Method for preparing low-fibrillated lyocell fiber

Abstract

The present application belongs to the technical field of fiber preparation. Disclosed is a method for preparing a low-fibrillated Lyocell fiber. The method comprises: acquiring Lyocell fiber filaments; cutting up the Lyocell fiber filaments, so as to obtain Lyocell short fibers; subjecting the Lyocell short fibers to laying formation and a fiber web cross-linking treatment, so as to obtain a Lyocell fiber web; and subjecting the Lyocell fiber web to a post-treatment, so as to obtain low-fibrillated Lyocell fibers, wherein the fineness value range of the low-fibrillated Lyocell fibers is 1.2 dtex to 1.6 dtex; the number of times of wear of the low-fibrillated Lyocell fibers is more than or equal to 200 times, and the variation coefficient is less than or equal to 40%; the low-fibrillated Lyocell fibers show an upward trend as the placement time increases, and the maximum value of the number of times of wet wear is 800-1200 times; and the initial pH value range of the low-fibrillated Lyocell fibers is 8-11, and the pH of the low-fibrillated Lyocell fibers is more than or equal to 6 during the quality guarantee period. The Lyocell fiber prepared by means of the method has the advantages of the wet wear value of the cross-linked fiber increasing as the placement time increases, low production energy consumption, a long quality guarantee time, good use performance, etc.

Description

Preparation method of low fibrillation Lyocell fiber

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on July 31, 2023, with application number 202310948984.5 and application name “Method for preparing low-fibrillated Lyocell fibers”, the entire contents of which are incorporated by reference into the application. Technical Field

[0002] The present application relates to the technical field of fiber preparation, and in particular to a method for preparing low-fibrillation Lyocell fibers. Background Art

[0003] Lyocell fiber is a cellulose fiber produced by a dry-jet wet-spinning method using N-methylmorpholine-N-oxide (NMMO) as a solvent. Lyocell fiber is made from wood pulp, bamboo pulp, and cotton pulp. The N-methylmorpholine-N-oxide (NMMO) recovery rate during production exceeds 99.5%, making it economical and environmentally friendly.

[0004] Lyocell fibers have a high degree of crystallinity and orientation. They easily absorb water and swell in wet conditions, disrupting the hydrogen bonds between the fibrils and weakening their lateral binding strength. Consequently, mechanical forces can cause the fibrils to separate, stripping the fiber surface and causing fibrillation. This tendency to fibrillate causes pilling in textiles during washing, severely limiting the application of Lyocell fibers.

[0005] Application Contents

[0006] In view of this, the present application provides a method for preparing low-fibrillation Lyocell fibers. The Lyocell fibers prepared by this method have the advantages of increased wet wear value of cross-linked fibers with increasing storage time, low production energy consumption, long shelf life, and excellent application performance, making them more suitable for practical use.

[0007] In order to achieve the above-mentioned purpose, the technical solution of the preparation method of low-fibrillation Lyocell fiber provided in this application is as follows:

[0008] The preparation method of low-fibrillation Lyocell fiber provided in this application comprises the following steps:

[0009] Obtain Lyocell fiber filament;

[0010] cutting the Lyocell fiber filaments to obtain Lyocell staple fibers;

[0011] The Lyocell staple fibers are laid into a web and subjected to a fiber web cross-linking treatment to obtain a Lyocell fiber web, wherein the cross-linking treatment includes an alkali auxiliary agent treatment and a cross-linking agent treatment; during the cross-linking agent treatment, the effective component of the cross-linking agent is 2,4-dichloro-6-hydroxy-1,3,5-triazine sodium salt, and the content of the effective component of the cross-linking agent in the Lyocell staple fibers is in the range of 10 kg / t fiber to 50 kg / t fiber;

[0012] After the Lyocell fiber web is post-treated, the low-fibrillation Lyocell fiber is obtained, wherein:

[0013] The fineness of the low fibrillated Lyocell fiber ranges from 1.2 dtex to 1.6 dtex;

[0014] The low fibrillation Lyocell fiber is initially subjected to wear times ≥ 200 times and a coefficient of variation ≤ 40%;

[0015] The low fibrillation Lyocell fiber shows an increasing trend with the increase of storage time, and the maximum number of wet abrasion times is 800-1200 times;

[0016] The initial pH value of the low-fibrillation Lyocell fiber ranges from 8 to 11, and the pH of the low-fibrillation Lyocell fiber is ≥6 during the shelf life.

[0017] The preparation method of low-fibrillation Lyocell fiber provided in this application can also be further implemented by adopting the following technical measures.

[0018] Preferably, the Lyocell short fibers are laid out and subjected to a fiber web cross-linking treatment to obtain a Lyocell fiber web, wherein the cross-linking treatment includes the steps of alkali auxiliary agent treatment and cross-linking agent treatment.

[0019] The alkali auxiliary agent treatment is processed via a first circulation system;

[0020] The cross-linking agent treatment is processed via a second circulation system;

[0021] The first circulation process and the second circulation process are two independent circulation systems.

[0022] Preferably, the circulation system includes a circulation unit and a circulation tank.

[0023] The circulation unit includes a first pressing roller and a second pressing roller, and the Lyocell fiber to be processed is pressed out from between the first pressing roller and the second pressing roller to obtain the pressed Lyocell fiber and the pressed solution.

[0024] The pressed solution flows back to the circulation tank.

[0025] As a preference,

[0026] The circulation unit includes at least one circulation unit monomer, and the circulation tank includes a circulation tank monomer.

[0027] The liquid outlet of the circulation unit cell is communicated with the liquid inlet of the circulation tank cell, and the liquid outlet of the circulation tank cell is communicated with the liquid inlet of the circulation unit cell.

[0028] As a preference,

[0029] The circulation unit includes n circulation unit monomers and n circulation tank monomers, wherein n is a natural number.

[0030] The liquid outlet of the first circulation unit monomer is communicated with the liquid inlet of the first circulation tank monomer, and the liquid outlet of the first circulation tank monomer is communicated with the liquid inlet of the second circulation unit monomer;

[0031] The liquid outlet of the second circulation unit monomer is communicated with the liquid inlet of the second circulation tank monomer, and the liquid outlet of the second circulation tank monomer is communicated with the liquid inlet of the third circulation unit monomer;

[0032] And so on,

[0033] The liquid outlet of the last circulation unit monomer is communicated with the liquid inlet of the last circulation tank monomer, and the liquid outlet of the last circulation tank monomer is communicated with the liquid inlet of the first circulation unit monomer.

[0034] As a preference,

[0035] The applied temperature of the first circulation treatment system ranges from 0°C to 80°C;

[0036] The applied temperature of the second circulation treatment system ranges from 30°C to 100°C;

[0037] The fiber web cross-linking treatment is performed without passing through a heating device and only heat preservation is performed, or the fiber web is subjected to a heating device at a heating temperature of 60° C.-100° C.

[0038] Preferably, the step of obtaining the low-fibrillation Lyocell fiber after the Lyocell fiber web is post-treated comprises the following steps:

[0039] The Lyocell fiber web is treated with an auxiliary agent to obtain an intermediate product;

[0040] After the intermediate product is dried, the low-fibrillation Lyocell fiber is obtained, wherein the pH of the low-fibrillation Lyocell fiber is ≥9.

[0041] Preferably, in the step of obtaining the intermediate product after the Lyocell fiber web is treated with an additive, the additive treatment is to apply the additive in an oil, the pH value of the oil is in the range of 4-8, and the pH value after applying the additive in the oil is in the range of 5-12.

[0042] Preferably, in the step of obtaining the low-fibrillation Lyocell fiber after the intermediate product is dried, an auxiliary agent is applied during the drying process, and the content of the active ingredient of the auxiliary agent is at least 30 mmol / kg of fiber.

[0043] Preferably, the auxiliary agent is selected from a solution of one or a mixture of sodium bicarbonate, sodium carbonate, ammonia water, ammonium chloride, borate, boric acid, hexamethylenetetramine, potassium hydrogen phthalate, aminoacetic acid, phosphate, hydrogen phosphate or dihydrogen phosphate.

[0044] Preferably, between the step of forming the Lyocell short fiber web and subjecting the web to cross-linking treatment to obtain the Lyocell fiber web and the step of post-treating the Lyocell fiber web to obtain the low-fibrillation Lyocell fiber, there is also a step of cleaning the Lyocell fiber web with a cleaning agent.

[0045] Preferably, the cleaning agent is selected from water or an acidic solution, and the mass percentage of the solute in the acidic solution ranges from 0.005% to 2.5%.

[0046] Preferably, the acid in the acidic solution is selected from one or more of acetic acid, hydrochloric acid, sulfuric acid and oxalic acid.

[0047] As a preference,

[0048] The fiber pH test method includes the following steps: weigh 1.0 ± 0.05 g of fiber and place it in a beaker. Then weigh 10.0 ± 0.5 g of desalted water and pour it into the beaker containing the fiber, allowing the fiber to fully contact the water. Seal the beaker with a lid or parafilm and let it sit at room temperature for 12 hours. Remove the fiber and drain any excess water. The pH of the solution is then measured using a pH meter. It is important to note that the pH meter must be calibrated in advance.

[0049] As a preference,

[0050] The fiber aging test method includes the following steps: weighing 10g of low-fibrillation fiber and aging the fiber in a constant temperature and humidity chamber at 40°C and 80% humidity. Sampling is performed every seven days to measure the number of wet abrasions and the fiber pH. A fiber failure index of less than 200 wet abrasions is used to determine the final aging time.

[0051] The crosslinking agent in the low-fibrillation Lyocell fiber prepared by the preparation method of the low-fibrillation Lyocell fiber provided in the present application does not completely react with the cellulose. During the placement process or in the subsequent wet treatment process (dyeing treatment), the crosslinking agent will gradually react with the fiber. The added auxiliary agent will promote the crosslinking reaction and protect the fiber to prevent the acidic substances produced by the reaction from damaging the fiber, thereby keeping the crosslinking effect in a state of continuous increase. Therefore, low-fibrillation Lyocell fiber can be prepared, wherein the fineness of the low-fibrillation Lyocell fiber ranges from 1.2dtex to 1.6dtex; the initial wear times of the low-fibrillation Lyocell fiber are ≥200 times, and the coefficient of variation is ≤40%; the low-fibrillation Lyocell fiber shows an upward trend with the increase of the placement time, and the maximum number of wet wear times is 800-1200 times; the initial pH value of the low-fibrillation Lyocell fiber ranges from 8 to 11, and the pH of the low-fibrillation Lyocell fiber is ≥6 during the shelf life. DETAILED DESCRIPTION

[0052] In view of this, the present application provides a method for preparing low-fibrillation Lyocell fibers. The Lyocell fibers prepared by this method have the advantages of increased wet wear value of cross-linked fibers with increasing storage time, low production energy consumption, long shelf life, and excellent application performance, making them more suitable for practical use.

[0053] After arduous efforts, the inventor discovered that

[0054] Many researchers have conducted extensive research in this area, seeking ways to reduce its fibrillation tendency. Among the products successfully marketed are Lenzing's Lyocell LF and Tencel A100 crosslinked fibers. Lyocell LF uses 2,4-dichloro-6-hydroxy-1,3,5-triazine sodium salt (NHDT) as the crosslinking agent, while Tencel A100 uses 1,3,5-triacryloylhexahydro-1,3,5-triazine (TAHT) as the crosslinking agent.

[0055] Some technologies use NHDT as a crosslinking agent, where fibers in the form of filament bundles come into contact with the crosslinking agent and react, a process known as "tow crosslinking." However, this process has disadvantages such as high equipment cost and large floor space requirements.

[0056] Some technologies use NHDT as a crosslinking agent, applying a buffer to the fiber to stabilize its crosslinking performance. However, overall, the fiber's wet abrasion resistance continues to decline. In later applications, the crosslinking performance deteriorates significantly, thus affecting its use.

[0057] The fibers are in contact with the crosslinking agent in the form of short fibers after being cut and react, and the process is called "short fiber crosslinking". The present application is to lay the cut short fibers into a fiber mesh, and then perform crosslinking treatment and oiling treatment. In some technologies for fiber mesh forming, it is mentioned that a crosslinking process is used for the NHDT crosslinker so that the fiber contains a large amount of crosslinking agent that has not completely reacted, and an auxiliary agent is applied before or during drying. In this way, the crosslinking agent will gradually react with the fiber during the placement process or in the subsequent wet treatment process (dyeing treatment). The added auxiliary agent will promote the crosslinking reaction and protect the fiber to avoid the acidic substances produced by the reaction from damaging the fiber, so that the crosslinking effect is in a state of continuous increase. As a result, the wet wear value of the low-fibrillation fiber is in a long-term and stable growth state, which can greatly improve the application performance of the low-fibrillation fiber and extend the shelf life of the fiber.

[0058] To further illustrate the technical means and effectiveness of this application to achieve its intended purpose, the following describes a method for preparing low-fibrillation Lyocell fibers according to this application, along with its specific implementation, structure, features, and effectiveness, in conjunction with preferred embodiments. In the following description, different references to "one embodiment" or "embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics of one or more embodiments may be combined in any suitable manner.

[0059] The term "and / or" in this article is merely a description of the association relationship between associated objects, indicating that three relationships may exist. For example, A and / or B, specifically understood as: A and B may be included at the same time, A may exist alone, or B may exist alone, and any of the above three situations may exist.

[0060] The preparation method of the low-fibrillation Lyocell fiber provided in the embodiment of the present application comprises the following steps:

[0061] Step S1: Obtaining Lyocell fiber filaments;

[0062] Step S2: cutting the Lyocell fiber filaments to obtain Lyocell short fibers;

[0063] Step S3: Lyocell staple fibers are laid into a web and subjected to a fiber web cross-linking treatment to obtain a Lyocell fiber web, wherein the cross-linking treatment includes an alkali additive treatment and a cross-linking agent treatment; during the cross-linking agent treatment, the effective component of the cross-linking agent is 2,4-dichloro-6-hydroxy-1,3,5-triazine sodium salt, and the content of the effective component of the cross-linking agent in the Lyocell staple fibers is in the range of 10 kg / t fiber to 50 kg / t fiber;

[0064] Step S4: After the Lyocell fiber web is post-treated, low-fibrillation Lyocell fibers are obtained, wherein:

[0065] The fineness of low fibrillated Lyocell fibers ranges from 1.2dtex to 1.6dtex;

[0066] The initial wear times of low fibrillation Lyocell fiber are ≥200 times and the coefficient of variation is ≤40%;

[0067] The low fibrillation Lyocell fiber showed an increasing trend with the increase of storage time, and the maximum number of wet abrasion times was between 800 and 1200 times;

[0068] The initial pH value range of the low fibrillation Lyocell fiber is 8-11, and the pH of the low fibrillation Lyocell fiber is ≥6 during the shelf life.

[0069] The crosslinking agent in the low-fibrillation Lyocell fiber prepared by the preparation method of the low-fibrillation Lyocell fiber provided in the present application does not completely react with the cellulose. During the placement process or in the subsequent wet treatment process (dyeing treatment), the crosslinking agent will gradually react with the fiber. The added auxiliary agent will promote the crosslinking reaction and protect the fiber to prevent the acidic substances produced by the reaction from damaging the fiber, thereby keeping the crosslinking effect in a state of continuous increase. Therefore, low-fibrillation Lyocell fiber can be prepared, wherein the fineness of the low-fibrillation Lyocell fiber ranges from 1.2dtex to 1.6dtex; the initial wear times of the low-fibrillation Lyocell fiber are ≥200 times, and the coefficient of variation is ≤40%; the low-fibrillation Lyocell fiber shows an upward trend with the increase of the placement time, and the maximum number of wet wear times is 800-1200 times; the initial pH value of the low-fibrillation Lyocell fiber ranges from 8 to 11, and the pH of the low-fibrillation Lyocell fiber is ≥6 during the shelf life.

[0070] Among them, Lyocell short fibers are laid into a web and then cross-linked to obtain a Lyocell fiber web, wherein the cross-linking treatment includes the steps of alkali agent treatment and cross-linking agent treatment, the alkali agent treatment is processed through a first circulation system; the cross-linking agent treatment is processed through a second circulation system; wherein the first circulation treatment and the second circulation treatment are two independent circulation systems.

[0071] The circulation system includes a circulation unit and a circulation tank. The circulation unit includes a first pressing roller and a second pressing roller. Lyocell fibers to be processed are pressed out from between the first pressing roller and the second pressing roller to obtain the pressed Lyocell fibers and the pressed solution. The pressed solution then flows back to the circulation tank.

[0072] The circulation unit includes at least one circulation unit monomer, the circulation tank includes a circulation tank monomer, the liquid outlet of the circulation unit monomer is connected to the liquid inlet of the circulation tank monomer, and the liquid outlet of the circulation tank monomer is connected to the liquid inlet of the circulation unit monomer.

[0073] Among them, the circulation unit includes n circulation unit monomers and n circulation tank monomers, wherein n is a natural number, the liquid outlet of the first circulation unit monomer is connected to the liquid inlet of the first circulation tank monomer, and the liquid outlet of the first circulation tank monomer is connected to the liquid inlet of the second circulation unit monomer; the liquid outlet of the second circulation unit monomer is connected to the liquid inlet of the second circulation tank monomer, and the liquid outlet of the second circulation tank monomer is connected to the liquid inlet of the third circulation unit monomer; and so on, the liquid outlet of the last circulation unit monomer is connected to the liquid inlet of the last circulation tank monomer, and the liquid outlet of the last circulation tank monomer is connected to the liquid inlet of the first circulation unit monomer.

[0074] Among them, the applied temperature range of the first circulation treatment system is 0℃-80℃; the applied temperature range of the second circulation treatment system is 30℃-100℃; among them, the fiber web cross-linking treatment does not pass through the heating equipment but only keeps warm, or, passes through the heating equipment, the heating temperature is 60℃-100℃.

[0075] The process of obtaining low-fibrillation Lyocell fibers after post-treatment of the Lyocell fiber web includes the following steps: the Lyocell fiber web is treated with an auxiliary agent to obtain an intermediate product; the intermediate product is dried to obtain low-fibrillation Lyocell fibers, wherein the pH of the low-fibrillation Lyocell fibers is ≥9.

[0076] Among them, in the step of obtaining the intermediate product after the Lyocell fiber web is treated with an additive, the additive treatment is to apply the additive to the oil, the pH value range of the oil is 4-8, and the pH value range after applying the additive to the oil is 5-12.

[0077] In the step of obtaining low-fibrillation Lyocell fibers after the intermediate product is dried, an auxiliary agent is applied during the drying process, and the content of the active ingredient of the auxiliary agent is at least 30 mmol / kg of fiber.

[0078] The auxiliary agent is selected from one or a mixture of sodium bicarbonate, sodium carbonate, ammonia water, ammonium chloride, borate, boric acid, hexamethylenetetramine, potassium hydrogen phthalate, aminoacetic acid, phosphate, hydrogen phosphate or dihydrogen phosphate.

[0079] Among them, between the step of forming the Lyocell short fiber web and undergoing fiber web cross-linking treatment to obtain the Lyocell fiber web and the step of obtaining low-fibrillation Lyocell fibers after post-processing the Lyocell fiber web, there is also a step of using a cleaning agent to clean the Lyocell fiber web.

[0080] The cleaning agent is selected from water or acidic solution, and the mass percentage of the solute in the acidic solution ranges from 0.005% to 2.5%.

[0081] The acid in the acidic solution is selected from one or more of acetic acid, hydrochloric acid, sulfuric acid and oxalic acid.

[0082] The fiber pH test method includes the following steps: weigh 1.0±0.05g of fiber and place it in a beaker. Then weigh 10.0±0.5g of desalted water and pour it into the beaker containing the fiber, allowing the fiber to fully contact the water. Seal the beaker with a lid or sealing film and let it sit at room temperature for 12 hours. Remove the fiber and drain any excess water. Then test the pH of the solution with a pH meter. It's important to note that the pH meter needs to be calibrated in advance.

[0083] The fiber aging test method includes the following steps: weighing 10g of low-fibrillation fiber and aging the fiber in a constant temperature and humidity chamber at 40°C and 80% humidity. Sampling is performed every seven days to measure the number of wet abrasions and the fiber pH. A final wet abrasion count of less than 200 is considered failure, and the final aging time is obtained.

[0084] Example 1

[0085] Low-fibrillation fibers were prepared using an existing "fiber web crosslinking" process. The fibers were then cleaned with acetic acid and then treated with an oil containing sodium carbonate. Finally, the fibers were unwound, dried, and packaged. The sodium carbonate concentration was controlled at 60 mmol / kg fiber. The results are shown in Table 1.

[0086] Example 2

[0087] Low-fibrillation fibers were prepared using an existing "fiber web cross-linking" process. The fibers were then cleaned with sulfuric acid and treated with an oil containing dipotassium hydrogen phosphate. Finally, the fibers were unwound, dried, and packaged. The concentration of dipotassium hydrogen phosphate was controlled at 100 mmol / kg of fiber. The results are shown in Table 1.

[0088] Example 3

[0089] Low-fibrillation fibers were prepared using an existing "fiber web crosslinking" process. The fibers were then cleaned with sulfuric acid and treated with an oil containing sodium carbonate, sodium bicarbonate, and dipotassium hydrogen phosphate. Finally, the fibers were unwound, dried, and packaged. The additive concentration was controlled at 80 mmol / kg fiber. The results are shown in Table 1.

[0090] Example 4

[0091] Low-fibrillation fibers were prepared using an existing "fiber web cross-linking" process. The fibers were then cleaned with sulfuric acid and treated with an oil containing sodium carbonate and sodium bicarbonate. Finally, the fibers were unwound, dried, and packaged. The additive concentration was controlled at 75 mmol / kg fiber. The results are shown in Table 1.

[0092] Comparative Example 1

[0093] Low-fibrillation fibers were prepared using an existing cross-linking process. The fibers were then cleaned with sulfuric acid, treated with an additive-free oil, and finally de-webbed, dried, and packaged. Samples were taken daily for testing, and the results are shown in Table 1.

[0094] Table 1

[0095] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present application.

[0096] Obviously, those skilled in the art may make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application is intended to include these modifications and variations.

Claims

1. A method for preparing low fibrillation Lyocell fibers, wherein: The following steps are involved: Obtain Lyocell fiber filament; Cutting the Lyocell fiber filaments to obtain Lyocell short fibers; The Lyocell short fibers are laid and formed into a web and subjected to a fiber web cross-linking treatment to obtain a Lyocell fiber web, wherein the cross-linking treatment includes an alkali auxiliary agent treatment and a cross-linking agent treatment; during the cross-linking agent treatment, the effective component of the cross-linking agent is 2,4-dichloro-6-hydroxy-1,3,5-triazine sodium salt, and the content of the effective component of the cross-linking agent on the Lyocell short fibers is in the range of 10kg / t fiber to 50kg / t fiber; After the Lyocell fiber web is post-treated, the low-fibrillation Lyocell fiber is obtained, wherein: The fineness of the low fibrillated Lyocell fiber ranges from 1.2 dtex to 1.6 dtex; The low fibrillation Lyocell fiber is initially worn ≥200 times and has a coefficient of variation ≤40%; The low fibrillation Lyocell fiber shows an increasing trend with the increase of placement time, and the maximum number of wet wear times is 800-1200 times; The initial pH value range of the low fibrillation Lyocell fiber is 8-11, and the pH of the low fibrillation Lyocell fiber is ≥6 during the shelf life.

2. The method for preparing low fibrillation Lyocell fiber according to claim 1, wherein: The Lyocell short fibers are laid out and cross-linked to obtain a Lyocell fiber web, wherein the cross-linking treatment includes the steps of alkali auxiliary agent treatment and cross-linking agent treatment. The alkali auxiliary agent treatment is processed via a first circulation system; The cross-linking agent treatment is processed via a second circulation system; The first circulation process and the second circulation process are two independent circulation systems.

3. The method for preparing low fibrillation Lyocell fiber according to claim 2, wherein: The circulation system comprises a circulation unit and a circulation tank. The circulation unit comprises a first pressing roller and a second pressing roller, and the Lyocell fiber to be treated is pressed out from between the first pressing roller and the second pressing roller to obtain the pressed Lyocell fiber and the pressed solution. The pressed solution is returned to the circulation tank.

4. The method for preparing low fibrillation Lyocell fiber according to claim 3, wherein: The circulation unit includes at least one circulation unit monomer, and the circulation tank includes a circulation tank monomer. The liquid outlet of the circulation unit cell is communicated with the liquid inlet of the circulation tank cell, and the liquid outlet of the circulation tank cell is communicated with the liquid inlet of the circulation unit cell.

5. The method for preparing low fibrillation Lyocell fiber according to claim 3, wherein: The circulation unit comprises n circulation unit monomers and n circulation tank monomers, wherein n is a natural number. The liquid outlet of the first circulation unit monomer is communicated with the liquid inlet of the first circulation tank monomer, and the liquid outlet of the first circulation tank monomer is communicated with the liquid inlet of the second circulation unit monomer; The liquid outlet of the second circulation unit monomer is communicated with the liquid inlet of the second circulation tank monomer, and the liquid outlet of the second circulation tank monomer is communicated with the liquid inlet of the third circulation unit monomer; And so on. The liquid outlet of the last circulation unit monomer is communicated with the liquid inlet of the last circulation tank monomer, and the liquid outlet of the last circulation tank monomer is communicated with the liquid inlet of the first circulation unit monomer.

6. The method for preparing low fibrillation Lyocell fiber according to claim 2, wherein: The applied temperature of the first circulation treatment system ranges from 0°C to 80°C; The applied temperature of the second circulation treatment system ranges from 30°C to 100°C; The fiber web cross-linking treatment is performed without heating equipment but only heat preservation, or the fiber web is subjected to heating equipment at a heating temperature of 60°C-100°C.

7. The method for preparing low fibrillation Lyocell fiber according to claim 1, wherein: After the Lyocell fiber web is post-treated, the process of obtaining the low-fibrillation Lyocell fiber includes the following steps: The Lyocell fiber web is treated with an auxiliary agent to obtain an intermediate product; After the intermediate product is dried, the low-fibrillation Lyocell fiber is obtained, wherein the pH of the low-fibrillation Lyocell fiber is ≥9.

8. The method for preparing low fibrillation Lyocell fiber according to claim 7, wherein: In the step of obtaining the intermediate product after the Lyocell fiber web is treated with an auxiliary agent, the auxiliary agent treatment is to apply the auxiliary agent in an oil agent, the pH value range of the oil agent is 4-8, and the pH value range after applying the auxiliary agent in the oil agent is 5-12.

9. The method for preparing low fibrillation Lyocell fiber according to claim 7, wherein: In the step of obtaining the low-fibrillation Lyocell fiber after the intermediate product is dried, an auxiliary agent is applied during the drying process, and the content of the active ingredient of the auxiliary agent is at least 30 mmol / kg of fiber.

10. The method for preparing low fibrillation Lyocell fiber according to claim 7, wherein: The auxiliary agent is selected from sodium bicarbonate, sodium carbonate, ammonia water, ammonium chloride, borate, boric acid, hexamethylenetetramine, potassium hydrogen phthalate, aminoacetic acid, phosphate, hydrogen phosphate or dihydrogen phosphate, or a mixture of the above-mentioned solutions.

11. The method for preparing low fibrillation Lyocell fiber according to claim 1, wherein: Between the step of forming a Lyocell short fiber web and subjecting the web to cross-linking treatment to obtain a Lyocell fiber web and the step of post-treating the Lyocell fiber web to obtain the low-fibrillation Lyocell fiber, there is also a step of cleaning the Lyocell fiber web with a cleaning agent.

12. The method for preparing low fibrillation Lyocell fiber according to claim 11, wherein: The cleaning agent is selected from water or an acidic solution, and the mass percentage content of the solute in the acidic solution ranges from 0.005% to 2.5%.

13. The method for preparing low fibrillation Lyocell fiber according to claim 12, wherein: The acid in the acidic solution is selected from one or more of acetic acid, hydrochloric acid, sulfuric acid and oxalic acid.

14. The method for preparing low fibrillation Lyocell fiber according to claim 1, wherein: The fiber pH test method includes the following steps: weigh 1.0±0.05g of fiber and place it in a beaker, then weigh 10.0±0.5g of desalted water and pour it into the beaker containing the fiber to allow the fiber to fully contact the water, seal the beaker with a lid or sealing film, place it at room temperature for 12 hours, take out the fiber, drain the excess water, and test the pH value of the solution with a pH meter. It is worth noting that the pH meter needs to be calibrated in advance.

15. The method for preparing low fibrillation Lyocell fiber according to claim 1, wherein: The fiber aging test method includes the following steps: weighing 10g of low fibrillation fiber, placing the low fibrillation fiber in a constant temperature and humidity chamber for aging, the aging temperature is 40°C, the aging humidity is 80%, sampling is performed every 7 days, and the wet wear times and fiber pH value are tested. The final wet wear times of the fiber <200 times is taken as the failure index, and the final value of the aging time is obtained.

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