Low-energy-consumption dyeing process for polyester fabric

Abstract

The invention relates to the technical field of textile dyeing, and discloses a polyester fabric low-energy-consumption dyeing process which comprises the following steps: S1, preparing dye liquor; s2, performing plasma surface treatment on the polyester fabric; s3, performing real-time monitoring on humidity and Zeta potential of dye liquor in the dyeing process by using dynamic double-feedback control, and adjusting a temperature-sensitive polymer dispersant and a pH value; s4, regulating and controlling the dyeing temperature through a pulse type heating management and temperature control strategy; s5, carrying out color fixation treatment by using a photocatalyst, and carrying out color fixation through ultraviolet irradiation; s6, after the wastewater is subjected to primary treatment, closed-loop regeneration is carried out through photocatalytic degradation, catalyst recovery and electrodialysis treatment. The wastewater treatment scheme combining photocatalytic degradation and electrodialysis technologies is adopted, dyes and auxiliaries in the wastewater can be efficiently removed, the recovery rate is high, the pollution level of the wastewater is remarkably reduced, and reutilization of resources is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of textile dyeing, in particular to a low-energy consumption dyeing process for polyester cloth. Background Art

[0002] With rising living standards, people's demands for the quality of daily necessities continue to rise, especially when it comes to dyes. The dyeing quality and environmental friendliness of textiles, such as clothing and home furnishings, have become particularly important. While widely used in the market, existing dyeing technologies face challenges such as poor dyeing uniformity and difficult wastewater treatment. This not only affects the appearance quality of the final product but also poses risks of environmental pollution and resource waste.

[0003] Existing dyeing technologies rely heavily on traditional dye dissolution and fixation methods. These methods, after years of application, have proven effective in meeting certain dyeing needs and have achieved large-scale industrial production. While traditional dyeing methods can effectively control basic dyeing effects, such as color stability and fixation, they often suffer from uneven dyeing due to a lack of precise control over dye dispersion and dye-fiber affinity. This is particularly true when dyeing complex patterns or dark colors, where color differences and color fastness are particularly problematic.

[0004] However, traditional technologies still have many problems in practical applications, especially in terms of uniformity of the dyeing process, wastewater treatment, and resource recovery. Traditional dyes are often difficult to disperse completely, the dyeing effect is unstable, and the dye particles are easy to aggregate, resulting in uneven color distribution on the fabric and poor color fastness. In addition, the removal rate of dyes and auxiliaries in wastewater is low. Although traditional chemical precipitation methods can remove some dyes, they cannot effectively recycle resources, and harmful substances remain in the wastewater, which will pollute the environment. Moreover, most traditional dyeing processes rely on manual adjustment of the temperature and humidity of the dyeing process, which makes it easy for human errors to occur during the dyeing process, and the dyeing effect and quality are difficult to guarantee. To this end, those skilled in the art have proposed a low-energy dyeing process for polyester fabrics to solve the above problems. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the present invention provides a low-energy consumption dyeing process for polyester fabrics, which solves the problems of uneven dyeing effect, low wastewater treatment efficiency and environmental pollution in the existing technology.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions: A low-energy consumption dyeing process for polyester fabrics, comprising the following steps: S1, preparing a dye solution, wherein the dye solution includes a disperse dye, a temperature-sensitive polymer dispersant, a color fixing auxiliary agent and a buffer; Prepare the dye solution. This step involves adding disperse dyes, a thermosensitive polymer dispersant, a fixing agent, and a buffer. Precisely controlling the ratio of these ingredients ensures dye solution stability and optimal dyeing results.

[0007] Disperse dyes improve dyeing uniformity by forming tiny particles in the aqueous phase. Thermosensitive polymer dispersants can respond to temperature changes under experimental conditions, further enhancing the stability of the dye's dispersion. The addition of a fixing agent reduces the surface tension between the dye and the fabric, improving dye adhesion and achieving excellent color fixation. The buffer helps maintain the dye solution's pH within the appropriate range, promoting chemical reactions between the dye and the fabric.

[0008] S2. Plasma surface treatment of polyester fabric; The polyester fabric is subjected to plasma surface treatment. The purpose of this step is to enhance the hydrophilicity of the fabric through plasma treatment, improve its surface polarity and the adhesion of the dye.

[0009] Plasma treatment introduces high-energy nitrogen or argon gases, altering the surface molecular structure and enhancing the fabric's affinity for dyes. The reactive groups generated by this process effectively increase the number of hydroxyl and carboxyl groups on the fabric surface, thereby improving the efficient deposition of dyes onto fabric fibers. This innovative step not only increases dyeing speed but also improves dye uniformity and fastness, representing an improvement over traditional dye adsorption processes.

[0010] S3, using dynamic dual feedback control to monitor the humidity and zeta potential of the dye solution in real time during the dyeing process, and to adjust the temperature-sensitive polymer dispersant and pH value; Dynamic dual feedback control is used for real-time monitoring. In this step, an infrared humidity sensor is used to monitor the humidity of the fabric surface, while an electrochemical Zeta potential probe is used to measure the Zeta potential of the dye solution in real time.

[0011] Dynamic dual-feedback control technology allows real-time adjustment of humidity and potential changes during the dyeing process to achieve optimal dyeing results. When humidity is too high or the zeta potential is unstable, the uniform distribution of the dye on the fabric surface may be affected. Machine learning models (such as LSTM neural networks) are used to predict the dye aggregation risk index (ARI). Once the set threshold is exceeded, the system automatically adjusts the injection rate of the thermosensitive polymer dispersant and the pH value of the dye liquor to ensure more ideal dyeing conditions. This mechanism effectively improves the control accuracy of the dye liquor, and its innovation lies in reducing human operational errors through intelligent means.

[0012] S4, regulating the dyeing temperature through pulse temperature management and temperature control strategy; The dyeing temperature is adjusted through pulsed temperature management and temperature control strategy. A two-stage temperature increase strategy is designed in this step to promote the adsorption and diffusion of the dye solution.

[0013] Pulsed heating management can be divided into an adsorption-promoting phase and a diffusion-stabilizing phase. The first phase of heating promotes dye adsorption onto the fabric, while the second phase, by maintaining a higher temperature, facilitates the diffusion of dye molecules deep into the fabric fibers. The intermittent pulse heating method prevents drastic temperature fluctuations and ensures uniform dyeing. This innovative approach reduces damage to the fabric caused by overheating and improves dyeing efficiency and reliability.

[0014] S5, performing color fixing treatment using a photocatalyst and fixing the color by ultraviolet light irradiation; The dye is fixed by using a photocatalyst and fixed by UV light. After the dyeing is completed, the photocatalyst and UV light are used to ensure the color of the dye is fixed.

[0015] Photocatalytic color fixation uses composite materials such as Fe3O4@TiO2@rGO as catalysts. UV light excites free radicals generated on the catalyst surface, which react with dye molecules to form strong covalent bonds. This process significantly improves the color fastness of the dye, preventing the fabric from fading easily during subsequent use. Furthermore, the enhanced photocatalytic process allows for efficient color fixation in a shorter time, reducing the labor required by traditional color fixation methods.

[0016] S6. After primary treatment, the wastewater is regenerated in a closed loop through photocatalytic degradation, catalyst recovery and electrodialysis treatment.

[0017] After primary treatment, the wastewater is regenerated in a closed loop through photocatalytic degradation, catalyst recovery and electrodialysis. This step aims to achieve the reuse of wastewater treatment in the dyeing process and form a closed-loop economy.

[0018] After initial filtration to remove large suspended solids, the wastewater is then decomposed through a photocatalytic reaction to remove harmful dyes and additives. Leveraging the excellent degradation capabilities of the Fe3O4@TiO2@rGO catalyst, significant degradation results are achieved in a short period of time. The catalyst is then recovered using an electromagnet, ensuring a reuse rate exceeding 95%, demonstrating excellent economic efficiency. Recovering ions from the wastewater through an electrodialysis membrane not only improves overall resource utilization but also reduces potential environmental pollution risks, further emphasizing the advantages of this invention in sustainable dyeing processes.

[0019] Preferably, the dye solution preparation step comprises: Mixing disperse dye and water in a ratio of 1:3-3.5 to obtain a disperse dye solution; Adding a thermosensitive polymer dispersant to the disperse dye solution, wherein the amount of the thermosensitive polymer dispersant added accounts for 50% to 120% of the mass of the disperse dye; and adding a color fixing auxiliary agent, wherein the amount of the color fixing auxiliary agent added accounts for 30%-80% of the mass of the disperse dye; A buffer solution is added to the dye solution to maintain the pH value between 4.5 and 5.0, and the concentration of the buffer solution is 2-4 g / L.

[0020] Dye liquor preparation is fundamental to efficient dyeing. Disperse dyes are mixed with deionized water in an appropriate proportion to ensure a uniform dispersion, allowing them to effectively penetrate the fabric fibers during the subsequent dyeing stage. Disperse dyes contain aromatic hydrocarbon groups or aromatic ring structures. Examples include Disperse Red 60, which produces a bright red color and is widely used in polyester fabric dyeing; Disperse Blue 56, which produces a deep blue color with excellent lightfastness and washability; and Disperse Yellow 211, which provides a bright yellow color and good dispersibility, making it suitable for high-temperature dyeing. The addition of a thermosensitive polymer dispersant, whose molecular chains undergo conformational changes at specific temperatures, improves dye dispersion and reduces precipitation and aggregation. Fixing aids, such as sodium benzyl benzoate, improve the affinity between the dye and the fabric, ultimately significantly enhancing dye fastness. A buffer stabilizes the dye liquor's pH, maintaining its chemical environment and ensuring a smooth dyeing process. This innovation lies in its systematic consideration of various dyeing conditions, significantly improving the overall stability of the dye liquor and the dyeing results.

[0021] Preferably, the thermosensitive polymer dispersant is poly (N-isopropylacrylamide) grafted with sulfonic acid groups, and its molecular weight ranges from 10,000 to 50,000 Da; The color fixing auxiliary agent is benzyl benzoate sodium salt; The buffer is phosphate buffer.

[0022] The introduction of poly (N-isopropylacrylamide) grafted with sulfonic acid groups (WCS) exhibits unique temperature-sensitive properties. Its advantage lies in that the polymer's solubility behavior influences the dispersion state of the dye as temperature changes, fully leveraging its adaptive properties during the dyeing process. The choice of a color-fixing auxiliary, sodium benzyl chlorobenzoate, further enhances the dye's binding by interacting with the fabric surface. Therefore, this innovation lies in achieving a balance between intelligent dyeing solutions, environmental adaptability, and high efficiency, providing a stable and efficient chemical environment for the dyeing process.

[0023] Preferably, the plasma surface treatment step comprises: The polyester fabric is fed into the plasma treatment equipment for surface activation treatment; The power of the plasma treatment is 200-300W, and the treatment time is 2-3 minutes.

[0024] Plasma treatment technology is used to activate the surface of fabrics. By subjecting the fabric surface to high-energy plasma treatment, it can form abundant polar groups, such as hydroxyl and carboxyl groups. These polar groups effectively increase the physical and chemical interactions between the dye and the fabric, enhancing the dye's adsorption capacity. The innovation of this mechanism lies in its ability to significantly increase the hydrophilicity of polyester fabrics, thus laying a good foundation for the subsequent dyeing stage. Under the same dyeing conditions, plasma-treated fabrics can significantly improve dyeing results and shorten dyeing time, which is difficult to achieve with traditional methods.

[0025] Preferably, the plasma surface treatment gas is nitrogen with a flow rate of 50-100 L / min and a gas pressure of 0.1-0.3 MPa.

[0026] The advantage of choosing nitrogen as the treatment gas lies in its relatively low chemical reactivity, which effectively reduces potential damage to the fabric. Precise control of the nitrogen flow rate and pressure ensures uniformity and stability in the plasma treatment. The selected flow rate and pressure provide sufficient active gas for the plasma chemical reaction, thereby enhancing the activation effect and thus improving the dyeability of the fabric. This innovation enables precise control of surface treatment conditions and further optimizes the fabric preparation process before dyeing.

[0027] Preferably, the dynamic dual feedback control step includes: The surface humidity of the fabric is monitored in real time through an infrared humidity sensor with a monitoring accuracy of ±0.5%; The zeta potential of the dye solution is measured in real time by an electrochemical zeta potential probe with a monitoring accuracy of ±0.1mV; Based on real-time data, an LSTM neural network is used to predict the dye aggregation risk index (ARI). When the ARI value exceeds 0.8, the injection of a thermosensitive polymer dispersant is initiated. The injection amount of the thermosensitive polymer dispersant accounts for 5%-15% of the total mass of the dye solution, and the injection rate is 0.1-0.3L / min. When the ARI exceeds 0.8, the pH value is adjusted by the automatic adjustment system to maintain it between 4.8 and 5.2, with a titration accuracy of ±0.1.

[0028] Leveraging advanced sensor technology for real-time monitoring, infrared humidity sensors capture changes in fabric humidity in real time, optimizing the liquid state required for dyeing. Zeta potential probes assess the surface charge characteristics of dye particles in the dye liquor. By analyzing changes in the dye's zeta potential, it's possible to determine whether the dye is in an aggregated state. The innovation of this mechanism lies in its feedback control, enabling controllable and dynamic adjustments during the dyeing process. Combined with an LSTM neural network model to predict the dye aggregation risk index, this effectively identifies potential dyeing failures in advance, enabling proactive adjustments to ensure optimal dyeing conditions.

[0029] Preferably, the pulse heating management and temperature control strategy includes: During the dyeing process, stage 1, adsorption promotion period: the temperature is increased from 80°C to 95°C at a rate of 1-3°C / min, and this temperature range is maintained; Stage 2, diffusion stabilization period: The temperature is further increased to between 95°C and 110°C, and intermittent pulse heating control is adopted, that is, each heating is performed for 2 minutes and then paused for 1 minute.

[0030] The pulsed heating strategy provides the dye with varying heat supply at different stages, tailored to its adsorption and diffusion behavior on the fabric. The initial temperature increase facilitates the initial bonding of dye molecules to the fiber surface, while the maintained high temperature in the subsequent stages facilitates the diffusion of the dye deeper into the fabric. This not only reduces thermal damage to the fabric but also enhances dyeing uniformity and fastness, demonstrating that this invention improves and optimizes traditional dyeing methods.

[0031] Preferably, the step of performing color fixation treatment on the photocatalyst comprises: The wastewater is initially filtered through a ceramic ultrafiltration membrane to remove large suspended solids. The pore size of the ultrafiltration membrane is 50nm and the retention rate reaches 99%; The wastewater was photocatalytically degraded by the Fe3O4@TiO2@rGO catalyst, which has good degradation ability for dyes and additives in the wastewater, with a degradation time of 15-30 minutes; The Fe3O4@TiO2@rGO catalyst was recovered using an electromagnet, with a recovery rate of over 95%; The wastewater is treated by electrodialysis, and the recovery rate of benzyl benzoate sodium salt is 70%-90%.

[0032] The Fe3O4@TiO2@rGO composite catalyst, based on photocatalytic WET, generates free radicals upon UV irradiation, forming covalent bonds with the dye, firmly anchoring it to the fabric surface. The Fe3O4@TiO2@rGO catalyst preparation method involves three steps: first, Fe3O4 nanoparticles are prepared by coprecipitation; then, TiO2 is coated on the Fe3O4 surface by a sol-gel method; and finally, graphene oxide is reduced to rGO by chemical reduction, which is then composited with the Fe3O4@TiO2. The resulting composite catalyst exhibits magnetic properties, excellent photocatalytic properties, and superior electrical conductivity, making it widely applicable in environmental purification and catalytic reactions. The highlight of this implementation step is that it enhances the chemical stability of the dye fixation process by utilizing photocatalytic technology, overcoming the reliance on high temperatures or chemical reagents associated with traditional dye fixation methods, thereby reducing the environmental burden of the process. Furthermore, the high efficiency of this step significantly improves the time efficiency of dye fixation, playing a significant role in promoting green technological innovation in the dyeing process.

[0033] Preferably, the closed-loop regeneration process comprises: The wastewater is initially filtered through a ceramic ultrafiltration membrane to remove large suspended solids. The pore size of the ultrafiltration membrane is 50nm. The wastewater was photocatalytically degraded by the Fe3O4@TiO2@rGO catalyst, which has good degradation ability for dyes and additives in the wastewater, with a degradation time of 15-30 minutes; Fe3O4@TiO2@rGO catalyst was recovered using electromagnet; The wastewater is treated by electrodialysis.

[0034] In wastewater treatment, ceramic ultrafiltration membranes are used to intercept large particle pollutants, significantly improving the efficiency of subsequent treatment. Photocatalytic degradation, with the help of recycled Fe3O4@TiO2@rGO catalysts, can effectively decompose wastewater containing dyes and additives, and the active oxides generated during the photocatalytic process can reduce the concentration of harmful substances in the wastewater. The gradually advancing electrodialysis process can recover valuable ions and additives for secondary utilization, which marks the economy and resource utilization of wastewater treatment. The innovation of the present invention in this link lies in significantly improving the environmental friendliness of the dyeing process and effectively promoting the recycling of resources by realizing a closed loop of wastewater treatment.

[0035] Preferably, the light source of the photocatalytic degradation reactor is a visible light LED with a light intensity of 50-100 W / m 2 , the reaction time is 15-30 minutes.

[0036] The use of visible light LEDs not only reduces energy consumption but also significantly improves reactor safety and efficiency. Their wavelength range precisely matches the light absorption characteristics of the catalyst, ensuring efficient reaction. Compared to the high-energy light sources used in traditional methods, LEDs offer low heat generation, low cost, and low energy consumption, better meeting the demands of modern, green production. This improvement demonstrates the technical advantages of this invention in photocatalysis and promotes the sustainable development of the dyeing industry.

[0037] In summary, this application includes at least one of the following beneficial technical effects: 1. The present invention adopts a wastewater treatment scheme that combines photocatalytic degradation and electrodialysis technology, which can efficiently remove dyes and additives in wastewater with a high recovery rate. It not only significantly reduces the pollution level of wastewater, but also realizes the recycling of resources. Compared with the traditional chemical precipitation method for treating wastewater, the present invention effectively reduces the residual harmful substances and improves the wastewater treatment efficiency.

[0038] 2. The present invention uses a dynamic dual-feedback control system to adjust the dyeing process in real time, and can accurately control the humidity, temperature and dye solution potential. This innovative technology ensures the parameter stability during the dyeing process and effectively avoids the uneven distribution of dyes during the dyeing process. Compared with the manual adjustment method, the present invention reduces the difficulty and error of operation and improves the uniformity and stability of the dyeing effect.

[0039] 3. The present invention utilizes plasma surface treatment technology to enhance the adhesion of fabric to dyes and improve the dyeing effect. By introducing polar groups on the fabric surface, the adsorption capacity of dyes is increased. Compared with traditional chemical treatment methods, this treatment method not only improves dyeing uniformity but also shortens dyeing time.

[0040] 4. The present invention effectively improves the dispersibility of the dye in the dye solution and avoids the aggregation of dye particles by using a thermosensitive polymer dispersant. Compared with the technical solution without using such a dispersant, the dye adheres to the fabric more evenly and the color fastness is significantly improved, ensuring the stability of dyeing and high-quality output. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a schematic flow chart of the process steps of the present invention. DETAILED DESCRIPTION

[0042] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the present specification. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0043] Unless otherwise specified, the raw materials and reagents used in the following examples are commercially available or can be prepared by known methods.

[0044] Please see the attached Figure 1 : Example 1: 1. Dye solution preparation: Preparation of disperse dye solution: Disperse Red 60 was used as a disperse dye with a mass of 30 g. Deionized water was added with a ratio of water to disperse dye of 1:3 (90 g of water), and the mixture was stirred until completely dissolved to obtain a disperse dye solution.

[0045] Thermosensitive polymer dispersants: Poly (N-isopropylacrylamide grafted with sulfonic acid groups) (WCS) with a molecular weight of 25,000 Da was added to the disperse dye solution in an amount of 80% (24 g) of the disperse dye mass.

[0046] Color fixing agent: Add benzyl benzoate sodium salt in an amount of 50% (15 g) of the disperse dye mass.

[0047] Buffer: Phosphate buffer was added to the dye solution at a concentration of 3 g / L to adjust the pH value of the dye solution to 4.8.

[0048] 2. Fabric pretreatment: Plasma surface treatment: Plasma treatment equipment was used with a nitrogen flow rate of 80 L / min, a gas pressure of 0.2 MPa, a treatment power of 250 W, and a treatment time of 2 minutes.

[0049] After plasma treatment, polar groups such as hydroxyl and carboxyl groups are generated on the surface of the fabric, which enhances the hydrophilicity of the fabric and the adhesion of the dye.

[0050] 3. Dynamic dual feedback control: Real-time monitoring of humidity and zeta potential: An infrared humidity sensor is used to monitor the humidity of the cloth surface with an accuracy of ±0.5%.

[0051] The zeta potential of the dye solution was measured in real time using an electrochemical zeta potential probe with an accuracy of ±0.1 mV.

[0052] The LSTM neural network is used to predict the dye aggregation risk index (ARI). When the ARI value exceeds 0.8, the injection amount of the thermosensitive polymer dispersant is automatically adjusted to 12% of the total dye solution, and the pH value of the dye solution is adjusted to 4.9.

[0053] 4. Temperature control management: Pulse heating strategy: The temperature was raised from 80°C to 95°C at a rate of 2°C / min and maintained at 95°C ± 2°C for 15 minutes.

[0054] Then the temperature was raised to 105°C with intermittent pulse heating, heating for 2 minutes and then pausing for 1 minute, and maintained until dyeing was completed.

[0055] 5. Color fixing treatment: Photocatalytic color fixation: Fe3O4@TiO2@rGO composite catalyst was used, and the amount of catalyst added was 70% (21 g) of the total amount of the dye solution.

[0056] The dyed fabric was exposed to a UV LED light source with a wavelength of 365nm and an irradiation intensity of 70W / m 2 , the irradiation time is 20 minutes.

[0057] 6. Wastewater treatment and regeneration: Wastewater closed-loop regeneration: The wastewater was initially filtered using a ceramic ultrafiltration membrane with a pore size of 50 nm and a retention rate of 99%.

[0058] Photocatalytic degradation was carried out using Fe3O4@TiO2@rGO catalyst, and the degradation time was 20 minutes.

[0059] The catalyst recovery rate reaches more than 95%, and the wastewater is treated by electrodialysis, and the recovery rate of benzyl benzoate sodium salt is 80%.

[0060] Example 2: 1. Dye solution preparation: Preparation of disperse dye solution: Disperse Red 60 was used as a disperse dye with a mass of 20 g. Deionized water was added with a ratio of water to disperse dye of 1:3 (60 g of water), and the mixture was stirred until completely dissolved to obtain a disperse dye solution.

[0061] Thermosensitive polymer dispersants: Poly (N-isopropylacrylamide grafted with sulfonic acid groups) (WCS) with a molecular weight of 10,000 Da was added to the disperse dye solution in an amount of 50% (10 g) of the disperse dye mass.

[0062] Color fixing agent: Add benzyl benzoate sodium salt in an amount of 30% (6 g) of the disperse dye mass.

[0063] Buffer: Phosphate buffer was added to the dye solution at a concentration of 2 g / L to adjust the pH value of the dye solution to 4.5.

[0064] 2. Fabric pretreatment: Plasma surface treatment: A plasma treatment device was used with a nitrogen flow rate of 50 L / min, a gas pressure of 0.1 MPa, a treatment power of 200 W, and a treatment time of 2 minutes.

[0065] 3. Dynamic dual feedback control: Real-time monitoring of humidity and zeta potential: An infrared humidity sensor is used to monitor the humidity of the cloth surface with an accuracy of ±0.5%.

[0066] The zeta potential of the dye solution was measured in real time using an electrochemical zeta potential probe with an accuracy of ±0.1 mV.

[0067] The LSTM neural network is used to predict the dye aggregation risk index (ARI). When the ARI value exceeds 0.8, the injection amount of the thermosensitive polymer dispersant is automatically adjusted to 5% of the total dye solution, and the pH value of the dye solution is adjusted to 4.8.

[0068] 4. Temperature control management: Pulse heating strategy: The temperature was raised from 80°C to 90°C at a rate of 1°C / min and maintained at 90°C ± 2°C for 15 minutes.

[0069] Then the temperature was raised to 100°C, with intermittent pulse heating, heating for 2 minutes and then pausing for 1 minute, and maintained until dyeing was completed.

[0070] 5. Color fixing treatment: Photocatalytic color fixation: Fe3O4@TiO2@rGO composite catalyst was used, and the amount of catalyst added was 50% (15 g) of the total amount of the dye solution.

[0071] The dyed fabric was exposed to a UV LED light source with a wavelength of 365nm and an irradiation intensity of 50W / m 2 , the irradiation time is 15 minutes.

[0072] 6. Wastewater treatment and regeneration: Wastewater closed-loop regeneration: The wastewater was initially filtered using a ceramic ultrafiltration membrane with a pore size of 50 nm and a retention rate of 99%.

[0073] Photocatalytic degradation was carried out using Fe3O4@TiO2@rGO catalyst, and the degradation time was 15 minutes.

[0074] The catalyst recovery rate reaches more than 90%, and the wastewater is treated by electrodialysis, and the recovery rate of benzyl benzoate sodium salt is 70%.

[0075] Example 3: 1. Dye solution preparation: Preparation of disperse dye solution: Disperse Red 60 was used as a disperse dye with a mass of 40 g. Deionized water was added with a ratio of water to disperse dye of 1:3 (120 g of water), and the mixture was stirred until completely dissolved to obtain a disperse dye solution.

[0076] Thermosensitive polymer dispersants: Poly (N-isopropylacrylamide grafted with sulfonic acid groups) (WCS) with a molecular weight of 50,000 Da was added to the disperse dye solution in an amount of 120% (48 g) of the disperse dye mass.

[0077] Color fixing agent: Add benzyl benzoate sodium salt in an amount of 80% (32 g) of the disperse dye mass.

[0078] Buffer: Phosphate buffer was added to the dye solution at a concentration of 4 g / L to adjust the pH value of the dye solution to 5.0.

[0079] 2. Fabric pretreatment: Plasma surface treatment: Plasma treatment equipment was used with a nitrogen flow rate of 100 L / min, a gas pressure of 0.3 MPa, a treatment power of 300 W, and a treatment time of 3 minutes.

[0080] 3. Dynamic dual feedback control: Real-time monitoring of humidity and zeta potential: An infrared humidity sensor is used to monitor the humidity of the cloth surface with an accuracy of ±0.5%.

[0081] The zeta potential of the dye solution was measured in real time using an electrochemical zeta potential probe with an accuracy of ±0.1 mV.

[0082] The LSTM neural network is used to predict the dye aggregation risk index (ARI). When the ARI value exceeds 0.8, the injection amount of the thermosensitive polymer dispersant is automatically adjusted to 15% of the total dye solution, and the pH value of the dye solution is adjusted to 5.2.

[0083] 4. Temperature control management: Pulse heating strategy: The temperature was increased from 80°C to 100°C at a rate of 3°C / min and maintained at 100°C ± 2°C for 15 minutes.

[0084] Then the temperature was raised to 110°C with intermittent pulse heating, heating for 2 minutes and then pausing for 1 minute, and maintained until dyeing was completed.

[0085] 5. Color fixing treatment: Photocatalytic color fixation: Fe3O4@TiO2@rGO composite catalyst was used, and the amount of catalyst added was 100% (30 g) of the total amount of the dye solution.

[0086] The dyed fabric was exposed to a UV LED light source with a wavelength of 365nm and an irradiation intensity of 100W / m 2 , the irradiation time is 30 minutes.

[0087] 6. Wastewater treatment and regeneration: Wastewater closed-loop regeneration: The wastewater was initially filtered using a ceramic ultrafiltration membrane with a pore size of 50 nm and a retention rate of 99%.

[0088] Photocatalytic degradation was carried out using Fe3O4@TiO2@rGO catalyst, and the degradation time was 30 minutes.

[0089] The catalyst recovery rate reaches more than 98%, and the wastewater is treated by electrodialysis, and the recovery rate of benzyl benzoate sodium salt is 90%.

[0090] Comparative Example 1: Compared with Example 1, the difference is that conventional polyvinyl alcohol is used as the dispersant instead of the temperature-sensitive polymer dispersant, and the rest are the same.

[0091] Comparative Example 2: Compared with Example 1, the difference is that plasma surface treatment is not used, but traditional chemical treatment methods (such as acid washing) are used to increase the hydrophilicity of the fabric. The rest are the same.

[0092] Comparative Example 3: Compared with Example 1, the difference is that the dynamic dual feedback control system is not used, but the dyeing process is controlled by manually adjusting the humidity and pH value. The rest are the same.

[0093] Comparative Example 4: Compared with Example 1, the difference is that pulse temperature rise management is not adopted, but continuous heating is adopted to control the dyeing temperature. The rest are the same.

[0094] Comparative Example 5: Compared with Example 1, the difference is that no photocatalyst color fixing treatment is used, but a traditional chemical color fixing agent is used for color fixing, and the rest are the same.

[0095] Comparative Example 6: Compared with Example 1, the difference is that the wastewater treatment does not use photocatalytic degradation and electrodialysis technology, but uses traditional chemical treatment and precipitation method for wastewater treatment, and the rest are the same.

[0096] Experiment 1: Purpose of the experiment: This experiment aimed to compare the dyeing results of Example 1 with those of Comparative Examples 1 and 2, focusing on testing the dispersibility, uniformity, color fastness, and depth of dye. By comparing the dyeing results of different experimental groups, we explored the effects of temperature-sensitive polymer dispersants and plasma surface treatment on dyeing quality.

[0097] Experimental groups: Example 1: Using innovative processes such as thermosensitive polymer dispersants, plasma surface treatment, and photocatalytic color fixation treatment.

[0098] Comparative Example 1: No temperature-sensitive polymer dispersant was used, and other steps were the same as in Example 1.

[0099] Comparative Example 2: No plasma surface treatment was performed, and other steps were the same as in Example 1.

[0100] Experimental steps: 1. Sample preparation: Prepare the corresponding dye solution according to the dye solution preparation method of different groups (Example 1 uses a thermosensitive polymer dispersant and plasma treatment; Comparative Example 1 does not use a thermosensitive polymer dispersant; Comparative Example 2 does not perform plasma surface treatment).

[0101] 2. Dyeing process: Place the prepared fabrics into the corresponding dye solution and dye according to the standard dyeing process. During the dyeing process, record various operating parameters such as dyeing temperature and humidity.

[0102] 3. Dyeing effect detection: Color depth test: Use a spectrophotometer to measure the color depth of the dyed fabric and record the data.

[0103] Uniformity Assessment: The uniformity of the fabric is checked by visual inspection or with a colorimeter, recording the color differences between dyed areas.

[0104] Color fastness test: Conduct standard washing and rubbing fastness tests to record the stability of dye adhesion and evaluate color fastness.

[0105] 4. Result analysis: Compare the differences in color depth, uniformity and color fastness between Example 1 and the comparative example group (experimental data are shown in Table 1).

[0106] Table 1: Dyeing effect data of Experiment 1 From Table 1, we can get: Comparative testing of the dyeing results in Example 1 and Comparative Examples 1 and 2 clearly demonstrates the significant impact of the thermosensitive polymer dispersant and plasma surface treatment on dyeing. In Example 1, the thermosensitive polymer dispersant effectively enhanced the dispersion of the dye in the dye liquor, preventing dye aggregation and thus improving dyeing uniformity. Combined with the plasma surface treatment, the hydrophilicity of the fabric was improved, resulting in stronger adhesion of the dye to the fabric surface and a more stable and uniform dyeing effect.

[0107] Experimental data show that Example 1 exhibits a shallower color depth, better uniformity, and significantly higher color fastness than Comparative Examples 1 and 2. In particular, Example 1 exhibits higher color fastness in washing and rubbing fastness tests, indicating a stronger bond between the dye and the fabric. This also demonstrates the role of the thermosensitive polymer dispersant and plasma treatment technology in improving dyeing results.

[0108] The introduction of a thermosensitive polymer dispersant stabilizes the dye molecules in the dye liquor, reducing aggregation and precipitation, and improving dyeing uniformity. Plasma surface treatment, by introducing polar groups onto the fabric surface, enhances the affinity between the dye and the fabric, thereby improving dyeing uniformity and fastness. Furthermore, the innovative process in Example 1 demonstrates significant advantages over the comparative example, particularly in terms of color fastness and uniformity, demonstrating the effectiveness of these innovative steps in improving dyeing quality.

[0109] Experiment 2: Purpose of the experiment: This experiment aimed to compare the dyeing process stability in Example 1 with that in Comparative Examples 3 and 4, focusing on the effects of a dynamic dual-feedback control system, temperature management, and traditional manual control on dyeing process stability. By comparing the stability, uniformity, and ease of operation of each control method, the impact of each control method on dyeing quality was explored.

[0110] Experimental groups: Example 1: Using innovative processes such as dynamic dual feedback control system and pulse temperature rise management.

[0111] Comparative Example 3: The dynamic dual-feedback control system was not used, and the humidity and pH value were manually adjusted to control the dyeing process.

[0112] Comparative Example 4: Pulse temperature rise management was not used, and continuous heating was adopted to control the dyeing temperature.

[0113] Experimental steps: 1. Sample preparation: Dye solutions were prepared according to the dye solution preparation methods in Example 1, Comparative Examples 3 and 4 (Example 1 used a dynamic dual feedback control system and pulsed temperature rise management; Comparative Example 3 did not use dynamic dual feedback control; Comparative Example 4 did not use pulsed temperature rise management).

[0114] 2. Dyeing process: The dyeing processes of Example 1, Comparative Example 3, and Comparative Example 4 were performed respectively, and the operation difficulty, adjustment frequency, and process parameters (such as humidity, temperature, zeta potential, etc.) during the dyeing process were recorded for each group.

[0115] 3. Dyeing effect detection: Uniformity assessment: The uniformity of dyeing was measured by visual inspection and a colorimeter, and the color difference values ​​of different areas were recorded.

[0116] Color fastness testing: Washing fastness and rubbing fastness tests are conducted to evaluate the adhesion of dyes to fabrics.

[0117] Stability test: The range of changes in temperature, humidity, and potential of each group during the dyeing process was recorded, and their effects on the dyeing effect were analyzed (the experimental data are shown in Table 2).

[0118] Table 2: Experiment 2 dyeing process control stability data From Table 2, we can get: By comparing the experimental results of dyeing process control stability in Example 1 with those in Comparative Examples 3 and 4, it can be observed that the dynamic dual feedback control system and pulsed temperature rise management significantly improve dyeing stability and effect. In Example 1, the dynamic dual feedback control system can monitor humidity, temperature, and zeta potential in real time and automatically adjust the dye liquor conditions according to the risk of dye aggregation, thereby ensuring the stability of parameters during the dyeing process. This real-time adjustment not only improves dyeing uniformity, but also enhances the adhesion of the dye and significantly improves color fastness.

[0119] In contrast, Comparative Examples 3 and 4, which did not employ a dynamic adjustment system, experienced significant fluctuations in temperature, humidity, and potential during the dyeing process, resulting in uneven dye distribution, unstable dyeing results, and low color fastness. This demonstrates that the intelligent control system in Example 1 plays a key role in the dyeing process, helping to reduce human error and improve operational stability.

[0120] The dynamic dual-feedback control system automatically adjusts the dye liquor ratio when the risk of dye aggregation increases by monitoring humidity and potential in real time, avoiding dye precipitation and aggregation, thereby achieving a more uniform dyeing effect. The pulsed temperature management, by increasing the temperature in stages, avoids the negative impact of temperature fluctuations on the dyeing effect, further ensuring the stability of the dyeing process. Therefore, the dyeing process of Example 1 has significant advantages over traditional methods in terms of stability and dyeing effect.

[0121] Experiment 3: Purpose of the experiment: This experiment aimed to compare the wastewater treatment and environmental impact of Example 1 with Comparative Examples 5 and 6, focusing on testing the removal efficiency of dyes and additives from wastewater, the wastewater's recycling and reuse capacity, and the environmental impact of wastewater treatment. By comparing the wastewater treatment effects of different treatment methods, the advantages of photocatalytic degradation and electrodialysis technologies in resource recovery and environmental protection were explored.

[0122] Experimental groups: Example 1: Wastewater treatment using photocatalytic degradation and electrodialysis technology, combined with photocatalytic color fixation technology.

[0123] Comparative Example 5: The photocatalytic degradation technology was not used, and the traditional chemical fixation method was adopted, and the traditional chemical precipitation method was adopted for wastewater treatment.

[0124] Comparative Example 6: Photocatalytic degradation and electrodialysis technologies were not used, and traditional chemical precipitation method was adopted for wastewater treatment.

[0125] Experimental steps: 1. Preparation of wastewater samples: According to the wastewater treatment steps in Example 1, Comparative Examples 5 and 6, wastewater samples were prepared respectively (Example 1 used photocatalytic degradation and electrodialysis technology; Comparative Example 5 used a traditional color fixation method; Comparative Example 6 used a traditional chemical precipitation method to treat wastewater).

[0126] 2. Wastewater treatment: Example 1: Photocatalytic degradation and electrodialysis technology are used to treat wastewater. Photocatalytic degradation is carried out using Fe3O4@TiO2@rGO catalyst. After the catalyst is recovered, the wastewater is treated by electrodialysis to recover valuable chemicals (such as sodium benzyl benzoate).

[0127] Comparative Example 5: Traditional chemical fixing agents were used for color fixation, and the wastewater was treated by chemical precipitation.

[0128] Comparative Example 6: The wastewater was treated by conventional chemical precipitation method without using any photocatalytic or electrodialysis technology.

[0129] 3. Wastewater testing: Dye removal rate test: The removal efficiency of dyes in wastewater was tested by UV-visible spectrophotometer.

[0130] Additive removal rate test: Use chemical analysis method to detect the removal efficiency of additives in wastewater.

[0131] Water quality assessment: Measure residual chemical components in wastewater and evaluate the impact of water quality on the environment.

[0132] 4. Result analysis: Compare the removal rates of dyes and auxiliaries in wastewater from different groups, and analyze the wastewater recovery efficiency and environmental impact (experimental data are shown in Table 3).

[0133] Table 3: Experiment 3 wastewater treatment and environmental impact data From Table 3 we can get: Comparative experiments comparing the wastewater treatment effects of Example 1 with Comparative Examples 5 and 6 clearly demonstrate the significant advantages of photocatalytic degradation and electrodialysis in terms of dye and additive removal, catalyst recovery, and water quality improvement. The photocatalytic degradation technology in Example 1 efficiently degrades dyes and additives in wastewater, with a high catalyst recovery rate of over 98%, significantly reducing environmental pollution. Furthermore, electrodialysis further improves wastewater resource recovery efficiency by recovering valuable chemical substances (such as benzyl benzoate sodium salt).

[0134] In contrast, the traditional wastewater treatment methods (chemical fixation and chemical precipitation) used in Comparative Examples 5 and 6 were less efficient. The dye and auxiliary agent removal rates in Comparative Example 5 were low (only 60%-65%), and the COD value in the wastewater was high, indicating significant environmental pollution potential. The wastewater treatment results in Comparative Example 6 were even less than ideal, with dye and auxiliary agent removal rates of 45% and 50%, respectively, and a COD value as high as 150, demonstrating significant drawbacks in traditional chemical wastewater treatment methods.

[0135] From the perspective of mechanism, photocatalytic degradation technology destroys the chemical structure of dye by generating free radicals and reacting with dye molecules, thereby achieving efficient degradation. Electrodialysis technology separates the ionic components (such as dye and auxiliary agent) in the solution through the action of an electric field, recycles useful chemicals, and further reduces the harmful components in the wastewater. Therefore, the wastewater treatment technology of Example 1 has shown obvious advantages in reducing pollution, improving resource recovery, and realizing sustainable dyeing.

[0136] The examples of this specific embodiment are all preferred embodiments of this application and are not intended to limit the scope of protection of this application. Identical components are represented by the same reference numerals. Therefore, any equivalent changes made based on the structure, shape, and principle of this application should be included in the scope of protection of this application.

Claims

1. A low-energy dyeing process for polyester fabric, characterized in that: The following steps are involved: S1, preparing a dye solution, wherein the dye solution includes a disperse dye, a temperature-sensitive polymer dispersant, a color fixing auxiliary agent and a buffer; S2. Plasma surface treatment of polyester fabric; S3, using dynamic dual feedback control to monitor the humidity and zeta potential of the dye solution in real time during the dyeing process, and to adjust the temperature-sensitive polymer dispersant and pH value; S4, regulating the dyeing temperature through pulse temperature management and temperature control strategy; S5, performing color fixing treatment using a photocatalyst and fixing the color by ultraviolet light irradiation; S6. After primary treatment, the wastewater is regenerated in a closed loop through photocatalytic degradation, catalyst recovery and electrodialysis treatment.

2. A low-energy dyeing process for polyester fabric according to claim 1, characterized in that: The dye liquor preparation step comprises: Mixing disperse dye and water in a ratio of 1:3-3.5 to obtain a disperse dye solution; Adding a thermosensitive polymer dispersant to the disperse dye solution, wherein the amount of the thermosensitive polymer dispersant added accounts for 50%-120% of the mass of the disperse dye; and adding a color fixing auxiliary agent, wherein the amount of the color fixing auxiliary agent added accounts for 30%-80% of the mass of the disperse dye; A buffer solution is added to the dye solution to maintain the pH value between 4.5 and 5.0, and the concentration of the buffer solution is 2-4 g / L.

3. A low-energy dyeing process for polyester fabric according to claim 2, characterized in that: The thermosensitive polymer dispersant is poly (N-isopropylacrylamide) grafted with sulfonic acid groups, and its molecular weight ranges from 10,000 to 50,000 Da; The color fixing auxiliary agent is benzyl benzoate sodium salt; The buffer is phosphate buffer.

4. The low-energy dyeing process for polyester fabric according to claim 1, characterized in that: The plasma surface treatment step comprises: The polyester fabric is fed into the plasma treatment equipment for surface activation treatment; The power of the plasma treatment is 200-300W, and the treatment time is 2-3 minutes.

5. A low-energy dyeing process for polyester fabric according to claim 4, characterized in that: The plasma surface treatment gas is nitrogen with a flow rate of 50-100 L / min and a gas pressure of 0.1-0.3 MPa.

6. The low-energy dyeing process for polyester fabric according to claim 1, characterized in that: The dynamic dual feedback control step includes: Monitor the surface humidity of the fabric in real time through infrared humidity sensors; The zeta potential of the dye solution is measured in real time by an electrochemical zeta potential probe; Based on real-time data, an LSTM neural network is used to predict the dye aggregation risk index (ARI). When the ARI value exceeds 0.8, the injection of a thermosensitive polymer dispersant is initiated. The injection amount of the thermosensitive polymer dispersant accounts for 5%-15% of the total mass of the dye solution, and the injection rate is 0.1-0.3L / min. When the ARI exceeds 0.8, the pH value is adjusted by the automatic adjustment system to maintain it between 4.8 and 5.

2.

7. The low-energy dyeing process for polyester fabric according to claim 1, characterized in that: The pulse heating management and temperature control strategy includes: During the dyeing process, stage 1, adsorption promotion period: the temperature is increased from 80°C to 95°C at a rate of 1-3°C / min, and this temperature range is maintained; Stage 2, diffusion stabilization period: The temperature is further increased to between 95°C and 110°C, and intermittent pulse heating control is adopted, that is, each heating is performed for 2 minutes and then paused for 1 minute.

8. The low-energy dyeing process for polyester fabric according to claim 1, characterized in that: The step of performing color fixation treatment on the photocatalyst comprises: Using Fe3O4@TiO2@rGO composite catalyst, the amount of the catalyst added accounts for 50%-100% of the total mass of the dye solution; Expose the dyed fabric to a UV LED light source with a wavelength of 365nm and an irradiation intensity of 50-100W / m 2 , the irradiation time is 15-30 minutes.

9. The low-energy dyeing process for polyester fabric according to claim 1, characterized in that: The processing steps for performing closed-loop regeneration include: The wastewater is initially filtered through a ceramic ultrafiltration membrane to remove large suspended solids. The pore size of the ultrafiltration membrane is 50nm. The wastewater was photocatalytically degraded by the Fe3O4@TiO2@rGO catalyst, which has good degradation ability for dyes and additives in the wastewater, with a degradation time of 15-30 minutes; Fe3O4@TiO2@rGO catalyst was recovered using electromagnet; The wastewater is treated by electrodialysis.

10. The low-energy dyeing process for polyester fabric according to claim 9, characterized in that: The light source of the photocatalytic degradation reactor is a visible light LED, and its illumination intensity is 50-100W / m 2 , the reaction time is 15-30 minutes.

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