Anti-cutting Kevlar fiber yarn and preparation method thereof

Abstract

The invention discloses an anti-cutting Kevlar fiber yarn which comprises an anti-cutting main fiber and a winding fiber wound on the outer surface of the anti-cutting main fiber. The anti-cutting main fiber is formed by arranging carbon fibers and anti-cutting Kevlar fibers in parallel, the anti-cutting Kevlar fibers comprise carbon nano tubes, the nano fibers and Kevlar simultaneously process Kevlar long fiber filter residues, and both the nano fibers and the carbon fibers have the effects of mechanical property addition and anti-cutting effect enhancement; the surface modified Kevlar fiber can change the coating effect to enhance the multifunctionality of the fiber. The winding fiber on the outer surface of the anti-cutting main fiber is the ultra-high molecular weight polyethylene fiber, and a twisting mode of sequentially and alternately winding is adopted, so that not only are better elasticity and anti-cutting performance achieved, but also air gaps can be formed between yarns firstly, and the air permeability of the yarn woven fabric is improved. The yarn disclosed by the invention has the advantages of excellent mechanical property, good anti-cutting effect and good air permeability of a woven fabric.

Description

Technical Field

[0001] This invention relates to the field of textile fiber yarn preparation technology, specifically to a cut-resistant Kevlar fiber yarn and its preparation method. Background Technology

[0002] Since its commercialization by DuPont in the 1970s, Kevlar fiber (aramid 1414) has become a core material in the fields of bulletproof and cut-resistant applications due to its high strength, high modulus, and high-temperature resistance. Traditional Kevlar fiber yarns can improve abrasion resistance and cut resistance through twisting and plying processes (such as 1000D / 2 specification), but the single structure still has limitations such as poor breathability and limited functionality. With the upgrading of special protection needs, such as industrial cut-resistant gloves and stab-resistant vests, the market urgently needs fiber materials that combine cut resistance with comfort. Current technologies often enhance protection through composite metal wires or coatings, but this can easily lead to material stiffness, reduced breathability, and potential failure due to metal fatigue after long-term use. Therefore, developing a cut-resistant Kevlar fiber yarn that achieves synergistic multi-performance through modification or composite technologies has become a key direction for industry breakthroughs.

[0003] In view of this, we disclose a method for preparing cut-resistant Kevlar fiber yarn. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a cut-resistant Kevlar fiber yarn and its preparation method.

[0005] To achieve the above objectives, the present invention proposes the following technical solution:

[0006] A cut-resistant Kevlar fiber yarn, a cut-resistant main fiber, and a winding fiber wrapped around the outer surface of the cut-resistant main fiber;

[0007] The cut-resistant main fiber includes carbon fiber and cut-resistant Kevlar fiber; the winding fiber is alternately wound around the outer surface of the carbon fiber and cut-resistant Kevlar fiber in sequence;

[0008] The winding fiber is ultra-high molecular weight polyethylene fiber.

[0009] Furthermore, the cut-resistant Kevlar fiber includes at least one set of modified Kevlar fibers, and each set of modified Kevlar fibers includes a first fiber and a second fiber formed by twisting and plying.

[0010] The first fiber is carbon nanotube modified Kevlar fiber, and the second fiber is two-dimensional material surface modified Kevlar fiber.

[0011] Furthermore, the preparation method of the carbon nanotube-modified Kevlar fiber is as follows:

[0012] S1, Pretreatment of Kevlar Fibers

[0013] Kevlar long fibers were immersed in an ethanol solution and ultrasonically treated, and then dried at a low temperature of 40-45℃ in a vacuum drying oven to obtain ethanol-treated Kevlar fibers.

[0014] S2, Pre-processing

[0015] Before use, Kevlar fibers treated with ethanol are immersed in N-methylpyrrolidone to obtain pretreated Kevlar fibers;

[0016] S3. Preparation of mixed solutions

[0017] Pretreated Kevlar fibers were immersed in an alkaline / dimethyl sulfoxide solution and stirred slowly at 100-300 rpm for 4-8 hours at room temperature to obtain a fiber filament mixture containing Kevlar nanofibers.

[0018] S4, Separation of Mixed Solutions

[0019] The mixed solution was filtered through a nanosieve to obtain filtrate and Kevlar long fiber filter residue. The filtrate was stirred, and carbon nanotubes were added to the stirred filtrate. Then, it was ultrasonically treated to obtain a mixed dispersion.

[0020] The Kevlar long fiber filter residue is then opened, combined, and spun with the Kevlar fibers treated with ethanol in step S1 to obtain a preliminary mixed fiber bundle, and the mass ratio of the Kevlar long fiber filter residue to the ethanol-treated Kevlar fibers is 1.0%-1.5%.

[0021] S5, Modification Process

[0022] The mixed dispersion is placed in a material tank, and the pre-mixed fiber bundles are then immersed in the material tank for 15-25 minutes. After immersion, they are squeezed using two yarn guide rollers and then guided back to the material tank for immersion. This process is repeated at least three times. Finally, the fibers are air-dried to obtain carbon nanotube modified Kevlar fibers.

[0023] Furthermore, in step S3, the mass of carbon nanotubes in the mixed dispersion accounts for 2%-3% of the mass of Kevlar nanofibers;

[0024] Furthermore, the ultrasonic treatment conditions are as follows: power of 200W-400W and ultrasonic time of 20min-40min.

[0025] Furthermore, the alkali / dimethyl sulfoxide solution is a dimethyl sulfoxide solution of potassium hydroxide or sodium hydroxide, and the concentration of the alkali / dimethyl sulfoxide solution is 2.5-3.5M.

[0026] Furthermore, the molecular weight of the ultra-high molecular weight polyethylene fiber is 850,000-1,000,000.

[0027] Furthermore, the method for preparing the cut-resistant Kevlar fiber yarn includes the following steps:

[0028] S1. Raw material preparation: Prepare carbon fiber, cut-resistant Kevlar fiber and ultra-high molecular weight polyethylene fiber according to the yarn material feeding.

[0029] S2, Winding: The ultra-high molecular weight polyethylene fiber, carbon fiber, and cut-resistant Kevlar fiber filaments are wound separately.

[0030] S3. Yarn Combining: The ultra-high molecular weight polyethylene fiber, carbon fiber, and cut-resistant Kevlar fiber bobbins that have been wound are placed horizontally on the bobbin frame of the yarn combining machine, so that the carbon fiber and cut-resistant Kevlar fiber are arranged in parallel and combined together. The ultra-high molecular weight polyethylene fiber bobbin is placed at the vertical line position of the carbon fiber bobbin and the cut-resistant Kevlar fiber bobbin. After passing through the yarn clearer, tension plate, pressure roller, and winding device, it is finally wound onto the output bobbin to obtain the combined yarn.

[0031] S4. Pre-twisting treatment: The ultra-high molecular weight polyethylene fiber, carbon fiber, and cut-resistant Kevlar fiber after yarn plying are pre-twisted respectively.

[0032] S5. Composite twisting: The pre-twisted ultra-high molecular weight polyethylene fiber and elastic fiber are composite twisted to make the wound fiber tightly adhere to the outer surface of carbon fiber and cut-resistant Kevlar fiber.

[0033] S6. Post-processing: Post-processing of the finished yarn, including setting, oiling, inspection and packaging.

[0034] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0035] This invention discloses a cut-resistant Kevlar fiber yarn, comprising a cut-resistant main fiber and wound fibers wrapped around the outer surface of the cut-resistant main fiber. The cut-resistant main fiber is composed of carbon fibers and cut-resistant Kevlar fibers arranged side by side. The cut-resistant Kevlar fibers contain carbon nanotubes and nanofibers, and are treated with Kevlar long-fiber filter residue, thus enhancing both mechanical properties and cut resistance, along with the carbon fibers. Surface-modified Kevlar fibers can alter the coating effect and enhance the fiber's multifunctionality. The wound fibers on the outer surface of the cut-resistant main fiber are ultra-high molecular weight polyethylene fibers, twisted in an alternating winding manner. This not only provides good elasticity and cut resistance but also creates air gaps between the yarns, improving the breathability of the woven fabric. The yarn of this invention has the advantages of excellent mechanical properties, good cut resistance, and good breathability of the woven fabric.

[0036] It should be understood that all combinations of the foregoing concepts and the additional concepts described in more detail below can be considered part of the subject matter disclosure of the present invention, provided that such concepts do not contradict each other.

[0037] The foregoing and other aspects, embodiments, and features of the teachings of this invention will be more fully understood from the following description. Other additional aspects of the invention, such as features and / or beneficial effects of exemplary embodiments, will become apparent from the following description or may be learned through practice of specific embodiments according to the teachings of this invention. Attached Figure Description

[0038] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0039] Figure 1 This is a schematic diagram of the yarn structure of the present invention;

[0040] Figure 2 This is a schematic diagram of the yarn cross-section structure in Embodiment 1 of the present invention;

[0041] Figure 3 This is a schematic diagram of the modified Kevlar fiber structure.

[0042] Figure 4 This is a schematic diagram showing multiple strands of the yarn of this invention stacked at different angles.

[0043] 1. Cut-resistant main fiber; 2. Wrapping fiber; 11. Carbon fiber; 12. Cut-resistant Kevlar fiber; 121. First fiber; 122. Second fiber. Detailed Implementation

[0044] To enable those skilled in the art to better understand the technical solutions of the present invention, the preferred embodiments of the present invention are described below in conjunction with specific examples, but these should not be construed as limiting the present patent.

[0045] Unless otherwise specified, the test methods or experimental methods described in the following examples / comparative examples are conventional methods; unless otherwise specified, the reagents and materials are obtained from conventional commercial sources or prepared by conventional methods.

[0046] In this invention, the winding fibers on the outer surface of the cut-resistant main fiber are ultra-high molecular weight polyethylene fibers. The alternating winding twisting method not only provides good elasticity and cut-resistant performance but also creates air gaps between the yarns, improving the breathability of the woven fabric. The added ultra-high molecular weight polyethylene fibers, as the winding fibers 2, utilize the high strength of ultra-high molecular weight polyethylene fibers to further enhance the overall cut-resistant performance of the fiber. Furthermore, the cut-resistant Kevlar fiber 12 contains carbon nanotubes and nanofibers, which, along with the Kevlar long fiber filter residue, enhance mechanical properties and cut-resistant effects. Surface-modified Kevlar fibers can alter the coating effect and enhance the fiber's multifunctionality.

[0047] Furthermore, the preparation method of the carbon nanotube-modified Kevlar fiber is as follows:

[0048] S1, Pretreatment of Kevlar Fibers

[0049] Kevlar long fibers were immersed in an ethanol solution and ultrasonically treated, and then dried at a low temperature of 40-45℃ in a vacuum drying oven to obtain ethanol-treated Kevlar fibers.

[0050] S1. Pre-use processing

[0051] Before use, Kevlar fibers treated with ethanol are immersed in N-methylpyrrolidone to obtain pretreated Kevlar fibers;

[0052] S3. Preparation of mixed solutions

[0053] Pretreated Kevlar fibers were immersed in an alkaline / dimethyl sulfoxide solution and stirred slowly at 100-300 rpm for 4-8 hours at room temperature to obtain a fiber filament mixture containing Kevlar nanofibers.

[0054] The precise control of stirring speed and time ensures that, in an alkaline environment, the amide groups of the Kevlar fibers react with the alkali to form soluble salts, resulting in a nanofiber dispersion, which can be used as a modification material. Simultaneously, some Kevlar fibers remain unreacted, retaining their original structure as filaments, thus forming a mixed solution of Kevlar nanofibers and filaments. Exceeding this range in both speed and time will easily result in the complete formation of a nanofiber dispersion; conversely, insufficient time will prevent the formation of a nanofiber dispersion. The mixed solution containing Kevlar nanofibers and filaments comprises Kevlar nanofibers, short Kevlar fibers, and a mixture of filaments. It should be noted that the length of the filaments in this mixed solution is necessarily shorter than that of Kevlar fibers treated with ethanol, as some of their structure is contributed to the nanofibers. Therefore, before the subsequent drawing process with ethanol-treated Kevlar fibers, it is necessary to perform uniform carding, then card and mix the short fibers (relative to ethanol-treated Kevlar fibers) with the long Kevlar fibers, i.e., combine them, and finally draw the filaments to obtain the filament bundles.

[0055] S4, Separation of Mixed Solutions

[0056] The mixed solution was filtered through a nanosieve to obtain filtrate and Kevlar long fiber filter residue. The filtrate was stirred, and carbon nanotubes were added to the stirred filtrate. Then, it was ultrasonically treated to obtain a mixed dispersion.

[0057] The mixed dispersion contains carbon nanotubes and Kevlar nanofibers, both of which contribute to improving the mechanical properties and cut resistance of the fibers. In particular, carbon nanotubes and carbon fibers, being carbon-based materials, exhibit a significant strength-enhancing effect. It should be noted that, based on calculations, the solid content of Kevlar nanofibers in the filtrate is 0.5%-3.5%.

[0058] Furthermore, the Kevlar long fiber filter residue is opened, combined, and spun with the Kevlar fibers treated with ethanol in step S1 to obtain a preliminary mixed fiber bundle, and the mass ratio of the Kevlar long fiber filter residue to the ethanol-treated Kevlar fibers is 1.0%-1.5%.

[0059] S4, Modification Process

[0060] The mixed dispersion is placed in a material tank, and the pre-mixed fiber bundles are then immersed in the material tank for 15-25 minutes. After immersion, they are squeezed using two yarn guide rollers and then guided back to the material tank for immersion. This process is repeated at least three times. Finally, the fibers are air-dried to obtain carbon nanotube modified Kevlar fibers.

[0061] Furthermore, the second fiber 122 is a two-dimensional material surface-modified Kevlar fiber. Specifically, the preparation method of the two-dimensional material surface-modified Kevlar fiber includes three steps: fiber pretreatment, preparation of composite aerogel mixed dispersion, and fiber modification. The specific methods are as follows:

[0062] Step 1: Fiber Pretreatment

[0063] Kevlar fibers were immersed in N-methylpyrrolidone and ultrasonically treated. The ultrasonically treated Kevlar fibers were then immersed in N-methylpyrrolidone again to obtain pretreated Kevlar fibers. They were then immersed in KOH / dimethyl sulfoxide solution and stirred at room temperature for 60-100 hours to obtain Kevlar nanofiber solution.

[0064] Step 2: Preparation of Composite Aerogel

[0065] Ti3AlC2 was added to a mixed solution of HCl and LiF, and MXene powder was prepared by in-situ etching. Then, graphene oxide powder and MXene powder were mixed at a mass ratio of (5-6):1 and hydrothermally heated at 120-130℃ for 15-20h to obtain MXene-rGO-based aerogel, i.e., composite aerogel. Kevlar nanofiber solution was then mixed with composite aerogel and stirred evenly. The mixture was then ultrasonically treated with a 100-200W ultrasonic machine for 4-6h to obtain a composite aerogel dispersion, wherein the composite aerogel accounts for 2%-3% of the mass of Kevlar nanofiber.

[0066] Step 3: Fiber Modification

[0067] Finally, the pretreated Kevlar fibers were subjected to a two-dip and two-roll process in a composite aerogel dispersion to obtain two-dimensional surface-modified Kevlar fibers. The two-dimensional surface-modified Kevlar fibers utilize the highly porous structure of the aerogel design, enabling the formation of an air layer on the fiber surface; furthermore, the MXene-rGO-based aerogel, due to the addition of two-dimensional materials, exhibits improved flame retardancy.

[0068] Furthermore, the post-processing described in this invention includes setting treatment, oiling treatment, and inspection and packaging. The setting treatment involves setting the yarn coated with ultra-high molecular weight polyethylene fibers at a temperature of 100-150℃ for 1-5 minutes. The oiling treatment involves applying an oil to the yarn surface, ensuring a uniform coating of textile oil. Finally, the inspection and packaging process involves quality inspection of the finished cut-resistant Kevlar yarn, including testing its strength, elasticity, twist, and appearance. After passing inspection, the yarn is packaged.

[0069] Performance testing

[0070] Mechanical property testing

[0071] Mechanical property testing was conducted according to the standard GB / T 19975-2005 "Test Method for Tensile Properties of High-Strength Fiber Filaments". Specifically, a material tensile testing machine was used, with a load sensor capacity of 500N, a test force accuracy of 0.5% of the displayed value, a test speed of 250mm / min, a test temperature of 25℃, and a 500N winding clamp. The tensile strength and elongation at break of the yarn were obtained by testing multiple times and the average value was taken.

[0072] Cut resistance

[0073] The cut resistance test of the yarn was conducted in accordance with the provisions of the American ANSI / ISEA 105-2016 standard regarding cut resistance testing. The specific test method is as follows: A small rectangular sample of glove material is placed on the metal mandrel of a cutting test apparatus. The apparatus uses a special blade to move laterally towards the sample until it penetrates the sample. When the blade penetrates the sample and makes electrical contact with the metal mandrel, the cutting resistance test apparatus measures the distance the blade travels before penetrating the sample. This distance is determined by the different weights loaded on the arm of the test apparatus holding the blade. Therefore, the test result is usually defined as the weight required for the blade to penetrate the cut-resistant sock material by cutting 20 mm. According to the results measured by this test method, a higher weight indicates higher cut resistance of the glove material. The cut resistance indicators tested using this standard are shown in Table 1 below.

[0074] Table 1 Standard Cut Resistance Rating Table grade Weight (grams) required for the blade to move 20mm and penetrate the material. A1 ≥200 A2 ≥500 A3 ≥1000 A4 ≥1500 A5 ≥2200 A6 ≥3000 A7 ≥4000 A8 ≥5000 A9 ≥6000

[0075] Flame retardant properties

[0076] The yarn is woven into a standard fabric, and the low oxygen concentration required for flaming combustion of the sample in an oxygen-nitrogen mixed gas flow is tested using a JF-3 digital oxygen index meter according to the GB / T 2406.2-2009 standard. The value is expressed as the volume percentage of oxygen, i.e., the limiting oxygen index (LOI).

[0077] Breathability

[0078] Yarn breathability is mainly reflected in the process of weaving or using multiple yarns in parallel, such as Figure 4 The spacing between the yarns creates air gaps, contributing to the fabric's breathability and moisture permeability. The breathability of the woven fabric was tested according to GB / T 21529-2008 "Test of Water Vapor Transmission Rate of Plastic Films and Sheets - Electrolytic Sensor Method," with a test temperature of 38℃, a relative humidity of 90%, a sample diameter of 10cm, and a test area of ​​63.58cm². 2The test results were compared based on 24-hour moisture permeability, with units of g / (m³). 2 •24h).

[0079] Example 1

[0080] like Figure 1-3 As shown, a cut-resistant Kevlar fiber yarn includes: a cut-resistant main fiber 1, and a winding fiber 2 wound around the outer surface of the cut-resistant main fiber 1; the cut-resistant main fiber 1 includes carbon fiber 11 and cut-resistant Kevlar fiber 12; the winding fiber 2 is wound alternately around the outer surface of the carbon fiber 11 and the cut-resistant Kevlar fiber 12 in sequence; the winding fiber 2 is ultra-high molecular weight polyethylene fiber.

[0081] Furthermore, the cut-resistant Kevlar fiber 12 comprises a group of modified Kevlar fibers, and each group of modified Kevlar fibers comprises a first fiber 121 and a second fiber 122 formed by twisting and plying. The first fiber 121 is a carbon nanotube modified Kevlar fiber, and the second fiber 122 is a two-dimensional material surface modified Kevlar fiber.

[0082] Furthermore, the preparation method of the carbon nanotube-modified Kevlar fiber is as follows:

[0083] S1, Kevlar fiber pretreatment

[0084] Kevlar long fibers were immersed in an ethanol solution and ultrasonically treated, and then dried at a low temperature of 42°C in a vacuum drying oven to obtain ethanol-treated Kevlar fibers.

[0085] S1. Pre-use processing

[0086] Before use, Kevlar fibers treated with ethanol are immersed in N-methylpyrrolidone to obtain pretreated Kevlar fibers;

[0087] S3. Preparation of mixed solutions

[0088] Pretreated Kevlar fibers were immersed in an alkaline / dimethyl sulfoxide solution and slowly stirred at 300 rpm for 4 hours at room temperature to obtain a fiber filament mixture containing Kevlar nanofibers.

[0089] S4, Separation of Mixed Solutions

[0090] The mixed solution was filtered through a nanosieve to obtain filtrate and Kevlar long fiber filter residue. The filtrate was stirred, and carbon nanotubes were added to the stirred filtrate. Then, it was ultrasonically treated to obtain a mixed dispersion.

[0091] The Kevlar long fiber filter residue is then opened, combined, and spun with the Kevlar fibers treated with ethanol in step S1 to obtain a preliminary mixed fiber bundle, and the mass ratio of the Kevlar long fiber filter residue to the ethanol-treated Kevlar fibers is 1.0%.

[0092] S5, Modification Process

[0093] The mixed dispersion was placed in a material tank, and the pre-mixed fiber bundles were then immersed in the material tank for 20 minutes. After immersion, they were squeezed using two yarn guide rollers and then guided back into the material tank for immersion. This process was repeated at least three times. Finally, the fibers were air-dried to obtain carbon nanotube modified Kevlar fibers.

[0094] Furthermore, the carbon nanotubes in the mixed dispersion account for 2% of the mass of the Kevlar nanofibers; the ultrasonic treatment conditions are: power of 200W and ultrasonic time of 40min.

[0095] Furthermore, the alkali / dimethyl sulfoxide solution is a potassium hydroxide / dimethyl sulfoxide solution, and the concentration of the alkali / dimethyl sulfoxide solution is 2.5M.

[0096] Preferably, the molecular weight of the ultra-high molecular weight polyethylene fiber in this embodiment is 850,000.

[0097] Example 2

[0098] Unlike Example 1 above, in the preparation process of a cut-resistant Kevlar fiber yarn and carbon nanotube modified Kevlar fiber, the Kevlar long fiber filter residue in step S3 is mixed with the Kevlar fiber dried by ethanol treatment in step S1 to obtain a preliminary mixed fiber. The mass ratio of the Kevlar long fiber filter residue to the Kevlar fiber in step S1 is 1.5%. Furthermore, the mass of carbon nanotubes in the mixed dispersion accounts for 3% of the mass of Kevlar nanofibers. The ultrasonic treatment conditions are: power of 400W and ultrasonic time of 20min.

[0099] In this embodiment, the alkali / dimethyl sulfoxide solution is a potassium hydroxide / dimethyl sulfoxide solution, and the concentration of the alkali / dimethyl sulfoxide solution is 3.5M. Preferably, the molecular weight of the ultra-high molecular weight polyethylene fiber is 1,000,000.

[0100] Example 3

[0101] A cut-resistant Kevlar fiber yarn, which differs from the above embodiment 1 in that the cut-resistant Kevlar fiber 12 includes two sets of modified Kevlar fibers.

[0102] Other operating steps are the same as in Example 1.

[0103] Comparative Example 1

[0104] Unlike Example 1, the first fiber 121, the second fiber 122, the carbon fiber 11, and the winding fiber 2 are directly twisted in parallel.

[0105] Other operating steps are the same as in Example 1.

[0106] Comparative Example 2

[0107] Unlike Example 1, the cut-resistant main fiber 1 only includes carbon fiber 11.

[0108] Other operating steps are the same as in Example 1.

[0109] Comparative Example 3

[0110] Unlike Example 1, the cut-resistant main fiber 1 only includes cut-resistant Kevlar fiber 12.

[0111] Other operating steps are the same as in Example 1.

[0112] Comparative Example 4

[0113] Unlike Embodiment 1, the cut-resistant main fiber 1 only includes cut-resistant Kevlar fiber 12, and the first fiber 121 in the cut-resistant Kevlar fiber 12 is replaced by the second fiber 122.

[0114] Other operating steps are the same as in Example 1.

[0115] Comparative Example 5

[0116] Unlike Embodiment 1, the cut-resistant main fiber 1 only includes cut-resistant Kevlar fiber 12, and the second fiber 122 in the cut-resistant Kevlar fiber 12 is replaced by the first fiber 121.

[0117] Other operating steps are the same as in Example 1.

[0118] Comparative Example 6

[0119] Unlike Example 1, the cut-resistant main fiber 1 consists only of cut-resistant Kevlar fiber 12. Furthermore, the second fiber 122 in the cut-resistant Kevlar fiber 12 is replaced by the first fiber 121. Moreover, the first fiber 121 is a modified Kevlar fiber and does not contain carbon nanotubes.

[0120] The original steps S3 and S4 of modifying Kevlar fibers with carbon nanotubes are modified as follows:

[0121] S3, Preparation of Mixed Dispersion

[0122] The mixed solution is filtered through a nano-sieve to obtain a filtrate and a Kevlar long fiber filter residue. The filtrate is stirred and then ultrasonically treated to obtain a single-component mixed dispersion. The Kevlar long fiber filter residue is then mixed with the Kevlar fibers dried after being treated with ethanol in step S1 to obtain a preliminary mixed fiber.

[0123] S4, processing fluid

[0124] The mixed dispersion in S3 is placed in a material tank. The pre-mixed fibers are then impregnated in the material tank and squeezed using two yarn guide rollers. The yarn is then guided back to the material tank for impregnation. This process is repeated at least three times. Finally, the fibers are air-dried to obtain modified Kevlar fibers.

[0125] Other operating steps are the same as in Example 1.

[0126] Comparative Example 7

[0127] Unlike Example 1, the cut-resistant main fiber 1 only includes cut-resistant Kevlar fiber 12. Furthermore, the second fiber 122 in the cut-resistant Kevlar fiber 12 is replaced by the first fiber 121. Moreover, the first fiber 121 is a common, commercially available, untreated Kevlar fiber of the same type.

[0128] Other operating steps are the same as in Example 1.

[0129] Comparative Example 8

[0130] Unlike Example 1, the cut-resistant Kevlar fiber 12 is replaced with ordinary commercially available untreated Kevlar fiber, and the carbon fiber 11 is replaced with the same ordinary commercially available untreated Kevlar fiber.

[0131] Then, parallel fibers with the same structure are formed using the same twisting and plying process. Ultra-high molecular weight polyethylene fibers are then wound onto the outer surface of the parallel fibers in the same manner. The resulting yarn is compared with the cut-resistant Kevlar yarn of Example 1.

[0132] The yarns of the above embodiments and comparative examples were subjected to relevant performance tests according to different standards. The test results are shown in Table 2 below.

[0133] Table 2 Test Result Analysis Table

[0134] As shown in Table 2 above, the cut-resistant Kevlar fiber yarn of this invention includes a cut-resistant main fiber and wound fibers wrapped around the outer surface of the cut-resistant main fiber. The cut-resistant main fiber is composed of carbon fibers and cut-resistant Kevlar fibers arranged side by side. The cut-resistant Kevlar fibers contain carbon nanotubes and nanofibers, and are treated with Kevlar long fiber filter residue, which, along with the carbon fibers, enhances mechanical properties and cut resistance. Surface-modified Kevlar fibers can alter the coating effect and enhance the fiber's multifunctionality. The wound fibers on the outer surface of the cut-resistant main fiber are ultra-high molecular weight polyethylene fibers, twisted in an alternating winding manner. This not only provides good elasticity and cut resistance but also creates air gaps between the yarns, helping to improve the breathability of the woven fabric.

[0135] It should be noted that in Comparative Example 2, carbon fiber was used instead of Kevlar fiber, and its overall mechanical properties were better than those of cut-resistant Kevlar fiber alone or a combination of cut-resistant Kevlar fiber and carbon fiber. This is because although cut-resistant Kevlar fiber uses other elements to enhance its cut resistance, its strength increase still cannot reach the high strength characteristics of carbon fiber itself.

[0136] The yarn of this invention has the advantages of excellent mechanical properties, good cut resistance, and good breathability of the woven fabric, and can be further promoted for use.

[0137] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Those skilled in the art can make various modifications and refinements without departing from the spirit and scope of the invention. Therefore, the scope of protection of the present invention shall be determined by the claims.

Claims

1. A cut-resistant Kevlar fiber yarn, characterized in that, include: Cut-resistant main fiber (1), and wound fiber (2) wrapped around the outer surface of the cut-resistant main fiber (1); The cut-resistant main fiber (1) includes carbon fiber (11) and cut-resistant Kevlar fiber (12); the winding fiber (2) is alternately wound around the outer surface of the carbon fiber (11) and the cut-resistant Kevlar fiber (12); The wound fiber (2) is ultra-high molecular weight polyethylene fiber.

2. The cut-resistant Kevlar fiber yarn according to claim 1, characterized in that, The cut-resistant Kevlar fiber (12) includes at least one set of modified Kevlar fibers, and each set of modified Kevlar fibers includes a first fiber (121) and a second fiber (122) formed by twisting together.

3. The cut-resistant Kevlar fiber yarn according to claim 2, characterized in that, The first fiber (121) is carbon nanotube modified Kevlar fiber, and the second fiber (122) is two-dimensional material surface modified Kevlar fiber.

4. The cut-resistant Kevlar fiber yarn according to claim 3, characterized in that, The preparation method of the carbon nanotube modified Kevlar fiber is as follows: S1, Kevlar fiber pretreatment Kevlar long fibers were immersed in an ethanol solution and ultrasonically treated, and then dried at a low temperature of 40-45℃ in a vacuum drying oven to obtain ethanol-treated Kevlar fibers. S2, Pre-processing Before use, Kevlar fibers treated with ethanol are immersed in N-methylpyrrolidone to obtain pretreated Kevlar fibers; S3. Preparation of mixed solutions Pretreated Kevlar fibers were immersed in an alkaline / dimethyl sulfoxide solution and stirred slowly at 100-300 rpm for 4-8 hours at room temperature to obtain a fiber filament mixture containing Kevlar nanofibers. S4, Separation of Mixed Solutions The mixed solution was filtered through a nanosieve to obtain filtrate and Kevlar long fiber filter residue. The filtrate was stirred, and carbon nanotubes were added to the stirred filtrate. Then, it was ultrasonically treated to obtain a mixed dispersion. The Kevlar long fiber filter residue is then opened, combined, and spun with the Kevlar fibers treated with ethanol in step S1 to obtain a preliminary mixed fiber bundle, and the mass ratio of the Kevlar long fiber filter residue to the ethanol-treated Kevlar fibers is 1.0%-1.5%. S5, Modification Process The mixed dispersion is placed in a material tank, and the pre-mixed fiber bundles are then immersed in the material tank for 15-25 minutes. After immersion, they are squeezed using two yarn guide rollers and then guided back to the material tank for immersion. This process is repeated at least three times. Finally, the fibers are air-dried to obtain carbon nanotube modified Kevlar fibers.

5. The cut-resistant Kevlar fiber yarn according to claim 4, characterized in that, In step S3, the mass of carbon nanotubes in the mixed dispersion accounts for 2%-3% of the mass of Kevlar nanofibers.

6. The cut-resistant Kevlar fiber yarn according to claim 4, characterized in that, The ultrasonic treatment conditions were as follows: power of 200W-400W and ultrasonic time of 20min-40min.

7. The cut-resistant Kevlar fiber yarn according to claim 4, characterized in that, The alkaline solution / dimethyl sulfoxide solution is a dimethyl sulfoxide solution of potassium hydroxide or sodium hydroxide, and the concentration of the alkaline solution / dimethyl sulfoxide solution is 2.5-3.5M.

8. The cut-resistant Kevlar fiber yarn according to claim 5, characterized in that, The molecular weight of the ultra-high molecular weight polyethylene fiber is 850,000-1,000,000.

9. A method for preparing cut-resistant Kevlar fiber yarn as described in any one of claims 1-8, characterized in that, Includes the following steps: S1. Raw material preparation: Prepare carbon fiber, cut-resistant Kevlar fiber and ultra-high molecular weight polyethylene fiber according to the yarn material feeding. S2, Winding: The ultra-high molecular weight polyethylene fiber, carbon fiber, and cut-resistant Kevlar fiber filaments are wound separately. S3. Yarn Combining: The ultra-high molecular weight polyethylene fiber, carbon fiber, and cut-resistant Kevlar fiber bobbins that have been wound are placed horizontally on the bobbin frame of the yarn combining machine, so that the carbon fiber and cut-resistant Kevlar fiber are arranged in parallel and combined together. The ultra-high molecular weight polyethylene fiber bobbin is placed at the vertical line position of the carbon fiber bobbin and the cut-resistant Kevlar fiber bobbin. After passing through the yarn clearer, tension plate, pressure roller, and winding device, it is finally wound onto the output bobbin to obtain the combined yarn. S4. Pre-twisting treatment: The ultra-high molecular weight polyethylene fiber, carbon fiber, and cut-resistant Kevlar fiber after yarn plying are pre-twisted respectively. S5, Composite twisting: The pre-twisted ultra-high molecular weight polyethylene fiber and elastic fiber are composite twisted so that the wound fiber (2) is tightly attached to the outer surface of the carbon fiber (11) and the cut-resistant Kevlar fiber (12). S6. Post-processing: Post-processing of the finished yarn, including setting, oiling, inspection and packaging.

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