Method, system, apparatus, and medium for preparing antibacterial and ultraviolet functional composite fiber

Abstract

The application discloses an antibacterial and anti-ultraviolet functional composite fiber preparation method, system, equipment and medium, and particularly relates to the technical field of textile materials, and comprises the following steps: preparing surface-modified nano-silver antibacterial master batches and surface-modified nano-zinc oxide anti-ultraviolet master batches; after the fiber matrix resin is melted, the fiber matrix resin is divided into three melt flow paths; an antibacterial agent concentration continuously decreasing and an anti-ultraviolet agent concentration continuously increasing reverse gradient melt is prepared through online dynamic gradient mixing; then, the reverse gradient melt is formed into a skin-core structure with an antibacterial gradient outer layer, an anti-ultraviolet gradient intermediate layer and a pure matrix core layer through coaxial three-layer composite spinning; finally, the gradient distribution is fixed through gradient side-blowing air cooling, multi-stage stretching and constant-tension heat setting, so that the antibacterial and anti-ultraviolet functional composite fiber is obtained. The application solves the problem of mutual antagonism of functional components, and the prepared fiber has long-acting antibacterial and high-efficiency anti-ultraviolet performances.

Description

Technical Field

[0001] This invention relates to the field of textile materials technology, and more specifically, to a method, system, equipment, and medium for preparing antibacterial and UV-resistant functional composite fibers. Background Technology

[0002] Currently, in the field of functional textile materials, antibacterial and UV-resistant fibers are mostly prepared by blend spinning, surface coating or simple composite modification processes. Typically, nano-silver is used as the antibacterial component and nano-zinc oxide is used as the UV-resistant component. Functional particles are directly blended with the fiber matrix resin and then conventionally spun, or the functional components are added in combination through a simple core-sheath structure, thereby giving the fiber dual functions of antibacterial and UV resistance.

[0003] However, in practical use, it still has some drawbacks. For example, direct blending of nano-silver and nano-zinc oxide can easily lead to functional antagonism, making it impossible to achieve effective spatial isolation between the two functional components. Functional particles are prone to agglomeration, resulting in poor dispersion uniformity, which leads to insufficient fiber functional stability and decreased mechanical properties. Conventional processes cannot form a precise continuous reverse concentration gradient structure, and the concentration of functional components at the interface is too high, which can easily cause functional decay of the fiber during long-term use. At the same time, the melt splitting and gradient mixing control precision is low, resulting in poor spinning stability and making it difficult to meet the preparation requirements of high-end functional textile materials. Summary of the Invention

[0004] In order to overcome the above-mentioned defects of the prior art, the present invention provides a method, system, equipment and medium for preparing antibacterial and UV-resistant functional composite fibers, and solves the problems mentioned in the background art through the following solutions.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a method for preparing antibacterial and UV-resistant functional composite fibers, comprising:

[0006] S1: Surface-modified nano-silver with a particle size of 10-50nm is melt-blended and extruded with the first carrier resin to obtain an antibacterial masterbatch with a silver content of 5-15wt%.

[0007] Surface-modified nano zinc oxide with a particle size of 20-80 nm is melt-blended and extruded with a second carrier resin to obtain an anti-UV masterbatch with a zinc oxide content of 10-25 wt%.

[0008] Both the first carrier resin and the second carrier resin are homologous polymers to the fiber matrix resin;

[0009] S2: The dried fiber matrix resin is fed into a screw extruder to melt, and the total matrix resin melt is obtained. It is then divided into a first matrix melt flow path, a second matrix melt flow path, and a third matrix melt flow path by a melt distributor.

[0010] S3: A gradient metering pump unit is used in conjunction with an online dynamic gradient mixing unit to perform functional gradient mixing on the first and second matrix melt flow paths respectively:

[0011] Antibacterial masterbatch is added to the first matrix melt flow path in a continuous gradient from high to low concentration to obtain an antibacterial gradient melt;

[0012] UV-resistant masterbatch is added to the second matrix melt flow path in a continuous gradient from low to high concentration to obtain UV-resistant gradient melt;

[0013] The third matrix melt flow path does not add any functional masterbatch and is used as a pure matrix resin melt.

[0014] S4: The antibacterial gradient melt, the anti-UV gradient melt, and the pure matrix resin melt are respectively fed into a coaxial three-layer spinneret for composite spinning to form nascent fibers with a reverse concentration gradient core-sheath structure:

[0015] The outermost layer is an antibacterial gradient layer, with the concentration of nano-silver decreasing continuously from the fiber surface to the interior;

[0016] The middle layer is an anti-UV gradient layer, and the concentration of nano-zinc oxide continuously decreases from the inside of the fiber to the surface;

[0017] The core layer is a pure matrix resin layer; at the interface between the antibacterial gradient layer and the anti-ultraviolet gradient layer, the concentrations of nano-silver and nano-zinc oxide are both ≤0.2wt%, achieving spatial isolation between the two functional components.

[0018] S5: Nascent fibers are cooled by side blowing, stretched in multiple stages and heat-set to obtain antibacterial and UV-resistant composite fibers.

[0019] An antibacterial and UV-resistant functional composite fiber preparation system includes:

[0020] Antibacterial masterbatch preparation module: used to prepare antibacterial masterbatch with a silver content of 5-15wt%. The antibacterial masterbatch is prepared by melt blending surface-modified nano-silver with a first carrier resin. The first carrier resin and the fiber matrix resin are homologous polymers.

[0021] UV-resistant masterbatch preparation module: used to prepare UV-resistant masterbatch with zinc oxide content of 10-25wt%. The UV-resistant masterbatch is prepared by melt blending surface-modified nano zinc oxide with a second carrier resin. The second carrier resin and the fiber matrix resin are homologous polymers.

[0022] Matrix melt distribution module: used to melt the dried fiber matrix resin to obtain the total matrix resin melt, and precisely divide it into the first matrix melt flow path, the second matrix melt flow path and the third matrix melt flow path;

[0023] Dual-channel online dynamic gradient mixing module: used to add antibacterial masterbatch to the first matrix melt flow path in a continuous gradient from high to low concentration to obtain antibacterial gradient melt, and to add anti-UV masterbatch to the second matrix melt flow path in a continuous gradient from low to high concentration to obtain anti-UV gradient melt; the third matrix melt flow path does not add any functional masterbatch and serves as pure matrix resin melt.

[0024] Coaxial three-layer composite spinning module: used to composite spin antibacterial gradient melt, anti-ultraviolet gradient melt and pure matrix resin melt to form nascent fibers with a reverse concentration gradient core-sheath structure;

[0025] Post-processing module: used to sequentially perform side-blowing cooling, multi-stage stretching and heat setting on the nascent fibers to obtain the final antibacterial and UV-resistant functional composite fibers.

[0026] This application provides an electronic device that adopts the following technical solution: it includes a processor, at least one communication bus, a user interface, a network interface, and a memory; and a computer program stored in the memory and executable on the processor, wherein the computer program, when executed by the processor, implements the method for preparing the antibacterial and UV-resistant functional composite fiber.

[0027] This application provides a computer-readable storage medium, which adopts the following technical solution: the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, it implements the method for preparing antibacterial and anti-ultraviolet functional composite fibers.

[0028] The technical effects and advantages of this invention are as follows:

[0029] 1. This invention achieves spatial isolation of antibacterial and anti-UV functional components through a reverse concentration gradient core-sheath structure, solving the antagonistic problem of the two functional particles, allowing the fiber to simultaneously possess long-lasting antibacterial and highly efficient anti-UV properties, thus improving functional synergy;

[0030] 2. This invention uses chemical bonding surface modification treatment on nano-silver and nano-zinc oxide to avoid functional particle agglomeration, improve the interfacial compatibility between particles and matrix resin, ensure stable fiber mechanical properties, and avoid problems such as strength reduction and uneven yarn distribution.

[0031] 3. This invention relies on high-precision melt splitting and servo-driven gradual metering pump control to achieve continuous linear regulation of functional component concentration. Combined with dynamic and static combined mixing unit to ensure mixing uniformity, stable spinning process, and high product performance consistency.

[0032] 4. After gradient cooling, multi-stage stretching and constant tension heat setting, the gradient distribution of functional components is permanently fixed, and the fibers are not prone to particle migration during long-term use and washing, resulting in excellent functional durability and dimensional stability. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0034] Figure 2 This is a schematic diagram of the structure of the method for preparing antibacterial and UV-resistant functional composite fibers according to the present invention.

[0035] Figure 3 This is a schematic diagram of the system module structure of the present invention.

[0036] Figure 4 This is a schematic diagram of the electronic device structure of the present invention. Detailed Implementation

[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] refer to Figures 1-2 The method for preparing the antibacterial and UV-resistant functional composite fiber shown includes:

[0039] The preparation of the S1 highly compatible functional masterbatch involves addressing the hard agglomeration problem of nano-functional particles through chemical bonding modification, achieving interfacial molecular-level compatibility between the masterbatch and the fiber matrix resin. The specific implementation is as follows:

[0040] Preparation of S101 antibacterial masterbatch includes:

[0041] S101-1 Nano Silver Surface Modification

[0042] Take a particle size of The spherical silver nanoparticles have both excellent antibacterial activity and low migration within this particle size range. When the particle size is less than 10 nm, it tends to agglomerate and migrate too quickly, while when it is greater than 50 nm, the specific surface area is insufficient, resulting in a decrease in antibacterial efficiency.

[0043] Nano-silver was dispersed in anhydrous ethanol to prepare a solution with a mass fraction of [missing value]. The concentration of the suspension is such that it ensures sufficient processing efficiency while avoiding uneven dispersion caused by excessively high suspension viscosity.

[0044] In power Ultrasonic dispersion The intermittent ultrasound mode (3 seconds of ultrasound followed by 2 seconds of pause) is used to prevent local overheating from causing secondary aggregation of nano-silver and effectively break up the primary aggregates.

[0045] The amount of silane coupling agent KH-570 added to the suspension is calculated using the following formula:

[0046]

[0047] in: The mass of silane coupling agent KH-570 is expressed in grams. The value represents the mass of the silver nanoparticles, expressed in grams.

[0048] It should be further explained that KH-570 was chosen as the modifier because its molecule contains double bonds, which allow it to undergo grafting reactions with subsequent polyester, polyolefin, and other matrix resins to form a chemically bonded interface. In contrast, ordinary silane coupling agents can only form physical adsorption, resulting in weak interfacial bonding. A dosage of 1.8% is just enough to form a monolayer coating on the surface of the nano-silver; insufficient dosage leads to incomplete coating, while excessive dosage results in the formation of a multilayer, which reduces interfacial compatibility.

[0049] The pH of the system was adjusted to [value missing] using glacial acetic acid. At this pH value, the hydrolysis rate of the silane coupling agent is moderate, which can ensure sufficient hydrolysis to generate silanol groups, while avoiding excessive hydrolysis that could lead to self-condensation.

[0050] At temperature Under constant temperature stirring reaction The stirring speed was controlled at 300 rpm to ensure that the coupling agent molecules were firmly grafted onto the surface of the silver nanoparticles through Si-O-Ag chemical bonds.

[0051] After the reaction is complete, the suspension is rotated at a speed of [missing information]. Lower centrifugal separation These centrifugation conditions allow for the complete separation of modified silver nanoparticles from unreacted coupling agents.

[0052] Collect the precipitate, wash it three times with anhydrous ethanol to remove residual coupling agent and ethanol, and then heat it at a suitable temperature. Vacuum drying The material is brought to constant weight, and the vacuum level is controlled at -0.095 MPa to prevent the nano-silver from oxidizing during the drying process.

[0053] Surface-modified silver nanoparticles were obtained, and the particle size of their secondary aggregates was controlled within [specific range]. The particle size distribution is measured using a laser particle size analyzer to ensure that the dispersion meets the requirements for subsequent spinning.

[0054] S101-2 Melt Blending Granulation

[0055] The modified nano-silver and the first carrier resin were mixed in a mass ratio of... The first carrier resin and the fiber matrix resin used subsequently are homologous polymers, and the melt flow rate deviates from that of the matrix resin by no more than ±5g / 10min.

[0056] The use of homologous carrier resins is to ensure that the masterbatch and the matrix melt have completely consistent thermodynamic compatibility, and to avoid interfacial delamination and melt fracture.

[0057] The mixture is fed into a twin-screw extruder for melt blending and extrusion. The twin-screw extruder is a co-rotating type with a length-to-diameter ratio of 40:1. The temperatures of each zone are set sequentially from the feed port to the die head as follows: The head temperature is .in The melting point of the fiber matrix resin

[0058] Screw speed Residence time of material in the extruder This residence time ensures that the nano-silver is fully dispersed while preventing the resin from degrading at high temperatures for an extended period.

[0059] The extrudate is cooled in a circulating water cooling tank at 25°C for 3 meters to ensure complete solidification. It then enters a pelletizer for pelletizing, with the pelletizing speed synchronized with the extrusion speed, yielding cylindrical masterbatch with a particle size of 3-4 mm.

[0060] masterbatch in After vacuum drying for 8 hours, antibacterial masterbatch was obtained, and its silver content was calculated using the following formula:

[0061]

[0062] The silver content of the prepared antibacterial masterbatch =9 Melt flow rate (Test conditions:) (2.16 kg), the cross-section of the masterbatch was observed by scanning electron microscopy, and the nano-silver was uniformly dispersed without obvious agglomerates. This melt flow rate was used to characterize the melt flowability of the antibacterial masterbatch, ensuring that it matches the flowability of the fiber matrix resin, facilitating subsequent online mixing and coaxial spinning.

[0063] Preparation of S102 UV-resistant masterbatch includes:

[0064] S102-1 Nano Zinc Oxide Surface Modification

[0065] Take a particle size of The hexagonal zinc oxide nanoparticles have a much higher UV shielding efficiency than cubic zinc oxide. Zinc oxide in this particle size range has a full-band shielding effect against UV light of 280-400nm, and has high visible light transmittance, which will not cause the fibers to yellow severely.

[0066] Nano zinc oxide was dispersed in deionized water to prepare a solution with a mass fraction of [missing value]. The suspension, in power Ultrasonic dispersion Similarly, intermittent ultrasonic mode is used to break up the hard agglomerates of nano zinc oxide.

[0067] Stearic acid is added to the suspension as a surface modifier, and its dosage is calculated according to the following formula:

[0068]

[0069] in: This represents the mass of stearic acid, in grams. The value represents the mass of the nano zinc oxide powder, expressed in grams.

[0070] It should be further explained that the carboxyl groups in stearic acid molecules can undergo esterification with the hydroxyl groups on the surface of nano-zinc oxide to form zinc stearate, which changes the surface of nano-zinc oxide from hydrophilic to lipophilic, improving its compatibility in organic polymer matrices. A dosage of 2.6% can form a complete hydrophobic monolayer on the zinc oxide surface; insufficient dosage results in incomplete lipophilic modification, while excessive dosage leads to stearic acid residue, reducing the mechanical properties of the masterbatch.

[0071] The pH of the system was adjusted using ammonia. At this pH value, the esterification rate of stearic acid is the fastest, and it does not cause the dissolution of nano zinc oxide.

[0072] At temperature Under constant temperature stirring reaction The stirring speed is controlled at 350 rpm to ensure that the reaction proceeds uniformly.

[0073] After the reaction is complete, the suspension is rotated at a speed of [missing information]. Lower centrifugal separation Collect the precipitate and wash it three times with deionized water to remove residual ammonia and unreacted stearic acid.

[0074] At temperature Vacuum drying After reaching constant weight and controlling the vacuum degree to -0.095 MPa, surface-modified nano-zinc oxide was obtained, with the secondary agglomerate particle size controlled within [specific parameters]. .

[0075] S102-2 Melt Blending Granulation

[0076] The modified nano zinc oxide and the second carrier resin were mixed in the following mass ratio. The mixture is uniformly mixed, and the second carrier resin is also a homologous polymer to the fiber matrix resin, and the melt flow rate deviates from that of the matrix resin by no more than ±5g / 10min.

[0077] The mixture is fed into a twin-screw extruder for melt blending and extrusion. The length-to-diameter ratio of the twin-screw extruder is 44:1, and the temperatures of each zone from the feed port to the die head are set sequentially as follows: The head temperature is .

[0078] The extrusion temperature is 4°C higher than that of the antibacterial masterbatch because nano zinc oxide has better thermal conductivity than nano silver, requiring a higher temperature to ensure that the resin melts fully and improves the dispersion effect.

[0079] Screw speed Residence time of material in the extruder A longer residence time is beneficial for the full dispersion of nano zinc oxide in high-viscosity melt.

[0080] The extrudate is cooled in a circulating water cooling tank at a water temperature of 28℃ for a length of 3.5m, and then enters a pelletizer to be pelletized to obtain cylindrical masterbatch with a particle size of 3-4mm.

[0081] masterbatch in After vacuum drying for 8 hours, the UV-resistant masterbatch was obtained, and its zinc oxide content was calculated using the following formula:

[0082]

[0083] The zinc oxide content of the obtained UV-resistant masterbatch =18 Melt flow rate (Test conditions:) (2.16 kg). Scanning electron microscopy revealed that the cross-section of the masterbatch showed uniform dispersion of nano-zinc oxide with no agglomerates larger than 200 nm. This melt flow rate was used to characterize the melt flowability of the UV-resistant masterbatch, ensuring its match with the flowability of the fiber matrix resin and the antibacterial masterbatch, thus guaranteeing a stable spinning process.

[0084] S2 Matrix Resin Melting and Precise Flow Division: A uniform, stable, bubble-free, and degradation-free matrix resin melt is prepared and precisely divided into three independent flow paths with identical temperature, pressure, and flow rate. The specific implementation is as follows:

[0085] The fiber matrix resin is subjected to temperature Vacuum drying The vacuum level is controlled at -0.1 MPa. Among these... The glass transition temperature is the temperature of the fiber matrix resin.

[0086] The drying temperature is 12°C lower than the glass transition temperature of the resin, which ensures that the moisture evaporates fully and prevents the resin particles from sticking together and clumping.

[0087] A drying time of 15 hours can reduce the moisture content of the resin. When the moisture content is higher than 30 ppm, the resin will undergo hydrolytic degradation during the melting process, resulting in molecular chain breakage, a decrease in fiber mechanical properties of more than 30%, and the generation of a large number of bubbles, causing the spinning ends to break.

[0088] The dried fiber matrix resin is fed into a single-screw extruder for melt plasticization. The single-screw extruder has a length-to-diameter ratio of 30:1 and uses a barrier-type screw to improve plasticization uniformity. The temperatures of each zone are set sequentially from the feed port to the die head as follows: The head temperature is .

[0089] Screw speed At this rotational speed, the shear rate of the melt is moderate, which can ensure sufficient plasticization while avoiding resin degradation caused by overheating due to shearing.

[0090] A uniform and stable total matrix resin melt is obtained, and its melt pressure Pressure fluctuations are controlled within ±0.05MPa, and are monitored and adjusted in real time by a high-precision pressure sensor installed at the machine head.

[0091] The total matrix resin melt is fed into a high-precision static melt distributor. This distributor adopts a multi-stage symmetrical flow distribution structure, and the inner wall of the flow channel is mirror polished with a roughness Ra≤0.02μm to avoid melt retention and degradation.

[0092] Through precise calculation of the flow channel geometry and pressure balance design, the total melt is accurately divided into three independent and stable matrix melt flow paths, namely the first matrix melt flow path, the second matrix melt flow path and the third matrix melt flow path.

[0093] Each of the three flow paths is equipped with an independent temperature control system and pressure sensor to ensure that the melt temperature deviation is controlled within a specified range. Within this range, the melt pressure deviation is controlled within... Within this range, the shunting accuracy reaches ±0.4%.

[0094] The flow rates of the three flow paths are distributed according to the following formula:

[0095] in: These are the volumetric flow rates of the first, second, and third matrix melt flow paths, respectively, in units of... ; These represent the thicknesses of the antibacterial gradient layer, the UV-resistant gradient layer, and the pure matrix core layer of the target fiber, respectively, in μm.

[0096] In coaxial three-layer spinning, the volume flow rate ratio of each layer is equal to its thickness ratio, because the density of the three melts is basically the same and the flow rate at the spinneret outlet is the same.

[0097] This implementation setting =28:42:30, therefore =28:42:30. The 28% thickness of the antibacterial layer ensures sufficient surface antibacterial concentration, the 42% thickness of the UV-resistant layer provides excellent UV shielding, and the 30% thickness of the core layer ensures the mechanical properties of the fiber and reduces costs.

[0098] S3 online dynamic gradient mixing prepares functional gradient melts: Through the synergistic effect of a servo-driven gradual metering pump group and a series-connected dynamic-static combined online mixing unit, functional melts with continuous linear concentration gradients are prepared, precisely controlling the concentration variation of functional components and providing a precise material basis for the subsequent formation of a reverse gradient core-skin structure. The specific implementation is as follows:

[0099] Gradient mixing is achieved by using a servo-driven gradient metering pump set in conjunction with a series-connected dynamic-static online mixing unit.

[0100] The gradient metering pump set includes two independent servo-driven metering pumps, which adopt a high-precision gear pump structure and achieve a metering accuracy of ±0.09%.

[0101] The servo motor is connected to the PLC control system via an encoder, enabling continuous linear flow regulation from 0-100% with a flow response time of [missing information]. It can quickly respond to flow rate change commands and ensure the linearity of the concentration gradient.

[0102] The online mixing unit employs a series combination of an SK-type static mixer and a micro dynamic stirrer. The SK-type static mixer contains 14 mixing elements arranged in alternating left-hand and right-hand rotations, enabling multiple splitting, merging, and shearing of the melt for initial mixing. The micro dynamic stirrer, installed at the outlet of the static mixer, uses a paddle-type structure and a rotational speed... This can further eliminate mixing dead zones and improve mixing uniformity. Mixing time The extremely short mixing time ensures that the functional masterbatch and the matrix melt are uniformly mixed in a very short time, avoiding the disruption of the gradient distribution caused by melt flow in the subsequent flow channel.

[0103] Preparation of S301 antibacterial gradient melt

[0104] The first matrix melt flow path operates at a constant volumetric flow rate. Entering the first online mixing unit, the antibacterial masterbatch is melted and plasticized by a dedicated small single-screw extruder, and then fed into the first graded metering pump at a volumetric flow rate. Add the first online mixing unit.

[0105] The temperature setting of the dedicated single-screw extruder is consistent with the die head temperature during the preparation of antibacterial masterbatch, ensuring that the viscosity of the masterbatch melt matches the viscosity of the matrix melt.

[0106] control From the formula below linearly decreasing to :

[0107]

[0108] in: The gradient control time for the gradual metering pump is calculated from the point when the flow rate begins to adjust linearly, and the unit is seconds (s). The time of one spinning cycle, measured in seconds (s). The maximum volumetric flow rate of the antibacterial masterbatch, in units of ; The minimum volumetric flow rate of the antibacterial masterbatch, in units of .

[0109] in, and Calculate using the following formula:

[0110]

[0111]

[0112] By controlling the flow rate as described above, the amount of antibacterial masterbatch added to the first matrix melt can be linearly reduced from the highest value to the lowest value, thereby obtaining an antibacterial gradient melt with a continuous linear change in antibacterial agent concentration.

[0113] The concentration distribution of the antibacterial agent in the resulting antibacterial gradient melt is calculated using the following formula:

[0114]

[0115] In the prepared antibacterial gradient melt, the concentration of antibacterial agent ranges from... Decrease continuously to Mixing uniformity The concentration distribution of the melt is monitored in real time using an online infrared spectrometer to ensure that the gradient linearity meets the requirements. This mixing uniformity is used to characterize the mixing effect between the antibacterial masterbatch and the matrix melt, ensuring that the nano-silver is evenly distributed in the melt, guaranteeing stable antibacterial performance and a smooth spinning process.

[0116] Preparation of S302 UV-resistant gradient melt

[0117] The second matrix melt flow path operates at a constant volumetric flow rate. Entering the second online mixing unit, the UV-resistant masterbatch, after being melted and plasticized by another dedicated small single-screw extruder, is then fed into a second gradual metering pump at a volumetric flow rate. Add a second online mixing unit.

[0118] control From the formula below linearly increasing to :

[0119]

[0120] in: The maximum volumetric flow rate of the UV-resistant masterbatch, in units of ; Minimum volumetric flow rate of UV-resistant masterbatch, in units of .

[0121] in, and Calculate using the following formula:

[0122]

[0123]

[0124] The amount of UV-resistant masterbatch added increases linearly from the minimum value to the maximum value, which is opposite to the direction of change of the amount of antibacterial masterbatch added, thus obtaining a UV-resistant gradient melt with opposite concentration change direction.

[0125] The concentration distribution of the UV stabilizer in the resulting UV-resistant gradient melt is calculated using the following formula:

[0126]

[0127] In the prepared UV-resistant gradient melt, the concentration of the UV stabilizer ranges from... continuously increasing to Mixing uniformity The concentration distribution was also detected in real time using an online infrared spectrometer. This mixing uniformity is used to characterize the mixing effect between the UV-resistant masterbatch and the matrix melt, ensuring that the nano-zinc oxide is evenly distributed in the melt and avoiding local agglomeration that could cause spinning abnormalities and uneven UV resistance.

[0128] S303 pure matrix resin melt

[0129] The third matrix melt flow path maintains a constant volumetric flow rate. Without adding any functional masterbatch, it is directly delivered to the spinning assembly as a pure matrix resin melt.

[0130] The pure matrix core layer has three main functions: first, to provide the main mechanical properties of the fiber and avoid the decline in fiber mechanical properties due to excessive functional components; second, to reduce production costs and reduce the amount of functional components used; and third, to act as a physical barrier to prevent the migration of nano zinc oxide in the UV-resistant layer into the fiber interior and ensure the stability of the gradient distribution.

[0131] S4 coaxial three-layer composite spinning forms a reverse gradient core-skin structure: By precisely matching the flow rate change rate of the gradual metering pump with the residence time of the melt in the flow channel, two functional melts with reverse concentration gradients are combined with a pure matrix melt to form a reverse concentration gradient core-skin structure with an "antibacterial outer gradient layer - anti-UV inner gradient layer - pure matrix core layer," achieving submicron-level spatial isolation between the two functional components and completely eliminating antagonistic effects. The specific implementation is as follows:

[0132] It adopts a custom high-precision coaxial three-layer spinneret, which is made of stainless steel and undergoes precision machining and heat treatment to ensure dimensional stability.

[0133] spinneret diameter Aspect Ratio This aspect ratio allows the melt to relax fully within the spinneret, reducing the elastic memory effect and preventing melt breakage during spinning.

[0134] The three-layer flow channel adopts a concentric circle structure, consisting of an outer layer flow channel, an intermediate layer flow channel, and a core layer flow channel from the outside to the inside. The inlet angle of each flow channel is 30°, and the outlet junction adopts a rounded transition to avoid eddies in the melt flow.

[0135] Concentricity deviation of the three-layer flow channel Excessive concentricity deviation can lead to eccentricity of the three fiber layers, uneven thickness of the functional layer, and serious impact on the consistency of fiber performance.

[0136] The antibacterial gradient melt is fed into the outermost channel of the spinneret, the UV-resistant gradient melt is fed into the middle channel of the spinneret, and the pure matrix resin melt is fed into the core channel of the spinneret.

[0137] S401 Key Process Matching Control

[0138] Precisely matching the flow rate variation cycle of the variable metering pump with the residence time of the melt in the flow channel is the core of forming a perfect reverse gradient structure. The residence time of the melt from the mixing unit outlet to the spinneret outlet... Calculate using the following formula:

[0139]

[0140] in: The total flow channel volume from the mixing unit outlet to the spinneret outlet, in units of ; This represents the total melt volumetric flow rate for the corresponding flow path, in units of... .

[0141] Controlling the flow rate variation cycle of the variable metering pump Equal to the residence time of the melt in the flow channel ,Right now Through this precise matching, it is possible to:

[0142] When the antibacterial gradient melt reaches the spinneret outlet, the part with the highest concentration forms the outermost surface of the fiber, and the part with the lowest concentration reaches the interface between the outer and middle layers.

[0143] When the UV-resistant gradient melt reaches the spinneret outlet, the part with the lowest concentration reaches the interface between the middle layer and the outer layer, and the part with the highest concentration reaches the interface between the middle layer and the core layer.

[0144] if Greater than This will lead to a lag in gradient distribution, insufficient concentration of antibacterial agent on the fiber surface, and excessively high concentration of functional components at the interface; if Less than This will cause the gradient distribution to be ahead of the curve, with the part with the highest concentration of antibacterial agent entering the fiber interior and the part with the highest concentration of UV protectant reaching the interface, making it impossible to achieve effective spatial isolation.

[0145] S402 spinning process parameters

[0146] Spinning temperature At this temperature, the melt has moderate viscosity and good fluidity, which can ensure the uniform composite of the three-layer melt and prevent resin degradation due to excessive temperature.

[0147] Spinning speed This spinning speed falls within the medium-speed spinning range, ensuring both production efficiency and proper orientation of the nascent fibers, facilitating subsequent stretching.

[0148] Spinning component pressure The component uses a three-layer filter (200 mesh + 300 mesh + 200 mesh) to filter impurities in the melt and prevent clogging of the spinneret orifices. Initial side-blowing air temperature. The side air blows towards the fiber starting 10cm below the spinneret.

[0149] Through the above process control, the final nascent fibers have the following structural characteristics:

[0150] The outermost layer is an antibacterial gradient layer, with a thickness of [missing information]. =8.4 The concentration of nano-silver from the fiber surface Decrease continuously inwards to the interface ;

[0151] The middle layer is an anti-UV gradient layer with a thickness of [missing information]. =12.6 The concentration of nano zinc oxide at the interface Continuously increasing inwards to the core layer interface ;

[0152] The core layer is a pure matrix resin layer with a thickness of [missing information]. =9.0 ;

[0153] At the interface between the antibacterial gradient layer and the anti-UV gradient layer, the concentrations of both nano-silver and nano-zinc oxide are ≤0. This achieves complete spatial isolation between the two functional components.

[0154] The three-layer structure can be clearly seen by observing the fiber cross-section with a scanning electron microscope; the reverse concentration gradient distribution and interfacial concentration of nano-silver and nano-zinc oxide can be verified by performing line scanning along the radial direction of the fiber through energy dispersive spectroscopy (EDS).

[0155] S5 post-processing: The nascent fibers undergo gradient cooling, multi-stage stretching, and constant-tension heat setting to improve their mechanical properties and dimensional stability. Simultaneously, it permanently fixes the gradient distribution of functional components, preventing their migration during subsequent use and washing. The specific implementation is as follows:

[0156] S501 Side-blowing cooling

[0157] The nascent fibers are cooled and cured using a gradient side-blowing method, with the air temperature linearly decreasing from 23°C to 19°C along the fiber axis, and the air velocity... relative humidity Cooling length .

[0158] The reason for using gradient cooling is that the temperature of the nascent fiber is relatively high when it is first extruded from the spinneret. The higher initial air temperature can prevent the fiber from cooling down suddenly, which would cause excessive internal stress and produce differences in the core-sheath structure. As the fiber moves downward, the temperature gradually decreases. Lowering the air temperature can accelerate the cooling rate, allowing the fiber to solidify quickly and preventing the gradient distribution from shifting due to melt flow.

[0159] A wind speed of 0.38 m / s ensures sufficient cooling efficiency while avoiding excessive wind speed that could cause fiber swaying and uneven yarn distribution.

[0160] S502 Multi-stage Tension

[0161] A two-stage stretching process is adopted, with stretching performed on hot rollers. The speed ratio between the first and second hot rollers is the stretching ratio.

[0162] First-stage tensile temperature This temperature is slightly higher than the glass transition temperature of the resin, and the macromolecular chains have sufficient mobility to orient themselves axially under external force without breaking; first-stage draw ratio. It is the main component that completes most of the orientation process.

[0163] Second-stage tensile temperature Higher temperatures can further relax the macromolecular chains, eliminating the internal stress generated by the first stage of stretching, while simultaneously improving the degree of orientation; the second stage stretching ratio... Times, total stretch ratio times.

[0164] It should be further explained that the total stretch ratio It can enable the fiber to obtain the best mechanical properties. If the stretch ratio is too low, the orientation will be insufficient and the mechanical properties will be poor; if the stretch ratio is too high, the fiber will be easy to break and the elongation will be too low.

[0165] S503 heat setting

[0166] The process employs a dry heat setting method, which is carried out in a heat setting chamber at a specific temperature. This temperature is lower than the resin's melting point of 32°C, which allows the macromolecular chains to rearrange and crystallize to a certain extent, eliminating internal stress, without causing the fibers to melt and stick together.

[0167] Setting time Sufficient setting time ensures that internal stress is fully eliminated, thus improving dimensional stability.

[0168] Shaping tension Appropriate tension can prevent fibers from shrinking during heat setting, thus maintaining the fiber orientation and gradient structure.

[0169] During the heat setting process, the polymer molecular chains crystallize to form stable crystalline regions, which firmly encapsulate the functional particles in the amorphous regions, permanently fixing the gradient distribution of the functional components and preventing their migration during subsequent use and washing.

[0170] The final product is an antibacterial and UV-resistant composite fiber.

[0171] Based on the above method, this application also discloses a system for preparing antibacterial and UV-resistant functional composite fibers, referencing... Figure 3 The antibacterial and UV-resistant functional composite fiber preparation system shown includes:

[0172] Antibacterial masterbatch preparation module: used to prepare antibacterial masterbatch with a silver content of 5-15wt%. The antibacterial masterbatch is prepared by melt blending surface-modified nano-silver with a first carrier resin. The first carrier resin and the fiber matrix resin are homologous polymers.

[0173] UV-resistant masterbatch preparation module: used to prepare UV-resistant masterbatch with zinc oxide content of 10-25wt%. The UV-resistant masterbatch is prepared by melt blending surface-modified nano zinc oxide with a second carrier resin. The second carrier resin and the fiber matrix resin are homologous polymers.

[0174] Matrix melt distribution module: used to melt the dried fiber matrix resin to obtain the total matrix resin melt, and precisely divide it into the first matrix melt flow path, the second matrix melt flow path and the third matrix melt flow path;

[0175] Dual-channel online dynamic gradient mixing module: used to add antibacterial masterbatch to the first matrix melt flow path in a continuous gradient from high to low concentration to obtain antibacterial gradient melt, and to add anti-UV masterbatch to the second matrix melt flow path in a continuous gradient from low to high concentration to obtain anti-UV gradient melt; the third matrix melt flow path does not add any functional masterbatch and serves as pure matrix resin melt.

[0176] Coaxial three-layer composite spinning module: used to composite spin antibacterial gradient melt, anti-ultraviolet gradient melt and pure matrix resin melt to form nascent fibers with a reverse concentration gradient core-sheath structure;

[0177] Post-processing module: used to sequentially perform side-blowing cooling, multi-stage stretching and heat setting on the nascent fibers to obtain the final antibacterial and UV-resistant functional composite fibers.

[0178] See Figure 4 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Figure 4 As shown, the electronic device 1000 may include: at least one processor 1001, at least one communication bus 1002, user interface 1003, network interface 1004, and memory 1005.

[0179] The communication bus 1002 is used to realize the connection and communication between the above components, and to ensure the stable transmission of process parameter data, melt state monitoring data, metering pump flow control commands, spinning synchronization signals, and post-processing adjustment commands.

[0180] The user interface 1003 may include a display screen, a touch screen, a keyboard, a mouse, and physical buttons, etc., for receiving process parameter setting instructions input by the user, and displaying real-time process operation status, equipment alarm information, and product quality statistics to the user.

[0181] The network interface 1004 may include a wired Ethernet interface and a wireless Wi-Fi / 5G interface, which are used to realize data interaction between electronic devices and various actuators, sensors and host computer systems in the spinning production line, and support remote monitoring and remote control functions.

[0182] The memory 1005 can be a high-speed RAM memory or a non-volatile memory, such as at least one disk storage device.

[0183] The memory 1005 stores a computer program for implementing the preparation method of the antibacterial and UV-resistant functional composite fiber of the present invention, as well as a database of related process parameters, specifically including:

[0184] The masterbatch preparation control module 10051 is used to store process parameter templates for nanoparticle surface modification and melt blending granulation, and to control parameters such as reactor temperature, stirring speed, ultrasonic power, and extruder temperature profile.

[0185] The gradient mixing control module 10052 is used to calculate the flow rate change curve of the gradient metering pump according to the thickness ratio of each layer of the target fiber, and adjust the output flow rate of the metering pump in real time.

[0186] The spinning synchronization control module 10053 is used to precisely match the flow rate change cycle of the gradual metering pump with the residence time of the melt in the flow channel to ensure the accurate formation of the reverse gradient structure.

[0187] The post-processing control module 10054 is used to control the gradient cooling curve of the side blowing air, the temperature and multiple of the two-stage stretching, and the temperature, time and tension of the heat setting.

[0188] The data acquisition and analysis module 10055 is used to collect data such as melt pressure, temperature, flow rate, and fiber linear density in real time, and to perform anomaly detection and alarm.

[0189] The processor 1001 may be a central processing unit (CPU), a digital signal processor (DSP), an application-specific integrated circuit (ASIC), or a field-programmable gate array (FPGA). The processor 1001 calls a computer program stored in memory 1005 to perform the following steps:

[0190] The masterbatch preparation unit controls the surface modification of nano-silver and nano-zinc oxide, as well as the melt blending and granulation of antibacterial masterbatch and anti-UV masterbatch.

[0191] The matrix melt distribution unit precisely divides the matrix resin melt into three independent flow paths, ensuring that the temperature, pressure and flow rate of the three flow paths are consistent;

[0192] The online dynamic gradient mixing unit is controlled to prepare antibacterial gradient melt and anti-UV gradient melt, and the concentration distribution of functional components is monitored and corrected in real time.

[0193] Controlling the coaxial three-layer spinning unit to combine three melts to form nascent fibers with a reverse gradient sheath-core structure, achieving submicron-level spatial isolation of functional components;

[0194] The post-processing unit controls the gradient cooling, multi-stage stretching and constant tension heat setting of the nascent fibers to obtain the final antibacterial and UV-resistant functional composite fibers.

[0195] An electronically readable storage medium, wherein a computer program is stored on the computer program, and when the computer program is executed by a processor, the steps of the method for preparing antibacterial and UV-resistant functional composite fibers as described in any one of the above claims are implemented.

[0196] Specifically, the computer-readable storage medium may include, but is not limited to, various media capable of storing computer programs, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0197] When the computer program is executed by the processor, it can precisely control the process parameters of the entire process of the preparation method of the present invention, especially to realize the continuous linear adjustment of the flow rate of the gradual metering pump, the precise matching of the flow rate change period and the melt residence time, and the automatic control of the gradient side blowing, so as to ensure the stability and repeatability of the reverse concentration gradient structure and the spatial isolation effect, thereby preparing an antibacterial and UV-resistant composite fiber with excellent functionality, durability and comfort.

[0198] Secondly: The accompanying drawings of the embodiments disclosed in this invention only involve the structures involved in the embodiments disclosed in this invention. Other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of this invention can be combined with each other.

[0199] In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing antibacterial and UV-resistant functional composite fibers, characterized in that, include: S1: Surface-modified nano-silver with a particle size of 10-50nm is melt-blended and extruded with the first carrier resin to obtain an antibacterial masterbatch with a silver content of 5-15wt%. Surface-modified nano zinc oxide with a particle size of 20-80 nm is melt-blended and extruded with a second carrier resin to obtain an anti-UV masterbatch with a zinc oxide content of 10-25 wt%. Both the first carrier resin and the second carrier resin are homologous polymers to the fiber matrix resin; S2: The dried fiber matrix resin is fed into a screw extruder to melt, and the total matrix resin melt is obtained. It is then divided into a first matrix melt flow path, a second matrix melt flow path, and a third matrix melt flow path by a melt distributor. S3: A gradient metering pump unit is used in conjunction with an online dynamic gradient mixing unit to perform functional gradient mixing on the first and second matrix melt flow paths respectively: Antibacterial masterbatch is added to the first matrix melt flow path in a continuous gradient from high to low concentration to obtain an antibacterial gradient melt; UV-resistant masterbatch is added to the second matrix melt flow path in a continuous gradient from low to high concentration to obtain UV-resistant gradient melt; The third matrix melt flow path does not add any functional masterbatch and is used as a pure matrix resin melt. S4: The antibacterial gradient melt, the anti-UV gradient melt, and the pure matrix resin melt are respectively fed into a coaxial three-layer spinneret for composite spinning to form nascent fibers with a reverse concentration gradient core-sheath structure: The outermost layer is an antibacterial gradient layer, with the concentration of nano-silver decreasing continuously from the fiber surface to the interior; The middle layer is an anti-UV gradient layer, and the concentration of nano-zinc oxide continuously decreases from the inside of the fiber to the surface; The core layer is a pure matrix resin layer; at the interface between the antibacterial gradient layer and the anti-ultraviolet gradient layer, the concentrations of nano-silver and nano-zinc oxide are both ≤0.2wt%, achieving spatial isolation between the two functional components. S5: Nascent fibers are cooled by side blowing, stretched in multiple stages and heat-set to obtain antibacterial and UV-resistant composite fibers.

2. The method for preparing antibacterial and UV-resistant functional composite fibers according to claim 1, characterized in that, The concentration gradient range of the antibacterial agent in the antibacterial gradient melt is 3-0.

1. The concentration gradient range of the UV stabilizer in the UV-resistant gradient melt is 0.1-5%. .

3. The method for preparing antibacterial and UV-resistant functional composite fibers according to claim 1, characterized in that, The antibacterial masterbatch and the UV-resistant masterbatch include: The antibacterial masterbatch is prepared by melt blending and extrusion of nano-silver modified by chemical bonding agent KH-570 with a first carrier resin; the anti-ultraviolet masterbatch is prepared by melt blending and extrusion of nano-zinc oxide modified by stearate esterification with a second carrier resin; the melt flow rate of the antibacterial masterbatch and the anti-ultraviolet masterbatch deviates from the melt flow rate of the fiber matrix resin by no more than ±5g / 10min.

4. The method for preparing antibacterial and UV-resistant functional composite fibers according to claim 1, characterized in that, The distribution of the matrix melt flow path includes: using a high-precision static melt distributor for multi-stage symmetrical flow splitting; the inner wall of the flow channel is mirror-polished to avoid melt retention and degradation; each of the three matrix melt flow paths is equipped with an independent temperature control system and pressure sensor to adjust and maintain the melt temperature deviation ≤ ±0.8℃ and the melt pressure deviation ≤ ±0.09MPa in real time, with a flow splitting accuracy of ±0.4%; the volumetric flow rate ratio of the three flow paths is consistent with the thickness ratio of the antibacterial gradient layer, the anti-UV gradient layer, and the pure matrix core layer in the target fiber.

5. The method for preparing antibacterial and UV-resistant functional composite fibers according to claim 1, characterized in that, The functionalized gradient blending includes: The first matrix melt flow path operates at a constant volumetric flow rate. Entering the first online mixing unit, the antibacterial masterbatch, after being melted, is fed through the first gradual metering pump at a volumetric flow rate. Join, control from linearly decreasing to The concentration of the antibacterial agent was obtained from Decrease continuously to Antibacterial gradient melt; The second matrix melt flow path operates at a constant volumetric flow rate. Entering the second online mixing unit, the UV-resistant masterbatch, after being melted, is fed through a second gradual metering pump at a volumetric flow rate. Join, control from linearly increasing to The concentration of the UV protectant was obtained from continuously increasing to UV-resistant gradient melt; Both the first online mixing unit and the second online mixing unit adopt a series structure of SK-type static mixer and micro dynamic stirrer, with a mixing time ≤1.8s and mixing uniformity ≥96% and ≥95%, respectively.

6. The method for preparing antibacterial and UV-resistant functional composite fibers according to claim 1, characterized in that, The reverse concentration gradient core-shell structure includes: composite spinning using a coaxial three-layer spinneret with a spinneret orifice diameter of 0.28 mm, an aspect ratio of 11:1, and a concentricity deviation of the three-layer flow channels ≤ 0.009 mm; precisely controlling the flow rate variation cycle of the gradient metering pump to be equal to the residence time of the melt from the mixing unit outlet to the spinneret orifice outlet, so that the antibacterial gradient melt forms the outermost layer of the fiber, the anti-UV gradient melt forms the middle layer of the fiber, and the pure matrix resin melt forms the core layer of the fiber; at the interface between the antibacterial gradient layer and the anti-UV gradient layer, the concentrations of nano-silver and nano-zinc oxide are both ≤ This achieves submicron-level spatial isolation between the two functional components.

7. The method for preparing antibacterial and UV-resistant functional composite fibers according to claim 1, characterized in that, The S5 includes: The nascent fibers are cooled and solidified by side-blowing air with a gradient cooling along the fiber axis to prevent the gradient distribution from shifting due to melt flow. A two-stage stretching process with progressively increasing temperature is used to stretch and orient the cooled fibers, thereby improving their mechanical properties. The stretched fibers are treated with a constant tension dry heat setting process, which permanently fixes the gradient distribution of functional components through polymer crystallization, preventing their migration during use and washing.

8. A system for preparing antibacterial and UV-resistant functional composite fibers, characterized in that, include: Antibacterial masterbatch preparation module: used to prepare antibacterial masterbatch with a silver content of 5-15wt%. The antibacterial masterbatch is prepared by melt blending surface-modified nano-silver with a first carrier resin. The first carrier resin and the fiber matrix resin are homologous polymers. UV-resistant masterbatch preparation module: used to prepare UV-resistant masterbatch with zinc oxide content of 10-25wt%. The UV-resistant masterbatch is prepared by melt blending surface-modified nano zinc oxide with a second carrier resin. The second carrier resin and the fiber matrix resin are homologous polymers. Matrix melt distribution module: used to melt the dried fiber matrix resin to obtain the total matrix resin melt, and precisely divide it into the first matrix melt flow path, the second matrix melt flow path and the third matrix melt flow path; Dual-channel online dynamic gradient mixing module: used to add antibacterial masterbatch to the first matrix melt flow path in a continuous gradient from high to low concentration to obtain antibacterial gradient melt; to add UV-resistant masterbatch to the second matrix melt flow path in a continuous gradient from low to high concentration to obtain UV-resistant gradient melt; the third matrix melt flow path does not add any functional masterbatch and serves as pure matrix resin melt. Coaxial three-layer composite spinning module: used to composite spin antibacterial gradient melt, anti-ultraviolet gradient melt and pure matrix resin melt to form nascent fibers with a reverse concentration gradient core-sheath structure; Post-processing module: used to sequentially perform side-blowing cooling, multi-stage stretching and heat setting on the nascent fibers to obtain the final antibacterial and UV-resistant functional composite fibers.

9. An electronic device, characterized in that, include: At least one processor, at least one communication bus, user interface, network interface, and memory; And a computer program stored in the memory and executable on the processor, wherein the computer program, when executed by the processor, implements the method for preparing antibacterial and UV-resistant functional composite fibers according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, which, when executed by a processor, implements the method for preparing antibacterial and UV-resistant functional composite fibers according to any one of claims 1 to 7.

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