Low-energy-consumption polyester fabric pretreatment dyeing one-bath method manufacturing process

Abstract

The invention relates to the field of fabric dyeing, and particularly discloses a low-energy-consumption manufacturing process of a polyester fabric pretreatment dyeing one-bath method. The invention relates to a low-energy-consumption polyester fabric pretreatment dyeing one-bath method production process, which comprises: preparing a pretreatment dyeing one-bath liquid, wherein the one-bath liquid comprises 3-5 g / L of sodium carbonate, 1-2 g / L of a nonionic surfactant, 0.5-1 g / L of a chelating agent, 1-2 g / L of a lignosulfonate dispersant, and 2-5 o.w.f of a disperse dye accounting for the weight percentage of the fabric; immersing the polyester fabric into the same bath liquid, and treating at 115-120 DEG C for 30-50 minutes; the fabric is taken out, and processing is completed after gradient washing and drying. The low-energy-consumption polyester fabric pretreatment dyeing one-bath method manufacturing process has the advantages of achieving efficient impurity removal and dye dyeing while being low in consumption and environmentally friendly.

Description

Technical Field

[0001] The present application relates to the field of fabric dyeing, and more specifically, to a low-energy consumption all-polyester fabric pre-treatment dyeing one-bath production process. Background Art

[0002] In the textile dyeing and finishing sector, the pretreatment and dyeing processes for all-polyester fabrics have long employed a traditional, step-by-step approach: pretreatment first removes impurities and finishing agents from the fabric surface, followed by dyeing to ensure color uniformity and stability. However, this two-step process has exposed significant drawbacks in practical application: the production process consumes enormous amounts of energy and water resources, and is accompanied by significant wastewater discharge, which clearly conflicts with current green production concepts. The inherent flaws of traditional step-by-step processing have become a bottleneck for the industry's development. On the one hand, the separation of process steps leads to low production efficiency, and energy costs and equipment investment continue to rise. On the other hand, the use of large amounts of chemical agents not only drives up raw material costs, but also creates wastewater treatment issues that put pressure on the ecological environment. Although the industry has attempted to combine pretreatment and dyeing into a "one-step" process to optimize the process, the existing one-bath method faces key technical barriers in practical application: pretreatment impurity removal is difficult to achieve, and dye uptake is limited, making this process difficult to popularize in large-scale industrial production. With tightening global environmental regulations and the growing demand for energy conservation and emission reduction, the development of efficient, low-consumption, all-polyester fabric dyeing processes has become a core area of ​​technological breakthrough for the industry. The market's urgent demand for green textile products, coupled with advances in materials science and dyeing and finishing technologies, has provided ample room for innovation in new dyeing processes. In particular, integrated processes that balance energy consumption reduction, pollution reduction, and production efficiency improvement are becoming a frontier of exploration within the industry. Summary of the Invention

[0003] In order to achieve efficient impurity removal and dyeing with low energy consumption and environmental protection, the present application provides a low-energy consumption all-polyester fabric pretreatment and dyeing one-bath production process.

[0004] The present application provides a low-energy consumption all-polyester fabric pretreatment and dyeing one-bath production process using the following technical solutions: A low-energy consumption all-polyester fabric pre-treatment and dyeing one-bath production process comprises the following steps: (1) preparing a pre-treatment dyeing bath solution: the bath solution comprises, by concentration, 3-5 g / L of sodium carbonate, 1-2 g / L of a nonionic surfactant, 0.5-1 g / L of a chelating agent, 1-2 g / L of a lignin sulfonate dispersant, and 20.5-50.0 g / L of a disperse dye in an amount of 1% by weight of the fabric; (2) immersing the polyester fabric in the bath solution and treating at 115-120° C. for 30-50 minutes; (3) Take out the fabric, wash it with gradient water and dry it to complete the processing.

[0005] By adopting the above technical solution, sodium carbonate, nonionic surfactants, chelating agents, lignin sulfonate dispersants, and disperse dyes are compounded to form a one-bath system, achieving synergistic pretreatment and dyeing under weakly alkaline conditions. Sodium carbonate can destroy the molecular structure of impurities on the fabric surface, promoting the removal of pollutants such as oils and waxes from the fibers; nonionic surfactants dissolve hydrophobic impurities through emulsification, while also reducing the surface tension of the dye bath and enhancing fiber wettability; chelating agents complex metal ions in the water, preventing them from forming precipitation with the dye or affecting dyeing uniformity; and lignin sulfonate dispersants prevent dye particle aggregation through steric hindrance, ensuring dyeing uniformity.

[0006] Optionally, the sodium carbonate in step (1) is sodium carbonate, the nonionic surfactant is fatty alcohol polyoxyethylene ether, and the chelating agent is EDTA.

[0007] By adopting the above technical solution, sodium carbonate is selected as sodium carbonate, and its weak alkalinity (pH about 8-10) can not only meet the alkaline environment required for the expansion of polyester fibers, but also avoid the damage of strong alkalinity to the structure of disperse dyes; fatty alcohol polyoxyethylene ether has good cloud point stability under neutral to weak alkaline conditions, can form stable micelles in the dye bath, and enhance the emulsification and removal of grease on the fabric surface; EDTA has a high complexation constant for calcium and magnesium ions, can effectively soften water quality, prevent metal ions from forming color lakes with dyes, and ensure the purity of dyeing color.

[0008] Optionally, ultrasonic assisted treatment is used in step (2), and the ultrasonic power density is 0.3-0.8W / cm 2 , the frequency is 35-45kHz, and the ultrasonic treatment is carried out in two stages: Use 0.5-0.8W / cm for the first 15 minutes 2 High power density; The subsequent treatment stage uses 0.3-0.5W / cm 2 Low power density.

[0009] By adopting the above technical solution, the ultrasonic assisted treatment was introduced in stages, with high power density (0.5-0.8W / cm 2 ) The micro jet generated by the cavitation effect impacts the fiber surface, accelerating the removal of impurities and promoting the expansion of the amorphous area of ​​the fiber, opening up a channel for dye penetration; in the latter stage, the power density is low (0.3-0.5W / cm 2Mechanical vibration maintains dye dispersion and prevents aggregation. This technology reduces the single-bath processing temperature by 5-8°C compared to processes without ultrasonic waves, improves impurity removal by 10-15%, and increases dye utilization by 8-10%, effectively resolving the dilemma of incomplete impurity removal and insufficient dye uptake in single-bath processes.

[0010] Optionally, the bath solution further comprises 0.5-1.5 g / L of enzymatically hydrolyzed lignin, with a molecular weight of ≤5000 Da.

[0011] By adopting this technical solution and adding a bio-based synergist based on enzymatically degraded lignin, the glycosidic bonds or phenolic hydroxyl groups in its molecular structure can form hydrogen bonds with the hydroxyl groups on the fiber surface, enhancing wetting and penetration. Furthermore, the amphiphilic structure of the bio-based material can synergize with the surfactant to emulsify impurities. Its small molecular weight of ≤5000 Da allows it to easily penetrate the fiber pores and assist in removing micro- and nano-scale impurities. This synergist can reduce the amount of non-ionic surfactant used by 20-30%, and its biodegradability is >90%, simultaneously improving the process's environmental friendliness and impurity removal efficiency.

[0012] Optionally, the gradient water washing in step (3) includes: The first stage of water washing: washing with hot water at 60±2℃ for 3-5 minutes; Second stage water washing: wash with warm water at 40±2℃ for 3-5 minutes; The third stage of water washing: rinse with clean water at 25±2℃ for 3-5 minutes.

[0013] By adopting this technical solution, the gradient washing process utilizes staged temperature control (60°C → 40°C → room temperature) to promote the dissolution of residual dyes and auxiliaries within the fiber pores. The first stage, a 60°C hot water wash, dissolves most floating color. The second stage, a 40°C warm water wash, reduces dye solubility to minimize backstaining. The third stage, a room-temperature rinse, completely removes residual dyes. This process saves 30-40% water compared to traditional high-temperature washing, shortens washing time by 50%, and reduces wastewater COD by 15-20%, addressing the high water consumption and heavy wastewater treatment load of traditional processes.

[0014] Optionally, the disperse dye is one of an azo-type or anthraquinone-type disperse dye, and its particle size distribution satisfies D90≤1 μm.

[0015] By adopting the above technical solution, azo or anthraquinone disperse dyes are selected, whose molecular structures strongly interact with the hydrophobicity of polyester fibers and are stable under weak alkaline conditions. Controlling the particle size D90 ≤ 1 μm significantly increases the specific surface area of ​​the dye, improving the dyeing rate and levelness. Experiments have shown that the diffusion coefficient of nano-sized dye particles is three times higher than that of conventional dyes (D90 ≈ 5 μm), shortening the dyeing equilibration time by 40% and increasing the dyeing depth (K / S value) by 10-15%, thus resolving the technical bottleneck of low dye uptake in the same-bath process.

[0016] Optionally, the bath solution further comprises 0.1-0.3 g / L of an anionic wetting agent, wherein the wetting agent is selected from sodium dodecylbenzenesulfonate or sodium α-olefinsulfonate.

[0017] By adopting the above technical solution, the addition of sodium dodecylbenzene sulfonate or sodium α-olefin sulfonate anionic wetting agents causes the sulfonate groups to ionize in water, generating a negative charge. This electrostatic repulsion forms with the weakly negatively charged fiber surface, accelerating dye bath penetration. Simultaneously, the anionic groups form a complex system with nonionic surfactants, synergistically lowering the critical micelle concentration (CMC) and reducing the wetting time from the traditional 10-15 seconds to less than 5 seconds. This technology is particularly suitable for high-density polyester fabrics, eliminating white core dyeing defects caused by insufficient wetting and improving the first-pass dyeing rate.

[0018] Optionally, 0.2-0.5 g / L of a modified zeolite molecular sieve with a pore size of 0.5-0.8 nm and a silicon-aluminum ratio of ≥5:1 is added to the bath solution.

[0019] By adopting this technical solution, the nanoporous structure of modified zeolite molecular sieves (pore size 0.5-0.8nm, silicon-aluminum ratio ≥5:1) selectively adsorbs calcium and magnesium ions and dye hydrolysis products in water, dynamically purifying the dye bath and preventing impurity deposition. The silanol groups on their surface form hydrogen bonds with dye molecules, acting as "nanoadsorption centers" to promote uniform dye distribution. Adding 0.2-0.5g / L of modified zeolite can reduce dye bath turbidity by 30-40%, dye aggregation by 25%, and reduce chelating agent usage by 15-20%, improving process stability while reducing chemical consumption.

[0020] In summary, this application has the following beneficial effects: 1. Since this application adopts a compound same-bath system combined with ultrasonic stage-by-stage auxiliary treatment, the processing time is shortened, energy consumption is reduced, and integrated low-consumption production of "decontamination-dyeing" is achieved.

[0021] 2. In this application, bio-based synergists, gradient water washing and modified zeolite are preferably used to purify the dye bath, thereby reducing the amount of chemical agents used, lowering the COD value of wastewater, and breaking through the high pollution bottleneck of traditional processes.

[0022] 3. In this application, it is preferred to achieve a 10-15% increase in the impurity removal rate, a dye uptake rate ≥ 92%, and a 10-15% increase in the dyeing depth (K / S value) through nano-scale dye regulation, surfactant compounding and ultrasonic cavitation effect, thereby solving the compatibility problem of impurity removal and dyeing in the same bath process. DETAILED DESCRIPTION

[0023] The present application is further described in detail below with reference to the examples. It is particularly noted that if no specific conditions are specified in the following examples, the reactions are carried out according to conventional conditions or the conditions recommended by the manufacturer. Unless otherwise specified, the raw materials used in the following examples can be obtained from common commercial sources. Example

[0024] Example 1 A low-energy consumption all-polyester fabric pre-treatment dyeing one-bath production process is as follows: Preparation of pre-treatment dyeing bath Add the following components to the dye bath in concentrations: Sodium carbonate: 4g / L sodium carbonate; Nonionic surfactant: 1.5g / L fatty alcohol polyoxyethylene ether (AEO-9); Chelating agent: 0.8g / L sodium tripolyphosphate; Dispersant: 1.5g / L sodium lignin sulfonate; Disperse dye: 3o.wf (azo disperse red 60, D90 particle size 0.8 μm); Adjust the pH of the solution to 7.5±0.2 with dilute acetic acid and stir thoroughly until the solution is evenly dissolved.

[0025] Dyeing treatment The polyester woven fabric (weight 150g / m 2 ) were immersed in the same bath solution at a bath ratio of 1:10, heated to 118±2°C at a rate of 2°C / min, and kept warm for 75 minutes, during which a mechanical circulation pump was used to keep the solution flowing.

[0026] After taking out the fabric, it was washed in warm water at 60°C and 20°C for 6 minutes respectively, and finally dried with hot air at 100°C to obtain the finished dyed product.

[0027] Example 2 A low-energy consumption all-polyester fabric pretreatment and dyeing one-bath production process is different from Example 1 in that 0.8 g / LEDTA is used as the chelating agent.

[0028] Example 3 A low energy consumption all-polyester fabric pre-treatment dyeing one-bath production process, the difference from Example 1 is that the all-polyester woven fabric (weight 150g / m 2 ) were immersed in the same bath solution at a bath ratio of 1:10, and the temperature was raised to 118±2°C at a rate of 2°C / min. The solution was kept warm for 60 minutes, during which a mechanical circulation pump was used to keep the solution flowing.

[0029] Example 4 A low energy consumption all-polyester fabric pre-treatment dyeing one-bath production process, the difference from Example 1 is that the all-polyester woven fabric (weight 150g / m 2) were immersed in the same bath solution at a bath ratio of 1:10, and the temperature was raised to 118±2°C at a rate of 2°C / min. The solution was kept warm for 90 minutes, during which a mechanical circulation pump was used to keep the solution flowing.

[0030] Example 5 A low energy consumption all-polyester fabric pre-treatment dyeing one-bath production process, the difference from Example 1 is that the all-polyester woven fabric (weight 150g / m 2 ) were immersed in the same bath solution at a bath ratio of 1:10, heated to 93±2°C at a rate of 2°C / min, kept warm for 75 minutes, and assisted by ultrasonic treatment: First 15 minutes: 0.65W / cm 2 , 40kHz; Subsequent 60 minutes: 0.4W / cm 2 , 35kHz; Adopts sandwich type ultrasonic vibration plate (material: titanium alloy).

[0031] Example 6 A low energy consumption all-polyester fabric pre-treatment dyeing one-bath production process, the difference from Example 5 is that the all-polyester woven fabric (weight 150g / m 2 ) were immersed in the same bath solution at a bath ratio of 1:10, heated to 118±2°C at a rate of 2°C / min, kept warm for 75 minutes, and assisted by ultrasonic treatment: First 15 minutes: 0.5W / cm 2 , 40kHz; Subsequent 60 minutes: 0.3W / cm 2 , 35kHz; Adopts sandwich type ultrasonic vibration plate (material: titanium alloy).

[0032] Example 7 A low energy consumption all-polyester fabric pre-treatment dyeing one-bath production process, the difference from Example 5 is that the all-polyester woven fabric (weight 150g / m 2 ) were immersed in the same bath solution at a bath ratio of 1:10, heated to 118±2°C at a rate of 2°C / min, kept warm for 75 minutes, and assisted by ultrasonic treatment: First 15 minutes: 0.8W / cm 2 , 40kHz Subsequent 60 minutes: 0.5W / cm 2 , 35kHz Adopts sandwich type ultrasonic vibration plate (material: titanium alloy).

[0033] Example 8 A low-energy consumption all-polyester fabric pretreatment and dyeing one-bath production process is provided, which differs from Example 1 in that a bio-based synergist with a content of 1 g / L is further added to the pretreatment and dyeing bath solution, and the bio-based synergist is enzymatically hydrolyzed lignin with a molecular weight of ≤5000 Da.

[0034] Example 9 A low-energy consumption all-polyester fabric pretreatment dyeing one-bath production process, which differs from Example 8 in that a bio-based synergist with a content of 0.5 g / L is further added to the pretreatment dyeing bath solution, and the bio-based synergist is enzymatically hydrolyzed lignin with a molecular weight of ≤5000 Da.

[0035] Example 10 A low-energy consumption all-polyester fabric pretreatment dyeing one-bath production process, which differs from Example 8 in that a bio-based synergist with a content of 1.5 g / L is further added to the pretreatment dyeing bath solution, and the bio-based synergist is enzymatically hydrolyzed lignin with a molecular weight of ≤5000 Da.

[0036] Example 11 A low-energy consumption all-polyester fabric pretreatment and dyeing one-bath production process is provided, which differs from Example 1 in that after taking out the fabric, it is washed in warm water at 60°C, 40°C, and 20°C for 4 minutes respectively, and finally dried with hot air at 100°C to obtain the dyed product.

[0037] Example 12 A low-energy consumption one-bath pretreatment dyeing process for all-polyester fabrics is provided, which differs from Example 1 in that anthraquinone-type disperse blue 56 with D90=0.9 μm is used as the disperse dye.

[0038] Example 13 A low-energy consumption all-polyester fabric pretreatment dyeing one-bath production process, which differs from Example 1 in that the bath solution further contains 0.2 g / L of an anionic wetting agent, and the wetting agent is selected from sodium dodecylbenzene sulfonate.

[0039] Example 14 A low-energy consumption all-polyester fabric pretreatment dyeing one-bath production process, which differs from Example 1 in that the bath solution also contains 0.2 g / L of an anionic wetting agent, and the wetting agent is selected from sodium α-olefin sulfonate.

[0040] Example 15 A low-energy consumption all-polyester fabric pretreatment dyeing one-bath production process, which differs from Example 1 in that 0.35g / L ZSM-5 modified zeolite molecular sieve with a pore size of 0.6nm and a silicon-aluminum ratio of 10:1 is added to the bath liquid.

[0041] Example 16 A low-energy consumption all-polyester fabric pretreatment dyeing one-bath production process, which differs from Example 15 in that 0.2 g / L ZSM-5 modified zeolite molecular sieve with a pore size of 0.6 nm and a silicon-aluminum ratio of 10:1 is added to the bath liquid.

[0042] Example 17 A low-energy consumption all-polyester fabric pretreatment dyeing one-bath production process, which differs from Example 15 in that 0.5 g / L ZSM-5 modified zeolite molecular sieve with a pore size of 0.6 nm and a silicon-aluminum ratio of 10:1 is added to the bath liquid.

[0043] Comparative Example Comparative Example 1 A low energy consumption all-polyester fabric pre-treatment dyeing one-bath production process, the difference from Example 1 is that the all-polyester woven fabric (weight 150g / m 2 ) were immersed in the same bath solution at a bath ratio of 1:10, and the temperature was raised to 130±2°C at a rate of 2°C / min. The solution was kept warm for 75 minutes, during which a mechanical circulation pump was used to keep the solution flowing.

[0044] Comparative Example 2 A low-energy consumption all-polyester fabric pretreatment dyeing one-bath production process, which differs from Example 1 in that the bath solution contains 2 g / L sodium carbonate, 0.5 g / L nonionic surfactant, 0.1 g / L chelating agent, 0.5 g / L lignin sulfonate dispersant, and 10.0% disperse dye by weight of the fabric.

[0045] Comparative Example 3 A low-energy consumption all-polyester fabric pretreatment dyeing one-bath production process, which differs from Example 1 in that the bath solution contains 6 g / L of sodium carbonate, 3 g / L of nonionic surfactant, 1.5 g / L of chelating agent, 2.5 g / L of lignin sulfonate dispersant, and 60.5 WF of disperse dye as a percentage of the weight of the fabric.

[0046] Comparative Example 4 A low-energy consumption all-polyester fabric pretreatment dyeing one-bath production process, which is different from Example 1 in that the pH of the bath solution is 5.5.

[0047] Performance testing 1. Impurity removal rate Test standard: GB / T8629-2017 "Household washing and drying procedures for textile testing"; Methods: 10cm×10cm fabric was taken and the oil content before and after treatment was determined by Soxhlet extraction (solvent: n-hexane); Calculation: impurity removal rate (%) = (1-weight of oil after treatment / weight of oil before treatment) × 100%.

[0048] 2. Dye uptake rate Test standard: GB / T2397-2012 "Determination of color uptake of disperse dyes"; Methods: The absorbance of the residual solution was determined by ultraviolet spectrophotometry (λmax corresponds to the characteristic wavelength of the dye); Calculation: Dye uptake (%) = (1-residual dye concentration / initial dye concentration) × 100%.

[0049] 3. Dyeing depth (K / S value) Instrument: Datacolor 650 spectrophotometer (D65 light source, 10° viewing angle); Calculation: Kubelka-Munk equation K / S = (1-R) 2 / (2R) (R is the reflectivity).

[0050] 4. Hair effect (pre-treatment effect) Test standard: GB / T5556-2015 "Determination of wetting power of surfactant textile auxiliaries"; Method: Vertical climbing height (cm) of distilled water on fabric within 30 minutes.

[0051] 5. Energy consumption calculation Steam consumption: Q = c·m·ΔT (c = 4.18 kJ / kg·°C, m = water mass, ΔT = temperature difference).

[0052] Converted standard coal: standard coal (kg) = Q (kJ) / 29270 6. Wastewater COD Test standard: HJ828-2017 "Water quality - Determination of chemical oxygen demand - Dichromate method".

[0053] Table 1 Test data Combining Example 1 with Comparative Example 1 and Table 1, it can be seen that while the impurity removal rate (89.5%) and dye uptake (98.2%) of Comparative Example 1, when the treatment temperature was increased to 130°C, were slightly higher than those of Example 1, the steam energy consumption was 2.3 times that of Example 1, and the wastewater COD increased by 37%. This indicates that while high temperatures can improve dyeing results, they significantly increase energy consumption and pollution, confirming the drawbacks of traditional high-temperature processes. The 115-120°C process of the present application achieves a balance between energy consumption and performance.

[0054] In combination with Example 1 and Comparative Examples 2-3 and in combination with Table 1, it can be seen that the content of each effective component in the bath solution in Comparative Example 2 is lower than the scope of Example 1 of the present application, resulting in the impurity removal rate being reduced to 72.6%, the dye uptake being 82.4%, and the capillary effect being only 5.8 cm / 30 min, indicating that when the effective component concentration in the bath solution is insufficient, the synergistic effect of impurity removal and dyeing is weakened; the concentration of each component in the bath solution of Comparative Example 3 is higher than that in Example 1 of the present application, the dye uptake is reduced to 90.7%, the wastewater COD soars to 1120 mg / L, the high concentration of alkali agent destroys the dye stability, and the sodium carbonate concentration needs to be controlled in the optimized range of 3-5 g / L. In summary, it can be seen that the bath solution effect is best within the scope of the present application.

[0055] Combining Example 1 with Comparative Example 4 and Table 1, it can be seen that in Comparative Example 4, adjusting the pH to an acidic environment of 5.5 significantly reduces the impurity removal rate (76.3%) and dye uptake (84.2%). This is because the acidic conditions weaken the saponification of impurities by sodium carbonate, and disperse dyes tend to aggregate in acidic baths. Experiments show that weak alkalinity (pH 7-8) is key to ensuring impurity removal and dye stability, which is consistent with the pH design logic of Claim 1.

[0056] Combining Examples 1, 2, and 3 with Table 1, it can be seen that Example 2 uses EDTA as a chelating agent, and the impurity removal rate is increased by 0.9%, the dye uptake is increased by 1.2%, and the K / S value is increased to 12.8 compared with Example 1 (sodium tripolyphosphate). This is because EDTA has a stronger complexing ability for calcium and magnesium ions, effectively preventing metal ions from interfering with dyeing.

[0057] Combining Examples 1, 3, and 4 with Table 1, we can see that Example 4, extending the treatment time to 90 minutes, achieved superior impurity removal efficiency (87.4%) and K / S ratio (13.1) to Example 1, but with a 4.3% increase in energy consumption. Example 3, shortening the treatment time to 60 minutes, saw a 5-8% decrease in all indicators. This data indicates that 75 ± 5 minutes is the optimal treatment time for balancing efficiency and energy consumption.

[0058] Combining Examples 1, 5, 6, and 7 with Table 1, it can be seen that after the introduction of ultrasound, the impurity removal rate of Example 6 is increased to 93.8%, the dyeing rate is 96.2%, the energy consumption is reduced by 10.5%, and the staged power density (high at the beginning and low at the end) is better than the single power effect. High power stage (0.65W / cm 2 ) accelerates the removal of impurities, and the dye dispersion is maintained in the low-power stage, which verifies the effectiveness of ultrasonic staged treatment in solving the "impurity removal-dyeing" contradiction.

[0059] Combining Examples 1, 8, 9, and 10 with Table 1, we can see that adding 1 g / L of enzymatically hydrolyzed lignin increased the impurity removal rate by 3.5%, the dye uptake by 1.8%, and the wastewater COD by 17.7% to 510 mg / L. Furthermore, a concentration of 1 g / L was more cost-effective than 0.5 g / L and 1.5 g / L. The hydrogen bonding and emulsification synergistic effects of the bio-based synergist not only improved impurity removal efficiency but also reduced the amount of chemical additives used.

[0060] Combining Examples 1 and 11 with Table 1, it can be seen that Example 11 employs a three-stage gradient wash (60°C → 40°C → 20°C), resulting in a 22.6% reduction in wastewater COD compared to Example 1, and a 33% reduction in wash time. This segmented temperature control utilizes temperature differences to promote the dissolution of floating color and reduce backstaining, demonstrating the advantages of gradient washing in terms of water conservation and emission reduction.

[0061] Combining Examples 1 and 12 with Table 1, it can be seen that Example 12 uses anthraquinone-type disperse blue 56, and the dye uptake (93.8%) is slightly higher than that of the azo dye in Example 1. This is because the anthraquinone structure has a stronger hydrophobic interaction with polyester fibers. This confirms that both types of disperse dyes can meet the requirements of the same-bath process, broadening the range of dye selection.

[0062] Combining Examples 1, 13, and 14 with Table 1, it can be seen that after adding 0.2 g / L sodium dodecylbenzenesulfonate, the capillary effect is improved to 8.9 cm / 30 min, and the first-time dyeing pass rate reaches 98%. This is because the combination of the anionic wetting agent and the nonionic surfactant reduces the critical micelle concentration and accelerates the dye bath penetration, which is particularly suitable for high-density fabrics.

[0063] Combining Examples 1, 15, 16, and 17 with Table 1, it can be seen that adding 0.35 g / L of modified zeolite reduced dyebath turbidity by 35%, increased dye uptake by 2.8%, and lowered wastewater COD to 460 mg / L. This is due to the adsorption of calcium and magnesium ions and dye hydrolysis products through the zeolite's nanopores, dynamically purifying the dyebath. A concentration of 0.35 g / L offers a more cost-effective solution than 0.2 g / L and 0.5 g / L.

[0064] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A low-energy consumption polyester fabric pre-treatment dyeing process in one bath, characterized by: The following steps are involved: (1) Preparing a pretreatment dyeing bath solution: the bath solution contains, by concentration, 3-5 g / L of sodium carbonate, 1-2 g / L of a nonionic surfactant, 0.5-1 g / L of a chelating agent, 1-2 g / L of a lignin sulfonate dispersant, and 20.5-50.0 g / L of disperse dye in an amount of 1% by weight of the fabric; (2) Immerse the polyester fabric in the bath solution and treat at 115-120°C for 30-50 minutes; (3) Take out the fabric, wash it with gradient water and dry it to complete the processing.

2. The manufacturing process according to claim 1, characterized in that: The sodium carbonate in step (1) is sodium carbonate, the nonionic surfactant is fatty alcohol polyoxyethylene ether, and the chelating agent is EDTA.

3. The manufacturing process according to claim 1, characterized in that: In step (2), ultrasonic assisted treatment is used, with an ultrasonic power density of 0.3-0.8 W / cm² and a frequency of 35-45 kHz. The ultrasonic treatment is carried out in two stages: Use a power density of 0.5-0.8W / cm² for the first 15 minutes; The subsequent processing stage uses a power density of 0.3-0.5W / cm².

4. The manufacturing process according to claim 1, characterized in that: The bath solution also contains 0.5-1.5 g / L of enzymatically hydrolyzed lignin, with a molecular weight of ≤5000 Da.

5. The manufacturing process according to claim 1, characterized in that: The gradient water washing in step (3) includes: The first stage of water washing: washing with hot water at 60±2℃ for 3-5 minutes; Second stage water washing: wash with warm water at 40±2℃ for 3-5 minutes; The third stage of water washing: rinse with clean water at 25±2℃ for 3-5 minutes.

6. The manufacturing process according to claim 1, characterized in that: The disperse dye is one of an azo-type or anthraquinone-type disperse dye, and its particle size distribution satisfies D90≤1 μm.

7. The manufacturing process according to claim 1, characterized in that: The bath solution further comprises 0.1-0.3 g / L of an anionic wetting agent, wherein the wetting agent is selected from sodium dodecylbenzenesulfonate or sodium α-olefinsulfonate.

8. The manufacturing process according to claim 1, characterized in that: 0.2-0.5 g / L of modified zeolite molecular sieve is added to the bath solution, wherein the pore size of the modified zeolite molecular sieve is 0.5-0.8 nm and the silicon-aluminum ratio is ≥5:1.

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