Lyocell woven fabric and integrated processing method

Abstract

The present application relates to the field of textile dyeing and finishing processing. The present application discloses an integrated processing method of lyocell woven fabric, which comprises the following steps: a pretreatment process of singeing, alkali piling and flat washing on lyocell woven grey cloth; a process of dyeing and cross-linking in the same bath by adding anti-fibrillation cross-linking agent and reactive dyes to inhibit fibrillation of fibers during dyeing; a functional finishing process of padding functional microcapsule working fluid with alkali-resistant polymer material as wall material and then pre-drying and curing to fix the microcapsule on the surface of the fiber through the cross-linking agent; and a post-treatment process of flat mechanical beating soft finishing and setting. Compared with the prior art, the present application integrates dyeing and anti-fibrillation cross-linking into one bath, simplifies the process, reduces energy consumption, and avoids damage to fiber strength caused by separate cross-linking. By selecting alkali-resistant wall material, the microcapsule can withstand the alkali environment of the previous dye bath, realizing the integration of functional finishing and dyeing cross-linking process.

Description

Technical Field

[0001] This invention relates to the field of textile dyeing and finishing, and in particular to a lyocell woven fabric and its integrated processing method. Background Technology

[0002] Lyocell fiber is a regenerated cellulose fiber produced from natural wood pulp using an N-methylmorpholine-N-oxide solvent spinning process. Its production process is environmentally friendly, the fiber boasts excellent mechanical properties, and it exhibits good moisture absorption and breathability, earning it the reputation of a green fiber for the 21st century. Lyocell fiber undergoes significant radial swelling under wet conditions, leading to fiber cortex cracking and exposure of internal microfibrils. Under mechanical friction or water shearing, fibrillation easily occurs on the fiber surface. This fibrillation not only causes the fabric surface to pill, fade, and appear worn, affecting the product's appearance and performance, but also easily causes defects such as abrasions, white spots, and frost during dyeing and finishing processes. To address this issue, existing technologies primarily employ cross-linking modification, introducing chemical cross-linking bonds between cellulose molecular chains to enhance the lateral connections between microfibrils and inhibit fibrillation and peeling under wet conditions. Cross-linking can be performed during the fiber production stage, such as the cross-linked Lyocell CL series offered by Sateri; it can also be performed during the dyeing and finishing stages, including pre-dyeing cross-linking, dyeing-in-bath cross-linking, and post-treatment cross-linking. Simultaneous dyeing and crosslinking involves treating antifibrillation crosslinking agents and reactive dyes in the same dye bath. This process has a shorter flow rate and causes less damage to fiber strength, making it a current research and application hotspot. Companies such as China Textile Chemical, Demei, and Transfar have developed corresponding simultaneous dyeing and crosslinking agent products. Related patents, such as those from Qingdao Jifa Group, disclose a method for antifibrillation finishing of lyocell fabrics, using crosslinking agents containing multifunctional active groups and reactive dyes treated in the same bath. However, existing simultaneous dyeing and crosslinking technologies still suffer from problems such as low crosslinking agent solubility and difficulty in meeting the production requirements of small-liquor-ratio equipment.

[0003] In the field of functional finishing, with the increasing demand from consumers for multifunctional textiles, the use of microencapsulation technology to endow fabrics with functions such as fragrance, antibacterial properties, mosquito repellency, cooling, and temperature sensitivity has become a research hotspot in the industry. Microcapsules encapsulate functional core materials through wall materials and are then applied to the fabric through subsequent finishing processes, enabling the slow release of functional components. Existing patents disclose processing methods for lyocell fabrics with sustained-release functions from artemisia microcapsules, as well as methods for preparing long-lasting aromatic lyocell fibers with bio-enzyme-immobilized temperature-sensitive microcapsules. Current functional microcapsule finishing technologies are typically implemented as a separate finishing process after fabric dyeing. Due to the insufficient alkali resistance of conventional microcapsule wall materials, they are prone to rupture under alkaline conditions, thus making integration with the dyeing process impossible. In existing technologies, microcapsules are mainly attached to the fiber surface through adhesives or simple physical adsorption. After repeated washing, the microcapsules easily detach, resulting in low retention of the functional core material and insufficient wash resistance to meet the requirements of high-end textiles. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention discloses a processing method that organically integrates dyeing, anti-fibrillation crosslinking, and functional microcapsule finishing, thereby simplifying the process flow while improving the overall performance of the fabric. This invention relates to a Lyocell woven fabric and its integrated processing method.

[0005] This invention discloses an integrated processing method for lyocell woven fabrics, which includes the following steps:

[0006] S1: Pre-treatment process: The Lyocell woven fabric is singed, alkali piled and flat washed to remove the sizing and impurities on the surface of the fabric and obtain the pre-treated fabric.

[0007] S2: Dyeing and crosslinking process: The pretreated fabric obtained in step S1 is placed into the dyeing equipment, water is added, along with dyeing auxiliaries and anti-fibrillation crosslinking agents. After the auxiliaries are evenly dispersed, reactive dyes are added, followed by dyeing accelerators. Then, the dye bath is added in portions in the form of an alkaline solution, and the dye bath is heated to the set holding temperature. The fabric is kept at the set holding temperature, allowing the reactive dyes to undergo a color-fixing reaction with the fibers under alkaline conditions. At the same time, the anti-fibrillation crosslinking agents undergo a crosslinking reaction with the fibers under alkaline conditions, inhibiting fiber fibrillation. After the holding period, the fabric is cooled and drained to obtain the dyed and crosslinked fabric.

[0008] S3: Functional finishing process: The dyed cross-linked fabric obtained in step S2 is sequentially impregnated with functional microcapsule working solution, pre-dried and baked, so that the functional microcapsules are fixed to the surface of the fabric fibers by cross-linking agent; the wall material of the functional microcapsules is an alkali-resistant polymer material;

[0009] S4: Post-processing: The fabric obtained in step S3 is subjected to flat-width mechanical beating and softening treatment and softener is applied. Then, it is subjected to setting treatment to obtain the finished fabric.

[0010] Furthermore, in step S1, the alkaline solution used for alkaline pile treatment is a caustic soda solution with a concentration of 10-30 g / L, a pile temperature of 20-40℃, and a pile time of 4-12 hours.

[0011] Furthermore, in step S2, the antifibrillation crosslinking agent is a multifunctional triazine compound or a crosslinking agent containing epoxy groups;

[0012] The amount of antifibrillating crosslinking agent used is 2%-8% of the fabric weight;

[0013] Set the insulation temperature to 50-65℃ and the insulation operation time to 30-80 minutes.

[0014] Furthermore, in step S2, the dyeing auxiliary agent is a leveling and dispersing agent, and its dosage is 0.5-5 g / L;

[0015] The dyeing accelerator is sodium sulfate, and the dosage is 20-60 g / L, added in 2-5 portions, with an interval of 5-15 minutes between each addition;

[0016] The alkali is sodium carbonate, and the dosage is 10-30 g / L, added in 3-5 portions, with an interval of 10-15 minutes between each addition;

[0017] The heating rate is 0.5-1.0℃ / min; the bath ratio is 1:10-1:50;

[0018] The cooling rate of the liquid being cooled and drained is 0.8-2.0℃ / min.

[0019] Furthermore, in step S3, the wall material of the functional microcapsules, after being treated in an alkaline aqueous solution at pH 9-11 and 50-65℃ for 60 minutes, has a wall material rupture rate of no more than 10%. The rupture rate is calculated by converting the core material content in the leachate using ultraviolet spectrophotometry.

[0020] Further, in step S3, the functional microcapsule is one or more of the following: long-acting aromatic microcapsule, antibacterial microcapsule, mosquito repellent microcapsule, cooling microcapsule, or warming microcapsule with sustained-release function.

[0021] The wall material of the functional microcapsules is polyurea or high cross-linking density melamine resin;

[0022] The functional microcapsules have an average particle size of 0.5-20 μm and a particle size distribution span of ≤1.5.

[0023] Further, in step S3, the functional microcapsule working solution comprises, by mass-volume ratio: 50-150 g / L of functional microcapsules, 20-50 g / L of crosslinking agent, 1-3 g / L of penetrant, and 20-40 g / L of softener, and the pH of the working solution is adjusted to 4.5-6.5;

[0024] The rolling allowance is 65%-80%.

[0025] Furthermore, in step S3, the crosslinking agent is a blocked isocyanate crosslinking agent or an epoxy resin crosslinking agent;

[0026] The pre-drying temperature is 80-110℃ and the pre-drying time is 2-5 minutes; the baking temperature is 140-170℃ and the baking time is 30-60 seconds.

[0027] Furthermore, in step S3, the functional microcapsules achieve firm fixation on the fiber surface through the combined action of covalent bonding and physical anchoring with the crosslinking agent; the covalent bonding is that the crosslinking agent molecules form chemical bonds with the active groups on the fiber and the microcapsule wall material respectively, and the physical anchoring is that the microcapsule particles are embedded in the pores and grooves on the fiber surface and inside the yarn and are locked by the fixation effect of the crosslinking agent;

[0028] Functional microcapsules achieve the slow release of functional core materials through triboelectric release, thermal release, or diffusion release mechanisms.

[0029] This invention discloses a lyocell woven fabric, which is prepared by any one of the methods described above, comprising:

[0030] Functional microcapsules are fixed to the surface of the fabric and are anchored to the fiber surface by a cross-linking agent.

[0031] After 50 standard washes, the retention rate of functional core material is ≥60%, and the fibrillation level of the fabric surface is ≥4.

[0032] Furthermore, the fabric's tear strength, rubbing color fastness, washing color fastness, and pilling resistance are ≥200N, ≥4, ≥4, and ≥4, respectively.

[0033] The beneficial effects of this invention are:

[0034] This invention combines the dyeing process with the anti-fibrillation crosslinking process into one, completing the crosslinking reaction simultaneously with reactive dyeing. This eliminates the need for separate crosslinking finishing processes before and after dyeing, significantly shortening the processing time and improving production efficiency. It also reduces water, electricity, and steam consumption, aligning with clean production and energy conservation policies. The simultaneous dyeing and crosslinking method avoids the high-temperature baking or secondary mechanical treatment required for separate crosslinking finishing, effectively reducing repeated stress on the fabric during processing and maintaining the original tear strength and abrasion resistance of lyocell fibers. This solves the technical problem of reduced fiber strength and a stiffer hand feel caused by pre-dyeing or post-dyeing crosslinking methods in existing technologies. This invention performs functional microcapsule finishing after the dyeing and cross-linking process. By selecting alkali-resistant polymer materials such as polyurea or high-cross-linking-density melamine resin as microcapsule wall materials, the microcapsules can withstand the alkaline high-temperature environment of the preceding dyeing and cross-linking process without rupture. This invention adds a cross-linking agent to the functional microcapsule working solution. Through padding, pre-drying, and baking treatments, the cross-linking agent forms covalent bonds between the fiber and the microcapsule wall material. Combined with the physical anchoring of microcapsule particles on the fiber surface and inside the yarn, this achieves firm fixation of the microcapsules on the fiber surface. This dual fixation mechanism of chemical bonding and physical anchoring effectively avoids the defects of microcapsules relying solely on adhesives or physical adsorption to adhere to the fiber surface, which easily detach after multiple washes. This allows the fabric to retain over 60% of its functional core material after 50 standard washes, far exceeding the level of similar products where the function significantly declines after 10-20 washes. Attached Figure Description

[0035] Figure 1 This is a process flow diagram of an integrated processing method for a lyocell woven fabric according to an embodiment of this application.

[0036] Figure 2 This is a process flow diagram of the fiber locking process in the embodiments of this application.

[0037] Figure 3 This is a test image for fabric surface testing of a product in an embodiment of this application.

[0038] Figure 4 This is another inspection diagram for fabric surface inspection of the product in the embodiments of this application.

[0039] Figure 5 This is a friction fastness test diagram for testing the fabric surface of the product in the embodiments of this application.

[0040] Figure 6 This is a test chart for the color fastness to soap washing of the product in the embodiments of this application.

[0041] Figure 7This is a test image for water washing to prevent fibrillation of the fabric surface in the embodiments of this application.

[0042] Figure 8 This is another test image for water washing to prevent fibrillation of the product in the embodiments of this application.

[0043] Figure 9 This is another test image for water washing to prevent fibrillation of the product in the embodiments of this application.

[0044] Figure 10 This is another test image for water washing to prevent fibrillation of the product in the embodiments of this application. Detailed Implementation

[0045] To enable those skilled in the art to better understand the present invention, the technical solutions in the specific embodiments of the present invention will be clearly and completely described below.

[0046] This invention discloses an integrated processing method for lyocell woven fabrics, which includes the following steps:

[0047] S1: Pre-treatment process: The Lyocell woven fabric is singed, alkali piled and flat washed to remove the sizing and impurities on the surface of the fabric and obtain the pre-treated fabric.

[0048] S2: Dyeing and crosslinking process: The pretreated fabric obtained in step S1 is placed into the dyeing equipment, water is added, along with dyeing auxiliaries and anti-fibrillation crosslinking agents. After the auxiliaries are evenly dispersed, reactive dyes are added, followed by dyeing accelerators. Then, the dye bath is added in portions in the form of an alkaline solution, and the dye bath is heated to the set holding temperature. The fabric is kept at the set holding temperature, allowing the reactive dyes to undergo a color-fixing reaction with the fibers under alkaline conditions. At the same time, the anti-fibrillation crosslinking agents undergo a crosslinking reaction with the fibers under alkaline conditions, inhibiting fiber fibrillation. After the holding period, the fabric is cooled and drained to obtain the dyed and crosslinked fabric.

[0049] S3: Functional finishing process: The dyed cross-linked fabric obtained in step S2 is sequentially impregnated with functional microcapsule working solution, pre-dried and baked, so that the functional microcapsules are fixed to the surface of the fabric fibers by cross-linking agent; the wall material of the functional microcapsules is an alkali-resistant polymer material;

[0050] S4: Post-processing: The fabric obtained in step S3 is subjected to flat-width mechanical beating and softening treatment and softener is applied. Then, it is subjected to setting treatment to obtain the finished fabric.

[0051] The integrated processing method for lyocell woven fabrics provided by this invention is based on the systematic optimization of the inherent relationship between the characteristics of lyocell fibers and processing procedures. Lyocell fibers are prone to radial expansion under wet conditions, leading to the peeling of fibrils and subfibrils on the fiber surface, resulting in fibrillation, which severely affects the stability of the fabric's appearance and feel. In step S2, this invention places reactive dyeing and anti-fibrillation crosslinking treatment in the same dye bath. The reactive dye, under alkaline conditions, covalently bonds with the hydroxyl groups on cellulose molecules to achieve color fixation. Simultaneously, the added multifunctional triazine compounds or epoxy-containing anti-fibrillation crosslinking agents, under the same alkaline conditions, can undergo crosslinking reactions with the active groups on the fiber macromolecular chains, forming a three-dimensional network structure within the fiber, thereby effectively inhibiting the fiber's tendency to fibrillate during subsequent wet processing. The design of the functional microcapsule finishing process in step S3 fully considers the process environment of the preceding dyeing and crosslinking processes. By selecting alkali-resistant polymer materials such as polyurea or high-crosslinking-density melamine resin as microcapsule wall materials, it is ensured that the microcapsules can maintain their integrity when in contact with the residual alkaline microenvironment on the fabric, with a wall material breakage rate of no more than 10%. This allows for covalent bonding between the microcapsules and the active groups on the fiber and microcapsule wall materials during subsequent padding, pre-drying, and baking processes, using blocked isocyanate crosslinking agents or epoxy resin crosslinking agents. Combined with physical anchoring, this firmly fixes the functional microcapsules to the fiber surface. Finally, the flat-width mechanical beating softening process in step S4 imparts a soft hand feel to the fabric, and the finishing treatment yields a dimensionally stable finished fabric. The entire process achieves integrated dyeing, anti-fibrillation crosslinking, and functional finishing through the synergistic cooperation between processes.

[0052] This invention combines the dyeing and anti-fibrillation crosslinking processes into one, completing the crosslinking reaction simultaneously with dyeing. This not only simplifies the process flow, shortens processing time, and improves production efficiency, but also avoids the additional strength damage to the fabric caused by separate crosslinking finishing, effectively maintaining the original tear strength and abrasion resistance of lyocell woven fabrics. Following the dyeing and crosslinking process, this invention performs functional microcapsule finishing. By selecting alkali-resistant microcapsule wall materials, it effectively avoids the microcapsules being directly subjected to the high-temperature alkaline dye bath of the dyeing and crosslinking process. Simultaneously, the alkali resistance of the wall material resists the localized effects of residual alkali on the fabric, allowing the microcapsules to enter subsequent finishing processes intact. Under the action of the crosslinking agent, they are firmly fixed to the fiber surface. After fifty standard washes, the functional core material retention rate still reaches over 60%, exhibiting excellent and durable functionality. In the dyeing and crosslinking process, the antifibrillation crosslinking agent constructs a crosslinking network inside the fiber, which not only effectively inhibits the fibrillation of the fiber and makes the fibrillation level of the fabric surface reach level four or above, but also provides a more stable fiber base for the subsequent fixation of microcapsules to a certain extent. This is conducive to the uniform distribution and firm bonding of the crosslinking agent on the fiber surface, thereby further improving the wash fastness of the microcapsules.

[0053] Microcapsules serve as the functional carrier for the integrated processing method of this invention. They are firmly anchored to the fiber surface by a cross-linking agent, and utilize the encapsulation barrier effect of polyurea or high-crosslinking-density melamine resin wall materials on the core material. During use, the core material is slowly released through friction, heat, or diffusion mechanisms, thereby endowing the finished fabric with long-lasting fragrance, antibacterial, mosquito-repellent, and cooling functions. The alkali resistance of the wall material and the anchoring effect of the cross-linking agent work synergistically to ensure that the microcapsules remain intact when in contact with the alkaline microenvironment remaining on the fabric and in subsequent alkaline household washing environments. Even after 50 standard household washes, they maintain a functional component retention rate of ≥60%, solving the technical problems of uncontrollable functional release rate and poor wash resistance in traditional functional finished fabrics, giving the finished fabric both excellent functional durability and wearability.

[0054] In one implementation method, in step S1, the alkaline solution used for alkaline pile treatment is a caustic soda solution with a concentration of 10-30 g / L, a pile temperature of 20-40°C, and a pile time of 4-12 hours.

[0055] In step S1, the alkali pile treatment is a crucial pretreatment step for lyocell woven fabric. It utilizes a caustic soda solution to chemically degrade and physically expand the sizing agents and impurities within the fibers on the fabric surface. When the caustic soda concentration is 10-30 g / L, the alkali solution can effectively penetrate into the fiber interior and yarn gaps, causing saponification, hydrolysis, and emulsification reactions of starch sizing agents, PVA sizing agents, and natural symbiotic substances such as pectin and waxes on the fabric surface. This generates soluble substances or well-dispersed small molecular fragments, which are then removed by washing in the subsequent flat washing process. The choice of a pile temperature of 20-40℃ is based on a comprehensive consideration of reaction kinetics and economy. Within this temperature range, the chemical reaction rate between caustic soda and the sizing agents and impurities is moderate, ensuring sufficient reactivity for complete sizing degradation while avoiding excessive expansion or potential strength damage to the lyocell fibers under high-temperature conditions. A 4-12 hour stacking time provides sufficient reaction time, ensuring that the caustic soda solution can thoroughly react with various sizing agents and impurities on the fabric under ambient to slightly warm conditions. This is especially beneficial for chemical or composite sizing agents applied during weaving; a longer stacking time allows for sufficient diffusion and reaction of the alkali solution within the yarn and between fibers, causing the sizing molecular chains to break and dissolve, creating favorable conditions for removal in the subsequent washing process. Simultaneously, the appropriate concentration of the caustic soda solution and the stacking conditions also allow for limited and uniform swelling of the lyocell fibers, which helps open the microporous structure of the fiber surface, increasing the specific surface area and reactivity of the fibers. This provides a favorable fiber morphology basis for the uniform dyeing and full reaction of the reactive dyes and anti-fibrillation crosslinking agents in the subsequent step S2. The matching relationship between the caustic soda concentration, stacking temperature, and stacking time must be controlled within the above-mentioned range. Excessive caustic soda concentration or prolonged stacking time can cause excessive transverse swelling of lyocell fibers, partially destroying the crystalline regions within the fibers, increasing the proportion of amorphous regions, and significantly raising the transverse swelling rate of the fibers. This leads to a decrease in fiber orientation and crystallinity, ultimately resulting in a reduction in fiber strength retention. The present invention, with its ambient temperature conditions of 20-30°C and a stacking time of 4-12 hours, ensures thorough removal of slurry and impurities while maintaining a fiber strength retention rate of over 90%, thus avoiding irreversible damage to the fiber's mechanical properties caused by excessive alkaline treatment.

[0056] In one embodiment, in step S2, the antifibrillation crosslinking agent is a multifunctional triazine compound or a crosslinking agent containing epoxy groups; the amount of the antifibrillation crosslinking agent is 2%-8% of the fabric weight;

[0057] Set the insulation temperature to 50-65℃ and the insulation operation time to 30-80 minutes.

[0058] The selection of the antifibrillation crosslinking agent and the setting of process parameters in step S2 are based on the molecular structural characteristics of the crosslinking agent and its reaction kinetics with lyocell fibers. Multifunctional triazine compounds contain multiple reactive groups in their molecular structure. Taking dichlorotriazine crosslinking agents as an example, under alkaline conditions, they can undergo nucleophilic substitution reactions with the hydroxyl groups on the cellulose macromolecular chains. The vinyl sulfone group and the chlorine atoms on the dichlorotriazine residues can both act as electrophilic active sites to participate in the crosslinking reaction, thereby forming multiple covalent bonds between adjacent cellulose molecular chains. Crosslinking agents containing epoxy groups form covalent bonds by ring-opening the epoxy groups under alkaline conditions and undergoing etherification reactions with the cellulose hydroxyl groups. Both types of crosslinking agents have multifunctional structures; one crosslinking agent molecule can react simultaneously with two or more cellulose macromolecular chains, constructing a three-dimensional network crosslinking structure within the fiber. The crosslinking agent dosage is 2%-8% of the fabric weight, determined based on the balance between crosslinking efficiency and fiber performance maintenance: when the dosage is below 2%, the crosslinking density is insufficient to form an effective network structure to inhibit fibrillation; when the dosage is above 8%, excessive crosslinking may lead to increased fiber stiffness, a harder hand feel, and strength damage. The holding temperature is set at 50-65℃, and the holding time is 30-80 minutes. At 50-65℃, the crosslinking agent has sufficient reactivity to ensure the crosslinking reaction with the fiber is completed within the holding time. This temperature range also coincides with the optimal fixing temperature range of reactive dyes, allowing dyeing and crosslinking to proceed synergistically in the same dye bath. The 30-80 minute holding time provides sufficient diffusion, penetration, and reaction time for the crosslinking agent molecules, ensuring that the crosslinking reaction proceeds uniformly and fully within and on the surface of the fiber. In step S2, after the heat preservation is completed, the fabric is cooled and drained, and then washed with cold water, soap, hot water and warm water in sequence. Finally, the fabric is neutralized with acetic acid to a pH of 6.0-7.0 to obtain the dyed cross-linked fabric.

[0059] In one embodiment, in step S2, the dyeing auxiliary is a leveling and dispersing auxiliary, and its dosage is 0.5-5 g / L;

[0060] The dyeing accelerator is sodium sulfate, and the dosage is 20-60 g / L, added in 2-5 portions, with an interval of 5-15 minutes between each addition;

[0061] The alkali is sodium carbonate, and the dosage is 10-30 g / L, added in 3-5 portions, with an interval of 10-15 minutes between each addition;

[0062] The heating rate is 0.5-1.0℃ / min; the bath ratio is 1:10-1:50;

[0063] The cooling rate of the liquid being cooled and drained is 0.8-2.0℃ / min.

[0064] After the heat treatment, the dye bath is cooled and drained at a rate of 0.8-2.0℃ / min. The fabric is then subjected to a water washing and neutralization treatment: a cold water wash (room temperature, 5 min), a soap wash (95℃, 2 g / L soaping agent, 10 min), a hot water wash (80℃, 5 min), and a warm water wash (50℃, 5 min). Finally, the pH of the fabric is adjusted to 6.0-7.0 with acetic acid to obtain the dyed cross-linked fabric. The purpose of this water washing and neutralization step is to remove residual unfixed reactive dyes (floating dye), sodium sulfate electrolyte, and sodium carbonate alkali from the dye bath, preventing these residues from being carried into the functional microcapsule working solution in the subsequent step S3. Without water washing and neutralization, the alkalinity (pH approximately 10-11) and salt (residual sodium sulfate) in the greige fabric will cause the pH of the weakly acidic working solution (pH 4.5-6.5) to rise, affecting the stability of the blocked isocyanate crosslinking agent. Simultaneously, residual loose dye will contaminate the working solution and impair the fabric's colorfastness, and high concentrations of electrolytes may cause the aggregation and sedimentation of microcapsule particles. The water washing and neutralization step ensures that the greige fabric entering the functional finishing process has a clean fiber surface and a suitable neutral pH environment, providing favorable conditions for the uniform impregnation of microcapsules and the stable fixation of the crosslinking agent. In step S2, the antifibrillation crosslinking agent has already formed a covalent crosslinking network with the fibers; the water washing process will not break these existing covalent bonds.

[0065] The synergistic design of process parameters such as the types, dosages, addition methods, heating / cooling rates, and liquor ratios of dyeing auxiliaries, dyeing accelerators, and alkalis in step S2 is based on the fixation kinetics and dyeing thermodynamics of reactive dyes on cellulose fibers. The dosage of the leveling and dispersing auxiliary is 0.5-5 g / L. Its molecular structure contains both hydrophilic and hydrophobic groups, which can effectively reduce the aggregation tendency between reactive dye molecules in the dye bath and improve the dispersion stability of the dye in the dye bath. Simultaneously, the leveling auxiliary can form hydrogen bonds or van der Waals forces with dye molecules, slowing down the diffusion rate of the dye to the fiber surface and making the adsorption of the dye on the fiber surface more uniform. Sodium sulfate is used as a dyeing accelerator at a dosage of 20-60 g / L. Its mechanism of action is that sodium ions can neutralize the negatively charged hydroxyl anions on the fiber surface, reduce the zeta potential of the fiber surface, thereby weakening the electrostatic repulsion of the fiber to the dye anions and promoting the diffusion and adsorption of dye into the fiber. It is added in 2-5 times with an interval of 5-15 minutes between each addition to avoid the sudden increase in electrolyte concentration in the dye bath caused by a one-time addition, which would cause the dye to be dyed suddenly and the surface adsorption to be too fast. This effectively prevents uneven dyeing and color spot phenomenon. Sodium carbonate, used as an alkali, is administered at a concentration of 10-30 g / L. In practice, a stock solution of 200-300 g / L is prepared by dissolving sodium carbonate in warm water beforehand. This stock solution is then injected into the dye bath in 3-5 stages during the dyeing heating process, with each stage spaced 10-15 minutes apart, via the feeding tank and pump system of the high-temperature, high-pressure overflow dyeing machine. The purpose of this is to allow the hydroxide ions generated by the ionization of sodium carbonate in water to slowly and gradually increase the pH value of the dye bath, ensuring that the covalent bonding reaction between the reactive dye and the fiber proceeds in a controlled manner. This avoids the rapid increase in pH value caused by a single addition of the alkali, which could lead to accelerated dye hydrolysis and uneven color fixation. The staged addition, coordinated with the heating process, allows the color fixation reaction to proceed gradually at different temperature stages. During the dyeing and cross-linking process in the same bath, the cross-linking reaction of the anti-fibrillation cross-linking agent and the color fixation reaction of the reactive dye occur simultaneously, exhibiting both competition and synergy in their reaction rates. After the cross-linking agent forms a three-dimensional network structure within the fiber, the fiber's swelling capacity decreases, which may affect the diffusion rate of the dye into the fiber. If the cross-linking reaction rate is too fast and completes dyeing before the dye, it may cause the pores on the fiber surface to shrink, preventing the dye from fully penetrating into the fiber interior, resulting in surface staining and color difference problems. This invention addresses this by adding sodium carbonate in 3-5 stages, with each stage spaced 10-15 minutes apart, gradually increasing the pH of the dye bath from neutral to alkaline. This ensures that the cross-linking reaction and the dye fixation reaction proceed in a matched, stepwise manner. In the initial stage of dyeing, the dye mainly adsorbs onto the fiber surface and diffuses into the fiber interior, while the degree of cross-linking reaction is low. As the alkali is added in stages, the pH gradually increases, and the cross-linking and fixation reactions intensify simultaneously, ultimately completing at the same time during the same heat treatment stage.This pH gradient control strategy effectively avoids the premature completion of the cross-linking reaction, which inhibits dye uptake and ensures uniform dyeing. The heating rate of 0.5-1.0℃ / min is based on the positive correlation between dye uptake rate and temperature. A slower heating rate helps dye molecules to gradually and uniformly diffuse and adsorb from the dye bath into the fiber interior during the heating process, avoiding uneven dyeing caused by excessively rapid dye uptake due to rapid heating.

[0066] In one implementation method, in step S3, the wall material of the functional microcapsules is treated in an alkaline aqueous solution at pH 9-11 and 50-65℃ for 60 minutes. The wall material rupture rate is not more than 10%. The rupture rate is calculated by converting the core material content in the leachate by ultraviolet spectrophotometry.

[0067] The limitation in step S3, where the functional microcapsule wall material's rupture rate does not exceed 10% after treatment in an alkaline aqueous solution at pH 9-11 and 50-65℃ for 60 minutes, is based on a comprehensive consideration of the alkaline microenvironment the microcapsules may encounter throughout the entire processing. Although the microcapsules are only applied to the fabric in step S3, trace amounts of sodium carbonate alkali used in the dyeing and cross-linking process in step S2 may still remain inside the fibers and between the yarns after drainage. When the microcapsule working solution in step S3 is applied to the fabric, the microcapsule wall material will locally come into contact with the alkaline microenvironment formed by the residual alkali from the previous process. Limiting the wall material's rupture rate to no more than 10% under such alkaline conditions ensures that the wall material maintains its structural integrity throughout the entire process from contact with the fabric to baking and fixing. Furthermore, this alkali resistance index also provides structural redundancy for the alkaline washing environment that the finished fabric may encounter during subsequent household washing, ensuring the slow-release function and wash fastness of the microcapsules during long-term use.

[0068] Polyurea wall materials are formed by the polymerization reaction of isocyanate and polyamine at the oil-water interface. Their molecular structure contains a high density of urea bonds. The strong hydrogen bonding interactions and cross-linking network between these bonds endow the wall material with excellent hydrolysis resistance. Under alkaline conditions of pH 9-11, the electron cloud density distribution of the urea bonds effectively inhibits the nucleophilic attack of hydroxyl ions on the carbonyl carbon by both steric hindrance and electronic effects, resulting in an extremely low hydrolysis rate. High-crosslink density melamine resin wall materials are formed by the condensation polymerization of melamine and formaldehyde to create a highly cross-linked triazine ring network structure. The high cross-linking density makes it difficult for alkaline water molecules to penetrate into the interior of the wall material. Simultaneously, the triazine ring structure itself has good alkali resistance and is not prone to ring-opening or degradation in alkaline media. The determination of a rupture rate not exceeding 10% employs ultraviolet spectrophotometry. The principle is that the core material molecular structure of functional microcapsules typically contains ultraviolet characteristic absorption groups. When the wall material of the microcapsule ruptures after treatment in an alkaline solution, the core material is released from the microcapsule into the solution. By measuring the absorbance value of the leachate at a characteristic wavelength and comparing it with a standard curve of core material of known concentration, the core material content in the leachate can be quantitatively calculated, and then the wall material rupture rate can be obtained. This detection method is highly sensitive, quantitatively accurate, and easy to operate.

[0069] In one implementation method, in step S3, the functional microcapsules are one or more of the following: long-acting aromatic microcapsules with sustained-release function, antibacterial microcapsules, mosquito-repellent microcapsules, cooling microcapsules, or warming microcapsules; the wall material of the functional microcapsules is polyurea or high-crosslinked density melamine resin; the average particle size of the functional microcapsules is 0.5-20 μm, and the particle size distribution span is ≤1.5. The span is calculated based on the volume distribution using the formula span=(Dv90-Dv10) / Dv50, where Dv10, Dv50, and Dv90 are the particle size values ​​corresponding to a cumulative volume distribution reaching 10%, 50%, and 90%, respectively.

[0070] The limitations on the type of functional microcapsule, wall material, average particle size, and particle size distribution in step S3 are based on the comprehensive principles of microcapsule preparation science, interfacial polymerization reaction mechanism, and textile functional finishing engineering. The functional microcapsules are selected from one or more of the following: long-acting aromatic microcapsules, antibacterial microcapsules, mosquito-repellent microcapsules, cooling microcapsules, or warming microcapsules. These microcapsules are all structural microcapsules with sustained-release function. Their core material contains volatile aromatic essential oils, antibacterial active ingredients, mosquito-repellent active ingredients, cooling agents, or phase change materials, etc. The core material is encapsulated inside the wall material, and the functional components are slowly released through the physical barrier effect of the wall material. The wall material is made of polyurea or high crosslinking density melamine resin. Polyurea wall material is prepared by polycondensation reaction of isocyanate monomer and polyamine monomer at the oil-water interface. Its molecular chain contains a high density of urea bond structure. The urea bonds interact with each other through strong hydrogen bonds to form a dense crosslinking network, which gives the wall material excellent alkali resistance and thermal stability. High crosslinking density melamine resin wall material is produced by polycondensation reaction of melamine and formaldehyde under specific pH conditions to generate a prepolymer. The prepolymer is further crosslinked and cured under acidic conditions to form a highly crosslinked triazine ring network structure. The high crosslinking density makes the wall material structure dense and has good sealing properties for the core material. The average particle size of the functional microcapsules is 0.5-20 μm, which is within the optimal particle size window for microcapsules used in textile finishing. Microcapsules with an average particle size of less than 0.5 μm are prone to agglomeration and sedimentation in the finishing working solution, affecting the stability of the working solution and the uniformity of finishing. Microcapsules with an average particle size of more than 20 μm are difficult to effectively penetrate into the yarn interior and the tiny pores between fibers during padding, resulting in microcapsules being mainly distributed on the fabric surface and having poor wash resistance.

[0071] In one embodiment, in step S3, the functional microcapsule working solution comprises, by mass-volume ratio: 50-150 g / L of functional microcapsules, 20-50 g / L of crosslinking agent, 1-3 g / L of penetrant, and 20-40 g / L of softener, and the pH of the working solution is adjusted to 4.5-6.5;

[0072] The rolling allowance is 65%-80%.

[0073] The working solution contains 50-150 g / L of functional microcapsules by mass-volume ratio. This concentration range is determined based on a balance of the required functional load per unit area of ​​fabric: when the concentration is below 50 g / L, the amount of microcapsules deposited on the fabric surface is insufficient to achieve a significant functional effect; when the concentration is above 150 g / L, the viscosity of the working solution is too high, which can easily lead to a decrease in the uniformity of microcapsule dispersion and particle agglomeration. A crosslinking agent of 20-50 g / L acts as a bridge in this system. The blocked isocyanate crosslinking agent unblocks and releases active isocyanate groups at baking temperature. These groups can react with hydroxyl groups on the fiber to form covalent bonds, and can also react with active hydrogen groups such as amino or hydroxyl groups on the surface of the microcapsule wall material, thereby forming chemical bonds between the fiber and the microcapsule. The epoxy resin crosslinking agent achieves a similar bridging and fixation effect by undergoing ring-opening addition reactions with active groups on the fiber and microcapsule wall material through epoxy groups under baking conditions. The addition of 1-3 g / L of penetrant aims to reduce the surface tension of the working solution, improve its wetting and penetration ability into the fabric fibers, and ensure that microcapsule particles and crosslinking agent molecules can effectively penetrate into the yarn interior and the micropores between fibers. The addition of 20-40 g / L of softener is based on the fact that the long-chain alkyl or polyether segments in the softener molecules can be directionally adsorbed onto the fiber surface, forming a lubricating film layer after baking, reducing the coefficient of friction between fibers, thereby improving the stiffness of the fabric that may occur after crosslinking and fixation treatment. The pH of the working solution is adjusted to 4.5-6.5. This weakly acidic environment is based on the fact that the stability of closed isocyanate crosslinking agents is better under acidic conditions than under alkaline conditions. Simultaneously, under weakly acidic conditions, the cellulose fiber surface carries a positive charge, which is conducive to the electrostatic adsorption of negatively charged or weakly negatively charged microcapsule particles on the fiber surface, promoting the uniform distribution and deposition of microcapsules on the fibers. The padding residue rate is 65%-80%. The principle of controlling the residue rate is to use the pressure of the rollers to evenly press the working fluid into the fabric and squeeze out excess liquid. When the residue rate is below 65%, the amount of liquid carried by the fabric is insufficient, the carrying capacity of microcapsules and crosslinking agents on the fibers is low, and the functional density after fixation does not meet the design requirements. When the residue rate is above 80%, the amount of liquid carried is too high, the moisture evaporation load during baking increases, and the microcapsules are prone to migrate to the fabric surface with the moisture, resulting in uneven distribution of microcapsules in the fabric thickness direction. The softener in S3 is to reduce the rigidity of the fibers after crosslinking and fixation and improve the hand feel after baking; it is a process aid. The softening finishing in S4 is the final style adjustment. The two can be used together, with non-ionic softeners preferred.

[0074] In one embodiment, in step S3, the crosslinking agent is a blocked isocyanate crosslinking agent or an epoxy resin crosslinking agent;

[0075] The pre-drying temperature is 80-110℃ and the pre-drying time is 2-5 minutes; the baking temperature is 140-170℃ and the baking time is 30-60 seconds.

[0076] In the molecular structure of blocked isocyanate crosslinking agents, the isocyanate groups are temporarily blocked by blocking agents such as phenol, caprolactam, or sodium bisulfite. At room temperature, the isocyanate groups are in a passivated state and do not react with water or active hydrogen groups on fibers, giving the working solution good storage stability and operational safety. When the temperature rises above 130°C, the blocking agent dissociates and is removed from the isocyanate groups, releasing highly active free isocyanate groups. These active groups can rapidly undergo nucleophilic addition reactions with hydroxyl groups on cellulose fibers and amino or hydroxyl groups containing active hydrogen on the surface of microcapsule wall materials, forming stable carbamate or urea bonds, thereby constructing a strong covalent bond bridge between the fiber and the microcapsule. Epoxy resin crosslinking agents contain multiple epoxy groups. At baking temperatures, these epoxy groups can undergo ring-opening addition reactions with nucleophilic groups such as hydroxyl and amino groups on fibers and microcapsule wall materials, forming covalent bonds such as ether or amine bonds. The pre-baking temperature is 80-110℃, and the pre-baking time is 2-5 minutes. This temperature is lower than the effective unblocking temperature of the blocked isocyanate crosslinking agent. Its main function is to gently evaporate and remove the moisture carried by the fabric after padding, while simultaneously allowing the microcapsules, crosslinking agent, and additives to be initially fixed and evenly distributed on and inside the fabric surface. This avoids uneven distribution caused by the rapid vaporization of moisture during direct high-temperature baking, which would lead to the microcapsules migrating to the fabric surface with the water vapor. The baking temperature is 140-170℃, and the baking time is 30-60 seconds. This temperature range is higher than the unblocking temperature of the blocked isocyanate crosslinking agent, ensuring that the crosslinking agent can be fully unblocked and complete the covalent bonding reaction with the fiber and microcapsule wall material. This temperature and time window also meets the activation energy requirements for the ring-opening addition reaction of the epoxy resin crosslinking agent. The short high-temperature baking of 30-60 seconds ensures the crosslinking reaction proceeds fully while avoiding thermal damage to the microcapsule wall material or thermal oxidative degradation of the lyocell fiber caused by excessively long high-temperature treatment.

[0077] In actual continuous production, a rapid transition section needs to be set between pre-drying and baking to allow the fabric to transition from the pre-drying temperature of 80-110℃ to the baking temperature of 140-170℃ within 15-30 seconds. This avoids the fabric remaining in the 110-140℃ transition temperature range for too long. This temperature range is precisely the initial unblocking temperature range of the closed isocyanate crosslinking agent. If the transition time is too long, the crosslinking agent may partially unblock and begin to react with the fiber before the fabric enters the baking zone, resulting in uneven migration and distribution of the crosslinking agent on the fiber surface. This leads to differences in the degree of crosslinking on the fabric surface and uneven hand feel. Partially unblocked crosslinking agent may adhere to the surface of the guide rollers, forming a resin skin after long-term operation, causing roller sticking and fabric surface contamination problems. The rapid transition section can be achieved by adjusting the guide distance between ovens, adding an infrared preheating device, or using a zoned temperature-controlled oven. This ensures that the crosslinking reaction mainly takes place in the baking zone, thereby guaranteeing the uniformity of crosslinking fixation and process stability.

[0078] In one implementation method, in step S3, the functional microcapsules achieve firm fixation on the fiber surface through the combined action of covalent bonding and physical anchoring of the crosslinking agent with the fiber; the covalent bonding is that the crosslinking agent molecules form chemical bonds with the active groups on the fiber and the microcapsule wall material respectively, and the physical anchoring is that the microcapsule particles are embedded in the pores and grooves on the fiber surface and inside the yarn and are locked by the fixation effect of the crosslinking agent;

[0079] Functional microcapsules achieve the slow release of functional core materials through triboelectric release, thermal release, or diffusion release mechanisms.

[0080] The realization of covalent bonding depends on the chemical bonding reaction between the active functional groups in the crosslinking agent molecule and the reactive groups on the fiber and microcapsule wall material under baking conditions. The blocked isocyanate crosslinking agent is deblocked and releases isocyanate groups at a baking temperature of 140-170℃. These groups undergo nucleophilic addition reaction with the hydroxyl groups on the cellulose fiber to form urethane bonds. At the same time, they also undergo the same addition reaction with the amino groups remaining in the polyurea wall material molecular chain or the hydroxyl groups on the surface of the melamine resin wall material. The crosslinking agent acts as a molecular bridge to connect the fiber and microcapsule together at the chemical level. The epoxy resin crosslinking agent, on the other hand, achieves covalent bridging at the chemical level by undergoing ring-opening addition reaction with the hydroxyl and amino groups on the fiber and wall material through epoxy groups under baking conditions to form ether bonds or amine bonds. Physical anchoring is achieved based on the geometric matching effect between the particle size of the microcapsules and the microstructure of the fiber surface. Microcapsule particles of 0.5-20μm are carried into the fabric by the working fluid during the impregnation process. Some of the microcapsules can be embedded in the tiny pores and grooves between fibers or between fibrils on the fiber surface. After baking, the fixation effect of the crosslinking agent locks the microcapsules in these physical spaces, forming a mechanical interlocking similar to an anchor bolt. Functional microcapsules achieve slow release of the core material through frictional release, thermal release, or diffusion release. The principle of frictional release is that when the microcapsule is subjected to external friction during fabric wear, local stress concentration occurs in the wall material, generating microcracks, from which the core material slowly seeps out. The principle of thermal release is that when the wall material is heated by body temperature or ambient temperature, the movement of polymer chain segments intensifies, the wall material changes from a glassy state to a highly elastic state, the free volume in the cross-linked network increases, and the diffusion and penetration rate of the core material molecules is significantly improved. The principle of diffusion release is that the core material molecules, driven by the concentration gradient, diffuse through the free volume gaps between the polymer chains of the wall material, achieving a continuous and stable output of the core material from the inside of the microcapsule to the external environment.

[0081] This invention discloses a lyocell woven fabric prepared by any of the above methods, comprising:

[0082] Functional microcapsules are fixed to the surface of the fabric and are anchored to the fiber surface by a cross-linking agent.

[0083] After 50 standard washes, the retention rate of functional core material is ≥60%, the fibrillation level of the fabric surface is ≥4, and the tear strength, rubbing fastness, washing fastness and anti-pilling level all meet the performance standards of woven fabrics.

[0084] The lyocell woven fabric obtained by this invention has functional microcapsules fixed to its surface, and these microcapsules are anchored to the fiber surface by a crosslinking agent. The formation of this microstructure is based on the synergistic effect of the aforementioned steps S2 to S3. The anchoring of the functional microcapsules to the fiber surface by the crosslinking agent involves a dual mechanism of chemical bonding and physical anchoring: In terms of chemical bonding, the active functional groups of the blocked isocyanate crosslinking agent or epoxy resin crosslinking agent undergo covalent bonding reactions with the hydroxyl groups on the cellulose fibers and the active hydrogen groups on the surface of the microcapsule polyurea wall material or melamine resin wall material at a baking temperature of 140-170℃, respectively. The crosslinking agent acts as a molecular bridge, connecting the microcapsules and fibers together at the chemical level. In terms of physical anchoring, the microcapsules with an average particle size of 0.5-20μm are carried into the yarn interior and the tiny pores and grooves between the fibers by the working fluid during padding. After baking and fixation, they are locked in these micro-spaces by the crosslinking network, forming a mechanical interlocking. The fabric's washability, with a functional core material retention rate of ≥60% after 50 standard washes, stems from the strong anchoring of the crosslinking agent and the structural stability of the polyurea or high-crosslinking-density melamine resin wall material itself. The covalent bonds formed between the crosslinking agent and the microcapsules have a higher energy than physical adsorption forces, resisting the peeling of external microcapsules by water penetration and mechanical rubbing during washing. Simultaneously, the alkali-resistant wall material maintains the integrity of its structure during the dyeing and crosslinking process, providing a robust encapsulation barrier for the slow release of the core material during subsequent use. The fabric's surface fibrillation level of ≥4 is achieved through the three-dimensional crosslinking network constructed within the fiber by multifunctional triazine compounds or epoxy-containing crosslinking agents in step S2. This network enhances the lateral bonding force between microfibrils through covalent bonds, making the surface fibrils less prone to peeling and pilling under wet conditions and mechanical action. The tear strength, rubbing fastness, washing fastness, and anti-pilling grade all meet the performance standards for woven fabrics. This is achieved through the design and coordination of mild conditions in each process of the integrated processing method. The mild conditions of the alkaline pile treatment in S1 avoid excessive fiber swelling and damage. The heating rate of 0.5-1.0℃ / min and the cooling rate of 0.8-2.0℃ / min in S2 avoid thermal shock and structural deterioration of the fibers. The segmented heat treatment of pre-drying and baking in S3 ensures that cross-linking and fixation are fully carried out without causing thermal degradation of the fibers. The flat-width mechanical beating softening finish in S4 further improves the hand feel and surface quality of the fabric.

[0085] The performance tests of the fabrics obtained in all embodiments and comparative examples of this invention were conducted using the following standard methods:

[0086] (1) Functional core material retention rate: 50 standard washes were performed according to ISO 6330:2021 "Textiles - Washing Test Procedures". After washing, the residual amount of functional core material in the fabric was determined by ultraviolet spectrophotometry. The core material retention rate was calculated by formula R=(C1 / C0)×100%, where C0 is the initial content of core material in the finished fabric and C1 is the residual content of core material in the fabric after 50 washes.

[0087] (2) Fabric surface fibrillation grade: After washing the fabric according to the 4N procedure in GB / T 8629-2017 "Textiles - Testing - Household Washing and Drying Procedures", the fabric was rated from 1 to 5 using a gray scale card, referring to the evaluation method of pilling grade in GB / T 4802.1-2008 "Textiles - Determination of Pilling Properties - Part 1: Circular Trajectory Method". The higher the grade, the lower the fibrillation degree and the better the surface smoothness. The specific method is as follows: After the washed fabric is conditioned under standard atmospheric conditions, three or more professional rating personnel independently rate it under standard light source, comparing it with the gray scale card, and the average value is taken.

[0088] (3) Tear strength: Tested in accordance with GB / T3917.3-2025 Textiles - Tear properties of fabrics - Part 3: Determination of tear strength of trapezoidal specimens.

[0089] (4) Color fastness to rubbing: Tested in accordance with GB / T3920-2008 "Textiles - Color Fastness Tests - Color Fastness to Rubbing".

[0090] (5) Color fastness to washing: Tested in accordance with GB / T3921-2008 "Textiles - Tests for color fastness to washing".

[0091] (6) Anti-pilling grade: Tested in accordance with GB / T4802.1-2008 "Textiles - Determination of pilling properties - Part 1: Circular trajectory method".

[0092] (7) Dimensional change rate after washing: The test was conducted in accordance with GB / T8630-2013 "Determination of dimensional change of textiles after washing and drying". The washing method was in accordance with GB / T8629-2017 procedure 4N, three washes and three drys.

[0093] (8) Sunlight fastness: Refer to AATCC™ 16-2003 standard.

[0094] Example 1

[0095] This embodiment provides an integrated processing method for lyocell woven fabrics, and the specific steps are as follows.

[0096] S1: Pre-treatment process. Select a 2 / 1 twill 100% Lyocell woven fabric with a 30s tight weave × 30s tight weave and a warp and weft density of 120 × 76 threads / inch. First, perform a singeing treatment using a gas singeing machine, singeing both sides of the fabric once each at a speed of 100 m / min. Then, perform an alkali pile treatment. Prepare an alkali solution with a concentration of 20 g / L, immerse the singed fabric in the alkali solution, and pad it with a padding rate of 85%. Afterward, pile it at 30°C for 8 hours. After piling, perform a flat washing treatment, sequentially washing with hot water (80°C), warm water (50°C), and cold water to remove sizing and impurities from the fabric surface, obtaining the pre-treated fabric.

[0097] S2: Dyeing and Crosslinking Process. The pretreated fabric obtained in step S1 is placed in a high-temperature, high-pressure overflow dyeing machine, and water is added at a bath ratio of 1:20. Dyeing auxiliaries (leveling and dispersing agent DM-3202) 2 g / L and anti-fibrillation crosslinking agent (multifunctional triazine compound DM-2488D, 4% of the fabric weight) are added, and the machine is run for 10 minutes to ensure uniform dispersion of the auxiliaries. Reactive dyes are added, and the machine is run for 10 minutes. Then, sodium sulfate (Glauber's salt) is added in three portions, 10 minutes apart, for a total of 40 g / L. The dye bath is heated to 60°C at a rate of 0.8°C / min. During the heating process, sodium carbonate (soda ash) is added in four portions, 12 minutes apart, for a total of 20 g / L. After reaching 60°C, the machine is kept at this temperature for 60 minutes to allow the reactive dyes to undergo a color-fixing reaction with the fibers under alkaline conditions, and simultaneously, to allow the anti-fibrillation crosslinking agent to undergo a crosslinking reaction with the fibers under alkaline conditions. After the heat preservation is completed, the liquid is cooled and drained at a rate of 1.5℃ / min. Then, the fabric is washed in sequence with cold water (room temperature, 5 min), soap (95℃, 2g / L soaping agent, 10 min), hot water (80℃, 5 min), and warm water (50℃, 5 min). Finally, the pH of the fabric is adjusted to 6.5 with acetic acid to obtain the dyed cross-linked fabric.

[0098] S3: Functional Finishing Process. Preparation of the functional microcapsule working solution: Weigh 100 g / L of functional microcapsules (long-lasting aromatic microcapsules, wall material is polyurea, average particle size 5 μm, span ≤ 1.5), 35 g / L of blocked isocyanate crosslinking agent, 2 g / L of penetrant, and 30 g / L of softener according to the mass-volume ratio. Adjust the pH of the working solution to 5.5 with acetic acid. Dip and pad the dyed crosslinked fabric obtained in step S2 into the above working solution for a single dip-and-puff finishing process, with a pad-off rate of 72%. Pre-dry the padded fabric at 95°C for 3 min, then bake at 155°C for 45 s to fix the functional microcapsules onto the fabric fiber surface through the crosslinking agent.

[0099] S4: Post-processing. The fabric obtained in step S3 is subjected to flat-width mechanical beating for softening at a frequency of 300 times / min for 5 minutes, while a softener is applied. Then, it is set at 150℃ for 60 seconds on a setting machine to obtain the finished fabric.

[0100] Example 2

[0101] The only difference between this embodiment and Embodiment 1 is that the fabric is a 1 / 1 plain weave 100% Lyocell woven fabric with a 60s tight weave × 60s tight weave and a warp and weft density of 126 × 77 threads / inch; the liquor ratio is 1:28; the remaining steps and parameters are the same as in Embodiment 1.

[0102] Example 3

[0103] The only difference between this embodiment and Example 1 is that: the amount of antifibrillation crosslinking agent (multifunctional triazine compound) is 8% of the fabric weight; the heat preservation temperature is set at 65℃ and the heat preservation operation time is 30 minutes; the amount of dyeing accelerator sodium sulfate is 60 g / L, added in 5 portions with an interval of 5 minutes between each addition; the amount of sodium carbonate is 30 g / L, added in 5 portions with an interval of 10 minutes between each addition; the heating rate is 1.0℃ / min; the liquor ratio is 1:20; and the cooling and draining rate is 2.0℃ / min.

[0104] Example 4

[0105] The only difference between this embodiment and Embodiment 1 is that in step S2, the antifibrillation crosslinking agent is a crosslinking agent containing epoxy groups, and its dosage is 2% of the fabric weight; the heat preservation temperature is set to 50℃, and the heat preservation operation time is 80 minutes; the dosage of the dyeing accelerator sodium sulfate is 20g / L, added in two portions with an interval of 15min each time; the dosage of sodium carbonate is 10g / L, added in three portions with an interval of 15min each time; the heating rate is 0.5℃ / min; the liquor ratio is 1:10; and the cooling and draining rate is 0.8℃ / min.

[0106] Example 5

[0107] The only difference between this embodiment and Embodiment 1 is that in step S3, the functional microcapsules are antibacterial microcapsules, the wall material is high cross-linking density melamine resin, and the average particle size is 0.5 μm; the working solution of the functional microcapsules contains a microcapsule concentration of 50 g / L, an epoxy resin cross-linking agent with a concentration of 20 g / L, a penetrant of 1 g / L, a softener of 20 g / L, and a working solution pH of 4.5; the roll-off rate is 65%; the pre-drying temperature is 80℃ and the pre-drying time is 5 min; the baking temperature is 140℃ and the baking time is 60 s.

[0108] Example 6

[0109] The only difference between this embodiment and Embodiment 1 is that in step S3, the functional microcapsules are a mixture of cooling microcapsules and warming microcapsules (mass ratio 1:1), the wall material is polyurea, and the average particle size is 20 μm; the working solution of the functional microcapsules contains a microcapsule concentration of 150 g / L, a blocked isocyanate crosslinking agent with a concentration of 50 g / L, a penetrant of 3 g / L, a softener of 40 g / L, and a working solution pH of 6.5; the roll-off rate is 80%; the pre-drying temperature is 110°C and the pre-drying time is 2 min; the baking temperature is 170°C and the baking time is 30 s.

[0110] Comparative Example 1

[0111] This comparative example uses conventional reactive dyeing processes in existing technologies, without any anti-fibrillation crosslinking treatment. Lyocell woven fabric, after S1 pretreatment, is directly dyed in an overflow dyeing machine using conventional reactive dyeing processes (without anti-fibrillation crosslinking agents). After dyeing, it is washed with water and soaped to remove excess color, and then set and softened to obtain the finished fabric. No functional microcapsule finishing is performed.

[0112] Comparative Example 2

[0113] This comparative example employs a step-by-step process in existing technologies, involving first roll dyeing to lock in the fibers, followed by vat dyeing. After S1 pretreatment, the lyocell woven fabric undergoes a fiber-locking treatment on a roll dyeing machine: an anti-fibrillation crosslinking agent (a multifunctional triazine compound, DM-2488D, at 4% of the fabric weight), 40 g / L sodium sulfate, and 20 g / L soda ash are added, and the fiber-locking crosslinking reaction is completed according to the roll dyeing fiber-locking process curve. After fiber-locking, the fabric is then placed in an overflow dyeing machine and dyed using conventional reactive dyes (without the anti-fibrillation crosslinking agent). After dyeing, the fabric is washed with water and soap to remove excess color, and then set and softened to obtain the finished fabric. No functional microcapsule finishing is performed.

[0114] Comparative Example 3

[0115] This comparative example uses the most conventional process route in the existing technology: after S1 pretreatment, the lyocell woven fabric is dyed using conventional reactive dyeing process (without adding anti-fibrillation crosslinking agent). After dyeing, it is washed with water and soaped to remove excess color. Then, it is impregnated with functional microcapsule working solution (without crosslinking agent, the microcapsule wall material is ordinary melamine resin, which is not alkali resistant) on conventional padding equipment. After pre-drying and baking, the functional finishing is completed, and then the finished fabric is obtained through post-treatment.

[0116] Comparative Example 4

[0117] This comparative example employs a step-by-step process of dyeing and crosslinking in the same bath and conventional functional finishing, as described in existing technologies. After pretreatment (S1), the Lyocell woven fabric undergoes dyeing and crosslinking treatment in the same bath as described in step S2 of Example 1 (4% crosslinking agent, 60°C, 60 min holding time) to obtain a dyed and crosslinked fabric. Then, it is impregnated with a functional microcapsule working solution (containing no crosslinking agent, and the microcapsule wall material is ordinary melamine resin) on a conventional padding machine. After pre-drying and baking, the functional finishing is completed, followed by post-treatment to obtain the finished fabric.

[0118] Comparative Example 5

[0119] The only difference between this comparative example and Example 1 is that the functional finishing process in step S3 is moved before the dyeing and crosslinking process in step S2. That is, after the Lyocell woven fabric undergoes pretreatment in S1, it first undergoes padding, pre-drying, and baking finishing of the functional microcapsules (process parameters are the same as in step S3 of Example 1), then the dyeing and crosslinking process (process parameters are the same as in step S2 of Example 1), and finally, the finished fabric is obtained through post-treatment. This comparative example is used to verify the contribution of the process sequence of dyeing and crosslinking followed by microcapsule finishing in this invention to the adhesion strength of the microcapsules.

[0120] Comparative Example 6

[0121] This comparative example employs a step-by-step process in existing technology, consisting of first roll dyeing to lock in fibers, then vat dyeing, and finally functional finishing. After S1 pretreatment, the lyocell woven fabric undergoes a fiber-locking treatment on a roll dyeing machine (DM-2488D 4%, sodium sulfate 40g / L, soda ash 20g / L). Following fiber locking, the fabric is placed in an overflow dyeing machine and dyed using conventional reactive dyes. After dyeing, it is impregnated with a functional microcapsule working solution (containing no crosslinking agent, and the microcapsule wall material is ordinary melamine resin) on a conventional padding machine. Functional finishing is completed through pre-drying and baking, followed by post-treatment to obtain the finished fabric.

[0122] The performance test results of each embodiment and comparative example are shown in Table 1 below.

[0123]

[0124] Table 1

[0125] Note: The fibrillation level is based on a rating standard of 1-5. The higher the level, the lower the degree of fibrillation and the better the surface finish. "—" indicates that no microencapsulation treatment was performed and no core material retention rate data is available.

[0126] The test results above show that:

[0127] (1) Regarding the retention rate of functional core material, the retention rate of core material in Examples 1-6 of the present invention after 50 standard water washes all reached over 60% (62%-72%), which is significantly better than that in Comparative Example 3 (22%), Comparative Example 4 (38%), Comparative Example 5 (41%) and Comparative Example 6 (35%). This indicates that the technical solution of the present invention, which uses a crosslinking agent to firmly anchor the microcapsules to the fiber surface, effectively improves the wash resistance of the microcapsules.

[0128] (2) Regarding the fibrillation level, the fibrillation levels of Examples 1-6 of the present invention all reach level 4.0 or above, which is comparable to Comparative Examples 2 and 4, and significantly better than Comparative Examples 1 and 3 (level 1.5) without any crosslinking treatment. When the fibrillation index is less than 6, the fabric surface is as smooth as new, and no significant difference from before washing can be seen with the naked eye. This indicates that the dyeing and crosslinking process in step S2 of the present invention effectively achieves the anti-fibrillation effect, and constructs an internal crosslinking network of the fiber while completing the dyeing process.

[0129] (3) Regarding tear strength, the tear strength of Examples 1-6 of the present invention is ≥200N, which is basically equivalent to that of the comparative examples, indicating that the integrated processing method of the present invention does not cause additional damage to the fiber strength. The strength damage caused by crosslinking in the same bath is much smaller than that caused by post-treatment crosslinking.

[0130] (4) The core material retention rate of Comparative Example 5 (microcapsule treatment followed by dyeing and crosslinking) was only 41%, far lower than the 68% of Example 1. This is because the microcapsules underwent an alkaline high-temperature environment (pH 9-11, 60°C) during the subsequent dyeing and crosslinking process, under which ordinary wall materials ruptured, resulting in premature release and loss of the core material. In contrast, this invention arranges microcapsule treatment after the dyeing and crosslinking process, so the microcapsules do not need to undergo the preceding alkaline high-temperature environment. Combined with the selection of alkali-resistant wall materials, this ensures the integrity and adhesion of the microcapsules.

[0131] (5) Of particular note is that the core material retention rate of Example 1 (68%) was significantly higher than that of Comparative Example 4 (38%). Although Comparative Example 4 also employed dyeing-crosslinking and microcapsule finishing, the two were carried out independently, and no crosslinking agent was used for anchoring during microcapsule finishing. In this invention, the crosslinking network constructed inside the fiber during the dyeing-crosslinking process provides a more stable fiber substrate for the subsequent fixation of microcapsules, which is conducive to the uniform distribution and firm bonding of the crosslinking agent on the fiber surface, thereby further improving the wash fastness of the microcapsules. This fully demonstrates the synergistic effect of the integrated dyeing-crosslinking process and the functional microcapsule finishing process of this invention.

[0132] (6) The fibrillation grade of Comparative Example 2 (first roll dyeing and then vat dyeing) is 4.0, which is comparable to Example 1. However, this process requires two steps, resulting in a longer process flow and higher energy consumption. In contrast, the present invention completes the fiber locking and dyeing in the same bath, which greatly simplifies the process flow.

[0133] The above results show that the performance indicators of the fabrics obtained in each embodiment of the present invention meet or exceed those of the comparative example, with the functional core material retention rate showing a significant advantage, which fully demonstrates the advanced nature and practicality of the technical solution of the present invention.

[0134] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. An integrated processing method for lyocell woven fabric, characterized in that, Includes the following steps: S1: Pre-treatment process: The Lyocell woven fabric is singed, alkali piled and flat washed to remove the sizing and impurities on the surface of the fabric and obtain the pre-treated fabric. S2: Dyeing and crosslinking process: The pretreated fabric obtained in step S1 is placed into the dyeing equipment, water is added, along with dyeing auxiliaries and anti-fibrillation crosslinking agents. The dyeing equipment is started to ensure that the auxiliaries are evenly dispersed, then reactive dyes are added, followed by dyeing accelerators. Then, the dyeing bath is added in portions in the form of an alkaline solution, and the dye bath is heated to the set holding temperature. The dyeing bath is kept at the set holding temperature to allow the reactive dyes to undergo a color-fixing reaction with the fibers under alkaline conditions. At the same time, the anti-fibrillation crosslinking agent undergoes a crosslinking reaction with the fibers under alkaline conditions to inhibit fiber fibrillation. After the holding period, the temperature is lowered and the liquid is drained to obtain the dyed and crosslinked fabric. S3: Functional finishing process: The dyed cross-linked fabric obtained in step S2 is sequentially impregnated with functional microcapsule working solution, pre-dried and baked, so that the functional microcapsules are fixed to the surface of the fabric fibers by cross-linking agent; the wall material of the functional microcapsules is an alkali-resistant polymer material; S4: Post-processing: The fabric obtained in step S3 is subjected to flat-width mechanical beating and softening treatment and softener is applied. Then, it is subjected to setting treatment to obtain the finished fabric.

2. The integrated processing method for Lyocell woven fabric according to claim 1, characterized in that: In step S1, the alkaline solution used for alkaline pile treatment is caustic soda solution with a concentration of 10-30 g / L, a pile temperature of 20-40℃, and a pile time of 4-12 hours.

3. The integrated processing method for Lyocell woven fabric according to claim 1, characterized in that: In step S2, the antifibrillation crosslinking agent is a multifunctional triazine compound or a crosslinking agent containing epoxy groups; The amount of antifibrillating crosslinking agent used is 2%-8% of the fabric weight; Set the insulation temperature to 50-65℃ and the insulation operation time to 30-80 minutes.

4. The integrated processing method for Lyocell woven fabric according to claim 1, characterized in that: In step S2, the dyeing auxiliary is a leveling and dispersing agent, and its dosage is 0.5-5 g / L; The dyeing accelerator is sodium sulfate, and the dosage is 20-60 g / L, added in 2-5 portions, with an interval of 5-15 minutes between each addition; The alkali is sodium carbonate, and the dosage is 10-30 g / L, added in 3-5 portions, with an interval of 10-15 minutes between each addition; The heating rate is 0.5-1.0℃ / min; the bath ratio is 1:10-1:50; The cooling rate of the liquid being cooled and drained is 0.8-2.0℃ / min.

5. The integrated processing method for Lyocell woven fabric according to claim 1, characterized in that: In step S3, the wall material of the functional microcapsules is treated in an alkaline aqueous solution at pH 9-11 and 50-65℃ for 60 min. The wall material rupture rate does not exceed 10%. The rupture rate is calculated by converting the core material content in the leachate by ultraviolet spectrophotometry.

6. The integrated processing method for Lyocell woven fabric according to claim 1, characterized in that: In step S3, the functional microcapsules are one or more of the following: long-acting aromatic microcapsules with sustained-release function, antibacterial microcapsules, mosquito repellent microcapsules, cooling microcapsules, or warming microcapsules. The wall material of the functional microcapsules is polyurea or high cross-linked density melamine resin; The functional microcapsules have an average particle size of 0.5-20 μm and a particle size distribution span of ≤1.

5.

7. The integrated processing method for Lyocell woven fabric according to claim 1, characterized in that: In step S3, the functional microcapsule working solution comprises, by mass-volume ratio: 50-150 g / L of functional microcapsules, 20-50 g / L of crosslinking agent, 1-3 g / L of penetrant, and 20-40 g / L of softener, and the pH of the working solution is adjusted to 4.5-6.

5. The rolling allowance is 65%-80%.

8. The integrated processing method for Lyocell woven fabric according to claim 1, characterized in that: In step S3, the crosslinking agent is a blocked isocyanate crosslinking agent or an epoxy resin crosslinking agent; The pre-drying temperature is 80-110℃ and the pre-drying time is 2-5 minutes; the baking temperature is 140-170℃ and the baking time is 30-60 seconds.

9. The integrated processing method for Lyocell woven fabric according to claim 1, characterized in that: In step S3, the functional microcapsules achieve firm fixation on the fiber surface through the combined action of covalent bonding and physical anchoring of the crosslinking agent with the fiber. The covalent bonding is that the crosslinking agent molecules form chemical bonds with the active groups on the fiber and the microcapsule wall material respectively, and the physical anchoring is that the microcapsule particles are embedded in the pores and grooves on the fiber surface and inside the yarn and are locked by the fixation effect of the crosslinking agent. Functional microcapsules achieve the slow release of functional core materials through triboelectric release, thermal release, or diffusion release mechanisms.

10. A lyocell woven fabric, characterized in that, Prepared by the method according to any one of claims 1 to 9, comprising: Functional microcapsules are fixed to the surface of the fabric and are anchored to the fiber surface by a cross-linking agent. After 50 standard washes, the retention rate of functional core material is ≥60%, and the fibrillation level of the fabric surface is ≥4. Furthermore, the fabric's tear strength, rubbing fastness, washing fastness, and anti-pilling grade are ≥200N, ≥4, ≥4, and ≥4, respectively.

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