°C, followed by washing and finishing.

[0039] Comparative Example 1 Compared with Embodiment 1, the difference is that: the microcapsules are not used. In S1, the inner core complex (i.e., the mixture of sodium carbonate and sodium bicarbonate) of the microcapsules used in Embodiment 1 is directly added into the treatment bath together with the biological enzyme and the dye. The remaining steps and parameters are the same.

[0040] Comparative Example 2 Compared with Embodiment 1, the difference is that: the latent buffer is not contained in the inner core of the microcapsules. The inner core complex used for preparing the microcapsules is only composed of the main alkali agent (anhydrous sodium carbonate), and the molar amount of the main alkali agent is equal to that in the inner core of Embodiment 1. The remaining preparation steps, process steps and parameters are the same.

[0041] Comparative Example 3 Compared with Embodiment 1, the difference is that: the shell layer of the microcapsules does not have a secondary function. The shell layer material used for preparing the microcapsules is replaced by inert paraffin with a melting point in the range of 60-62°C, and the inner core components and the encapsulation process remain unchanged. The steps and parameters of the dyeing and finishing process are the same.

[0042] Comparative Example 4 The difference compared with Example 1 is that the slow heating process in the temperature-controlled fixation step is cancelled. In S3, the temperature of the treatment bath is directly and quickly raised from 52°C to 62°C, instead of using a controlled heating rate of 1.2°C / min. The rest of the steps and parameters are the same.

[0043] Test Example 1: Dyeing uniformity This test aims to quantitatively evaluate the color uniformity of the resulting dyed fabrics under different process conditions. The dry dyed fabric samples prepared by Example 1, 2, 3 and Comparative Examples 1, 2 are selected for the experiment.

[0044] The experimental procedure is as follows: First, each fabric sample is conditioned for 24 hours in a constant temperature and humidity (20±2°C, 65±5% RH) environment. Then, using a computer color matching instrument, set D65 light source, 10° standard observer viewing angle. Before testing the sample, use the standard white board and black cylinder provided with the instrument for calibration. For each fabric sample to be tested, lay it flat on the test port, ensuring no wrinkles. Randomly select 10 non-overlapping test points on the surface of the sample, and measure the apparent depth value (K / S value) at the maximum absorption wavelength of each point. Record all the measured data and calculate the arithmetic mean and standard deviation (SD) of the K / S values of the 10 measurement points of each sample.

[0045] The experimental data is shown in Table 1: Table 1: Dyeing uniformity (leveling) test data for fabric samples Sample Average K / S value K / S value standard deviation (SD) Example 1 15.12 0.16 Example 2 13.98 0.23 Example 3 16.05 0.21 Comparative Example 1 13.55 1.32 Comparative Example 2 14.21 0.84 Experimental Conclusion: From the experimental data shown in Table 1, it can be clearly seen that the standard deviations of the K / S values of the fabric samples prepared by Examples 1, 2, 3 using the technical solution of the present application are in the extremely low range of 0.16 to 0.23, which indicates that the color distribution on the surface of the fabric is highly uniform. In contrast, the standard deviations of the K / S values of the fabric samples of Comparative Example 1 and Comparative Example 2 are as high as 1.32 and 0.84 respectively, showing significant color non-uniformity. This data difference directly proves the significant technical advantage of the technical solution of the present application in improving dyeing and finishing leveling.

[0046] The above results are due to the unique component design and mechanism of the core-shell microcapsule. In the process of Examples 1-3, when the temperature reaches the preset value, the microcapsule releases the core complex composed of the main alkali agent and the latent buffer. The complex can instantly build a dynamic pH buffer system in the treatment bath, which is not simply releasing alkali agent, but through the buffering effect, the process of changing the treatment bath environment from weak acid to target alkaline becomes stable, gradual and controllable. This controlled pH jump ensures that dye molecules are activated and fixed on the fiber in a uniform alkaline environment in any micro area of the fabric, thereby achieving excellent color uniformity of the final product.

[0047] In contrast, Comparative Example 1 directly mixed the alkali agent with the dye, resulting in a sharp and disordered mutation of the pH value of the treatment bath at the initial stage of temperature rise, and the dye was locally and too quickly fixed on the surface of the fabric, resulting in serious color spots and uneven dyeing. The high K / S standard deviation corresponds to it. In Comparative Example 2, although the alkali agent is released by the microcapsule, the lack of the key latent buffer component in the core still causes a local pH shock to the microenvironment around the fabric. Although this shock is weaker than that of Comparative Example 1, it is still enough to cause a certain degree of uneven dyeing, making its level dyeing much worse than that of the examples of the present application. Therefore, the compounding of the main alkali agent and the latent buffer in the core is the key to achieving high level dyeing.

[0048] Test Example 2: Dye fixation rate and color yield test This test aims to evaluate the fixation efficiency of the dye on the fiber and the final color performance under different process conditions. The dry dyed fabric samples prepared by Examples 1, 2, 3 and Comparative Examples 1, 2, 3 and 4 are selected for the experiment.

[0049] The experimental steps are divided into two parts: first, using a computer color matching instrument, the initial apparent depth value (K / S value) of each fabric sample is measured under the same conditions as Test Example 1, which is used as a measure of color yield. Second, to determine the fixation rate, accurately weigh about 2g of each dyed fabric sample, place it in a conical flask, add 100mL of 25% (v / v) pyridine aqueous solution, and heat treat in a boiling water bath for 10 minutes to completely strip all un-fixed and hydrolyzed dyes from the fabric. After the treatment, the fabric sample is washed with deionized water until the wash is clear, and the K / S value is measured again after drying. The fixation rate is calculated by the formula: Fixation rate (%) = (stripped K / S value / initial K / S value) x 100%.

[0050] The experimental data is shown in Table 2: Table 2 Fabric sample color yield and fixation rate test data Sample Initial K / S value (color yield) Fixation rate (%) Example 1 15.12 93.8 Example 2 13.98 91.5 Example 3 16.05 92.7 Comparative Example 1 13.55 68.2 Comparative Example 2 14.21 76.4 Comparative Example 3 14.88 84.1 Comparative Example 4 14.53 81.6 Experimental conclusion: As can be seen from the experimental data shown in Table 2, the dye fixation rates of Examples 1, 2 and 3 using the technical scheme of the present application are all stable at above 91%, which is significantly higher than all the comparative examples. At the same time, the initial K / S values also show excellent color yield. In contrast, the fixation rates of Comparative Examples 1 to 4 have obvious defects, especially in Comparative Example 1 where the microcapsules are cancelled, the fixation rate is only 68.2%, resulting in a huge waste of dyes and a serious potential environmental burden. This result powerfully proves the decisive role of the technical scheme of the present application in improving the utilization rate of dyes and the fixation efficiency.

[0051] The realization of this technical advantage is rooted in the precise control mechanism of the present application for the two competing reactions of reactive dye fixation and hydrolysis. In the process of the examples, the improvement of dye fixation efficiency comes from the synergistic effect of two key technologies. First, the unique temperature-sensitive phase change characteristics of the microcapsule shell layer. During the temperature rising process in step S3, the shell material undergoes phase change to absorb latent heat, which can form a short constant temperature platform on the dye bath temperature rising curve. This platform appears at the critical moment of alkali release and fixation reaction initiation, and it greatly inhibits the rate of dye hydrolysis side reaction which is more sensitive to temperature, thus creating a more favorable kinetic window for the effective combination of dyes and fibers.

[0052] Second, this heat energy management mechanism complements the smooth pH jump environment provided by the core complex. The controlled pH environment avoids the instantaneous massive hydrolysis of dyes due to the excessive local alkali concentration. In Comparative Example 3, due to the use of inert paraffin shell layer, the protection of phase change constant temperature platform is lacking, even if the temperature-controlled release of alkali is achieved, its fixation rate is still much lower than the examples. In Comparative Example 4, the rapid heating rate exposes the dyes to a high-temperature high-alkali environment quickly, and the hydrolysis reaction is intensified, so the fixation rate is also not ideal. Therefore, the dual precise control of heat energy management and pH environment management by the multifunctional microcapsules of the present application jointly constitutes its high fixation rate and high color yield effect.

[0053] Test Example 3: Dyeing fastness test The test aims to evaluate the quality of the final dyed fabric, especially its soaping and rubbing fastness. The experimental samples are prepared from the dyed fabrics dried in Examples 1, 2, 3 and Comparative Example 3. Soaping fastness test: a 10 cm x 4 cm fabric sample is sewn with a piece of standard multi-fiber lining fabric, and placed in a test solution containing 2 g / L of standard soaping liquor, bath ratio 1:50, at 60°C for 30 minutes. After washing and drying, the color change grade of the original sample and the staining grade of the lining cotton fiber are evaluated using a standard gray scale. Rubbing fastness test: using a rubbing fastness tester, the sample is tested by rubbing with dry and wet standard white cloth respectively under standard atmospheric pressure, and the staining grade of the rubbing white cloth is evaluated using a standard gray scale. All grade evaluations are carried out in a standard light source box.

[0054] The experimental data are shown in Table 3 Table 3 Fabric sample dyeing fastness test data Sample Soaping fastness (color change) Soaping fastness (cotton staining) Dry rubbing fastness Wet rubbing fastness Example 1 4-5 4-5 4-5 4 Example 2 4-5 4 4 3-4 Example 3 4 4-5 4-5 4 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7 Comparative Example 8 Comparative Example 9 Comparative Example 10 Comparative Example 11 Comparative Example 12 Comparative Example 13 Comparative Example 14 Comparative Example 15 Comparative Example 16 Comparative Example 17 Comparative Example 18 Comparative Example 19 Comparative Example 20 Comparative Example 21 Comparative Example 22 Comparative Example 23 Comparative Example 24 Comparative Example 25 Comparative Example 26 Comparative Example 27 Comparative Example 28 Comparative Example 29 Comparative 4 3 4 2-3 Experimental conclusion: As can be clearly seen from the test data in Table 3, the dyeing fastness indicators of Examples 1, 2 and 3 using the technical solutions of the present application are all excellent. In particular, the soaping cotton staining and wet rubbing fastness, as key indicators, both reach the excellent level of grade 4 or above, indicating that the floating color on the fabric surface is removed very cleanly. In contrast, the sample of Comparative Example 3, although showing acceptable color change and dry rubbing fastness, has significantly lower grades in soaping cotton staining and wet rubbing fastness, only grade 3 and grade 2-3 respectively, which reveals its serious defects in the post-treatment process.

[0055] The internal mechanism of this performance difference directly points to the originality of the design of the microcapsule shell material in the present application, i.e. its indispensable secondary function after completing the main task of temperature-controlled release of alkali agent. In the process of the examples, when the shell layer composed of long-chain alkyl methacrylate-N-isopropyl acrylamide copolymer is dissolved or dispersed in step S3, its polymer chain segments immediately become efficient chelating agents and dispersants in the treatment bath. In the subsequent soaping step (S4) of post-treatment, these polymer chains can actively capture the hydrolyzed dye molecules and un-fixed dye aggregates suspended in the treatment bath, and effectively prevent these colored impurities from re-depositing or staining the surface of the cellulose fiber fabric through their own dispersion effect.

[0056] In contrast, Comparative Example 3 uses inert paraffin wax as the shell material. Although paraffin wax can achieve the function of temperature-controlled release of alkali agent by melting, it is an inert substance after melting and has no function to the treatment bath. In the soaping process, it cannot play any dispersing or chelating effect on the hydrolyzed and unfixed dyes, resulting in the inevitable redeposition of these dyes on the fabric surface during washing. This redeposition directly leads to poor wet rubbing fastness and soaping fastness of the final product. Therefore, by endowing the microcapsule shell with the secondary function of post-treatment auxiliary, the present application ingeniously builds an additional component in the traditional process into the core functional carrier, thereby fundamentally improving the quality of the final product.

[0057] Test Example 4: Overall process efficiency evaluation This test aims to quantitatively evaluate the overall performance of the process disclosed in the present application in terms of production efficiency and resource consumption. The experiment compares the process flow of Example 1 with a traditional two-bath process (defined as Comparative Example 5). The specific steps of Comparative Example 5 are as follows: First, complete the biological enzyme treatment in a treatment bath (process parameters same as step S2 of Example 1); then drain the treatment liquid and rinse once with clean water; then re-fill water in the same equipment, add dyes and alkali agent (directly add a mixture of sodium carbonate and sodium bicarbonate), complete dyeing and fixing (process parameters same as step S3 of Example 1); finally, the same post-treatment as Example 1 is performed. During the experiment, the total time consumed from the start of feeding to the completion of all post-treatment steps, the total water consumption per kilogram of fabric treated, and the estimated total energy consumption of the two process flows are accurately recorded and calculated. The estimation of total energy consumption is based on the heat consumed to heat the water required for each process from the initial temperature of 20°C to the target process temperature.

[0058] The experimental data are shown in Table 4 Table 4 Comparison of overall process efficiency test data Experimental conclusion: From the comparison data in Table 4, it can be concluded that the process flow disclosed in the present application has overwhelming advantages in production efficiency and resource conservation. Compared with the traditional two-bath process, the total process time of Example 1 is shortened by about 33%, the total water consumption is reduced by 20%, and the estimated total energy consumption is reduced by nearly 29%. This series of data proves from a macroscopic point of view that the technical solution of the present application has made significant technical progress in energy saving, emission reduction and efficiency improvement.

[0059] The present application fundamentally restructures the dyeing and finishing process paradigm of cellulose fibers by introducing multifunctional microcapsules. The present application successfully integrates the processes that must be placed in two independent treatment baths due to mutual repulsion in the chemical environment in the traditional process into the same treatment bath. By using temperature as the core control means, precise isolation of different chemical reaction stages in the time dimension is achieved, thereby completely eliminating a series of non-productive auxiliary steps such as intermediate discharge, cleaning, and rewatering that are necessary in the traditional process. The elimination of these steps is the direct cause of the significant reduction in total process time and significant reduction in total water consumption.

[0060] More deeply, the significant reduction in energy consumption also stems from the inherent integration of this process. In the traditional two-bath method, a large amount of energy is consumed in the process of reheating the cold water of the second bath (dyeing bath) to the fixation temperature. The present application smoothly raises the temperature of the treatment bath from the first preset temperature of the enzyme treatment stage to the second preset temperature of the fixation stage in a continuous process, which avoids the huge waste of energy in thermodynamics. Therefore, the present application is not simply a process superposition, but through a core technical carrier (multifunctional microcapsules), it connects the originally broken and contradictory process points into a smooth and efficient production line, achieving systematic and all-round improvement in time, water resource and energy utilization efficiency.

Claims

1. An environmentally friendly dual-effect dyeing and finishing process for cellulose fiber fabrics, characterized in that, Includes the following steps: S1. Add cellulose fiber fabric, water, biological enzymes, dyes, and microcapsules containing an alkali agent in the core to the treatment bath at once, and adjust the environment of the treatment bath to be weakly acidic or neutral. S2. Raise the temperature of the treatment bath to and maintain it at a first preset temperature, so that the bio-enzyme treats the fabric; S3. The temperature of the treatment bath is raised from a first preset temperature to and maintained at a second preset temperature. During this process, the microcapsule releases the alkaline agent in its core, making the environment of the treatment bath alkaline, thereby fixing the dye. S4. After color fixing is completed, the fabric is washed.

2. The environmentally friendly dual-effect dyeing and finishing process for cellulose fiber fabrics according to claim 1, characterized in that, The microcapsule is a core-shell structure with multiple synergistic functions, wherein: The core is a complex composed of a primary alkali agent and a latent buffer, which is used to smoothly increase the pH value of the treatment bath when it is released in step S3; The shell is a thermosensitive phase change polymer. During the heating process in step S3, it utilizes its latent heat of phase change to form a short-term isothermal platform. After it dissolves or disperses, its molecules act as chelating agents or dispersing agents in the treatment bath.

3. The environmentally friendly dual-effect dyeing and finishing process for cellulose fiber fabrics according to claim 1, characterized in that, The primary base agent in the core is sodium carbonate, and the latent buffer is sodium bicarbonate, with a molar ratio of 3-5:

1.

4. The environmentally friendly dual-effect dyeing and finishing process for cellulose fiber fabrics according to claim 1, characterized in that, The shell is composed of a long-chain alkyl methacrylate-N-isopropylacrylamide copolymer.

5. The environmentally friendly dual-effect dyeing and finishing process for cellulose fiber fabrics according to claim 1, characterized in that, Step S2 includes: The first preset temperature is 50℃-55℃, the pH value of the treatment bath is maintained at 5.0-6.0, and the duration of this step is 35-50 minutes.

6. The environmentally friendly dual-effect dyeing and finishing process for cellulose fiber fabrics according to claim 1, characterized in that, Step S3 includes: The second preset temperature is 60℃-65℃, the pH range of the alkaline environment is 10.5-11.5, and the heat preservation time at this temperature is 45-60 minutes.

7. The environmentally friendly dual-effect dyeing and finishing process for cellulose fiber fabrics according to claim 1, characterized in that, In step S3, the heating rate from the first preset temperature to the second preset temperature is controlled within the range of 0.8℃ / min to 1.5℃ / min.

8. The environmentally friendly dual-effect dyeing and finishing process for cellulose fiber fabrics according to claim 1, characterized in that, The bioenzyme added in step S1 is an acidic, stable enzyme complex containing cellulase and pectinase.

9. The environmentally friendly dual-effect dyeing and finishing process for cellulose fiber fabrics according to claim 1, characterized in that, Step S4 specifically includes a soaping process performed at a temperature of 90°C to 95°C.

10. The environmentally friendly dual-effect dyeing and finishing process for cellulose fiber fabrics according to claim 1, characterized in that, The dye is a vinyl sulfone type low-temperature reactive dye.

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