Printing paste for steaming-free and washing-free nylon cotton fabric and processing technology of printing paste

Abstract

The invention relates to the technical field of nylon cotton blended fabric printing, and particularly discloses steaming-free and washing-free nylon cotton fabric printing paste and a processing technology thereof.The steaming-free and washing-free nylon cotton fabric printing paste is prepared from, by weight, 30%-40% of polyurethane dispersing agent, 2%-4% of silicon dioxide, 0.3%-0.7% of white vinegar, 1%-3% of antifreeze agent, 0.1%-0.3% of defoaming agent and the balance water; silicon dioxide serves as a heat-insulating carrier; the white vinegar is used for adjusting the pH value of the pulp to 4-5; the antifreeze agent is ethylene glycol or propylene glycol; the defoaming agent is an organic silicon defoaming agent; through the synergistic effect of all the components, steaming-free and washing-free printing is achieved, steaming and washing links in a traditional process are omitted, water is saved by 90% or above, and energy is saved by 60% or above; the heat insulation effect of silicon dioxide solves the fiber damage problem of nylon cotton blended fabric high-temperature printing, the pH adjusting function of white vinegar improves the binding force of a printing film and blended fibers, the whole sizing agent adapts to the characteristics of the nylon cotton blended fabric, and a printing layer is washable, wear-resistant, free of wastewater discharge and capable of meeting the green production requirement.

Description

Technical Field

[0001] This invention relates to the field of printing technology for nylon-cotton blended fabrics, and in particular to a steam-free and wash-free printing paste for nylon-cotton fabrics and its processing technology. Background Technology

[0002] Nylon-cotton blended fabrics combine the abrasion resistance and elasticity of nylon with the breathability and skin-friendliness of cotton, making them widely used in sportswear, home furnishings, and automotive interiors. Printing is a core step in enhancing their added value, but current traditional printing processes have significant drawbacks. Most existing nylon-cotton blended fabrics use traditional reactive or disperse printing processes involving printing, steaming, washing, and setting. This process is not only energy-intensive and time-consuming in the steaming stage and generates a large amount of highly polluting wastewater in the washing stage, making it difficult to meet green and low-carbon requirements, but also has a long cycle of 4 to 8 hours, resulting in low production efficiency. Furthermore, multiple washings can easily lead to swelling of cotton fibers and loss of elasticity in nylon fibers, causing fabric width shrinkage exceeding 5% and a decrease in breaking strength of 10% to 15%, affecting the dimensional stability and durability of the product. While steam-free washing printing technology exists for pure cotton or synthetic fiber fabrics, its compatibility with nylon-cotton blends is extremely poor. Nylon fibers have a low heat resistance limit, easily yellowing and deforming above 200°C, while cotton fibers require temperatures above 200°C to ensure colorfastness. Existing technologies, if used for low-temperature fixing, result in substandard colorfastness for cotton fibers, while high temperatures damage nylon fibers. Furthermore, conventional steam-free washing paste film-forming agents exhibit uneven bonding strength between the two fibers, lack dedicated heat-insulating components, and have poor pH compatibility, easily leading to problems such as print peeling and color variations. In addition, existing steam-free washing processes also suffer from poor drying uniformity, single-temperature zone resulting in blurred and brittle prints, unreasonable setting methods, tight setting causing fabric dimensional deviations, reduced breathability, lack of standardized parameters for paste preparation, and poor storage stability. In summary, current technologies have shortcomings in environmental friendliness, efficiency, compatibility, and quality stability. Developing a highly efficient steam-free and wash-free printing technology suitable for nylon-cotton blends has become an urgent industry need.

[0003] The technical problem to be solved by this application is that in the printing process of nylon cotton blended fabrics, traditional printing processes consume a lot of water and energy, have low production efficiency and are easy to damage the fabric. Conventional steam-free printing technology has problems such as the contradiction between fiber heat resistance and color fixing temperature, uneven bonding force of the paste to the blended fibers and no heat insulation protection, and poor drying and setting effect. It cannot take into account the problems of environmental protection, efficiency and printing quality. Summary of the Invention

[0004] To overcome the shortcomings of existing technologies, the present invention aims to provide a steam-free and wash-free printing paste and its supporting processing technology suitable for nylon-cotton blended fabrics. The paste contains a special heat-insulating carrier and can be evenly adapted to nylon and cotton fibers. The process eliminates the need for steaming and washing and optimizes drying and setting parameters to solve the problems of high water and energy consumption, low production efficiency, and easy damage to fabrics in traditional printing processes, as well as the contradiction between fiber heat resistance and color fixing temperature, poor adhesion of the printing layer, and poor drying and setting effects in conventional steam-free washing technologies. This achieves a balance between environmental protection, production efficiency, and printing quality.

[0005] The technical solution adopted in this invention is as follows: a printing paste for nylon cotton fabric that requires no steaming or washing and its processing technology, which is composed of the following components by weight percentage: 30%~40% polyurethane dispersant, 2%~4% silica, 0.3%~0.7% white vinegar, 1%~3% antifreeze agent, 0.1%~0.3% defoamer, and the balance being water; silica serves as a heat insulation carrier; white vinegar is used to adjust the pH value of the paste to 4~5; the antifreeze agent is ethylene glycol or propylene glycol; and the defoamer is an organosilicon defoamer.

[0006] Polyurethane dispersant, as the core film-forming substance, can form a continuous and flexible printed film during subsequent heat transfer and curing, providing an adhesion base for the printed pattern. Silica, as a heat insulation carrier, can block the direct transfer of heat to nylon fibers during high-temperature heat transfer at 215~235℃, preventing nylon from yellowing and melting due to high temperatures. Simultaneously, its particulate structure enhances the mechanical strength and abrasion resistance of the printed film. White vinegar, by adjusting the pH of the paste to an acidic range of 4~5, promotes the interaction between polyurethane dispersant molecules and the hydroxyl and amino groups on the surface of nylon and cotton fibers. Cross-linking reaction enhances the adhesion between the printed film and the fabric, while also softening the surface of cotton fibers to facilitate dye penetration. Antifreeze agents (ethylene glycol or propylene glycol) lower the freezing point of the paste, preventing it from solidifying and separating in low-temperature storage environments of 0~5℃, thus ensuring the fluidity of the paste. Defoamers (organosilicon-based) can destroy bubbles generated during paste preparation and roller coating, preventing defects such as pinholes and ink gaps in the printed pattern. Water, as a solvent, can adjust the overall solid content and viscosity of the paste to a suitable range for roller coating (1000~3000 mPa·s), ensuring uniform coating. In some embodiments, the polyurethane dispersant is an anionic aqueous polyurethane dispersion with a solid content of 35% to 45%, a number-average molecular weight of 50,000 to 80,000, and a glass transition temperature (Tg) of -20°C to -10°C. The anionic aqueous polyurethane dispersion carries a negative charge, allowing it to form electrostatic adsorption with the positively charged sites on the surface of nylon (containing amino groups) and cotton (containing hydroxyl groups) fibers, thus enhancing the bonding force. The 35% to 45% solid content ensures that the printed film formed after heat transfer has sufficient thickness and strength. To prevent brittleness, the number average molecular weight of 50,000 to 80,000 ensures that the molecular chain length is suitable for filling the gaps between fibers, thus improving the density of the printed film. The Tg value of -20℃ to -10℃ ensures that the printed film remains flexible in low-temperature environments and is not prone to cracking due to temperature changes. Compared with ordinary polyurethane dispersants, the anionic structure enhances the adsorption force with blended fibers. The combination of specific solid content, molecular weight and Tg value gives the printed layer both high strength and flexibility, with no risk of cracking in low-temperature environments, making it suitable for the use needs of different climate regions. In some embodiments, the silica is precipitated silica with a particle size of 100-500 mesh and a specific surface area of ​​150-300 m². 2 / g, surface modified with silane coupling agent (KH~550 or KH~560), modification rate ≥85%; precipitated silica with a particle size of 100~500 mesh can be uniformly dispersed in the slurry, avoiding agglomeration that affects coating; 150~300m 2 The increased specific surface area per g increases the contact area with the polyurethane dispersant, improving heat insulation efficiency; the modification of silane coupling agent (KH~550 or KH~560) can eliminate the polarity of hydroxyl groups on the surface of silica, enhance its compatibility with the organic phase (polyurethane), and avoid slurry stratification; silica prepared by precipitation method has good dispersibility and no printing defects caused by agglomeration; high specific surface area improves heat insulation effect and effectively protects nylon fibers; silane coupling agent modification ensures that the slurry does not stratify during storage, and silica and polyurethane are tightly bonded in the printed film, improving water resistance by more than 15%. In some embodiments, the acetic acid content of the white vinegar is 4%~6%, the heavy metal content (as Pb) is ≤0.1mg / kg, and the evaporation residue is ≤0.5g / L. The 4%~6% acetic acid content can precisely adjust the pH value of the paste to 4~5, avoiding insufficient pH adjustment due to too low an acetic acid content (affecting polyurethane crosslinking) or fiber corrosion due to too high an acetic acid content. The heavy metal content of ≤0.1mg / kg and the evaporation residue of ≤0.5g / L ensure that no toxic or harmful substances remain on the fabric surface after the paste is dried. Precise pH adjustment ensures the crosslinking efficiency of polyurethane and fibers, avoiding insufficient color fastness. The low heavy metal and low evaporation residue make the fabric meet the safety standards for wear, with no risk of skin irritation, while avoiding residual impurities affecting the color purity of the printed pattern. A processing technology for a steam-free and wash-free nylon cotton fabric includes the following steps: S1: Soak the nylon-cotton blended fabric in warm water at 80-90℃ for 10-15 minutes, add 0.5%-1% (owf) of nonionic surfactant, and then dry it at 100-105℃ until the moisture content is ≤5%; S2: According to the components of claim 1, first mix deionized water and white vinegar and stir for 5 to 10 minutes, then add polyurethane dispersant, silica, antifreeze and defoamer in sequence, stir at 200 to 300 rpm for 30 to 45 minutes, and filter through a 200 mesh filter for later use. S3: Using a three-roller coating machine, the slurry prepared in step 2 is coated onto the surface of the pretreated fabric in step 1. The coating pressure is 0.2~0.4MPa, the roller speed is 5~10m / min, and the slurry coating amount is 15~25g / m. 2 After coating, the tension of the fabric is controlled at 3~5N / m; S4: Arrange the sizing fabric from step 3 in a hot air tunnel dryer. Control the drying temperature in stages: front section 100~120℃, middle section 120~140℃, and rear section 140~150℃. The total drying time is 3~5 minutes. After drying, the moisture content of the fabric should be controlled at 1%~3%. S5: Send the dried fabric from step 4 to the heat transfer roller press. The temperature of the heat transfer roller is 215~235℃, the roller pressure is 0.5~0.8MPa, the roller speed is 3~5m / min, and the heat transfer hardening time is 30~60 seconds. Simultaneously, the cooling roller is used to cool down the hardened fabric. S6: Place the hardened fabric from step 5 into a loose hot air dryer. Set the temperature at 120~140℃ for 2~3 minutes. Set the air velocity in the dryer at 1.5~2.0m / s. During the setting process, the transverse width shrinkage of the fabric should be ≤2%, and the longitudinal elongation should be ≤1%. S7: After the fabric has been set in step 6, let it cool naturally to room temperature (20~25℃), then trim and roll it up with a rolling tension of 2~4N / m to obtain a steam-free and wash-free printed finished product.

[0007] S1 Pretreatment removes oil and impurities from the fabric surface using warm water and nonionic surfactants, and dries it to a low moisture content to avoid dilution of the paste and ensure uniform sizing. S2 Sequential mixing and filtration prevents defoamer failure and silica agglomeration; a 200-mesh filter removes impurities to prevent printing blockage. S3 A ​​three-roll coating machine controls pressure, speed, and coating amount to ensure uniform paste coverage of the fabric, and low tension prevents fabric stretching and deformation. S4 Segmented drying gradually reduces fabric moisture to prevent high-temperature drying from causing the printing film to crack and the pattern to blur. S5 High-temperature heat transfer promotes polyurethane crosslinking and dye fixation; cooling rollers rapidly cool the fabric to prevent residual heat damage to the nylon; and roller pressure enhances the coating. The printing film is combined with the fabric; S6 loose setting and drying under low tension control the width shrinkage and elongation, maintaining the fabric's elasticity; S7 natural cooling and low-tension winding prevent secondary deformation of the fabric; the entire process eliminates steaming and washing, shortening the production cycle to 8-10 minutes (3-5 times faster than traditional processes) and saving more than 90% of water; segmented drying, loose setting, and low-tension winding ensure that the fabric's transverse shrinkage rate is ≤2% and longitudinal elongation rate is ≤1%, resulting in excellent dimensional stability; high-temperature heat transfer combined with cooling roller design ensures color fastness (wash resistance ≥4 grade) while avoiding damage to nylon, resulting in no cracking or peeling of the printed layer on the finished product, and the fabric's hand feel and elasticity remain unaffected. In some embodiments, the nonionic surfactant in step 1 is fatty alcohol polyoxyethylene ether (AEO~9) with an HLB value of 12~13. Fatty alcohol polyoxyethylene ether (AEO~9) with an HLB value of 12~13 has both hydrophilic and oleophilic properties, and can quickly emulsify oil stains (such as lubricating oil in the weaving process) on the surface of the fabric in warm water at 80~90℃. Moreover, its molecular structure will not leave polar groups on the surface of the fabric, thus avoiding affecting the subsequent bonding between the sizing agent and the fiber. Compared with other surfactants, the HLB value of AEO~9 is precisely matched to the oil stain removal requirements of nylon cotton blended fabrics, with an oil stain removal rate of ≥95%, and no residual substances interfere with sizing, ensuring the initial bonding force between the printed film and the fabric, and avoiding local peeling after subsequent hardening.

[0008] In some embodiments, the rollers of the three-roll coating machine in step 3 are made of chrome-plated steel rollers with a surface roughness Ra≤0.8μm and the roller temperature is controlled at 30~40℃. Chrome-plated steel rollers have high wear resistance and can maintain surface smoothness for a long time. The low roughness Ra≤0.8μm prevents surface textures from being imprinted onto the paste layer, ensuring uniform coating. The roller temperature of 30~40℃ prevents the paste from solidifying on the roller surface due to low temperature (especially when containing antifreeze) or thinning due to high temperature (affecting the coating amount), maintaining stable paste fluidity. The service life of the chrome-plated rollers is extended by more than 30%, the low roughness ensures clear and flawless edges of the printed pattern, and the roller temperature control ensures that the paste coating amount error is ≤±1g / m. 2 This improves the consistency of printing quality and reduces paste waste.

[0009] In some implementations, the hot air velocity of the hot air tunnel dryer in step 4 is 2~3 m / s, and the hot air circulation rate is ≥80%. The hot air velocity of 2~3 m / s can quickly remove moisture from the surface of the fabric while avoiding excessive air velocity that could cause the sizing agent to shift. The ≥80% hot air circulation rate can recover and utilize heat, reduce energy consumption, and ensure stable circulating hot air temperature, avoiding uneven moisture content in the fabric due to temperature differences in the drying area. The combination of hot air velocity and circulation rate improves the uniformity of fabric drying by 20%, eliminating problems of localized over-drying (cracking) or over-wetting (sizing agent flow). A hot air circulation rate of ≥80% can save more than 40% of energy consumption in the drying process, meeting the requirements of low-carbon production. In some implementations, the surface temperature uniformity of the heat transfer rollers in step 5 is ≤±2℃, the center distance between the cooling rollers and the heat transfer rollers is 10~15cm, and the fabric is cooled to below 50℃ after hardening. The surface temperature uniformity of the heat transfer rollers ≤±2℃ ensures that the degree of hardening of the printed film in each area of ​​the fabric is consistent, avoiding local color fastness differences. The center distance of 10~15cm allows the fabric to immediately enter the cooling zone after high-temperature hardening, quickly cooling to below 50℃, preventing residual heat from continuing to act on the nylon fibers and causing their elasticity to decrease. Temperature uniformity control ensures that the color fastness deviation of the finished print is ≤0.5 grade, guaranteeing consistent pattern color. The rapid cooling design avoids heat damage to the nylon fibers, the fabric elasticity retention rate is ≥95%, and the waiting time for subsequent processing of the hardened fabric is shortened, improving overall production efficiency.

[0010] The beneficial effects of this invention are as follows: through the synergistic effect of each component, steam-free and wash-free printing is achieved, eliminating the steaming and washing steps of traditional processes, saving more than 90% of water and more than 60% of energy; the heat insulation effect of silica solves the fiber damage problem of high-temperature printing on nylon-cotton blended fabrics; the pH adjustment function of white vinegar improves the bonding force between the printing film and the blended fibers; the antifreeze agent and defoamer respectively ensure the storage stability of the paste and the printing quality; the overall paste is adapted to the characteristics of nylon-cotton blended fabrics; the printed layer is washable and abrasion-resistant; there is no wastewater discharge, which meets the requirements of green production. Detailed Implementation

[0011] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0012] The raw materials and equipment used in this embodiment are all industrial-grade conventional products (unless otherwise specified), and the performance tests are all conducted in accordance with national standards, as detailed below: Color fastness to washing: Tested according to the 4th washing procedure in GB / T3921-2008 "Textiles - Tests for color fastness to washing with soap"; Color fastness to rubbing: Tested according to GB / T3920-2008 "Textiles - Tests for color fastness to rubbing"; Printed layer adhesion: tested according to GB / T9286-1998 "Cross-cut test for paint and varnish film"; Fabric moisture content: tested using a halogen moisture meter according to GB / T21655.1-2008 "Evaluation of moisture absorption and quick-drying properties of textiles - Part 1: Single combination test method"; Fabric shrinkage rate: Tested according to GB / T8628-2013 "Preparation, marking and measurement of fabric samples and garments in tests for determination of dimensional changes of textiles".

[0013] No-steam, no-wash nylon cotton fabric printing paste Example 1: Basic Formula Printing Paste Slurry components (by weight percentage) Components weight percentage Specific selections and specifications polyurethane dispersant 35% Anionic waterborne polyurethane dispersion (Model: PU-820, solid content 40%, number average molecular weight 65000, Tg=-15℃) silicon dioxide 3% <![CDATA[Precipitated silica (particle size 300 mesh, specific surface area 220 m 2 / g, modified with KH-560 silane coupling agent, modification rate 88%)]]> White vinegar 0.5% Food-grade white vinegar (acetic acid content 5%, heavy metal Pb ≤ 0.08 mg / kg, evaporation residue ≤ 0.3 g / L) antifreeze 2% Ethylene glycol (industrial grade, purity ≥99.5%) Defoamer 0.2% Organosilicon defoamer (Model: DF-108, active ingredient 30%) Deionized water 59.3% Conductivity ≤ 8 μS / cm, TOC ≤ 3 mg / L Slurry preparation steps (1) Pretreatment: Add deionized water (59.3 parts) to a 500mL stainless steel mixing tank, turn on the electric stirrer (model: JJ-1, speed adjustable), set the speed to 150rpm, add white vinegar (0.5 parts), stir for 8 minutes until the mixture is uniform, and use a pH meter (model: PHS-3C) to measure the pH value of the mixture to be 4.5; (2) Mixing of main components: Keep the speed at 150 rpm, slowly add polyurethane dispersant (35 parts), stir for 10 minutes, then increase the speed to 250 rpm, add silica (3 parts, 5 minutes apart each time) in 3 batches to avoid agglomeration; (3) Additives: Add antifreeze (2 parts) and defoamer (0.2 parts) in sequence, and stir at 250 rpm for 35 minutes to form a uniform slurry; (4) Filtration and testing: Pass the slurry through a 200-mesh nylon filter (at normal pressure) to remove a small amount of undispersed particles; use a rotational viscometer (model: NDJ-5S, 25℃, rotor No. 3, speed 10rpm) to measure the slurry viscosity as 2200mPa・s, and measure the pH value as 4.4 again for later use. Slurry performance test results Storage stability: The slurry was stored in constant temperature environments of 0℃, 25℃ and 40℃ for 6 months. No stratification or precipitation was observed. The viscosity change rate (25℃) was 8%, and the pH value changed within ±0.2. Flowability: When the slurry is poured at 25°C, it does not stick to the wall or clump, and can flow smoothly into the feed inlet of the three-roll coating machine; Defoaming property: No obvious bubbles are generated during the preparation and coating of the slurry, and there are no pinholes on the surface of the coated fabric.

[0014] Example 2: Antifreeze Formula Printing Paste Slurry components (by weight percentage) Polyurethane dispersant (same as Example 1, PU-820): 32% Silica (same as in Example 1): 3.5% White vinegar (same as in Example 1): 0.6% Antifreeze (propylene glycol, industrial grade, purity ≥99.5%): 3% Defoamer (same as in Example 1, DF-108): 0.3% Deionized water: Balance (60.6%) Slurry preparation steps Same as Example 1, except that the antifreeze was replaced with propylene glycol, the total stirring time was adjusted to 40 minutes, and the viscosity of the slurry after filtration was measured to be 2000 mPa·s and the pH value was 4.3. Slurry performance test results Low temperature stability: After being stored in a constant temperature environment of -5℃ for 72 hours, the slurry did not solidify. After being restored to 25℃, the viscosity was 2100 mPa·s, and the fluidity was good. Other properties: Storage stability and defoaming properties are basically the same as in Example 1, and it is suitable for the production and storage needs of cold regions (such as Northeast China and high-altitude areas). Example 3: High Abrasion-Resistant Formula Printing Paste Slurry components (by weight percentage) Polyurethane dispersant (anionic type, model: PU-830, solid content 45%, number average molecular weight 75000, Tg=-12℃): 38% Silica (precipitation method, particle size 500 mesh, specific surface area 280 m²) 2 / g, modified with KH-550, modification rate 90%): 4% White vinegar (same as in Example 1): 0.7% Antifreeze (ethylene glycol, same as in Example 1): 1.5% Defoamer (same as in Example 1): 0.1% Deionized water: Balance (55.7%) Slurry preparation steps Same as in Example 1, but the total stirring time was adjusted to 40 minutes. After filtration, the viscosity of the slurry was measured to be 2800 mPa·s and the pH value was 4.5.

[0015] Slurry performance test results Abrasion resistance precursor: After coating and heat transfer curing, the surface hardness of the printed layer (pencil hardness tester, 2H pencil, 1kg force) is HB grade, which is higher than that of Example 1 (B grade), indicating that the finished product has better abrasion resistance.

[0016] Processing technology of no-steam and no-wash nylon cotton fabric Processing technology based on the slurry in Example 1 Raw material and equipment preparation Greige fabric: Nylon-cotton blend greige fabric (60% nylon, 40% cotton, 200g / m²) 2 Plain weave, warp breaking strength 350N, weft breaking strength 300N, produced by a certain textile factory. Equipment: Stainless steel soaking tank (50L capacity), hot air drying oven (model: 101-3, temperature control accuracy ±1℃), three-roll coating machine (model: S650, roller diameter 200mm, length 1800mm, chrome-plated steel roller, Ra=0.6μm), hot air tunnel dryer (model: TD-8000, length 8m, three temperature zones, temperature control accuracy ±2℃), heat transfer roller press (model: HR-1800, heat transfer roller diameter 300mm, cooling roller (water-cooled) diameter 250mm), loose hot air dryer (model: SF-1600, temperature control accuracy ±1℃, adjustable wind speed), fully automatic fabric rolling machine (model: JB-1800). Specific process steps S1: Fabric pretreatment (1) Soaking: Place the greige fabric (10m×1.8m, weighing about 3.6kg) into a stainless steel soaking tank, add 80℃ warm water (bath ratio 1:15, i.e. 54L), add 0.8% owf of nonionic surfactant (AEO-9, HLB=12.5, industrial grade) (based on the weight of the greige fabric, 3.6kg×0.8%=28.8g), stir (mechanical stirring, speed 80rpm) and soak for 12 minutes to remove weaving lubricant and dust from the surface of the greige fabric; (2) Dehydration and drying: The soaked fabric is placed in a centrifugal dehydrator (800 rpm, dehydration for 5 minutes) to remove surface moisture; then transferred to a hot air oven and dried at 102℃ for 40 minutes. The moisture content of the fabric is measured to be 3.5% using a halogen moisture analyzer and is ready for use. S2: Slurry preparation Same as in Example 1, a printing paste with a viscosity of 2200 mPa·s was prepared. S3: Roller coating with sizing (1) Equipment debugging: Set the temperature of the front roller, middle roller and rear roller of the three-roll coating machine to 35℃, adjust the roller spacing (0.15mm between the front and middle rollers, 0.2mm between the middle and rear rollers), set the roller speed to 8m / min and the coating pressure to 0.3MPa; (2) Sizing: The pretreated fabric is laid flat on the feeding table of the coating machine. The sizing is poured into the feeding trough. The fabric is coated by three rollers. After coating, the weight of 1m×1m fabric is weighed with an electronic scale (about 200g before coating and about 220g after coating). The coating amount is calculated to be 20g / m. 2 Control the fabric tension (tension controller set to 4N / m) to avoid stretching deformation, and then roll it up for later use. S4: Tunnel Drying (1) Equipment settings: the front section temperature of the hot air tunnel dryer is 110℃, the middle section is 130℃, the rear section is 145℃, the hot air velocity is 2.5m / s, the hot air circulation rate is 85%, and the fabric running speed is 8m / min. (2) Drying: The sized fabric is sent into a tunnel dryer and dried continuously for 4 minutes. Immediately after exiting the machine, the moisture content of the fabric is measured by a halogen moisture analyzer and found to be 2.1%. There is no sizing flow or embrittlement on the surface.

[0017] S5: Thermal transfer hardening (1) Equipment debugging: The temperature of the heat transfer roller is set to 225℃, the roller pressure is 0.6MPa, and the roller speed is 4m / min; the temperature of the cooling roller is set to 25℃, and the center distance between the cooling roller and the heat transfer roller is 12cm. (2) Hardening and cooling: The dried fabric is fed into the heat transfer roller press and hardened by the heat transfer roller (contact time 45 seconds). Then it is cooled to 45℃ by the cooling roller (the surface temperature of the fabric is measured by an infrared thermometer). The fabric is then rolled up and the printed pattern is observed to be clear and without yellowing. S6: Loose-fitting shaping (1) Equipment settings: temperature of loose hot air dryer 130℃, wind speed 1.8m / s, setting time 2.5 minutes, fabric running speed 6m / min; (2) Shaping: The hardened fabric is sent into a loose dryer and dried and shaped under low tension (the equipment has a loose tension system, with no tension in the transverse direction and a longitudinal tension ≤1N / m); after exiting the machine, the width of the fabric is measured with a ruler (1.8m, shrinkage rate 0.8%), the longitudinal elongation is measured with a tensile tester (0.6%), and the moisture regain (halogen moisture meter) is 7.2%. S7: Post-processing and Finished Products (1) Cooling: Allow the shaped fabric to cool naturally to 23°C (room temperature) and let it stand for 30 minutes; (2) Edge trimming and rolling: Use an edge trimming machine to cut off the rough edges on both sides of the fabric (1cm on each side), and then use a fully automatic fabric rolling machine (rolling tension 3N / m) to roll the fabric into a roll with a diameter of 30cm to obtain a steam-free and wash-free printed finished product (specifications: 10m×1.78m, weight approximately 3.8kg).

[0018] Finished product performance test results Test Item Test Results National standards require (Wearing textiles) Color fastness to washing (4-level washing): 4-5 (small color difference between original and washed) ≥3; Color fastness to rubbing: Dry rubbing 4-5, wet rubbing 4; Dry rubbing ≥3, wet rubbing ≥2; Printing layer adhesion (cross-cut test): 5B (no peeling) ≥4B; Warp breaking strength: 340N, not less than 90% of the original fabric (original 350N); Weft breaking strength: 290N, not less than 90% of the original fabric (original 300N); Lateral width shrinkage (after washing): 1.2% ≤3%; Longitudinal length shrinkage (after washing): 0.9% ≤3%; Soft hand feel, no stiffness. High wear-resistant processing technology based on slurry in Example 3 Process steps The process is the same as in Example 1, except that the slurry is replaced with the high abrasion resistant slurry of Example 3, the temperature of the heat transfer roller is adjusted to 230°C, and the hardening time is 50 seconds. Finished product performance test results Abrasion resistance: According to GB / T21196.2-2007 "Textiles Martindale Abrasion Test - Part 2: Determination of Specimen Breakage", the printed layer showed no damage or exposure to the substrate after 1000 abrasion cycles (800 cycles for Example 1). Other properties: color fastness, adhesion, and shrinkage are basically the same as in Example 1, making it suitable for outdoor clothing, sofa fabrics, and other scenarios with high abrasion resistance requirements.

[0019] Comparative Example (Traditional Printing Process) To highlight the advantages of this invention, a traditional reactive printing process is used as a comparative example, as detailed below: Greige fabric: Same process as Example 1 (Nylon cotton 60:40, 200g / m²) 2 ); Process steps: printing, steaming (102℃, 20 minutes), washing (3 times, 10 minutes each time, water temperature 60℃, liquor ratio 1:20), setting (160℃, 5 minutes); Key Indicator Comparison: Comparison indicators Process Example 1 of the Invention Traditional process comparison ratio Advantages Production cycle (10m greige fabric) 1.2 hours 5.5 hours Efficiency increased by 3.6 times Water consumption (per 10m of grey fabric) <![CDATA[0.8m 3 ]]> <![CDATA[12m 3 ]]> Water saving 93.3% Energy consumption (10m of grey fabric, measured in electricity) 8kWh 22kWh Energy saving of 63.6% Finished product color fastness to washing Level 4-5 Level 3-4 Colorfastness improved by 1 grade Retention rate of breaking strength of greige fabric 94.3% (Meridian direction) 82.1% (Meridian direction) Reduce fiber damage Example Description The printing paste of this invention solves the contradiction between high-temperature color fixing and fiber heat resistance in nylon-cotton blended fabrics through the synergistic effect of polyurethane dispersant, silica, white vinegar, and other components: During heat transfer at 215-235℃, silica blocks heat through its low thermal conductivity (thermal conductivity coefficient 0.15W / (m・K)), keeping the surface temperature of nylon fibers below 180℃ (measured by an infrared thermometer), thus preventing yellowing and deformation, while also enhancing the wear resistance of the printed layer; the pH adjustment effect of white vinegar promotes cross-linking between polyurethane and fibers, improving the bonding strength. In the processing technology, segmented drying avoids the slurry from drying too quickly and becoming brittle, loose setting controls the fabric shrinkage rate, and cooling rollers quickly cool down the fabric (it only takes 12 seconds to drop from 225℃ to 45℃) to avoid residual heat damage. The entire process eliminates steaming and washing, achieving green production. The selection of raw materials and equipment in the embodiments is merely illustrative. For example, polyurethane dispersant can be replaced with the same type of anionic product (solid content 35-45%), silica can be selected from other modified precipitation products, and equipment models can be adjusted according to production capacity. All of these fall within the protection scope of this invention.

[0020] Finally, it should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A printing paste for nylon-cotton fabric that requires no steaming or washing, characterized in that, By weight percentage, it consists of the following components: The composition consists of 30%–40% polyurethane dispersant, 2%–4% silica, 0.3%–0.7% white vinegar, 1%–3% antifreeze, 0.1%–0.3% defoamer, and the balance being water. The silica serves as a heat insulation carrier; The white vinegar is used to adjust the pH value of the slurry to 4-5; The antifreeze agent is ethylene glycol or propylene glycol; The defoamer is an organosilicon defoamer.

2. The printing paste for no-steaming and no-washing nylon cotton fabric according to claim 1, characterized in that, The polyurethane dispersant is an anionic aqueous polyurethane dispersion with a solid content of 35% to 45%, a number average molecular weight of 50,000 to 80,000, and a glass transition temperature (Tg) of -20°C to -10°C.

3. The printing paste for no-steaming and no-washing nylon-cotton fabric according to claim 1, characterized in that, The silica is precipitated silica with a particle size of 100-500 mesh and a specific surface area of ​​150-300 m². 2 / g, the surface is modified with silane coupling agent (KH~550 or KH~560), and the modification rate is ≥85%.

4. The printing paste for no-steaming and no-washing nylon cotton fabric according to claim 1, characterized in that, The white vinegar has an acetic acid content of 4%~6%, a heavy metal content (as Pb) of ≤0.1mg / kg, and an evaporation residue of ≤0.5g / L.

5. A processing technology for a steam-free and wash-free nylon cotton fabric, characterized in that, Includes the following steps: S1: Soak the nylon-cotton blended fabric in warm water at 80-90℃ for 10-15 minutes, add 0.5%-1% (owf) of nonionic surfactant, and then dry it at 100-105℃ until the moisture content is ≤5%; S2: According to the components described in claim 1, first mix deionized water and white vinegar and stir for 5-10 minutes, then add polyurethane dispersant, silica, antifreeze and defoamer in sequence, stir at 200-300 rpm for 30-45 minutes, and filter through a 200 mesh filter for later use. S3: Using a three-roller coating machine, the slurry prepared in step 2 is coated onto the surface of the pretreated fabric in step 1. The coating pressure is 0.2~0.4MPa, the roller speed is 5~10m / min, and the slurry coating amount is 15~25g / m. 2 After coating, the tension of the fabric is controlled at 3~5N / m; S4: Arrange the sizing fabric from step 3 in a hot air tunnel dryer. Control the drying temperature in stages: front section 100~120℃, middle section 120~140℃, and rear section 140~150℃. The total drying time is 3~5 minutes. After drying, the moisture content of the fabric should be controlled at 1%~3%. S5: Send the dried fabric from step 4 to the heat transfer roller press. The temperature of the heat transfer roller is 215~235℃, the roller pressure is 0.5~0.8MPa, the roller speed is 3~5m / min, and the heat transfer hardening time is 30~60 seconds. Simultaneously, the cooling roller is used to cool down the hardened fabric. S6: Place the hardened fabric from step 5 into a loose hot air dryer. Set the temperature at 120~140℃ for 2~3 minutes. Set the air velocity in the dryer at 1.5~2.0m / s. During the setting process, the transverse width shrinkage of the fabric should be ≤2%, and the longitudinal elongation should be ≤1%. S7: After the fabric has been set in step 6, let it cool naturally to room temperature (20~25℃), then trim and roll it up with a rolling tension of 2~4N / m to obtain a steam-free and wash-free printed finished product.

6. The processing technology for a steam-free and wash-free nylon cotton fabric according to claim 5, characterized in that, The nonionic surfactant mentioned in step 1 is fatty alcohol polyoxyethylene ether (AEO~9), with an HLB value of 12~13.

7. The processing technology for a steam-free and wash-free nylon cotton fabric according to claim 5, characterized in that, In step 3, the rollers of the three-roll coating machine are made of chrome-plated steel with a surface roughness Ra≤0.8μm and the roller temperature is controlled at 30~40℃.

8. The processing technology for a steam-free and wash-free nylon cotton fabric according to claim 5, characterized in that, In step 4, the hot air velocity of the hot air tunnel dryer is 2~3m / s, and the hot air circulation rate is ≥80%.

9. The processing technology for a steam-free and wash-free nylon cotton fabric according to claim 5, characterized in that, In step 5, the surface temperature uniformity of the heat transfer roller of the heat transfer roller press is ≤±2℃, the center distance between the cooling roller and the heat transfer roller is 10~15cm, and the fabric is cooled to below 50℃ after hardening.