Ultra-high molecular weight polyethylene fiber, preparation method thereof and product

Abstract

The invention discloses an ultra-high molecular weight polyethylene fiber as well as a preparation method and a product thereof. The preparation method comprises the following steps: blending ultra-high molecular weight polyethylene and polyformaldehyde, and adding a compatilizer and an antioxidant to obtain a blended polymer; and carrying out melt spinning by using the blended polymer, and carrying out traction setting to obtain the ultra-high molecular weight polyethylene fiber, wherein the weight part ratio of the ultra-high molecular weight polyethylene to the polyformaldehyde is (50-70): (30-50). Polyformaldehyde is introduced to carry out blending modification on ultra-high molecular weight polyethylene, so that melt spinning is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of textile materials, in particular to an ultra-high molecular weight polyethylene fiber obtained by melt spinning, a corresponding preparation method thereof, and an article based on the ultra-high molecular weight polyethylene fiber. BACKGROUND

[0002] Ultra-high molecular weight polyethylene (UHMWPE) fiber has high strength, high modulus, low density, and excellent wear resistance and impact resistance, etc., which makes it have unique advantages in many high-performance application fields, such as the applications of bulletproof clothing, stab-resistant clothing, space suits, marine cables, etc. However, due to the molecular weight of ultra-high molecular weight polyethylene being in the order of millions or more, it is difficult to process in actual melt spinning, which limits its industrialized mass production scale; and the melting point of ultra-high molecular weight polyethylene is about 130-140℃, which is prone to deformation and melting in high temperature environment, and has poor heat resistance. SUMMARY

[0003] In order to solve at least one of the above problems, the present application discloses an ultra-high molecular weight polyethylene fiber and a preparation method thereof, and an article. The ultra-high molecular weight polyethylene fiber is obtained by melt spinning after blending ultra-high molecular weight polyethylene and polyformaldehyde. This method introduces polyformaldehyde to enhance the processability of ultra-high molecular weight polyethylene, while maintaining its unique high strength, high modulus, and high wear resistance, etc.

[0004] The first aspect of the present application discloses a preparation method of an ultra-high molecular weight polyethylene fiber. The preparation method comprises: blending ultra-high molecular weight polyethylene and polyformaldehyde, and adding a compatibilizer and an antioxidant to obtain a blended polymer; melt spinning the blended polymer to obtain the ultra-high molecular weight polyethylene fiber after drawing and setting; wherein the weight fraction ratio of the ultra-high molecular weight polyethylene to the polyformaldehyde is (50-70):(30-50); and the melt index of the polyformaldehyde is not less than 35 g / 10 min at a measurement temperature of 190℃ and a measurement load of 2.16 kg.

[0005] According to some embodiments of the present application, the molecular weight of the ultra-high molecular weight polyethylene can be in the range of 1.5-3 million.

[0006] According to some embodiments of the present application, the melt index of the polyformaldehyde is in the range of 35-45 g / 10 min at a measurement temperature of 190℃ and a measurement load of 2.16 kg.

[0007] According to some embodiments of the present application, the weight fraction ratio of the ultra-high molecular weight polyethylene, the polyformaldehyde, the compatibilizer, and the antioxidant is (50-70):(30-50):(0.5-10):(0.1-0.6). According to some embodiments of the present application, the compatibilizer is selected from at least one of maleic anhydride grafted acrylonitrile-butadiene-styrene terpolymer, maleic anhydride grafted polyethylene, or maleic anhydride grafted polypropylene.

[0008] According to some embodiments of the present application, the antioxidant is selected from at least one of tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]pentaerythritol ester (1010), tris[2.4-di-tert-butylphenyl]phosphite (168), n-octadecyl-β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (1076), or N,N'-bis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine (1098).

[0009] According to some embodiments of the present application, the blending is achieved using a twin-screw extruder, wherein the screw rotation speed of the twin-screw extruder is 100-1000 rpm, the extrusion temperature is 180-230 °C, and the length-diameter ratio is (28-60): 1.

[0010] According to some embodiments of the present application, the total draw ratio of the drawing is 3-4.

[0011] The second aspect of the present application provides an ultra-high molecular weight polyethylene fiber prepared by the method as described above.

[0012] The third aspect of the present application provides an article, which can be manufactured from the ultra-high molecular weight polyethylene fiber as described above.

[0013] Additional aspects and advantages of the present application will be in part apparent and in part pointed out hereinafter. BRIEF DESCRIPTION OF DRAWINGS

[0014] The disclosure of the present application will become more fully understood from the detailed description, taken in conjunction with the accompanying drawings. It will be readily understood to those skilled in the art that the drawings are not intended to limit the present application, and that the disclosure is capable of further embodiments and applications. Also, like reference numerals are intended to represent like parts throughout the specification. Figure 1 is an exemplary flow chart of a method for preparing an ultra-high molecular weight polyethylene fiber according to some embodiments of the present application. DETAILED DESCRIPTION

[0015] In order to make the above objectives, features and advantages of the present application more clear and comprehensible, the detailed description of the specific embodiments of the present application is given below. In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be implemented in many different ways other than the ways described herein, and one of ordinary skill in the art can make similar improvements without departing from the spirit of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0016] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in this application, the term "comprises" or "comprising" and the like are intended to mean a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises more than one step, unit, or element employs at least those steps, units, or elements listed, but not excluding others.

[0017] The method for preparing the ultra-high molecular weight polyethylene fiber disclosed in the present application introduces polyformaldehyde to improve the processability of the ultra-high molecular weight polyethylene, thereby realizing melt spinning.

[0018] Some preferred embodiments of the present application are described below. It should be noted that the following description is for the purpose of illustration and is not intended to limit the scope of protection of the present application. The steps involved in the present application can be executed in sequence, or various steps can be processed in reverse order or simultaneously. Meanwhile, other operations can be added to these processes, or a step or several steps can be removed from these processes.

[0019] Reference Figure 1 , Figure 1 The method for preparing the ultra-high molecular weight polyethylene fiber according to some embodiments of the present application is shown in FIG. 1. As shown in FIG. 1, the method for preparing the ultra-high molecular weight polyethylene fiber can include the following steps. Figure 1

[0020] Step S1, blending the ultra-high molecular weight polyethylene and the polyformaldehyde, and adding a compatilizer and an antioxidant.

[0021] ​In some embodiments, the weight ratio of the ultra-high molecular weight polyethylene to the polyoxymethylene for blending can be (50-70):(30-50). For example, the ultra-high molecular weight polyethylene and the polyoxymethylene can be mixed in half, or the amount of the ultra-high molecular weight polyethylene can be increased while the amount of the polyoxymethylene introduced is reduced. For example, 70 parts by mass or 60 parts by mass of the ultra-high molecular weight polyethylene is combined with 30 parts by mass or 40 parts by mass of the polyoxymethylene. Any mass ratio within the above range is applicable to the present application.

[0022] For the two components, the molecular weight of the ultra-high molecular weight polyethylene can be 1.5-3 million. For example, the molecular weight of the ultra-high molecular weight polyethylene is 1.5 million, 1.6 million, 1.7 million, 1.8 million, 1.9 million, 2 million, 2.1 million, 2.2 million, 2.3 million, 2.4 million, 2.5 million, 2.6 million, 2.7 million, 2.8 million, 2.9 million, 3 million, or any increment or decrement of the above values, which is not specifically limited in the present application.

[0023] In the blending process of the present application, a twin-screw extruder is used, and those skilled in the art can understand that the key process parameters can be adjusted in a wide range in coordination to adapt to the characteristics of different materials and blending targets. Specifically, the screw speed can be selected in the range of about 100 rpm to about 1000 rpm: lower speed (such as 100-300 rpm) can provide longer residence time and milder shear, which is suitable for systems sensitive to shear or requiring sufficient melting; higher speed (such as 300-1000 rpm) can apply higher shear energy and achieve higher output, which is suitable for blending that pursues efficient dispersion. The extrusion temperature can be set between about 180°C and about 230°C according to the melting point and thermal stability of the polymer matrix and components, which can ensure that most general materials and some engineering materials are fully melted and remain stable processing. The length-diameter ratio of the twin-screw extruder can be selected between about 28:1 and about 60:1: shorter length-diameter ratio (such as 28:1-40:1) is suitable for basic blending with simple components or low mixing requirements; longer length-diameter ratio (such as 40:1-60:1) provides more sufficient conveying, melting, mixing, and devolatilization paths for the materials, which is especially suitable for complex blending systems with multiple components, high filling, or devolatilization, and is beneficial to obtain more uniform and stable blending products. Those skilled in the art can determine the appropriate parameter combination within the range based on the above principles, combined with specific materials and performance requirements, through routine experiments. In one specific embodiment, the parameters of screw speed 350 rpm, extrusion temperature 210°C, and length-diameter ratio 48:1 are used, and good blending effect is achieved.

[0024] For polyoxymethylene (POM), this application uses POM with a high melt flow rate. For example, the melt index of POM is not less than 35 g / 10 min at a test temperature of 190°C and a test load of 2.16 kg. Examples include 35 g / 10 min and 45 g / 10 min. Using POM with a higher melting point can increase the melting point of the mixture obtained after blending with ultra-high molecular weight polyethylene (UHMWPE), thereby improving the characteristics of UHMWPE, such as easy deformation and melting at high temperatures and poor heat resistance, and thus improving processing flow properties.

[0025] In some embodiments, the compatibilizer and the antioxidant can be added together during the blending of ultra-high molecular weight polyethylene and polyoxymethylene. The compatibilizer can improve the compatibility and adhesion between the blend components, namely ultra-high molecular weight polyethylene and polyoxymethylene, so as to make the blend system more stable. The antioxidant can inhibit oxidation during blending and subsequent use, and maintain the structural and performance stability of the blend system. In some embodiments, the weight ratio of ultra-high molecular weight polyethylene, polyoxymethylene, and the added compatibilizer and antioxidant is (50-70):(30-50):(0.5-10):(0.1-0.6). Optionally or preferably, the weight ratio of ultra-high molecular weight polyethylene, polyoxymethylene, and the added compatibilizer and antioxidant is (50-70):(30-50):8:0.5.

[0026] Suitable, but not limiting, compatibilizers may be selected from at least one of the following: maleic anhydride-grafted acrylonitrile-butadiene-styrene terpolymer, maleic anhydride-grafted polyethylene, maleic anhydride-grafted polypropylene, maleic anhydride-grafted ethylene propylene diene monomer (EPDM) rubber, glycidyl methacrylate-grafted polypropylene, maleic anhydride-grafted hydrogenated styrene-butadiene block copolymer, styrene-maleic anhydride copolymer, ethylene-acrylate copolymer, and ethylene-vinyl acetate copolymer. Optionally or preferably, the compatibilizer is maleic anhydride-grafted polyethylene.

[0027] Suitable but not limiting antioxidants may be selected from 2,6-di-tert-butyl-4-methylphenol, 2,2'-methylenebis(4-methyl-6-tert-butylphenol), pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, N,N'-bis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine, tris[2,4-di-tert-butylphenyl]phosphite, bis( 2,4-Di-tert-butylphenyl) pentaerythritol diphosphite, N-isopropyl-N'-phenyl-p-phenylenediamine, 2,2,4-trimethyl-1,2-dihydroquinoline polymer, dilauryl thiodipropionate, distearate thiodipropionate, N,N'-bis(β-hydroxyethyl)-5-methylhydrazine-1,3-dicarboxamide, 2,2'-thiodiethanol bis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), 1,3,5-trimethyl-2,4,6-tris(3,5-di-di-tert-butyl-4-hydroxyphenyl)propionate tert-Butyl-4-hydroxyphenyl)benzene, n-octyl 3,5-di-tert-butyl-4-hydroxybenzoate, 2,2'-methylenebis(4-ethyl-6-tert-butylphenol), distearate thiodipropionate, 2-(1,1-dimethylethyl)-6-[3-(1,1-dimethylethyl)-2-hydroxy-5-methylphenyl]methyl-4-methylphenol, n-dodecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, di(2,2,6,6-tetramethyl-4-piperidinyl) At least one of the following: sebacic acid ester, 2,2'-thionyldiethanol bis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 1,6-hexanediol bis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), 2,4-di-tert-butyl-6-(3-tert-butyl-2-hydroxy-5-methylbenzyl)phenol, pentamethylene bis(β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), and 2,2'-methylene bis(6-tert-butyl-4-ethylphenol). Optionally or preferably, the antioxidant is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate].

[0028] In some embodiments, the blending of the ultra-high molecular weight polyethylene, the polyoxymethylene, the compatibilizer, and the antioxidant can be achieved using a twin-screw extruder. An exemplary operation may include: after drying the raw materials, such as ultra-high molecular weight polyethylene and / or polyoxymethylene, weighing the ultra-high molecular weight polyethylene, the polyoxymethylene, the compatibilizer, and / or the antioxidant according to the formulation ratio, and then adding them to a mixing device for premixing. The mixing device used can be any type of device capable of performing mixing functions, such as a horizontal mixer, vertical mixer, double cone mixer, V-type mixer, trough mixer, kneader, planetary mixer, fluidized bed mixer, spiral cone mixer, belt mixer, tipping bucket mixer, airflow mixer, high-speed mixer, slurry mixer, vacuum mixer, etc. Taking dry mixing as an example, after each component is added to a high-speed mixer, it can be mixed at a preset stirring speed (e.g., 500-800 rpm) for a set time (e.g., 5-15 min) to obtain a premix. Premixing allows the additives to be initially and uniformly dispersed in ultra-high molecular weight polyethylene and polyoxymethylene. The premix will be fed into a twin-screw extruder, or, for heat-sensitive additives (such as certain antioxidants), to avoid decomposition and agglomeration after excessive retention time in the extruder, it can be fed into the extruder via side feeding. The material will be melted, dispersed, and homogenized under the shearing, conveying, and heating action of the screw. The material will be preheated in the conveying section, gradually melted in the melting section to obtain a pre-mixed solution, dispersed and distributed in the mixing section, and after degassing, the uniformly mixed solution will be conveyed out, pushed by the screw to a filter plate and filter screen to remove material particles and impurities, and then enter the die head mold (e.g., a round hole die head), and extruded through the die hole to form a continuous "strip". By selecting a suitable pelletizing method (e.g., water-cooled pelletizing), the continuous strip is cut into uniform pellets. These pellets can then undergo necessary processing, such as drying, sieving, and quality inspection, to become the final blended polymer.

[0029] In some embodiments, when using the twin-screw extruder for blending, the screw speed can be 350 rpm, the extrusion temperature can be 210°C, and the length-to-diameter ratio can be 48:1.

[0030] Step S2: The blended polymer is melt-spun and then drawn and shaped to obtain the ultra-high molecular weight polyethylene fiber.

[0031] Exemplary melt spinning can be performed using a single-screw extruder. For example, granular blended polymers can undergo melt formation, spinneret formation, and cooling solidification to form solid nascent fibers. After traction setting, the ultra-high molecular weight polyethylene fibers are obtained. Exemplarily, the granular blended polymers are completely melted by shearing and heating in the melt section of the single-screw extruder to form a homogeneous melt. This homogeneous melt can pass through a multi-stage filter or melt filter to remove unmelted particles, mechanical impurities, etc., before entering a gear metering pump. The melt output flow rate is controlled by the precise speed of the pump. This ensures that the melt extrusion rate is consistent with the spinneret orifice. The metered melt is evenly distributed to the spinneret through the melt piping of the spinning box. Under pressure, it passes through the spinneret orifice, forming a continuous melt stream that rapidly cools under the action of a cooling medium, transforming from a viscous flow state into solid nascent fibers.

[0032] The solid nascent fiber will achieve molecular chain orientation through traction, thereby improving its mechanical properties. In some embodiments, the total traction ratio can be 3-4. A total traction ratio exceeding this range will cause the nascent fiber to catalyze, while a ratio that is too low will result in insufficient strength.

[0033] In some embodiments, the setting process can be performed using various applicable setting methods, including but not limited to dry heat setting (e.g., placing the wound fiber in a hot air setting oven to eliminate internal stress and improve crystallization under heat), moist heat setting (e.g., immersing the fiber in a constant-temperature water body or introducing it into atmospheric pressure saturated steam to eliminate internal stress), steam setting (e.g., atmospheric pressure steam setting, high-pressure steam setting, etc., using saturated steam to rearrange the fiber's molecular chains and form stable crystals), and bath setting (e.g., using a specific chemical bath to immerse the fiber in a high-temperature bath for setting). The specific method can be adjusted according to actual conditions. In some embodiments, the setting process includes moist heat setting.

[0034] The method for preparing ultra-high molecular weight polyethylene (UHMWPE) fibers provided in this application achieves melt spinning of UHMWPE by introducing polyoxymethylene (POM) for blending modification.

[0035] The present application will be further described in detail below with reference to embodiments. It should be noted that the following embodiments are for illustrative purposes only and are not intended to limit the scope of protection claimed in this application.

[0036] Example 1 - Preparation of Ultra-High Molecular Weight Polyethylene Fiber In this embodiment, the materials were taken according to the mass ratio of ultra-high molecular weight polyethylene: polyoxymethylene: compatibilizer: antioxidant = 100: 0: 0: 0.5. The specific component selection, mass ratio and components are shown in Table 1.

[0037] The preparation process is as follows: The above raw materials were blended and then subjected to high-temperature melt shearing, water-cooled stranding, and granulation using a twin-screw extruder to obtain blended polymer particles. The twin-screw extruder had an extrusion temperature of 210℃, a screw speed of 350 rpm, and an aspect ratio of 48:1. The strand diameter was 3 mm. The blended polymer particles were then melt-spun to obtain fiber products. Melt spinning was performed using a single-screw spinning machine. The melt temperature was 225℃, and the spinning machine screw speed was 25 rpm. Five traction stages were used: traction speed 1 at 30 m / min, traction speed 2 at 120 m / min, traction speed 3 at 120 m / min, traction speed 4 at 120 m / min, and traction speed 5 at 120 m / min.

[0038] Example 2 - Preparation of ultra-high molecular weight polyethylene fiber In this embodiment, the materials were taken according to the mass ratio of ultra-high molecular weight polyethylene: polyoxymethylene: compatibilizer: antioxidant = 70:30:8:0.5. The specific component selection, mass ratio and composition are shown in Table 1.

[0039] The preparation process is as follows: The above raw materials were blended and then subjected to high-temperature melt shearing, water-cooled stranding, and granulation using a twin-screw extruder to obtain blended polymer particles. The twin-screw extruder had an extrusion temperature of 210℃, a screw speed of 350 rpm, and an aspect ratio of 48:1. The strand diameter was 3 mm. The blended polymer particles were then melt-spun to obtain fiber products. Melt spinning was performed using a single-screw spinning machine. The melt temperature was 225℃, and the spinning machine screw speed was 25 rpm. Five traction stages were used: traction speed 1 at 30 m / min, traction speed 2 at 120 m / min, traction speed 3 at 120 m / min, traction speed 4 at 120 m / min, and traction speed 5 at 120 m / min.

[0040] Example 3 - Preparation of ultra-high molecular weight polyethylene fiber In this embodiment, the materials were taken according to the mass ratio of ultra-high molecular weight polyethylene: polyoxymethylene: compatibilizer: antioxidant = 60:40:8:0.5. The specific component selection, mass ratio and composition are shown in Table 1.

[0041] The preparation process is as follows: The above raw materials were blended and then subjected to high-temperature melt shearing, water-cooled stranding, and granulation using a twin-screw extruder to obtain blended polymer particles. The twin-screw extruder had an extrusion temperature of 210℃, a screw speed of 350 rpm, and an aspect ratio of 48:1. The strand diameter was 3 mm. The blended polymer particles were then melt-spun to obtain fiber products. Melt spinning was performed using a single-screw spinning machine. The melt temperature was 225℃, and the spinning machine screw speed was 25 rpm. Five traction stages were used: traction speed 1 at 30 m / min, traction speed 2 at 120 m / min, traction speed 3 at 120 m / min, traction speed 4 at 120 m / min, and traction speed 5 at 120 m / min.

[0042] Example 4 - Preparation of ultra-high molecular weight polyethylene fiber In this embodiment, the materials were taken according to the mass ratio of ultra-high molecular weight polyethylene: polyoxymethylene: compatibilizer: antioxidant = 50: 50: 8: 0.5. The specific component selection, mass ratio and components are shown in Table 1.

[0043] The preparation process is as follows: The above raw materials were blended and then subjected to high-temperature melt shearing, water-cooled stranding, and granulation using a twin-screw extruder to obtain blended polymer particles. The twin-screw extruder had an extrusion temperature of 210℃, a screw speed of 350 rpm, and an aspect ratio of 48:1. The strand diameter was 3 mm. The blended polymer particles were then melt-spun to obtain fiber products. Melt spinning was performed using a single-screw spinning machine. The melt temperature was 225℃, and the spinning machine screw speed was 25 rpm. Five traction stages were used: traction speed 1 at 30 m / min, traction speed 2 at 120 m / min, traction speed 3 at 120 m / min, traction speed 4 at 120 m / min, and traction speed 5 at 120 m / min.

[0044] Example 5 - Preparation of ultra-high molecular weight polyethylene fiber In this embodiment, the materials were taken according to the mass ratio of ultra-high molecular weight polyethylene: polyoxymethylene: compatibilizer: antioxidant = 30: 70: 8: 0.5. The specific component selection, mass ratio and components are shown in Table 1.

[0045] The preparation process is as follows: The above raw materials were blended and then subjected to high-temperature melt shearing, water-cooled stranding, and granulation using a twin-screw extruder to obtain blended polymer particles. The twin-screw extruder had an extrusion temperature of 210℃, a screw speed of 350 rpm, and an aspect ratio of 48:1. The strand diameter was 3 mm. The blended polymer particles were then melt-spun to obtain fiber products. Melt spinning was performed using a single-screw spinning machine. The melt temperature was 225℃, and the spinning machine screw speed was 25 rpm. Five traction stages were used: traction speed 1 at 30 m / min, traction speed 2 at 120 m / min, traction speed 3 at 120 m / min, traction speed 4 at 120 m / min, and traction speed 5 at 120 m / min.

[0046] Example 6 - Preparation of Ultra-High Molecular Weight Polyethylene Fiber In this embodiment, the materials were prepared according to a mass ratio of ultra-high molecular weight polyethylene: polyoxymethylene: compatibilizer: antioxidant = 60:40:8:0.5. Specific component selection, mass ratios, and compositions are shown in Table 1. The difference from Example 1 lies in the molecular weight of the ultra-high molecular weight polyethylene used.

[0047] The preparation process is as follows: The above raw materials were blended and then subjected to high-temperature melt shearing, water-cooled stranding, and granulation using a twin-screw extruder to obtain blended polymer particles. The twin-screw extruder had an extrusion temperature of 210℃, a screw speed of 350 rpm, and an aspect ratio of 48:1. The strand diameter was 3 mm. The blended polymer particles were then melt-spun to obtain fiber products. Melt spinning was performed using a single-screw spinning machine. The melt temperature was 225℃, and the spinning machine screw speed was 25 rpm. Five traction stages were used: traction speed 1 at 30 m / min, traction speed 2 at 120 m / min, traction speed 3 at 120 m / min, traction speed 4 at 120 m / min, and traction speed 5 at 120 m / min.

[0048] Example 7 - Preparation of Ultra-High Molecular Weight Polyethylene Fiber In this embodiment, the materials were prepared according to a mass ratio of ultra-high molecular weight polyethylene: polyoxymethylene: compatibilizer: antioxidant = 60:40:8:0.5. Specific component selection, mass ratios, and compositions are shown in Table 1. The difference from Example 1 lies in the molecular weight of the ultra-high molecular weight polyethylene used.

[0049] The preparation process is as follows: The above raw materials were blended and then subjected to high-temperature melt shearing, water-cooled stranding, and granulation using a twin-screw extruder to obtain blended polymer particles. The twin-screw extruder had an extrusion temperature of 210℃, a screw speed of 350 rpm, and an aspect ratio of 48:1. The strand diameter was 3 mm. The blended polymer particles were then melt-spun to obtain fiber products. Melt spinning was performed using a single-screw spinning machine. The melt temperature was 225℃, and the spinning machine screw speed was 25 rpm. Five traction stages were used: traction speed 1 at 30 m / min, traction speed 2 at 120 m / min, traction speed 3 at 120 m / min, traction speed 4 at 120 m / min, and traction speed 5 at 120 m / min.

[0050] Example 8 - Preparation of ultra-high molecular weight polyethylene fiber In this embodiment, the materials were prepared according to a mass ratio of ultra-high molecular weight polyethylene: polyoxymethylene: compatibilizer: antioxidant = 60:40:8:0.5. Specific component selection, mass ratios, and composition are shown in Table 1. The difference from Example 6 lies in the melt flow index of the polyoxymethylene.

[0051] The preparation process is as follows: The above raw materials were blended and then subjected to high-temperature melt shearing, water-cooled stranding, and granulation using a twin-screw extruder to obtain blended polymer particles. The twin-screw extruder had an extrusion temperature of 210℃, a screw speed of 350 rpm, and an aspect ratio of 48:1. The strand diameter was 3 mm. The blended polymer particles were then melt-spun to obtain fiber products. Melt spinning was performed using a single-screw spinning machine. The melt temperature was 225℃, and the spinning machine screw speed was 25 rpm. Five traction stages were used: traction speed 1 at 30 m / min, traction speed 2 at 120 m / min, traction speed 3 at 120 m / min, traction speed 4 at 120 m / min, and traction speed 5 at 120 m / min.

[0052] Example 9 - Preparation of ultra-high molecular weight polyethylene fiber In this embodiment, the materials were prepared according to a mass ratio of ultra-high molecular weight polyethylene: polyoxymethylene: compatibilizer: antioxidant = 60:40:8:0.5. The specific component selection, mass ratio, and composition are shown in Table 1. The difference from Example 7 lies in the choice of compatibilizer.

[0053] The preparation process is as follows: The above raw materials were blended and then subjected to high-temperature melt shearing, water-cooled stranding, and granulation using a twin-screw extruder to obtain blended polymer particles. The twin-screw extruder had an extrusion temperature of 210℃, a screw speed of 350 rpm, and an aspect ratio of 48:1. The strand diameter was 3 mm. The blended polymer particles were then melt-spun to obtain fiber products. Melt spinning was performed using a single-screw spinning machine. The melt temperature was 225℃, and the spinning machine screw speed was 25 rpm. Five traction stages were used: traction speed 1 at 30 m / min, traction speed 2 at 120 m / min, traction speed 3 at 120 m / min, traction speed 4 at 120 m / min, and traction speed 5 at 120 m / min.

[0054] Example 10 - Preparation of ultra-high molecular weight polyethylene fiber In this embodiment, the materials were prepared according to a mass ratio of ultra-high molecular weight polyethylene: polyoxymethylene: compatibilizer: antioxidant = 60:40:8:0.5. The specific component selection, mass ratio, and composition are shown in Table 1. The difference from Example 7 lies in the choice of compatibilizer.

[0055] The preparation process is as follows: The above raw materials were blended and then subjected to high-temperature melt shearing, water-cooled stranding, and granulation using a twin-screw extruder to obtain blended polymer particles. The twin-screw extruder had an extrusion temperature of 210℃, a screw speed of 350 rpm, and an aspect ratio of 48:1. The strand diameter was 3 mm. The blended polymer particles were then melt-spun to obtain fiber products. Melt spinning was performed using a single-screw spinning machine. The melt temperature was 225℃, and the spinning machine screw speed was 25 rpm. Five traction stages were used: traction speed 1 at 30 m / min, traction speed 2 at 120 m / min, traction speed 3 at 120 m / min, traction speed 4 at 120 m / min, and traction speed 5 at 120 m / min.

[0056] Example 11 - Preparation of Ultra-High Molecular Weight Polyethylene Fiber In this embodiment, the materials were taken at a mass ratio of ultra-high molecular weight polyethylene: polyoxymethylene: compatibilizer: antioxidant = 60:40:8:0.5. The specific component selection, mass ratio, and composition are shown in Table 1. The difference from Example 7 is the choice of antioxidant.

[0057] The preparation process is as follows: The above raw materials were blended and then subjected to high-temperature melt shearing, water-cooled stranding, and granulation using a twin-screw extruder to obtain blended polymer particles. The twin-screw extruder had an extrusion temperature of 210℃, a screw speed of 350 rpm, and an aspect ratio of 48:1. The strand diameter was 3 mm. The blended polymer particles were then melt-spun to obtain fiber products. Melt spinning was performed using a single-screw spinning machine. The melt temperature was 225℃, and the spinning machine screw speed was 25 rpm. Five traction stages were used: traction speed 1 at 30 m / min, traction speed 2 at 120 m / min, traction speed 3 at 120 m / min, traction speed 4 at 120 m / min, and traction speed 5 at 120 m / min.

[0058] Example 12 - Preparation of Ultra-High Molecular Weight Polyethylene Fiber In this embodiment, the materials were taken at a mass ratio of ultra-high molecular weight polyethylene: polyoxymethylene: compatibilizer: antioxidant = 60:40:8:0.5. The specific component selection, mass ratio, and composition are shown in Table 1. The difference from Example 7 is the choice of antioxidant.

[0059] The preparation process is as follows: The above raw materials were blended and then subjected to high-temperature melt shearing, water-cooled stranding, and granulation using a twin-screw extruder to obtain blended polymer particles. The twin-screw extruder had an extrusion temperature of 210℃, a screw speed of 350 rpm, and an aspect ratio of 48:1. The strand diameter was 3 mm. The blended polymer particles were then melt-spun to obtain fiber products. Melt spinning was performed using a single-screw spinning machine. The melt temperature was 225℃, and the spinning machine screw speed was 25 rpm. Five traction stages were used: traction speed 1 at 30 m / min, traction speed 2 at 120 m / min, traction speed 3 at 120 m / min, traction speed 4 at 120 m / min, and traction speed 5 at 120 m / min.

[0060] Table 1. Raw material composition for the preparation of ultra-high molecular weight polyethylene fibers Table 1. Raw material composition for the preparation of ultra-high molecular weight polyethylene fibers (continued) Test Example 1 - Processing Flowability Test The melt flow index of the above-mentioned blended polymer particles was determined in accordance with the national standard GB / T 3682.1-2018, and the measured melt flow index was graded.

[0061] Test Example 2 - Melting Point Test A sample made of blended polymer particles was placed in a capillary tube and heated uniformly in silicone oil. The transmittance of the sample was monitored in real time as it turned green using a digital melting point apparatus, and the test results were automatically calculated.

[0062] Test Example 3 - Tensile Parameter Test The fiber is fixed in the upper and lower clamps of the electronic tensile testing machine, ensuring it is aligned with the center of the clamps. The electronic tensile testing machine is then started to stretch the fiber until it breaks, and the breaking tensile force and breaking displacement are automatically recorded.

[0063] The test results for the above test cases are summarized in Table 2.

[0064] Table 2 Test Results Table 2 Test Results (Continued) As shown in Table 2, the modification of ultra-high molecular weight polyethylene fiber by introducing polyoxymethylene not only increases the melting point of ultra-high molecular weight polyethylene fiber, but also improves its spinning process fluidity and the mechanical properties of the resulting product are excellent.

[0065] This application also discloses an ultra-high molecular weight polyethylene fiber, which can be prepared using the above method.

[0066] This application also discloses an article made from the aforementioned ultra-high molecular weight polyethylene fiber. This article can be applied in military protection fields such as bulletproof vests, shields, and parachutes; marine engineering and fisheries fields such as ropes, fishing nets, and submarine cables; safety protection and industrial fields such as cut-resistant gloves, safety belts, climbing ropes, and automotive parts; medical and health fields such as artificial joints, heart valves, and surgical sutures; aerospace fields such as aviation ropes, aircraft structural components, and parachute systems; and sports and leisure fields such as rackets, sportswear, and bowstrings. Alternatively, this article can be applied to other innovative applications such as robotic tendons, flexible electronics, new energy battery separators, and building materials.

[0067] This application has described the basic concepts. Obviously, for those skilled in the art, the above detailed disclosure is merely illustrative and does not constitute a limitation of this application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements, and corrections to this application. Such modifications, improvements, and corrections are suggested in this application, and therefore such modifications, improvements, and corrections still fall within the spirit and scope of the exemplary embodiments of this application.

[0068] Meanwhile, this application uses specific terms to describe its embodiments. For example, "an embodiment," "one embodiment," "some embodiments," and / or "some implementations" refer to a particular feature, structure, or characteristic related to at least one embodiment of this application. Therefore, it should be emphasized and noted that "an embodiment," "one embodiment," or "an alternative embodiment" mentioned twice or more in different locations in this application do not necessarily refer to the same embodiment. Furthermore, certain features, structures, or characteristics in one or more embodiments of this application can be appropriately combined.

[0069] It should be noted that the above embodiments are only used to illustrate the principles and effects of the present invention, and are not intended to limit the scope of protection of the present invention. Those skilled in the art can make various adjustments and changes to the material ratios and process parameters (such as rotational speed, temperature, and length-to-diameter ratio) in the above embodiments without departing from the concept and scope of the present invention. Such adjustments and changes all fall within the scope of protection of the present invention.

[0070] Similarly, it should be noted that, in order to simplify the description of this application and thus aid in the understanding of one or more embodiments of the invention, the foregoing description of the embodiments of this application sometimes combines multiple features into one embodiment or its description. However, this disclosure method does not imply that the subject matter of this application requires more features than those mentioned in the claims. In fact, the embodiments have fewer features than all the features of the single embodiments disclosed above.

[0071] Finally, it should be understood that the embodiments described in this application are merely illustrative of the principles of the embodiments of this application. Other modifications may also fall within the scope of this application. Therefore, alternative configurations of the embodiments of this application are considered as examples and not limitations, and are regarded as consistent with the teachings of this application. Accordingly, the embodiments of this application are not limited to the embodiments explicitly described and illustrated in this application.

Claims

1. A method for producing an ultrahigh molecular weight polyethylene fiber, characterized by, The preparation method comprises: blending ultra-high molecular weight polyethylene and polyformaldehyde, and adding a compatilizer and an antioxidant to obtain a blended polymer; using the blended polymer to perform melt spinning, and obtaining the ultra-high molecular weight polyethylene fiber after drawing and setting; wherein, a weight ratio of the ultra-high molecular weight polyethylene to the polyformaldehyde is (50-70):(30-50).

2. The production method according to claim 1, characterized by, The ultra-high molecular weight polyethylene has a molecular weight of 1.5-3 million.

3. The production method according to claim 1, characterized by, a weight ratio of the ultra-high molecular weight polyethylene, the polyformaldehyde, the compatilizer and the antioxidant is (50-70):(30-50):(0.5-10):(0.1-0.6).

4. The production method according to any one of claims 1 to 3, characterized by, The compatilizer is at least one of maleic anhydride grafted acrylonitrile-butadiene-styrene terpolymer, maleic anhydride grafted polyethylene or maleic anhydride grafted polypropylene.

5. The production method according to any one of claims 1 to 3, characterized by, The antioxidant is at least one of tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid]pentaerythritol ester, tri[2.4-di-tert-butylphenyl]phosphite, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid n-octadecyl ester or N,N'-bis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine.

6. The method of claim 1, wherein, The blending is realized by using a double-screw extruder, the double-screw extruder has a screw rotation speed of 100-1000 rpm, an extrusion temperature of 180-230 ℃ and a length-diameter ratio of (28-60):

1.

7. The preparation method according to claim 1, characterized in that, The total drawing multiple of the drawing is 3-4. 8.An ultra-high molecular weight polyethylene fiber prepared by the preparation method according to any one of claims 1-7. 9.An article manufactured by the ultra-high molecular weight polyethylene fiber according to any one of claims 1-8.

Images