Method and apparatus for anti-fibrillation finishing of lyocell yarn

Abstract

The application discloses a method for preventing fibrillation of lyocell yarn, comprising the following steps: (1) preparing finishing liquid; (2) continuous immersion: continuously immersing single yarn in the finishing liquid to make the yarn uniformly absorb the finishing liquid; (3) controlling liquid rate: treating the yarn uniformly immersed in the finishing liquid through a flexible water absorption component under tension; (4) contact drying: winding the yarn on the surface of a rotating drying heating component, and continuously and uniformly drying the yarn while the yarn is output; (5) contact baking: winding the single yarn on the surface of a rotating baking heating component, and continuously and uniformly baking and cross-linking the yarn while the yarn is output; and (6) winding: obtaining the lyocell yarn with the function of preventing fibrillation. The method effectively reduces the fibrillation tendency in the production and use of the yarn, efficiently utilizes the cross-linking agent material, and has the advantages of ultra-low preparation cost and high fiber cross-linking quality effect.

Description

Technical Field

[0001] This invention relates to the field of functional finishing technology for textiles, and in particular to a method and apparatus for preventing fibrillation of lyocell yarn. Background Technology

[0002] Lyocell is a regenerated cellulose spun from NMNO solution using a dry-jet wet-spinning process. The fiber production process is environmentally friendly and pollution-free, and the solvent NMNO can be recycled with a recovery rate of up to 99.5%. In addition to its eco-friendly properties, lyocell fiber also possesses excellent water absorption, high strength, a silky luster, and a soft hand feel. Based on these properties, it can be widely used in various processed products such as clothing, sewing thread, filter materials, coated fabrics, and non-woven fabrics, providing users with a comfortable and soft feel. Because lyocell fiber has a wide range of sources, is naturally renewable, has a clean and pollution-free processing technology, and is biodegradable after use, it is considered one of the most representative new green fibers of the 21st century.

[0003] However, lyocell also has a serious drawback: fibrillation. Fibrillation refers to the phenomenon where, under wet conditions and external force, fine fibrils appear on the surface of lyocell fibers. These fibrils become entangled and knotted, and under intense external force, pilling and fuzzing occur on the fabric surface. This phenomenon is known as fibrillation in lyocell fibers. On the one hand, fibrillation in lyocell fibers can be used to achieve specific finishing effects, such as a peach-skin finish, a silky feel, and soft denim. However, it primarily causes adverse effects on fabrics, such as making dyed fabrics look old, causing blemishes and white spots, and shortening the fabric's lifespan.

[0004] Currently, reducing the fibrillation tendency of Lyocell fibers is mainly achieved through antifibrillating crosslinking agents. Lyocell skeins are typically processed using traditional impregnation methods, which struggle to achieve uniform antifibrillation properties, especially during the baking stage, where it's difficult to ensure the yarn reaches the baking temperature evenly for crosslinking. Furthermore, the high liquor ratio used for impregnation leads to high energy and water consumption, low chemical utilization, and low production efficiency. The processing of Lyocell cone yarn involves winding the yarn onto perforated tubes, then immersing these tubes in an aqueous solution containing chemicals. During this process, the chemicals in the solution interact with the textile fibers, causing chemical molecules to react with the fiber macromolecules to achieve the desired properties.

[0005] The main solution to the fibrillation problem of lyocell fibers is cross-linking treatment, which includes the following technologies:

[0006] CN104005225A discloses a method for reducing the fibrillation tendency of lyocell cellulose fibers, comprising the following steps: (1) immersing lyocell fibers in a solution containing a crosslinking agent, a catalyst, and a penetrant; (2) pretreating the fibers at 75-85°C for 90-150 seconds after rolling them dry, and then baking them at 125-135°C for 90-150 seconds to solidify and crosslink the fibers; (3) washing the baked fibers 3-7 times with soft water at 50°C, followed by washing them 1-3 times with cold soft water; (4) finally drying the fibers at 80°C to obtain antigen-fibrillated lyocell cellulose fibers. The crosslinking agent provided by this invention is readily available, and by treating lyocell cellulose fibers using a specific method, lyocell fibers with antigen-fibrillation properties are obtained.

[0007] CN 111893749A provides an antigen-fibrillated treatment method for lyocell fibers. The method involves immersing the lyocell fibers in a crosslinking solution and performing a two-dip, two-roll process to obtain antigen-fibrillated lyocell fibers. The crosslinking solution includes a crosslinking agent and a latent acid catalyst. The crosslinking agent is a mixture of two or more C2-C6 dialdehyde compounds. The crosslinking agent used in this treatment method has a simple synthesis process, is inexpensive, requires minimal equipment, and exhibits high crosslinking efficiency.

[0008] CN 117090052A discloses a method for preparing antigen-fibrillated lyocell fiber. The method includes: S1) adding fiber at room temperature with a bath ratio of 1:4-10, and preparing an aqueous crosslinking agent solution with 2-5 g / L of antigen-fibrillating composition and 30-50 g / L of sodium sulfate; S2) heating to 60-80℃ and holding for 20 min, adding 15-30 g / L of soda ash, running for 10 min, adjusting the pH to 11-12 with a 30% sodium hydroxide solution, and continuing to run for 30 min; S3) removing from the tank, washing with water, neutralizing, washing with water, and drying. The antigen-fibrillating composition includes a crosslinking agent, a dispersant, and a buffer, with the following weight percentages: crosslinking agent: 60-90, dispersant: 30-50, buffer: 1-5. The solid antigen-fibrillating composition is obtained by spray drying after mixing the above components. This invention uses a mixture of multi-active crosslinking agents as the main body. Its structure has good stability under neutral conditions. One active group is hydrolyzed, while the other active group still reacts with the fiber, resulting in high reactivity. Furthermore, the two active groups with different acid and alkali resistances ensure good stability of the fiber-crosslinking agent bond after crosslinking.

[0009] As can be seen from the aforementioned patented technologies, the current basic process approach for addressing fibrillation in lyocell fabrics is "pad-drying-baking" or "impregnation + steaming." While this achieves the basic goal of preventing fibrillation, several problems remain. The aforementioned processing methods exhibit drawbacks similar to those of skein yarn processing, namely uneven treatment and significant temperature differences between the inside and outside of the yarn package during drying and baking. Both of these yarn processing techniques make it difficult for crosslinking chemicals to be fully utilized in lyocell yarns, thus hindering effective crosslinking between fibrils and affecting the antifibrillation effect. The antifibrillation effect falls far short of the requirements for textiles, becoming a factor affecting the antifibrillation effect. Padding in a rolling mill is not suitable for large-scale yarn production and finishing in factories. Furthermore, traditional impregnation methods consume a large amount of water, wasting a significant portion of the auxiliaries in the solution, resulting in low utilization of crosslinking auxiliaries and difficulty in impregnating the yarn with a sufficient concentration of crosslinking auxiliaries. This is another factor affecting the antifibrillation effect. How to make it suitable for mass production in factories, shorten the process flow, reduce costs, effectively improve the utilization rate of auxiliaries, significantly improve the crosslinking quality, and effectively reduce the tendency of yarn fibrillation during production and use has become a problem that textile dyeing and finishing technicians urgently need to solve. Summary of the Invention

[0010] To address the shortcomings of existing technologies, the technical problem to be solved by this invention is to provide a method and apparatus for preventing fibrillation of lyocell yarns that is suitable for mass production in factories, has a short process flow, low cost, effectively improves the utilization rate of auxiliaries, and significantly improves the quality of crosslinking.

[0011] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a method for preventing fibrillation of lyocell yarn, characterized by comprising the following steps:

[0012] (1) Preparation of finishing solution: Add a certain mass fraction of resin and catalyst respectively, stir evenly, so that the resin and catalyst are fully dissolved in water, and set aside for later use;

[0013] (2) Continuous impregnation: The single yarn is continuously immersed in the finishing solution so that the yarn absorbs the finishing solution evenly.

[0014] (3) Control the liquid retention rate: The yarn with uniform impregnation solution is treated by a flexible water-absorbing component under tension.

[0015] (4) Contact drying: The yarn obtained in step (3) is wound around the surface of the rotating drying heating element, and the yarn is continuously and uniformly dried while the yarn is output.

[0016] (5) Contact baking: The single yarn obtained after drying in step (4) is wound around the surface of the rotating baking heating element. While the yarn is being output, the yarn is continuously and uniformly baked and crosslinked.

[0017] (6) Winding: The baked and cross-linked Lyocell yarn is continuously wound onto the yarn bobbin to obtain Lyocell yarn that is resistant to fibrillation.

[0018] In the above-mentioned method for preventing fibrillation of lyocell yarn, in step (1), the resin is any one or more of the following: etherified modified dihydroxymethyl dihydroxyethylene urea resin, urea-formaldehyde resin, dihydroxymethyl ethylene urea (DMEU) resin, and melamine-formaldehyde resin, and the catalyst is one or more of the following: magnesium chloride, citric acid, and sodium fluoroborate.

[0019] In the above-mentioned antifibrillation finishing method for lyocell yarn, in step (1), the mass fraction of the resin is 60-100 g / L and the mass fraction of the catalyst is 12-30 g / L.

[0020] In the above-mentioned antifibrillation finishing method for lyocell yarn, in step (3), the liquid carrying rate of a single yarn is controlled to be 60%-100% by a flexible water-absorbing component.

[0021] In the above-mentioned antifibrillation finishing method for lyocell yarn, in step (4), the rotation speed of the drying heating element is 200-700 m / min, the drying temperature is 80-160℃, and the drying time is 0.5-6 s.

[0022] In the above-mentioned method for preventing fibrillation of lyocell yarn, in step (5), the rotation speed of the baking heating element is 200-700 m / min, the baking temperature is 160-200℃, and the baking time is 0.5-3 s.

[0023] In the above-mentioned method for preventing fibrillation of Lyocell yarn, in step (3), the flexible water-absorbing component is a sponge; in steps (4) and (5), the drying heating component is a drying roller, and the baking heating component is a baking roller. The yarn is wound sequentially around the surface of the drying roller and the baking roller along the conveying direction, and rotates synchronously with the drying roller and the baking roller respectively.

[0024] An apparatus for implementing an antifibrillation finishing method for lyocell yarn, comprising:

[0025] A working tank for holding the finishing solution;

[0026] A transfer roller for driving the Lyocell yarn to be processed into the working tank and impregnating the Lyocell yarn;

[0027] A flexible absorbent component used to control the liquid content of impregnated Lyocell yarn and drive the yarn output;

[0028] A drying heating element and a baking heating element for contact drying and baking crosslinking treatment of output Lyocell yarn;

[0029] A yarn tube used for winding lyocell yarn after baking and cross-linking treatment.

[0030] The drying heating element and the baking heating element are respectively a drying roller and a baking roller that extend perpendicular to the conveying direction of the Lyocell yarn. The Lyocell yarn is wound around the surface of the drying roller and the baking roller in sequence, forming a conveying area between the drying roller and the baking roller for moving the dried yarn toward the baking roller.

[0031] In the aforementioned device, the flexible absorbent component is a sponge that allows lyocell yarns to pass through.

[0032] In the aforementioned apparatus, the drying roller rotates at a speed of 500 m / min, the baking roller rotates at a speed of 400 m / min, the drying time is 1.13 s, and the baking time is 0.9 s.

[0033] The advantages of the anti-fibrillation finishing method and apparatus for lyocell yarn of the present invention are as follows: The present invention provides a crosslinking method for lyocell fibers based on room temperature impregnation and high temperature baking. This process can not only complete the uniform impregnation of the yarn in the finishing agent and the uniform drying and baking process of the impregnated yarn, thus overcoming the limitation of existing dyeing and printing equipment that can only perform overall finishing of packaged yarn and skein yarn, but also effectively reduce the tendency of fibrillation during yarn production and use, make full use of crosslinking agent materials with high efficiency, and have ultra-low preparation cost, high fiber crosslinking quality effect. Moreover, the process flow is short, there is no wastewater discharge, low cost, simple and easy to operate, and it can be widely applied to the crosslinking preparation of various lyocell yarns. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the structure of the sorting device of the present invention;

[0035] Figure 2 This is a FE-SEM image of the surface of a single fiber in the lyocell yarn obtained in Example 3 of the present invention, magnified 3000 times.

[0036] Figure 3 SEM images showing the surface of fabrics made from untreated yarn and yarn treated in Example 3 after washing, magnified 300 times.

[0037] Figure 4 SEM images showing the surface of fabrics made from untreated yarn and the yarn treated in Example 4, magnified 300 times after washing.

[0038] Figure 5 The images show SEM images of fabrics made from untreated yarn and the yarn treated in Example 5, magnified 300 times after washing. Detailed Implementation

[0039] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0040] In this invention, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in its actual use or operating state, specifically the drawing directions in the accompanying drawings; while "inner" and "outer" refer to the outline of the device. Furthermore, in the description of this application, the term "comprising" means "including but not limited to". The terms first, second, third, etc., are used merely as illustrative purposes and do not impose numerical requirements or establish an order. The term "multiple" means "two or more".

[0041] A method for preventing fibrillation of lyocell yarn includes the following steps:

[0042] (1) Preparation of finishing solution: Add a certain mass fraction of resin and catalyst respectively, stir evenly, so that the resin and catalyst are fully dissolved in water, and set aside for later use;

[0043] (2) Continuous impregnation: The single yarn is continuously immersed in the finishing solution so that the yarn absorbs the finishing solution evenly.

[0044] (3) Control the liquid retention rate: The yarn with uniform impregnation solution is treated by a flexible water-absorbing component under tension.

[0045] (4) Contact drying: The yarn obtained in step (3) is wound around the surface of the rotating drying heating element, and the yarn is continuously and uniformly dried while the yarn is output.

[0046] (5) Contact baking: The single yarn obtained after drying in step (4) is wound around the surface of the rotating baking heating element. While the yarn is being output, the yarn is continuously and uniformly baked and crosslinked.

[0047] (6) Winding: The baked and cross-linked Lyocell yarn is continuously wound onto the yarn bobbin to obtain Lyocell yarn that is resistant to fibrillation.

[0048] The resin used in this invention belongs to the amide-formaldehyde crosslinking agent category; it is etherified modified dimethyloldihydroxyvinyl urea resin (DMDHEU). Other types of amide-formaldehyde crosslinking agents include urea-formaldehyde resin, dimethyloldihydroxyvinyl urea (DMEU) resin, and melamine-formaldehyde resin (TMM, HMM); any one or more can be selected as needed. Etherification modification replaces the hydroxyl groups at the 4 and 5 positions of the 2D resin with ethoxy groups, inhibiting the transposition reaction and correspondingly improving the hydrolytic stability of the crosslinking bonds, effectively reducing the amount of formaldehyde released. The main etherifying agents used are polyethylene glycol, glycerol, methanol, diethylene glycol, ethanol, and mixed alcohols. The catalyst can be one or more of the following: metal salts, such as magnesium chloride; organic acids, such as citric acid; and organic acid salts, such as sodium fluoroborate. The mass fraction of the resin is 60-100 g / L, and the mass fraction of the catalyst is 12-30 g / L. During the impregnation process, the ratio of yarn to treatment solution is 1:3. The flexible absorbent component is a sponge, which controls the liquid retention rate of a single yarn to 60%-100%. The drying heating element rotates at 200-700 m / min, the drying temperature is 80-160℃, and the drying time is 0.5-6 s. The baking heating element rotates at 200-700 m / min, the baking temperature is 160-200℃, and the baking time is 0.5-3 s. The drying heating element is a drying roller, and the baking heating element is a baking roller. The yarn is sequentially wound around the surface of the drying roller and the baking roller along the conveying direction, rotating synchronously with the drying roller and the baking roller, respectively.

[0049] like Figure 1 As shown, an apparatus for implementing an antifibrillation finishing method for lyocell yarn includes a working tank 2 for holding a finishing solution 1 and a transfer roller 4 for driving the lyocell yarn 3 to be treated into the working tank 2 and impregnating the lyocell yarn 3. In order to ensure that the lyocell yarn 3 to be treated can fully contact the finishing solution 1, an impregnation roller 5 is installed in the working tank 2. The lyocell yarn 3 to be treated passes around the impregnation roller 5 to ensure that the lyocell yarn 3 to be treated is in full contact with the finishing solution 1 at the bottom of the impregnation roller 5.

[0050] It also includes a flexible absorbent component for controlling the liquid content of the impregnated Lyocell yarn and driving the yarn output. The flexible absorbent component is a sponge 6 that allows the Lyocell yarn to pass through. At the output end of the sponge 6, there is a drying heating component and a baking heating component for contact drying and baking crosslinking treatment of the output Lyocell yarn. The drying heating component and the baking heating component are a drying roller 7 and a baking roller 8, respectively, extending perpendicular to the conveying direction of the Lyocell yarn. The Lyocell yarn is wound sequentially around the surface of the drying roller 7 and the baking roller 8, forming a conveying zone 9 between the drying roller 7 and the baking roller 8 for moving the dried yarn toward the baking roller 8. After baking, the Lyocell yarn is led out and a yarn tube 10 is provided for winding the baked crosslinked Lyocell yarn.

[0051] In this invention, the drying roller 7 and baking roller 8 can be heated by traditional heating wires or electric heating tubes. The driving device can be a servo motor, reducer, or other power and transmission device. This technology is prior art and therefore is not shown in the accompanying drawings. To ensure that the lyocell yarn rotates synchronously with the drying roller 7 and baking roller 8 during drying and baking, respectively, thereby improving conveying and crosslinking efficiency, the surfaces of the drying roller 7 and baking roller 8 can be treated by increasing their roughness without damaging the lyocell yarn, for example, by covering them with a high-temperature resistant rubber coating.

[0052] Excessive tension can damage the strength of the yarn, while insufficient tension makes it impossible to accurately control the yarn liquid carry-over rate and affects efficiency. Therefore, the optimal parameters for this invention are: a drying roller 7 speed of 500 m / min, a baking roller 8 speed of 400 m / min, a drying time of 1.13 s, and a baking time of 0.9 s. The drying and baking times can be precisely controlled by adjusting the roller speed and the number of times the yarn wraps around the roller. Of course, the three processes of controlling the liquid carry-over rate (3), contact drying (4), and contact baking (5) can be carried out continuously or separately, depending on the actual production situation of the factory.

[0053] This invention, by adjusting the roller speed and controlling the amount of liquid carried by the sponge, enables the crosslinking agent to be absorbed, diffused, and fixed on the yarn evenly and quickly, without affecting the yarn surface hairs or internal structure. Moreover, the traditional impregnation method consumes a lot of water, and a considerable portion of the auxiliaries is wasted in the solution. Our process, however, uses rollers to drive the yarn to fully contact and absorb the solution, greatly avoiding water consumption and crosslinking agent loss. Almost all crosslinking agents can be absorbed by the yarn, achieving high utilization of the crosslinking agent and reducing production costs.

[0054] Sponge 6 has excellent hygroscopic properties, which can absorb excess solution on the surface of the yarn and replenish the solution for yarns that have not been fully wetted. In addition, the high resilience of sponge 6 means that it will not damage the surface hairs and internal structure of the yarn, and can maintain its good performance for a longer time without deformation or damage. It protects the yarn and allows for optimal control of the amount of crosslinking agent.

[0055] Traditional oven drying utilizes hot air convection to evaporate moisture from the sample surface. The drying speed in this method is greatly affected by the sample thickness and quantity. Since baking temperature and baking time are the two most crucial factors influencing cross-linking effectiveness, in actual production, oven baking inevitably leads to the problem of over-drying the surface yarn of skeins or cone yarns while maintaining high moisture content in the internal yarns. The inner and outer layers of the yarn cannot reach the baking temperature simultaneously, making it difficult to control the baking time. This not only significantly damages the strength of the surface yarn but also fails to guarantee the cross-linking effect within the yarn. However, using roller heating, which utilizes direct heat transfer through contact between the yarn and the roller surface, allows each yarn to absorb heat evenly. The baking temperature and time remain consistent, enabling precise control. The cross-linking effect is highly uniform and stable, completely solving the problem of uneven cross-linking in traditional oven heating.

[0056] The present application will be specifically described below through specific embodiments. The following embodiments are only some embodiments of the present application and are not intended to limit the present application.

[0057] Example 1:

[0058] A method for preventing fibrillation of lyocell yarn includes the following steps:

[0059] (1) Preparation of finishing solution: Add urea-formaldehyde resin with a mass fraction of 100g / L and magnesium chloride with a mass fraction of 30g / L respectively, stir evenly to fully dissolve the resin and catalyst in water, and set aside.

[0060] (2) Continuous impregnation: The single yarn is continuously immersed in the finishing solution so that the yarn absorbs the finishing solution evenly. The ratio of yarn to finishing solution is 1:3.

[0061] (3) Control the liquid carry-over rate: The yarns that are uniformly impregnated with finishing liquid are treated by a flexible water-absorbing component under tension to control the liquid carry-over rate of a single yarn to 60%.

[0062] (4) Contact drying: The yarn obtained in step (3) is wound around the surface of the rotating drying heating element. While the yarn is being output, the yarn is continuously and uniformly dried. The rotation speed of the drying heating element is 200 m / min, the drying temperature is 80℃, and the drying time is 6 s.

[0063] (5) Contact baking: The single yarn obtained after drying in step (4) is wound around the surface of the rotating baking heating element. While the yarn is being output, the yarn is continuously and uniformly baked and crosslinked. The rotation speed of the baking heating element is 200 m / min, the baking temperature is 160℃, and the drying time is 3s.

[0064] (6) Winding: The baked and cross-linked Lyocell yarn is continuously wound onto the yarn bobbin to obtain Lyocell yarn that is resistant to fibrillation.

[0065] Example 2:

[0066] (1) Preparation of finishing solution: Add 60 g / L of dimethylolpropionic acid (DMEU) resin and 12 g / L of citric acid respectively, stir evenly to fully dissolve the resin and catalyst in water, and set aside.

[0067] (2) Continuous impregnation: The single yarn is continuously immersed in the finishing solution so that the yarn absorbs the finishing solution evenly. The ratio of yarn to finishing solution is 1:3.

[0068] (3) Control the liquid carry-over rate: The yarn with uniform impregnation solution is treated by a flexible water-absorbing component under tension to control the liquid carry-over rate of a single yarn to 100%.

[0069] (4) Contact drying: The yarn obtained in step (3) is wound around the surface of the rotating drying heating element. While the yarn is being output, the yarn is continuously and uniformly dried. The rotation speed of the drying heating element is 300 m / min, the drying temperature is 100℃, and the drying time is 3s.

[0070] (5) Contact baking: The single yarn obtained after drying in step (4) is wound around the surface of the rotating baking heating element. While the yarn is being output, the yarn is continuously and uniformly baked and crosslinked. The rotation speed of the baking heating element is 400 m / min, the baking temperature is 170℃, and the drying time is 1 s.

[0071] (6) Winding: The baked and cross-linked Lyocell yarn is continuously wound onto the yarn bobbin to obtain Lyocell yarn that is resistant to fibrillation.

[0072] Example 3:

[0073] A method for preventing fibrillation of lyocell yarn includes the following steps:

[0074] (1) Preparation of finishing solution: Add etherified modified dihydroxymethyl dihydroxyethylene urea resin with a mass fraction of 80 g / L and magnesium chloride with a mass fraction of 24 g / L respectively, stir evenly to fully dissolve the resin and catalyst in water, and set aside for later use.

[0075] (2) Continuous impregnation: The single yarn is continuously immersed in the finishing solution so that the yarn absorbs the finishing solution evenly. The ratio of yarn to finishing solution is 1:3.

[0076] (3) Control the liquid carry-over rate: The yarns that are uniformly impregnated with finishing liquid are treated by a flexible water-absorbing component under tension to control the liquid carry-over rate of a single yarn to 80%.

[0077] (4) Contact drying: The yarn obtained in step (3) is wound around the surface of the rotating drying heating element. While the yarn is being output, the yarn is continuously and uniformly dried. The rotation speed of the drying heating element is 500 m / min, the drying temperature is 160℃, and the drying time is 1.13 s.

[0078] (5) Contact baking: The single yarn obtained after drying in step (4) is wound around the surface of the rotating baking heating element. While the yarn is being output, the yarn is continuously and uniformly baked and crosslinked. The rotation speed of the baking heating element is 400 m / min, the baking temperature is 200℃, and the drying time is 0.9 s.

[0079] (6) Winding: The baked and cross-linked Lyocell yarn is continuously wound onto the yarn bobbin to obtain Lyocell yarn that is resistant to fibrillation.

[0080] Example 4:

[0081] The parts that are the same as those in Example 3 will not be repeated here. The differences are as follows:

[0082] (5) Contact baking: The single yarn obtained after drying is wound around the surface of the rotating baking heating element. While the yarn is being output, the yarn is continuously and uniformly baked and crosslinked. The rotation speed of the baking heating element is 400m / min, the baking temperature is 180℃, and the drying time is 0.9s.

[0083] Example 5:

[0084] The parts that are the same as those in Examples 3 and 4 will not be repeated here. The differences are as follows:

[0085] (5) Contact baking: The single yarn obtained after drying is wound around the surface of the rotating baking heating element. While the yarn is being output, the yarn is continuously and uniformly baked and crosslinked. The rotation speed of the baking heating element is 400 m / min, the baking temperature is 160℃, and the drying time is 0.9 s.

[0086] Example 6:

[0087] A method for preventing fibrillation of lyocell yarn includes the following steps:

[0088] (1) Preparation of finishing solution: Add melamine-formaldehyde resin with a mass fraction of 90 g / L and sodium fluoroborate with a mass fraction of 27 g / L respectively, stir evenly to fully dissolve the resin and catalyst in water, and set aside for later use.

[0089] (2) Continuous impregnation: The single yarn is continuously immersed in the finishing solution so that the yarn absorbs the finishing solution evenly. The ratio of yarn to finishing solution is 1:3.

[0090] (3) Control the liquid carry-over rate: The yarns that are uniformly impregnated with finishing liquid are treated by a flexible water-absorbing component under tension to control the liquid carry-over rate of a single yarn to 80%.

[0091] (4) Contact drying: The yarn obtained in step (3) is wound around the surface of the rotating drying heating element. While the yarn is being output, the yarn is continuously and uniformly dried. The rotation speed of the drying heating element is 300 m / min, the drying temperature is 120℃, and the drying time is 3s.

[0092] (5) Contact baking: The single yarn obtained after drying in step (4) is wound around the surface of the rotating baking heating element. While the yarn is being output, the yarn is continuously and uniformly baked and crosslinked. The rotation speed of the baking heating element is 300 m / min, the baking temperature is 160℃, and the drying time is 3s.

[0093] (6) Winding: The baked and cross-linked Lyocell yarn is continuously wound onto the yarn bobbin to obtain Lyocell yarn that is resistant to fibrillation.

[0094] Example 7:

[0095] A method for preventing fibrillation of lyocell yarn includes the following steps:

[0096] (1) Preparation of finishing solution: Add etherified modified dihydroxymethyl dihydroxyethylene urea resin and urea-formaldehyde resin with a mass fraction of 100 g / L, and citric acid and sodium fluoroborate with a mass fraction of 30 g / L respectively, stir evenly to fully dissolve the resin and catalyst in water, and set aside for later use.

[0097] (2) Continuous impregnation: The single yarn is continuously immersed in the finishing solution so that the yarn absorbs the finishing solution evenly. The ratio of yarn to finishing solution is 1:3.

[0098] (3) Control the liquid carry-over rate: The yarns that are uniformly impregnated with finishing liquid are treated by a flexible water-absorbing component under tension to control the liquid carry-over rate of a single yarn to 70%.

[0099] (4) Contact drying: The yarn obtained in step (3) is wound around the surface of the rotating drying heating element. While the yarn is being output, the yarn is continuously and uniformly dried. The rotation speed of the drying heating element is 700 m / min, the drying temperature is 160℃, and the drying time is 0.5 s.

[0100] (5) Contact baking: The single yarn obtained after drying in step (4) is wound around the surface of the rotating baking heating element. While the yarn is being output, the yarn is continuously and uniformly baked and crosslinked. The rotation speed of the baking heating element is 700 m / min, the baking temperature is 200℃, and the drying time is 0.5 s.

[0101] (6) Winding: The baked and cross-linked Lyocell yarn is continuously wound onto the yarn bobbin to obtain Lyocell yarn that is resistant to fibrillation.

[0102] The performance test results of the Lyocell yarns prepared using the anti-fibrillation finishing method and apparatus in Examples 3-5 of this invention are as follows:

[0103] The crosslinking effect was tested using a washing method:

[0104] This invention conducted nine sets of experiments at three baking temperatures of 160℃, 180℃, and 200℃, with resin and catalyst concentrations of 70 g / L (21 g / L), 80 g / L (24 g / L), and 90 g / L (27 g / L), respectively. The details are as follows:

[0105]

[0106] The final lyocell yarn was prepared into loose bobbins, then woven into sheets, and the fabric was tested for its antifibrillation effect after washing. Following the washing procedure of ISO 6330:2012, MOD 4N, the samples and accompanying items were washed and dried. One sample was kept as a control sample, and the other samples and accompanying items were placed in the washing machine together; the samples and accompanying items were then washed.

[0107] The washing process was repeated five times, and the samples and accompanying fabrics were dried. The fibrillation changes of the fibers were observed under a microscope. The test samples were Lyocell fibers and fabrics obtained at resin and catalyst concentrations of 80 g / L and 24 g / L, and baking temperatures of 200°C, 180°C, and 160°C, respectively, namely Examples 3-5 of this invention.

[0108] like Figure 2 As shown, in the lyocell yarn prepared in Example 3, the fibers constituting the yarn exhibit a smooth surface with no obvious cracks. This indicates that the finishing method of the present invention does not damage the fiber surface, thus ensuring the basic mechanical properties of the fiber.

[0109] like Figure 3-5 As shown, when the auxiliary agent is 80 g / L and baked at 160°C, the fabric woven from the yarn shows localized fibrillation after washing, with a smaller fibrillation range than the untreated fabric, demonstrating an anti-fibrillation effect. When the auxiliary agent is 80 g / L and baked at 180°C, fibrillation begins to form on the surface of the fabric woven from the yarn after washing, with a smaller fibrillation range and shorter fibrillation fibers than the untreated fabric, demonstrating a significant anti-fibrillation effect. When the auxiliary agent is 80 g / L and baked at 200°C, almost no fibrillation occurs on the surface of the fabric woven from the yarn after washing, showing a clear contrast with the untreated fabric, demonstrating a significant anti-fibrillation effect. Therefore, Example 3 of the present invention is the preferred embodiment.

[0110] This technology allows for the adhesion of desired chemicals to individual yarns. Lyocell yarns are continuously treated with a crosslinking agent solution, with the absorption rate controlled at 60%-100% using a sponge. After drying, the yarns are baked at a higher temperature to crosslink the fibrils. Results show that the treated yarns and fabrics exhibit good antifibrillation properties after 5 hours of washing. Compared to traditional processing methods, this process offers advantages such as better air permeability, lower water consumption, and less wastewater discharge. The developed green and sustainable method can be used for finishing various yarns.

[0111] This invention uses etherified modified 2D resin for crosslinking. The 4,5-hydroxyl groups are replaced by ethoxy groups, inhibiting the transposition reaction and correspondingly improving the hydrolytic stability of the crosslinking bonds, effectively reducing the amount of formaldehyde released. This not only endows cellulose with unique properties such as low swelling rate, enhanced wrinkle resistance, and excellent anti-fibrillation effect, but most importantly, the whiteness, breathability, and formaldehyde release of textiles also reach satisfactory levels. The crosslinking agent has a simple synthesis process, is inexpensive, and has a longer shelf life, lasting for one year or even longer, with minimal change in product strength. It exhibits good anti-fibrillation effect, good wash resistance, and formaldehyde release meets standards, greatly reducing harm to human health and the environment. It is suitable for industrial-scale application.

[0112] Of course, the above description is not intended to limit the present invention, and the present invention is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present invention should be protected by the present invention.

Claims

1. A method for preventing fibrillation of lyocell yarn, characterized in that, Includes the following steps: (1) Preparation of finishing solution: Add a certain mass fraction of resin and catalyst respectively, stir evenly, so that the resin and catalyst are fully dissolved in water and set aside. The mass fraction of resin is 60-100g / L and the mass fraction of catalyst is 12-30g / L. (2) Continuous impregnation: The single yarn is continuously immersed in the finishing solution so that the yarn absorbs the finishing solution evenly. (3) Control the liquid retention rate: The yarns uniformly impregnated with finishing solution are treated with flexible absorbent components under tension; the liquid retention rate of a single yarn is controlled to be 60%-100% by the flexible absorbent components; (4) Contact drying: The yarn obtained in step (3) is wound around the surface of a rotating drying roller, and the yarn is continuously and uniformly dried while it is being output. The drying roller speed is 200-700 m / min, the drying temperature is 80-160℃, and the drying time is 0.5-6 s; (5) Contact baking: The single yarn obtained after drying in step (4) is wound around the surface of a rotating baking roller. At the same time as the yarn is output, the yarn is continuously and uniformly baked and crosslinked. The baking roller rotation speed is 200-700m / min, the baking temperature is 160-200℃, and the baking time is 0.5-3s; the yarn is wound sequentially around the surface of the drying roller and the baking roller along the conveying direction, and rotates synchronously with the drying roller and the baking roller respectively; (6) Winding: The baked and cross-linked Lyocell yarn is continuously wound onto the yarn bobbin to obtain Lyocell yarn that is resistant to fibrillation.

2. The method for preventing fibrillation of lyocell yarn according to claim 1, characterized in that: In step (1), the resin is any one or more of the following: etherified dihydroxymethyl dihydroxyethylene urea resin, urea-formaldehyde resin, dihydroxymethyl ethylene urea (DMEU) resin, and melamine-formaldehyde resin, and the catalyst is one or more of the following: magnesium chloride, citric acid, and sodium fluoroborate.

3. The method for preventing fibrillation of lyocell yarn according to claim 1, characterized in that, The apparatus used includes: A working tank for holding the finishing solution; A transfer roller for driving the Lyocell yarn to be processed into the working tank and impregnating the Lyocell yarn; A flexible absorbent component used to control the liquid content of impregnated Lyocell yarn and drive the yarn output; A drying heating element and a baking heating element for contact drying and baking crosslinking treatment of output Lyocell yarn; A yarn tube used for winding lyocell yarn after baking and cross-linking treatment; The drying heating element and the baking heating element are respectively a drying roller and a baking roller that extend perpendicular to the conveying direction of the Lyocell yarn. The Lyocell yarn is wound around the surface of the drying roller and the baking roller in sequence, forming a conveying area between the drying roller and the baking roller for moving the dried yarn toward the baking roller. The drying roller rotates at a speed of 500 m / min, the baking roller rotates at a speed of 400 m / min, the drying time is 1.13 s, and the baking time is 0.9 s.

4. The method for preventing fibrillation of lyocell yarn according to claim 3, characterized in that: The flexible absorbent component is a sponge that allows Lyocell yarn to pass through.

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