Antibacterial self-lubricating composite fiber and preparation method thereof

Abstract

The invention discloses an antibacterial self-lubricating composite fiber and a preparation method thereof, and the preparation method comprises the following steps: (1) mixing polyformaldehyde (POM) ultrafine powder with a dimethyl sulfoxide (DMSO) solvent to form a solution; adding hexamethyleneguanidine hydrochloride antibacterial powder into the solution, and carrying out ultrasonic-assisted dispersion; removing the solvent through heating evaporation or reduced pressure distillation, curing and slicing to obtain an antibacterial polyformaldehyde slice of an outer layer material; (2) spinning by using two-component spinning equipment, wherein the mass ratio of the antibacterial polyformaldehyde slices to the ultra-high molecular weight polyethylene slices of the outer layer material is 100: (20-30); and (3) controlling a temperature parameter, a pressure parameter and a speed parameter in the spinning process so as to realize uniform compounding and continuous extrusion of the fiber and prepare the antibacterial self-lubricating composite fiber. The preparation method provided by the invention can produce the composite fiber with antibacterial property and self-lubricating property, is suitable for multiple fields such as medical treatment, textile, industry and the like, and has wide application prospect.

Description

Technical Field

[0001] The invention relates to the technical field of new materials, and in particular to an antibacterial self-lubricating composite fiber and a preparation method thereof. Background Art

[0002] Modern industry and technology are booming at an unprecedented speed, profoundly changing people's production and lifestyle. Among them, high-performance fiber materials, as the key basic components of many advanced technologies and products, play an indispensable role in various important fields. Its market demand has also shown a sustained and strong growth momentum, becoming one of the important driving forces for the development of related industries.

[0003] In the biomedical field, as people's attention to health and medical safety continues to increase, the application scope of high-performance fiber materials is becoming increasingly wide. On the one hand, since these materials show good biocompatibility in the human body or when in contact with the human body, in order to protect the health of patients and ensure the safety and hygiene of various medical operations, the requirements for the antibacterial properties of fiber materials have been raised to an extremely strict standard. For example, in surgical sutures, a key medical device, if the fiber material does not have excellent antibacterial properties, during the wound healing process, bacteria can easily breed and multiply around the sutures, thereby causing wound infection and seriously affecting the patient's recovery process; the same is true for medical bandages and other materials based on textile materials. If they cannot effectively inhibit bacterial growth, they will not only fail to protect wounds and promote healing, but may become a medium for bacterial transmission, resulting in a significant increase in the risk of cross-infection; medical staff's work clothes, as protective equipment that directly contacts patients and the medical environment, need to maintain an antibacterial state at all times to prevent medical staff from being infected by bacteria themselves and avoid spreading bacteria to patients. On the other hand, some medical equipment components, such as the moving parts of implantable devices and the transmission parts of surgical instruments, require high-performance fiber materials with good self-lubricating properties during long-term use. This can ensure their smooth operation in complex operating environments and reduce friction and wear between components, thereby extending the service life of the equipment, reducing medical costs, and improving the quality and efficiency of medical services.

[0004] The protection field also has an urgent and diverse demand for high-performance fiber materials. In key protective equipment such as chemical protective clothing and bulletproof vests, fiber materials must not only have basic mechanical properties such as high strength and high toughness to resist the erosion of biological and chemical substances and the impact of bullets, but also need to take into account functions such as antibacterial and self-lubricating. In the face of complex and changeable biochemical protection scenarios, if the fiber materials in chemical protective clothing lack antibacterial properties, once contaminated by bacteria, they may pose a threat to the health of users during the protection process; and self-lubrication can ensure that users are more flexible and free when wearing chemical protective clothing to perform various actions, reduce discomfort and fatigue caused by friction, and improve protection effects and work efficiency. For bulletproof vests, self-lubrication helps to improve the stability and comfort of its internal structure, making soldiers more agile in action. At the same time, antibacterial properties can effectively prevent bacterial growth caused by long-term wear and protect the health of soldiers.

[0005] In the field of sports equipment, from the high-performance sportswear and sports shoes that professional athletes rely on in high-intensity training and competitions to the various types of sports equipment used by ordinary people for daily fitness exercises, there are clear and practical needs for antibacterial and self-lubricating properties. In terms of antibacterial properties, since the human body sweats a lot during exercise, it provides a breeding ground for bacteria. If the fiber material of sports equipment does not have antibacterial ability, bacteria will multiply on the equipment and produce unpleasant odors, which not only affects the user's wearing experience, but may also cause health problems such as skin allergies. Self-lubricating properties play an important role in improving the wearing comfort of equipment. For example, in the process of sportswear contacting human skin, good self-lubricating properties can make the clothing smoother during body movement, effectively reduce the friction discomfort between the skin, and avoid skin damage caused by friction; in sports shoes, self-lubricating properties help the flexible running-in between the soles, uppers and other parts, improve the overall performance of the shoes, and enable athletes to perform technical movements more freely during exercise, improving sports performance and competitive level.

[0006] In the field of marine engineering, high-performance fiber materials also have broad application prospects and can be used in marine equipment manufacturing, fishing nets and other aspects. For example, in marine equipment manufacturing, the self-lubricating property of fiber materials can reduce the friction resistance of equipment in seawater environment and improve the operating efficiency and stability of equipment; while the antibacterial property can prevent marine organisms from adhering and breeding on the surface of equipment, reducing equipment maintenance costs and performance degradation caused by biological adhesion. In terms of fishing nets, the antibacterial property can prevent the nets from rotting and being damaged due to bacterial growth, extending the service life of the nets, while the self-lubricating property helps the nets to be smoothly retracted and released in the water, improving the efficiency of fishery production.

[0007] However, the reality is that traditional antibacterial fibers and self-lubricating fibers have many insurmountable shortcomings, which seriously restrict their wide application and performance improvement in various fields. In terms of antibacterial properties, many traditional fiber materials cannot provide long-lasting and stable antibacterial effects. With the passage of time, as well as various situations such as washing, friction, and light experienced during daily use, their antibacterial ability will gradually weaken, and it is difficult to maintain effective inhibition of bacteria for a long time. This means that in practical applications, these fiber materials need to be frequently replaced or processed, increasing the cost of use and waste of resources. In terms of self-lubricating properties, although some fiber materials can exhibit a certain degree of self-lubricating properties in conventional and relatively mild environments, once they are faced with high-load usage scenarios, such as in high-intensity sports friction environments, or in special harsh environments (such as high temperature, high humidity, strong acid and alkali, etc.), their self-lubricating properties will rapidly decline, unable to meet actual needs, resulting in increased wear of equipment or equipment, shortened service life, and even potential safety hazards.

[0008] Moreover, in order to improve the antibacterial and self-lubricating properties of fibers, traditional methods often rely on adding additional chemical additives such as antibacterial agents or lubricants. This method not only greatly increases the production cost and weakens the market competitiveness of the product, but more importantly, during the use of fiber materials, these chemical additives may gradually be released from the fiber and enter the surrounding environment. These released chemicals may pollute the natural environment such as soil, water sources, and air, and destroy the ecological balance; at the same time, when people come into contact with fiber materials containing these chemical additives, they also pose a potential threat to human health, such as allergic reactions, endocrine disorders, and other problems. In addition, while pursuing antibacterial and self-lubricating properties, traditional fiber material preparation processes often ignore the mechanical properties and dimensional stability that the fiber should have. This results in the performance of these materials being not stable and reliable in actual applications, such as fiber breakage and dimensional deformation, which seriously affects their normal use effect and service life, and reduces the quality and safety of the product.

[0009] In contrast, antibacterial self-lubricating composite fibers show unique advantages. This fiber is composed of an antibacterial polyoxymethylene outer layer and an ultra-high molecular polyethylene core layer. The antibacterial polyoxymethylene outer layer has excellent antibacterial properties. Its antibacterial principle is based on the active groups in the molecular structure of polyoxymethylene, which can destroy the cell wall and cell membrane of bacteria, thereby effectively inhibiting the growth and reproduction of bacteria. Moreover, this antibacterial property has high stability and is not easily affected by external environmental factors. Ultra-high molecular polyethylene gives the fiber good self-lubricating properties. Its molecular chain is long and regular, and the intermolecular force is small, so that the fiber surface has an extremely low friction coefficient and can maintain excellent self-lubricating effects under various working conditions. Whether in a high-load sports friction environment or a special harsh environment, it can effectively reduce wear and extend service life. At the same time, the dyeing performance of polyoxymethylene fiber is good, which can effectively improve the defect of ultra-high molecular polyethylene dyeing difficulty, which makes the composite fiber more flexible in color application, can meet the needs of different fields for the diversification of fiber material colors, and further expand its application range. In addition, the composite structure of these two materials also guarantees the mechanical properties and dimensional stability of the fiber to a certain extent, enabling it to better meet the strict requirements of various fields for high-performance fiber materials in practical applications.

[0010] Under the background of continuous development and progress in various application fields, the requirements for material performance are becoming increasingly refined and diversified. For example, the medical industry urgently needs fiber materials that can effectively resist bacteria in the complex and changeable human physiological environment and medical operation environment to avoid cross infection, and can also maintain smoothness and reduce wear during the frequent operation of medical equipment to ensure the precise operation of the equipment; the protection field requires that the fiber materials of protective equipment can resist various external hazards for a long time while maintaining a comfortable wearing experience. Self-lubrication is indispensable and the antibacterial function must be durable and reliable to ensure the safety and health of users; the sports equipment field is even more eager for fiber materials to be able to effectively inhibit bacteria caused by sweating, and ensure the smoothness and stability of equipment during high-intensity and high-frequency exercise. Therefore, the antibacterial self-lubricating composite fiber composed of an antibacterial polyoxymethylene outer layer and an ultra-high molecular polyethylene core layer is an ideal material that has emerged in response to this demand trend. It has broad application prospects and market potential, and is expected to bring new breakthroughs and improvements to the development of various fields. Summary of the invention

[0011] The object of the present invention is to provide an antibacterial self-lubricating composite fiber and a preparation method thereof.

[0012] In order to solve the problems of the prior art, the technical solutions adopted by the present invention are as follows: In the first aspect, the present application provides a method for preparing an antibacterial self-lubricating composite fiber; in the second aspect, the present application provides an antibacterial self-lubricating composite fiber.

[0013] The first aspect of the present application provides a method for preparing an antibacterial self-lubricating composite fiber, comprising the following steps: the antibacterial self-lubricating composite fiber is a composite fiber with a skin-core structure, the core layer is composed of ultra-high molecular polyethylene (UHMWPE); the outer layer is coated with a blend of hexamethyleneguanidine hydrochloride and polyoxymethylene (POM), that is, antibacterial polyoxymethylene; (1) Raw material preparation: Outer layer material: dissolving polyoxymethylene (POM) ultrafine powder in dimethyl sulfoxide (DMSO) solvent to form a solution; adding hexamethyleneguanidine hydrochloride antibacterial powder to the solution and dispersing it with the assistance of ultrasound; removing the solvent by heating evaporation or reduced pressure distillation, and then curing and slicing to obtain antibacterial polyoxymethylene slices of the outer layer material; Core material: Ultra-high molecular weight polyethylene chips (UHMWPE) with excellent mechanical properties; (2) Melt preparation: Outer layer melt: The outer layer material antibacterial polyoxymethylene slices are prepared into a melt by melting. Premixing and melting can be performed in a twin-screw extruder to ensure uniform dispersion of the material; Core layer melt: The core layer material ultra-high molecular weight polyethylene chips (UHMWPE) are prepared into a melt by melting, and are also pre-mixed and melted in a twin-screw extruder to ensure that the material is evenly dispersed; (3) Twin-screw spinning: Use a two-component spinning device for spinning, where the mass ratio of the antibacterial polyoxymethylene chips of the outer layer material to the ultra-high molecular weight polyethylene is 100:20-30; control the parameters during the spinning process to achieve uniform composite and continuous extrusion of the fibers; (4) Fiber curing: Air curing: After the fiber is extruded from the spinneret, it naturally cures in the air. The temperature and humidity in the air will affect the curing speed and performance of the fiber; Cooling: Use cooling device to accelerate the solidification process of fiber and ensure the stability and uniformity of fiber; (5) Fiber molding: Drafting: Drafting is performed on the spun fibers to improve their orientation and mechanical properties. The drafting multiple is 2-5 times. Heat setting: Through heat setting treatment, the dimensional stability and mechanical properties of the fiber are improved. The heat setting temperature is 100-150°C and the time is 1-5 minutes to produce an antibacterial self-lubricating composite fiber.

[0014] Furthermore, in step (1), ultrafine polyoxymethylene (POM) powder is prepared: (1) Freezing: The polyoxymethylene spinning chips are cooled to -196℃, which is below the boiling point of liquid nitrogen. This temperature can make the polyoxymethylene sufficiently brittle, which is convenient for subsequent crushing operations. However, in actual operation, the temperature can be fine-tuned between -190℃ and -200℃ according to the specific characteristics of polyoxymethylene and the equipment conditions; the cooling time may need to be extended to 30-60 minutes to ensure that the inside can also be fully cooled and brittle; (2) Ultrasonic crushing stage: The frequency of the ultrasonic wave is 40kHz; the ultrasonic power of the polyoxymethylene spinning slice is 1500-2000W; the crushing time is 20-30 minutes, and the polyoxymethylene (POM) ultrafine powder is obtained.

[0015] Furthermore, in step (1), an antibacterial polyoxymethylene slice is prepared: (11) slowly adding polyoxymethylene (POM) ultrafine powder into a reaction vessel containing a solvent dimethyl sulfoxide (DMSO), wherein the weight ratio of the polyoxymethylene (POM) ultrafine powder to the solvent dimethyl sulfoxide (DMSO) is 1:4-10, stirring at a temperature of 100-150° C. for 1.5-6 hours in a closed environment, so that the powder is evenly dispersed to form a solution; (12) The solid antibacterial powder of hexamethyleneguanidine hydrochloride accounts for 3% to 10% of the total mass of the solid antibacterial powder of hexamethyleneguanidine hydrochloride and polyoxymethylene (POM) spinning chips. Hexamethyleneguanidine hydrochloride (PHMG) is slowly added to dimethyl sulfoxide (DMSO) under slow stirring to prevent the antibacterial agent from agglomerating; (13) Ultrasonic dispersion was assisted by ultrasound, with the ultrasonic frequency set to 20-40 kHz and the ultrasonic treatment time set to 10-30 minutes to ensure that the antimicrobial agent was evenly dispersed in the polyoxymethylene solution; (14) The antibacterial polyoxymethylene slices of the outer layer material are obtained by removing the solvent by heating evaporation or reduced pressure distillation, and then solidifying and slicing.

[0016] Furthermore, in step (1), for the outer layer material part, the outer layer material includes polyoxymethylene (POM) and hexamethyleneguanidine hydrochloride, the temperature of the area near the feed port is 170-180°C, the temperature of the subsequent area gradually increases, and the temperature of the area near the extruder head is 190-210°C; the outer layer of the antibacterial ultra-high molecular polyethylene is formed by mixing, heating and extruding in a screw machine; the average molecular weight of the polyoxymethylene (POM) is 100,000-300,000, and the melt index is 5-12g / 10min; Furthermore, in step (2), for the ultra-high molecular polyethylene chips (UHMWPE), the barrel temperature should be higher than its melting point and ensure good fluidity of the melt; the temperature near the feed port can be 180-200°C, the temperature in the middle area is 220-240°C, and the temperature near the extruder head is 230-250°C; the mold temperature is 190-220°C, and the spinneret temperature is 230-260°C to ensure continuous extrusion of the fiber. The average molecular weight of ultra-high molecular polyethylene is 1-10 million.

[0017] Further, in step (3), temperature: the spinning temperature is adjusted according to the melting point and flow characteristics of the material to ensure that the material maintains appropriate fluidity during the spinning process, and the melting temperatures of the outer layer and the core layer are 180-210°C and 200-260°C respectively; Screw speed: Adjust the screw speed to ensure uniform mixing and stable conveying of the two materials in the screw. The screw speed is 100-300 rpm; Pressure: Adjust the spinning pressure to ensure that the two materials are evenly mixed and extruded at the spinneret. The pressure is 10-50MPa; Spinning speed: Control the spinning speed to ensure the uniformity and continuity of the fiber. The spinning speed is 100-500 m / min.

[0018] The second aspect of the present application provides an antibacterial self-lubricating composite fiber obtained by a preparation method.

[0019] Beneficial effects: The antibacterial self-lubricating composite fiber of the present invention has excellent corrosion resistance, resistance to marine biological attachment, high strength and weather resistance, and is suitable for long-term deployment in the marine environment. While providing long-lasting antibacterial and excellent self-lubricating properties, the present invention also pays attention to the protection of the environment and human health, and is a high-performance fiber material preparation method with broad application prospects.

[0020] Compared with the prior art, the present invention has the following advantages: (1) The technical solution of the present invention provides a method for preparing an antibacterial self-lubricating composite fiber. Through an innovative skin-core structure design, ultra-high molecular weight polyethylene (UHMWPE) is used as the core material, and the outer layer is coated with a blend of hexamethyleneguanidine hydrochloride and polyoxymethylene (POM), thereby achieving a perfect combination of antibacterial and self-lubricating properties. The method has the following advantages: (2) Long-lasting antibacterial property: Hexamethyleneguanidine hydrochloride is a safe and efficient antibacterial agent that can provide long-lasting antibacterial effect and is friendly to the human body and the environment. Excellent self-lubricating property: Ultra-high molecular weight polyethylene (UHMWPE) is known for its excellent self-lubricating property. The combination with antibacterial blends enables the composite fiber to have good self-lubricating properties while maintaining antibacterial properties.

[0021] (3) Environmentally friendly: The present invention avoids the use of harmful chemicals and reduces potential risks to the environment and human health. Mechanical properties and dimensional stability: By precisely controlling the spinning parameters and post-processing steps, the composite fiber prepared by the present invention has excellent mechanical properties and dimensional stability, and is suitable for various high-performance application scenarios. DETAILED DESCRIPTION

[0022] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0023] In this application, the term "and / or" describes the association relationship of associated objects, indicating that there may be three types of relationships. For example, and / or B can mean: A exists alone, and B exists at the same time, and B exists alone. Among them, B can be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship.

[0024] In this application, "at least one" means one or more, and "plurality" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b, or c", or "at least one of b, and c", can all mean: b, c, -b (i.e., and b), -c, bc, or -bc, where b and c can be single or multiple, respectively.

[0025] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution, some or all of the steps can be executed in parallel or sequentially, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0026] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0027] The weight of the relevant components mentioned in the embodiment description of the present application can not only refer to the specific content of each component, but also indicate the proportional relationship between the weights of the components. Therefore, as long as the content of the relevant components is proportionally enlarged or reduced according to the embodiment description of the present application, it is within the scope disclosed in the embodiment description of the present application. Specifically, the mass described in the embodiment description of the present application can be a mass unit known in the chemical industry such as µg, mg, g, kg, etc.

[0028] A first aspect of the present application provides a method for preparing an antibacterial self-lubricating composite fiber, comprising the following steps: The antibacterial self-lubricating composite fiber is a composite fiber with a skin-core structure, wherein the core layer is composed of ultra-high molecular polyethylene (UHMWPE); the outer layer is coated with a blend of hexamethyleneguanidine hydrochloride and polyoxymethylene (POM), which is antibacterial polyoxymethylene; (1) Raw material preparation: Outer layer material: dissolving polyoxymethylene (POM) ultrafine powder in dimethyl sulfoxide (DMSO) solvent to form a solution; adding hexamethyleneguanidine hydrochloride antibacterial powder to the solution and dispersing it with the assistance of ultrasound; removing the solvent by heating evaporation or reduced pressure distillation, and then curing and slicing to obtain antibacterial polyoxymethylene slices of the outer layer material; Core material: Ultra-high molecular weight polyethylene chips (UHMWPE) with excellent mechanical properties; (2) Melt preparation: Outer layer melt: The outer layer material antibacterial polyoxymethylene slices are prepared into a melt by melting. Premixing and melting can be performed in a twin-screw extruder to ensure uniform dispersion of the material; Core layer melt: The core layer material ultra-high molecular weight polyethylene chips (UHMWPE) are prepared into a melt by melting, and are also pre-mixed and melted in a twin-screw extruder to ensure that the material is evenly dispersed; (3) Twin-screw spinning: Spinning is performed using a two-component spinning device, wherein the mass ratio of the antibacterial polyoxymethylene and ultra-high molecular weight polyethylene of the outer layer material is 100:20-30; the parameters during the spinning process are controlled to achieve uniform composite and continuous extrusion of the fibers; (4) Fiber curing: Air curing: After the fiber is extruded from the spinneret, it naturally cures in the air. The temperature and humidity in the air will affect the curing speed and performance of the fiber; Cooling: Use cooling device to accelerate the solidification process of fiber and ensure the stability and uniformity of fiber; (5) Fiber molding: Drafting: The spun fibers are drafted to improve their orientation and mechanical properties. The drafting multiple is 2 times. Heat setting: The dimensional stability and mechanical properties of the fiber are improved by heat setting treatment. The heat setting temperature is 120°C and the time is 5 minutes to obtain an antibacterial self-lubricating composite fiber.

[0029] In some embodiments, in step (3), twin-screw spinning: using a bicomponent spinning device for spinning, wherein the mass ratio of the antibacterial polyoxymethylene chips of the outer layer material to the ultra-high molecular weight polyethylene is 100:20; controlling the parameters during the spinning process to achieve uniform compounding and continuous extrusion of the fibers; In some embodiments, in step (3), twin-screw spinning: using a bicomponent spinning device for spinning, wherein the mass ratio of the antibacterial polyoxymethylene chips of the outer layer material to the ultra-high molecular weight polyethylene is 100:30; controlling the parameters during the spinning process to achieve uniform compounding and continuous extrusion of the fibers; In some embodiments, in step (5), the fiber is formed: Drafting: The spun fibers are drafted to improve their orientation and mechanical properties. The drafting multiple is 5 times. Heat setting: The dimensional stability and mechanical properties of the fiber are improved by heat setting treatment. The heat setting temperature is 100°C and the time is 5 minutes to obtain an antibacterial self-lubricating composite fiber.

[0030] In some embodiments, in step (5), the fiber is formed: Drafting: The spun fibers are drafted to improve their orientation and mechanical properties. The drafting multiple is 4 times. Heat setting: The dimensional stability and mechanical properties of the fiber are improved by heat setting treatment. The heat setting temperature is 150°C and the time is 4 minutes to produce an antibacterial self-lubricating composite fiber.

[0031] In some embodiments, in step (1), ultrafine polyoxymethylene (POM) powder is prepared: (1) Freezing: The polyoxymethylene spinning chips are cooled to -196℃, which is below the boiling point of liquid nitrogen. This temperature can make the polyoxymethylene sufficiently brittle, which is convenient for subsequent crushing operations. However, in actual operation, the temperature can be fine-tuned between -190℃ and -200℃ according to the specific characteristics of polyoxymethylene and the equipment conditions; the cooling time may need to be extended to 30 minutes to ensure that the inside can also be fully cooled and brittle; (2) Ultrasonic crushing stage: The frequency of the ultrasonic wave is 40 kHz; the ultrasonic power of the polyoxymethylene spinning slice is 2000 W; the crushing time is 20 minutes, and the polyoxymethylene (POM) ultrafine powder is obtained.

[0032] In some embodiments, in step (1), ultrafine polyoxymethylene (POM) powder is prepared: (1) Freezing: The polyoxymethylene spinning chips are cooled to below the boiling point of liquid nitrogen - 196°C. This temperature can make the polyoxymethylene sufficiently brittle, which is convenient for subsequent crushing operations. The cooling time may need to be extended to 60 minutes to ensure that the inside is also sufficiently cooled and brittle; (2) Ultrasonic crushing stage: The frequency of the ultrasonic wave is 40 kHz; the ultrasonic power of the polyoxymethylene spinning slice is 1500 W; the crushing time is 30 minutes, and polyoxymethylene (POM) ultrafine powder is obtained.

[0033] In some embodiments, in step (1), ultrafine polyoxymethylene (POM) powder is prepared: (1) Freezing: The polyoxymethylene spinning chips are cooled to -196℃, which is below the boiling point of liquid nitrogen. This temperature can make the polyoxymethylene sufficiently brittle, which is convenient for subsequent crushing operations. However, in actual operation, the temperature can be fine-tuned between -190℃ and -200℃ according to the specific characteristics of polyoxymethylene and the equipment conditions; the cooling time may need to be extended to 50 minutes to ensure that the inside can also be fully cooled and brittle; (2) Ultrasonic crushing stage: The frequency of the ultrasonic wave is 40 kHz; the ultrasonic power of the polyoxymethylene spinning slice is 1500 W; the crushing time is 25 minutes, and polyoxymethylene (POM) ultrafine powder is obtained.

[0034] In some embodiments, in step (1), an antibacterial polyoxymethylene slice is prepared: (11) slowly adding polyoxymethylene (POM) ultrafine powder into a reaction vessel containing a solvent dimethyl sulfoxide (DMSO), wherein the weight ratio of polyoxymethylene (POM) spinning chips to the solvent dimethyl sulfoxide (DMSO) is 1:4-10, stirring at a temperature of 100-150° C. for 1.5-6 hours in a closed environment, so that the powder is evenly dispersed to form a solution; (12) The solid antibacterial powder of hexamethyleneguanidine hydrochloride accounts for 3% to 10% of the total mass of the solid antibacterial powder of hexamethyleneguanidine hydrochloride and polyoxymethylene (POM) spinning chips. The hexamethyleneguanidine hydrochloride (PHMG) is slowly added to the polyoxymethylene / dimethyl sulfoxide (DMSO) solution under slow stirring to prevent the antibacterial agent from agglomerating; (13) Then, ultrasonic assisted dispersion is used, the ultrasonic frequency is set to 20-40 kHz power, and the ultrasonic treatment time is 10-30 minutes to ensure that the antibacterial agent is evenly dispersed in the ultra-high molecular weight polyethylene solution; (14) The antibacterial blend slices of the outer layer material are prepared by removing the solvent by heating evaporation or reduced pressure distillation, and then solidifying and slicing.

[0035] In some embodiments, in step (1), for the outer layer material part, the outer layer material includes polyoxymethylene (POM) and hexamethyleneguanidine hydrochloride, the temperature of the area near the feed port is 170°C, and the temperature of the subsequent area gradually increases, and the temperature of the area near the extruder head is 210°C; the outer layer of the antibacterial ultra-high molecular polyethylene is formed by mixing, heating, and extruding in a screw machine; the average molecular weight of polyoxymethylene (POM) is 300,000, and the melt index is 8g / 10min; the average molecular weight of ultra-high molecular polyethylene is 8 million. Mold temperature: The mold temperature has an important influence on the molding and quality of the fiber; the mold temperature is controlled at 190°C, so that the two-component melt extruded from the extruder can be well molded in the mold and the dimensional stability of the fiber is guaranteed.

[0036] In some embodiments, in step (1), for the outer layer material part, the outer layer material includes polyoxymethylene (POM) and hexamethyleneguanidine hydrochloride, the temperature of the area near the feed port is 180°C, and the temperature of the subsequent area gradually increases, and the temperature of the area near the extruder head is 190°C; the outer layer of the antibacterial ultra-high molecular polyethylene is formed by mixing, heating, and extruding in a screw machine; the average molecular weight of polyoxymethylene (POM) is 200,000, and the melt index is 12g / 10min; the average molecular weight of ultra-high molecular polyethylene is 1 million. Mold temperature: Mold temperature has an important influence on the molding and quality of the fiber; the mold temperature is controlled at 220°C, so that the two-component melt extruded from the extruder can be well molded in the mold and the dimensional stability of the fiber is guaranteed.

[0037] In some embodiments, in step (1), for the outer layer material part, the outer layer material includes polyoxymethylene (POM) and hexamethyleneguanidine hydrochloride, the temperature of the area near the feed port is 175°C, the temperature of the subsequent area gradually increases, and the temperature of the area near the extruder head is 200°C; the outer layer of the antibacterial ultra-high molecular polyethylene is formed by mixing, heating and extruding in a screw machine; the average molecular weight of polyoxymethylene (POM) is 100,000, and the melt index is 5g / 10min; the average molecular weight of ultra-high molecular polyethylene is 10 million. Mold temperature: The mold temperature has an important influence on the molding and quality of the fiber; the mold temperature is controlled at 200°C, so that the two-component melt extruded from the extruder can be well molded in the mold and the dimensional stability of the fiber is guaranteed.

[0038] In some embodiments, in step (2), for the ultra-high molecular weight polyethylene chip (UHMWPE) portion, the barrel temperature is higher than its melting point and ensures that the melt has good fluidity; the temperature near the feed port can be 180°C, the temperature in the middle area is 220°C, and the temperature near the extruder head is 230°C; the mold temperature is 220°C, and the spinneret temperature is 260°C to ensure continuous extrusion of the fiber.

[0039] In some embodiments, in step (2), for the ultra-high molecular weight polyethylene chip (UHMWPE) portion, the barrel temperature is higher than its melting point and ensures that the melt has good fluidity; the temperature near the feed port can be 190°C, the temperature in the middle area is 230°C, and the temperature near the extruder head is 240°C; the mold temperature is 190°C, and the spinneret temperature is 250°C to ensure continuous extrusion of the fiber.

[0040] In some embodiments, in step (2), for the ultra-high molecular weight polyethylene chip (UHMWPE) portion, the barrel temperature is higher than its melting point and ensures that the melt has good fluidity; the temperature near the feed port can be 200°C, the temperature in the middle area is 240°C, and the temperature near the extruder head is 250°C; the mold temperature is 210°C, and the spinneret temperature is 230°C to ensure continuous extrusion of the fiber.

[0041] In some embodiments, in step (3), temperature: the spinning temperature is adjusted according to the melting point and flow characteristics of the material to ensure that the material maintains appropriate fluidity during the spinning process, and the melting temperatures of the outer layer and the core layer are 210° C. and 240° C. respectively; Screw speed: Adjust the screw speed to ensure uniform mixing and stable conveying of the two materials in the screw. The screw speed is 200 rpm; Pressure: Adjust the spinning pressure to ensure that the two materials are evenly mixed and extruded at the spinneret. The pressure is 10 MPa. Spinning speed: Control the spinning speed to ensure the uniformity and continuity of the fiber. The spinning speed is 500 m / min.

[0042] In some embodiments, in step (3), temperature: the spinning temperature is adjusted according to the melting point and flow characteristics of the material to ensure that the material maintains appropriate fluidity during the spinning process, and the melting temperatures of the outer layer and the core layer are 200° C. and 260° C. respectively; Screw speed: Adjust the screw speed to ensure uniform mixing and stable conveying of the two materials in the screw. The screw speed is 300 rpm; Pressure: Adjust the spinning pressure to ensure that the two materials are evenly mixed and extruded at the spinneret. The pressure is 40 MPa. Spinning speed: Control the spinning speed to ensure the uniformity and continuity of the fiber. The spinning speed is 300 m / min.

[0043] In some embodiments, in step (3), temperature: adjusting the spinning temperature according to the melting point and flow characteristics of the material to ensure that the material maintains appropriate fluidity during the spinning process, the melting temperatures of the outer layer and the core layer are 190° C. and 240° C. respectively; Screw speed: Adjust the screw speed to ensure uniform mixing and stable conveying of the two materials in the screw. The screw speed is 100 rpm; Pressure: Adjust the spinning pressure to ensure that the two materials are evenly mixed and extruded at the spinneret. The pressure is 50 MPa. Spinning speed: Control the spinning speed to ensure the uniformity and continuity of the fiber. The spinning speed is 100 m / min.

[0044] A second aspect of an embodiment of the present application provides an antibacterial self-lubricating composite fiber obtained by a preparation method. Example 1

[0045] A method for preparing an antibacterial self-lubricating composite fiber of the present invention comprises the following steps: The antibacterial ultra-high molecular weight polyethylene fiber is a composite fiber with a skin-core structure, wherein the core layer is composed of ultra-high molecular weight polyethylene (UHMWPE); the outer layer is coated with a blend of hexamethyleneguanidine hydrochloride and polyoxymethylene (POM), which is the antibacterial polyoxymethylene; (1) Raw material preparation: Outer layer material: dissolving polyoxymethylene (POM) ultrafine powder in dimethyl sulfoxide (DMSO) solvent to form a solution; adding hexamethyleneguanidine hydrochloride antibacterial powder to the solution and dispersing it with the assistance of ultrasound; removing the solvent by heating evaporation or reduced pressure distillation, and then curing and slicing to obtain the antibacterial polyoxymethylene slices of the outer layer material; Core material: Ultra-high molecular weight polyethylene chips (UHMWPE) with excellent mechanical properties; The polyoxymethylene (POM) ultrafine powder is mixed with dimethyl sulfoxide (DMSO) solvent to form a solution; hexamethyleneguanidine hydrochloride antibacterial powder is added to the solution and dispersed by ultrasonic assistance; the solvent is removed by heating evaporation or reduced pressure distillation to solidify the slices, thereby obtaining the antibacterial polyoxymethylene slices of the outer layer material; Preparation of polyoxymethylene (POM) ultrafine powder: (1) Freezing: The polyoxymethylene spinning chips are cooled to -196℃, which is below the boiling point of liquid nitrogen. This temperature can make the polyoxymethylene sufficiently brittle, which is convenient for subsequent crushing operations. However, in actual operation, the temperature can be fine-tuned between -190℃ and -200℃ according to the specific characteristics of polyoxymethylene and the equipment conditions; the cooling time takes 30 minutes to ensure that the inside can also be fully cooled and brittle; (2) Ultrasonic crushing stage: The frequency of the ultrasonic wave is 40 kHz; the ultrasonic power of the polyoxymethylene spinning slice is 1800 W; the crushing time is 25 minutes, and polyoxymethylene (POM) ultrafine powder is obtained.

[0046] (2) Melt preparation: Outer layer melt: The outer layer material antibacterial polyoxymethylene slices are melted to prepare a melt. Premixing and melting can be performed in a twin-screw extruder to ensure uniform dispersion of the material; Core layer melt: The core layer material polyethylene (UHMWPE) is prepared into a melt by melting, and is also premixed and melted in a twin-screw extruder to ensure that the material is evenly dispersed; For the outer layer material, the outer layer material includes polyoxymethylene (POM) and hexamethyleneguanidine hydrochloride. The temperature of the area near the feed port is 180°C, and the temperature of the subsequent areas gradually increases, and the temperature of the area near the extruder head is 200°C; it is mixed, heated, and extruded in a screw machine to become the outer layer of the antibacterial ultra-high molecular polyethylene; the average molecular weight of polyoxymethylene (POM) is 200,000, and the melt index is 12g / 10min; the average molecular weight of ultra-high molecular polyethylene is 10 million.

[0047] (11) slowly adding polyoxymethylene (POM) ultrafine powder into a reaction vessel containing a solvent dimethyl sulfoxide (DMSO), wherein the weight ratio of polyoxymethylene (POM) spinning chips to the solvent dimethyl sulfoxide (DMSO) is 1:4, and stirring is performed at a temperature of 120° C. for 6 hours in a closed environment to uniformly disperse the powder to form a solution; (12) The solid antibacterial powder of hexamethyleneguanidine hydrochloride accounts for 10% of the total mass of the solid antibacterial powder of hexamethyleneguanidine hydrochloride and polyoxymethylene (POM) spinning chips. Hexamethyleneguanidine hydrochloride (PHMG) is slowly added into dimethyl sulfoxide (DMSO) under slow stirring to prevent the antibacterial agent from agglomerating; (13) Ultrasonic dispersion was then used, with the ultrasonic frequency set to 30 kHz and the ultrasonic treatment time set to 30 min to ensure that the antimicrobial agent was evenly dispersed in the polyoxymethylene solution; (14) The antibacterial polyoxymethylene slices of the outer layer material are obtained by removing the solvent by heating evaporation or reduced pressure distillation, and then solidifying and slicing.

[0048] (3) Twin-screw spinning: Use a two-component spinning device for spinning, in which the mass ratio of the antibacterial polyoxymethylene chips and the ultra-high molecular weight polyethylene chips of the outer layer material is 100:25; control the parameters during the spinning process to achieve uniform compounding and continuous extrusion of the fibers; control the temperature parameters, pressure parameters and speed parameters during the spinning process to achieve uniform compounding and continuous extrusion of the fibers, and stretch and heat-set the spun fibers to improve the mechanical properties and dimensional stability of the fibers.

[0049] Spinning was performed using a two-component spinning device, wherein the mass ratio of the antibacterial polyoxymethylene slices and the ultra-high molecular weight polyethylene slices of the outer layer material was 100:20; In step (2), for the ultra-high molecular weight polyethylene chips (UHMWPE) part, the barrel temperature must be higher than its melting point and ensure that the melt has good fluidity; the temperature near the feed port can be 180°C, the temperature in the middle area is 230°C, and the temperature near the extruder head is 250°C; the mold temperature is 220°C, and the spinneret temperature is 250°C to ensure continuous extrusion of the fiber.

[0050] (4) Fiber curing: Air curing: After the fiber is extruded from the spinneret, it naturally cures in the air. The temperature and humidity in the air will affect the curing speed and performance of the fiber; Cooling: Use cooling device to accelerate the solidification process of fiber and ensure the stability and uniformity of fiber; (5) Fiber molding: Drafting: Drafting is performed on the spun fibers to improve their orientation and mechanical properties. The drafting multiple is 2 times. Heat setting: The dimensional stability and mechanical properties of the fiber are improved by heat setting treatment. The heat setting temperature is 120°C and the time is 5 minutes to obtain an antibacterial self-lubricating composite fiber. Example 2

[0051] The difference between Example 2 and Example 1 is that the method for preparing an antibacterial self-lubricating composite fiber of the present invention comprises the following steps: In step (1), polyoxymethylene (POM) ultrafine powder is dissolved in dimethyl sulfoxide (DMSO) solvent to form a solution; hexamethyleneguanidine hydrochloride antibacterial powder is added to the solution and dispersed by ultrasonic assistance; the solvent is removed by heating evaporation or reduced pressure distillation to obtain antibacterial polyoxymethylene slices of the outer layer material; for the outer layer material part, the outer layer material includes polyoxymethylene (POM) and hexamethyleneguanidine hydrochloride, the temperature of the area near the feed port is 170°C, and the temperature of the subsequent area gradually increases, and the temperature of the area near the extruder head is 190°C; the outer layer of the antibacterial ultra-high molecular polyethylene is obtained by mixing, heating and extruding in a screw machine; the average molecular weight of the polyoxymethylene (POM) is 100,000, and the melt index is 9g / 10min; Preparation of polyoxymethylene (POM) ultrafine powder: (1) Freezing: The polyoxymethylene spinning chips are cooled to -196℃, which is below the boiling point of liquid nitrogen. This temperature can make the polyoxymethylene sufficiently brittle, which is convenient for subsequent crushing operations. However, in actual operation, the temperature can be fine-tuned between -190℃ and -200℃ according to the specific characteristics of polyoxymethylene and the equipment conditions; the cooling time may need to be extended to 60 minutes to ensure that the inside can also be fully cooled and brittle; (2) Ultrasonic crushing stage: The frequency of the ultrasonic wave is 40 kHz; the ultrasonic power of the polyoxymethylene spinning slice is 2000 W; the crushing time is 20 minutes, and the polyoxymethylene (POM) ultrafine powder is obtained.

[0052] In step (11), the polyoxymethylene (POM) ultrafine powder is slowly added into a reaction vessel containing a solvent of dimethyl sulfoxide (DMSO), the weight ratio of the polyoxymethylene (POM) spinning chips to the solvent of dimethyl sulfoxide (DMSO) being 1:8, and the mixture is stirred at 150° C. in a closed environment for 1.5 hours to uniformly disperse the powder into a solution; In step (12), the solid antibacterial powder of hexamethyleneguanidine hydrochloride accounts for 10% of the total mass of the solid antibacterial powder of hexamethyleneguanidine hydrochloride and polyoxymethylene (POM) spinning chips, and hexamethyleneguanidine hydrochloride (PHMG) is slowly added to dimethyl sulfoxide (DMSO) under slow stirring to prevent the antibacterial agent from agglomerating; In step (13), ultrasonic assisted dispersion is then used, with the ultrasonic frequency set to 40 kHz power and the ultrasonic treatment time set to 30 minutes to ensure that the antimicrobial agent is evenly dispersed in the polyoxymethylene / dimethyl sulfoxide (DMSO) solution; In step (14), the solvent is removed by heating evaporation or reduced pressure distillation, and then solidified and sliced ​​to prepare antibacterial polyoxymethylene slices of the outer layer material.

[0053] In step (3), a two-component spinning device is used for spinning, wherein the mass ratio of the antibacterial polyoxymethylene chips of the outer layer material to the ultra-high molecular polyethylene chips is 100:20; for the ultra-high molecular polyethylene chips (UHMWPE), the barrel temperature must be higher than its melting point and ensure that the melt has good fluidity; the temperature near the feed port can be 190°C, the temperature in the middle area is 220°C, and the temperature near the extruder head is 230°C; the mold temperature is 200°C, and the spinneret temperature is 260°C to ensure continuous extrusion of the fiber. The average molecular weight of the ultra-high molecular polyethylene is 1 million.

[0054] In step (5), the fiber is formed: Drafting: Drafting is performed on the spun fibers to improve their orientation and mechanical properties. The drafting multiple is 3 times. Fiber heat setting: The dimensional stability and mechanical properties of the fiber are improved through heat setting treatment. The heat setting temperature is 100°C and the time is 5 minutes to produce an antibacterial self-lubricating composite fiber. Example 3

[0055] The difference between Example 3 and Example 1 is that the method for preparing an antibacterial self-lubricating composite fiber of the present invention comprises the following steps: In step (1), polyoxymethylene (POM) ultrafine powder is dissolved in dimethyl sulfoxide (DMSO) solvent to form a solution; hexamethyleneguanidine hydrochloride antibacterial powder is added to the solution and dispersed by ultrasonic assistance; the solvent is removed by heating evaporation or reduced pressure distillation to obtain antibacterial polyoxymethylene slices of the outer layer material; for the outer layer material part, the outer layer material antibacterial polyoxymethylene slices, during the twin-screw spinning process, the temperature of the mixed material in the area close to the feed port is 175°C, and the temperature of the subsequent areas gradually increases, and the temperature of the area close to the extruder head is 210°C; the outer layer of the antibacterial ultra-high molecular polyethylene is obtained by mixing, heating and extruding in a screw machine; the average molecular weight of the polyoxymethylene (POM) is 300,000, and the melt index is 5g / 10min; the average molecular weight of the ultra-high molecular polyethylene is 9 million.

[0056] Preparation of polyoxymethylene (POM) ultrafine powder: (1) Freezing: The polyoxymethylene spinning slices are cooled to below the boiling point of liquid nitrogen - 196°C; the cooling time may need to be extended to 50 minutes to ensure that the inside is also fully cooled and brittle; (2) Ultrasonic crushing stage: The frequency of the ultrasonic wave is 40 kHz; the ultrasonic power of the polyoxymethylene spinning slice is 1500 W; the crushing time is 30 minutes, and polyoxymethylene (POM) ultrafine powder is obtained.

[0057] In step (11), the polyoxymethylene (POM) ultrafine powder is slowly added into a reaction vessel containing a solvent dimethyl sulfoxide (DMSO), the weight ratio of the polyoxymethylene (POM) spinning chips to the solvent dimethyl sulfoxide (DMSO) being 1:10, and the mixture is stirred at 100° C. in a closed environment for 5 hours to uniformly disperse the powder to form a solution; In step (12), the solid antibacterial powder of hexamethyleneguanidine hydrochloride accounts for 8% of the total mass of the solid antibacterial powder of hexamethyleneguanidine hydrochloride and polyoxymethylene (POM) spinning chips, and hexamethyleneguanidine hydrochloride (PHMG) is slowly added to the polyoxymethylene / dimethyl sulfoxide (DMSO) solution under slow stirring to prevent the antibacterial agent from agglomerating; In step (13), ultrasonic assisted dispersion is then used, the ultrasonic frequency is set to 20 kHz power, and the ultrasonic treatment time is 20 minutes to ensure that the antibacterial agent is evenly dispersed in the polyoxymethylene solution; In step (14), the solvent is removed by heating evaporation or reduced pressure distillation, and then solidified and sliced ​​to obtain antibacterial polyoxymethylene slices of the outer layer material.

[0058] In step (3), a two-component spinning device is used for spinning, wherein the mass ratio of the antibacterial polyoxymethylene chips and the ultra-high molecular weight polyethylene chips of the outer layer material is 100:30; for the ultra-high molecular weight polyethylene chips (UHMWPE) part, the barrel temperature must be higher than its melting point and ensure that the melt has good fluidity; the temperature of the area near the feed inlet can be 200°C, the temperature of the middle area is 240°C, and the temperature of the area near the extruder head is 240°C; the mold temperature is 190°C, and the spinneret temperature is 230°C to ensure continuous extrusion of the fiber.

[0059] In step (5), the fiber is formed: Drafting: The spun fibers are drafted to improve their orientation and mechanical properties. The drafting multiple is 5 times. Heat setting: The dimensional stability and mechanical properties of the fiber are improved by heat setting treatment. The heat setting temperature is 150°C and the time is 3 minutes to obtain an antibacterial self-lubricating composite fiber.

[0060] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and the scope of protection of the present invention is defined by the attached claims, description and their equivalents.

Claims

1. A method for preparing an antibacterial self-lubricating composite fiber, characterized in that The method comprises the following steps: the antibacterial self-lubricating composite fiber is a composite fiber with a skin-core structure, wherein the core layer is composed of ultra-high molecular weight polyethylene (UHMWPE); the outer layer is coated with a blend of hexamethylene guanidine hydrochloride and polyoxymethylene (POM), namely, the antibacterial polyoxymethylene; (1) Raw material preparation: Outer layer material: dissolving polyoxymethylene (POM) ultrafine powder in dimethyl sulfoxide (DMSO) solvent to form a solution; adding hexamethyleneguanidine hydrochloride antibacterial powder to the solution and dispersing it with the assistance of ultrasound; removing the solvent by heating evaporation or reduced pressure distillation, and then curing and slicing to obtain antibacterial polyoxymethylene slices of the outer layer material; Core material: Ultra-high molecular weight polyethylene chips (UHMWPE) with excellent mechanical properties; (2) Melt preparation: Outer layer melt: The antibacterial polyoxymethylene chips of the outer layer material are prepared into a melt by melting, and are premixed and melted in a twin-screw extruder to ensure that the material is evenly dispersed; Core layer melt: The core layer material ultra-high molecular weight polyethylene chips UHMWPE are prepared into a melt by melting, and are also pre-mixed and melted in a twin-screw extruder to ensure that the material is evenly dispersed; (3) Twin-screw spinning: Use a two-component spinning device for spinning, where the mass ratio of the antibacterial polyoxymethylene chips and the ultra-high molecular weight polyethylene chips of the outer layer material is 100:20-30; control the parameters during the spinning process to achieve uniform composite and continuous extrusion of the fibers; (4) Fiber curing: Air curing: After the fiber is extruded from the spinneret, it naturally cures in the air. The temperature and humidity in the air will affect the curing speed and performance of the fiber. Cooling: Use cooling device to accelerate the solidification process of fiber and ensure the stability and uniformity of fiber; (5) Fiber molding: Drafting: Drafting is performed on the spun fibers to improve their orientation and mechanical properties. The drafting multiple is 2-5 times. Heat setting: Through heat setting treatment, the dimensional stability and mechanical properties of the fiber are improved. The heat setting temperature is 100-150°C and the time is 1-5 minutes to produce an antibacterial self-lubricating composite fiber.

2. The method for preparing the antibacterial self-lubricating composite fiber according to claim 1, characterized in that: In step (1), polyoxymethylene (POM) ultrafine powder is prepared: (1) Freezing: The polyoxymethylene spinning slices are cooled to below the boiling point of liquid nitrogen - 196°C. The cooling time may need to be extended to 30 - 60 minutes to ensure that the inside is also fully cooled and brittle; (2) Ultrasonic crushing stage: The frequency of the ultrasonic wave is 40kHz; the ultrasonic power of the polyoxymethylene spinning slice is 1500-2000W; the crushing time is 20-30 minutes, and the polyoxymethylene POM ultrafine powder is obtained.

3. The method for preparing the antibacterial self-lubricating composite fiber according to claim 1, characterized in that: In step (1), antibacterial polyoxymethylene slices are prepared: (11) slowly adding the polyoxymethylene (POM) ultrafine powder into a reaction vessel containing a solvent of dimethyl sulfoxide (DMSO), wherein the weight ratio of the polyoxymethylene (POM) ultrafine powder to the solvent of dimethyl sulfoxide (DMSO) is 1:4-10, stirring at a temperature of 100-150° C. for 1.5-6 hours in a closed environment, so that the ultrafine powder is evenly dispersed to form a solution; (12) The solid antibacterial powder of hexamethyleneguanidine hydrochloride accounts for 3% to 10% of the total mass of the solid antibacterial powder of hexamethyleneguanidine hydrochloride and polyoxymethylene (POM) spinning chips. The hexamethyleneguanidine hydrochloride (PHMG) is slowly added to dimethyl sulfoxide (DMSO) under slow stirring to prevent the antibacterial agent from agglomerating; (13) Ultrasonic dispersion was assisted by ultrasound, with the ultrasonic frequency set to 20-40 kHz and the ultrasonic treatment time set to 10-30 minutes to ensure that the antimicrobial agent was evenly dispersed in the ultra-high molecular weight polyethylene solution; (14) The antibacterial polyoxymethylene slices of the outer layer material are obtained by removing the solvent by heating evaporation or reduced pressure distillation, and then solidifying and slicing.

4. The method for preparing the antibacterial self-lubricating composite fiber according to claim 1, characterized in that: In step (1), for the outer layer material part, the outer layer material antibacterial polyoxymethylene slices, the temperature of the area near the feed port is 170-180°C, and the temperature of the subsequent area gradually increases, and the temperature of the area near the extruder head is 190-210°C; the outer layer of the antibacterial ultra-high molecular polyethylene is formed by mixing, heating and extruding in a screw machine; the average molecular weight of polyoxymethylene POM is 100,000-300,000, and the melt index is 5-12g / 10min.

5. The method for preparing the antibacterial self-lubricating composite fiber according to claim 4, characterized in that: In step (2), for the UHMWPE part of the ultra-high molecular weight polyethylene slice, the barrel temperature must be higher than its melting point and ensure that the melt has good fluidity; the temperature near the feed port can be 180-200°C, the temperature in the middle area is 220-240°C, and the temperature near the extruder head is 230-250°C; the mold temperature is 190-220°C, and the spinneret temperature is 230-260°C to ensure continuous extrusion of the fiber; the average molecular weight of the ultra-high molecular weight polyethylene is 1-10 million.

6. The method for preparing the antibacterial self-lubricating composite fiber according to claim 5, characterized in that: In step (3), temperature: the spinning temperature is adjusted according to the melting point and flow characteristics of the material to ensure that the material maintains appropriate fluidity during the spinning process. The melting temperatures of the outer layer and the core layer are 180-210°C and 200-260°C respectively; Screw speed: Adjust the screw speed to ensure uniform mixing and stable conveying of the two materials in the screw. The screw speed is 100-300 rpm; Pressure: Adjust the spinning pressure to ensure that the two materials are evenly mixed and extruded at the spinneret. The pressure is 10-50 MPa. Spinning speed: Control the spinning speed to ensure the uniformity and continuity of the fiber. The spinning speed is 100-500 m / min.

7. The antibacterial self-lubricating composite fiber obtained by the preparation method according to any one of claims 1 to 6.