Preparation method of ultra-high molecular weight polyethylene coarse denier fiber

Abstract

This invention relates to the field of polymer material preparation, specifically to a method for preparing ultra-high molecular weight polyethylene (UHMWPE) coarse denier fibers. The method discloses a process where a spinning solution is extruded through a spinneret to obtain gel filaments. These gel filaments are then cooled twice, followed by preheating, stretching, oiling, and winding to obtain precursor fibers. The precursor fibers undergo multi-stage stretching to obtain UHMWPE coarse denier fibers. Through the two-stage cooling and preheating process, the "skin-core" structure of the fiber is first formed and then eliminated, allowing the solvent in the gel filaments to continuously precipitate out during the preparation process. This avoids fiber breakage and fuzzing caused by the "skin-core" structure during preparation. After the two cooling stages, a solid gel filament with a largely eliminated "skin-core" structure is obtained. Preheating softens and melts the solid gel filament, resulting in a stretchable gel filament. Finally, UHMWPE coarse denier fibers with high monofilament fineness and good mechanical properties are obtained.

Description

Technical Field

[0001] This invention relates to the field of polymer material preparation, specifically to a method for preparing ultra-high molecular weight polyethylene coarse denier fibers. Background Technology

[0002] Since the advent of gel spinning technology, the production technology of ultra-high molecular weight polyethylene fiber has made rapid progress. At present, the world's mainstream polyethylene fiber production technologies mainly include dry spinning and wet spinning.

[0003] Domestic wet-process technology is relatively mature and has been promoted and applied by dozens of enterprises in China. The fibers produced by this technology are characterized by coarse fineness, good uniformity, high strength, and high modulus, making them suitable for downstream applications. Dry-process technology has only been industrialized by Yizheng Chemical Fiber. It is characterized by fine denier, softness, good uniformity, high strength, and high modulus, and is widely used by downstream enterprises.

[0004] From the current development trend of domestic technology and products, wet-processed products have slightly more solvent residue than dry-processed products. This is reflected in the product's relatively larger denier and stiffer fibers, making them less prone to fuzzing during downstream processing and easier to process. They can be widely used in military and civilian fields. However, in fields such as medical devices where solvent residue requirements are high, further processing is needed to remove the solvent residue. Therefore, wet-processing technology has been developing towards finer denier fibers in recent years, both to expand application areas and to improve quality and strength. Dry-processing technology, due to the use of volatile solvents, has relatively lower solvent residue in its products. This is reflected in the product's finer denier, lighter weight, and high strength and modulus, making it widely applicable in military and civilian facilities. The fibers are soft and comfortable, but due to their fineness, they are prone to fuzzing during downstream processing and are more difficult to process. Therefore, in recent years, dry-processing technology has been developing towards coarser denier fibers, mainly to improve their ease of processing in downstream applications.

[0005] CN112609250A discloses a method for preparing ultra-high molecular weight polyethylene (UHMWPE) coarse denier monofilaments using a gel method. UHMWPE powder is mixed with white oil to prepare a spinning solution pre-swelling material, which is kept stirred and heated. The pre-swelling material is fed into a twin-screw extruder, then into a spinning assembly where it is filamentized by a spinneret and cooled in a cooling water tank to obtain UHMWPE gel-fiber monofilaments. These monofilaments are then allowed to settle and reach equilibrium. When the filaments fall into the drum, they are arranged in a cross-layered, circular pattern. The equilibrium-treated gel-fiber monofilaments are then extracted, dried, and hot-drawn. Finally, they are wound to obtain UHMWPE coarse denier monofilaments. This invention discloses a method that increases the fineness of monofilaments by 10 times, reaching 20-40 denier, with a diameter of 0.038-0.070 mm, without reducing strength. By replacing the original method of combining multiple fine denier monofilaments with coarse denier monofilaments, it effectively eliminates gaps between fine denier monofilaments while maintaining excellent strength and modulus. This method uses a wet process with a spinneret with a single hole diameter of 1.5-2mm. It employs a rapid cooling forming method, followed by a period of rest to eliminate the internal stress of the raw filament before high-ratio stretching.

[0006] CN101575745A discloses a coarse denier polyester fiber and its production method. The fiber has a monofilament fineness ranging from 7 to 20 dtex, and this coarse denier polyester fiber does not include polyester fibers with a total monofilament count of one. The production method includes: melting and extruding dried polyester chips, extruding and shaping them through a circular or shaped spinneret, cooling and solidifying them with side-blowing air, followed by oiling and cross-linking treatment, and finally winding them into shape using a winding device to directly obtain finished high-oriented polyester fiber (FDY), or semi-finished pre-oriented polyester fiber (POY). The semi-finished pre-oriented polyester fiber (POY) is then further processed to obtain the finished product. Furthermore, the production method of this product is simple, highly operable, and can meet the needs of further processing.

[0007] CN101899722A discloses a method for preparing polyvinyl alcohol coarse denier monofilament fibers. This method uses solid-phase alcoholysis spinning to prepare high-strength, high-modulus coarse denier polyvinyl alcohol monofilament fibers. Its key feature is the use of polyvinyl alcohol with low alcoholysis degree and plasticizing properties with a small amount of water for spinning. This allows for the preparation of coarse denier fibers at a lower temperature, avoiding extraction problems associated with plasticizers and the inability of wet spinning methods to produce coarse denier (≥1000D) fibers. A small amount of water is added to create a molten state. The fibers are extruded using a single screw extruder, metered by a metering pump, and then extruded from the spinneret. Any remaining moisture can be removed by heating. After drying, multi-stage stretching (10-16 times), and high-temperature tension heat setting, high-strength, high-modulus fibers are obtained. This method overcomes the deficiencies of existing technologies and commercially available products, meeting the needs of civil engineering projects for toughening and crack resistance in concrete. It uses a container that is easy to use to swell polyethylene, and then transports it to one of two alternately used containers for stirring. The liquid is then output through the outlet at the bottom of the container. There is still a concentration gradient in the container and sedimentation at the bottom. Therefore, the suspension cannot be output uniformly and continuously, and the uniformity of the products in subsequent processes cannot be guaranteed.

[0008] CN102154749A discloses a method for preparing coarse, ultra-high molecular weight polyethylene (UHMWPE) fiber yarn. The method includes spitting a polyethylene solution through a spinneret and then rapidly cooling it in a coagulation bath at 100°C-150°C to form gel fibers. The spinneret contains 20-50 sets of spinneret holes, each set consisting of 15-35 holes with a diameter of 0.7-1.0 mm. The gel fibers are then subjected to extraction drying and subsequent hot stretching to obtain the final product. This invention is simple to operate, requires minimal equipment, and produces coarse, ultra-high molecular weight polyethylene (UHMWPE) fiber yarn with a single fiber diameter of 0.7-1.0 mm. This fiber yarn exhibits high strength and is suitable for manufacturing high-strength ropes.

[0009] Due to the volatile nature of solvents, dry spinning technology can achieve high-speed stretching during processing, resulting in relatively fine fibers. Currently, the single filament fineness of domestically produced dry spinning products is basically between 0.8 and 1.3 dtex. To obtain products with higher single filament fineness, extensive process adjustments to the existing dry spinning technology are required. Summary of the Invention

[0010] The purpose of this invention is to overcome the problem of excessive fineness of ultra-high molecular weight polyethylene (UHMWPE) fibers prepared by dry spinning, and to provide a method for preparing UHMWPE coarse denier fibers. By cooling and preheating twice, the "core-sheath" structure of the fiber can be generated and then eliminated, avoiding fiber breakage and fuzzing during the preparation process, and finally obtaining UHMWPE coarse denier fibers with large single filament fineness and good mechanical properties.

[0011] To achieve the above objectives, the first aspect of the present invention provides a method for preparing ultra-high molecular weight polyethylene coarse denier fibers, wherein a spinning solution is extruded through a device to obtain gel filaments; the gel filaments are cooled twice, and then preheated, stretched, oiled and wound to obtain raw filaments; the raw filaments are subjected to multi-stage stretching to obtain ultra-high molecular weight polyethylene coarse denier fibers.

[0012] A second aspect of the present invention provides an ultra-high molecular weight polyethylene coarse denier fiber obtained by the aforementioned method.

[0013] Through the above technical solution, the present invention has the following beneficial effects:

[0014] (1) The present invention, through a specific process, especially the two cooling and preheating processes, first produces and then eliminates the "skin-core" structure of the fiber, so that the solvent in the gel fiber is continuously precipitated during the preparation process, avoiding the occurrence of fiber breakage and fuzz due to the "skin-core" structure of the gel fiber during the preparation process.

[0015] The first cooling process is rapid cooling and molding, forming a gel filament with a solidified exterior and a soft interior, resembling a "skin-core" structure. The second cooling process is deep cooling with high-speed cold air, which solidifies and molds the gel filament, accelerating the release of a large amount of solvent from the inside of the gel filament. After the two cooling processes, a solid gel filament with a largely eliminated "skin-core" structure is obtained. Preheating softens the solid gel filament, allowing the solvent to evaporate more fully and improving the spinnability of the gel filament.

[0016] (2) After the solvent is precipitated, it can be returned to the aforementioned module for reuse, thus realizing the recycling of the solvent.

[0017] (3) The ultra-high molecular weight polyethylene coarse denier fiber finally prepared has large single filament fineness and good mechanical properties. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of one embodiment of the fiber spinning system in this invention.

[0019] Explanation of reference numerals in the attached figures

[0020] 1. Metering pump 2. Coagulation bath 3. Wire guide cold drawing machine 4. Wire guide drying cold box 5. Cold drawing machine 6. Wire guide machine 7. Preheating tunnel 8. Wire guide machine 9. Preheating drying drawing box 10. Cold drawing machine 11. Drawing hot box 12. Cold drawing machine 13. Oiling machine 14. Winding machine Detailed Implementation

[0021] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0022] The first aspect of the present invention provides a method for preparing ultra-high molecular weight polyethylene coarse denier fiber, wherein a spinning solution is extruded through a device to obtain gel filaments; the gel filaments are cooled twice, and then preheated, stretched, oiled and wound to obtain raw filaments; the raw filaments are subjected to multi-stage stretching to obtain ultra-high molecular weight polyethylene coarse denier fiber.

[0023] In this invention, through specific processes, especially two cooling and preheating processes, the "skin-core" structure of the fibers first appears and then disappears, causing the solvent in the gel filaments to continuously precipitate out during the preparation process. This avoids the occurrence of fiber breakage and fuzzing caused by the "skin-core" structure of the gel filaments during the preparation process. After two cooling processes, a solid gel filament with the "skin-core" structure basically eliminated is obtained. Preheating softens and melts the solid gel filaments, resulting in a stretchable gel filament.

[0024] According to the present invention, the spinning solution comprises ultra-high molecular weight polyethylene and a solvent.

[0025] According to the present invention, the content of ultra-high molecular weight polyethylene is 5-10 wt% and the content of solvent is 90-95 wt%, based on the total mass of the spinning solution.

[0026] In this invention, when the content of ultra-high molecular weight polyethylene and solvent meets the above range, filament breakage and fuzz are less likely to occur during processing, and the performance of the final coarse denier fiber is further improved, achieving a balance between monofilament fineness and processing difficulty.

[0027] Furthermore, based on the total mass of the spinning solution, the content of ultra-high molecular weight polyethylene is 6-7 wt%, and the content of the solvent is 93-94 wt%.

[0028] In a particularly preferred embodiment of the present invention, the swelling temperature of the ultra-high molecular weight polyethylene is 95-100℃, preferably 96-98℃.

[0029] According to the present invention, the viscosity-average molecular weight of the ultra-high molecular weight polyethylene is 1 million to 10 million g / mol.

[0030] In this invention, when the viscosity-average molecular weight of ultra-high molecular weight polyethylene meets the above-mentioned range, its branching degree is low, it has good fluidity, and it is not easy to break during processing.

[0031] Furthermore, the viscosity-average molecular weight of the ultra-high molecular weight polyethylene is 4 million to 5 million g / mol.

[0032] According to the present invention, the solvent is selected from compounds containing a benzene ring.

[0033] According to the present invention, the boiling point of the solvent is 180-200°C, preferably 185-195°C.

[0034] According to the present invention, the solvent is selected from at least one of decahydronaphthalene, tetrahydronaphthalene and toluene, preferably decahydronaphthalene.

[0035] In this invention, the decahydronaphthalene is the decahydronaphthalene commonly used in the art. In a particularly preferred embodiment, the decahydronaphthalene is trans-decahydronaphthalene, which is an isomer of decahydronaphthalene.

[0036] According to the present invention, the equipment comprises a twin-screw extruder, a metering pump, a spinning box, and a spinneret.

[0037] According to the present invention, the extrusion process includes: the spinning solution is molten through the twin-screw extruder, accurately metered by the metering pump, flows through the spinning box, and is finally extruded from the spinneret.

[0038] According to the present invention, the temperature of the molten melt is 140-150°C.

[0039] In this invention, when the gel filaments meet the temperature range mentioned above, more solvent is flash-evaporated the instant they leave the spinneret, resulting in a lower solvent content in the gel filaments.

[0040] Furthermore, the temperature of the molten metal is 145-148°C.

[0041] In this invention, the temperature of the spinning box is not limited. In a particularly preferred embodiment, the temperature of the spinning box is 160-200°C, preferably 170-190°C.

[0042] According to the present invention, the diameter of a single hole in the spinneret is 0.5-2 mm, preferably 1.2-1.5 mm.

[0043] According to the present invention, the aspect ratio of the spinneret is 4-10:1, preferably 6-8:1.

[0044] According to the present invention, the spinneret is provided with a nozzle, and the draw ratio of the nozzle is 5-20 times.

[0045] In this invention, when the stretch ratio meets the above range, the solvent content in the gel filament can be controlled to remain within a suitable range. When the stretch ratio of the nozzle is less than the above range, the gel filament contains more solvent. When the stretch ratio of the nozzle is greater than the above range, fuzzy and broken filaments are prone to occur, affecting the performance of the final fiber.

[0046] Furthermore, the stretch ratio of the nozzle is 10-15 times.

[0047] According to the present invention, the extrusion rate is 2.5-5 m / min, preferably 3-3.5 m / min.

[0048] In this invention, the component pressure in the spinneret is a pressure commonly used in the art. In a particularly preferred embodiment, the component pressure in the spinneret is 0-1.8 MPa, preferably 0.5-1 MPa.

[0049] According to the present invention, the two cooling processes include a first cooling and a second cooling, wherein the first cooling is solution cooling and the second cooling is cold air cooling.

[0050] According to the present invention, the solution cooling is carried out in a coagulation bath, and the temperature at which the gel filaments are drawn out of the coagulation bath is ≤40°C, preferably ≤20°C.

[0051] In this invention, the solution cooling is a rapid cooling and molding process. The gel filaments pulled out of the coagulation bath are in an unstable state with a solidified surface and a soft interior, which is close to a "skin-core" structure. Moreover, as the surface of the gel filaments cools, solvent will continuously precipitate out on the surface of the gel filaments.

[0052] In this invention, the quenching solution in the coagulation bath is a conventional solution that is incompatible with the spinning aid. Preferably, it is selected from water, solvents included in the spinning solution, and solutions insoluble in the solvents, so as to facilitate the subsequent recycling of the solvent.

[0053] According to the present invention, the cold air cooling is carried out in a guide wire cold drawing machine, a guide wire drying cold box, and a cold drawing machine, wherein an air knife is provided in the guide wire drying cold box.

[0054] In this invention, the high-speed airflow generated by the air knife in the cold air cooling process deeply cools the gel filaments and dries the solvent precipitated on the surface of the gel filaments, thereby significantly reducing the solvent content inside the gel filaments, essentially eliminating the "skin-core" structure, and obtaining solid gel filaments.

[0055] According to the present invention, the outlet air temperature of the air knife is -10°C to 10°C.

[0056] In this application, the specific air outlet temperature of the air knife enables the filaments to be rapidly cryogenically solidified, forming stable gel filaments and accelerating the large-scale precipitation of solvent inside the gel filaments.

[0057] Furthermore, the outlet air temperature of the air knife is -5℃ to 0℃.

[0058] According to the present invention, the outlet air velocity of the air knife is 50-100 m / s.

[0059] In this application, the specific air knife outlet air velocity can remove the rapidly cooled solvent brought out from the coagulation bath on the fiber surface, while also drying the solvent that precipitates inside the gel filament due to cooling and shrinkage.

[0060] Furthermore, the outlet wind speed of the air knife is 70-75 m / s.

[0061] According to the present invention, the draw ratio of the cold drawing machine is 0.8-1.2 times.

[0062] In this invention, since the gel filaments will shrink to a certain extent in terms of length after cryogenic treatment, the specific drawing ratio of the cold drawing machine can prevent filament breakage and fuzzing during the production process.

[0063] Furthermore, the draw ratio of the cold drawing machine is 0.9-1 times.

[0064] According to the present invention, the preheating is carried out in a preheating tunnel, and the preheating temperature is 40-100°C.

[0065] In this invention, the preheating softens the cured gel filaments, facilitating subsequent solvent evaporation and directional stretching, thereby improving the spinnability of the gel filaments.

[0066] Furthermore, the preheating temperature is 70-80℃.

[0067] According to the present invention, the drawing is carried out in a preheating and drying drawing box and a drawing hot box, wherein the drawing machine in the preheating and drying drawing box is a hot drawing machine equipped with hot drawing rollers.

[0068] According to the present invention, the temperature of the preheating drying stretching box is 60-150°C, preferably 100-140°C.

[0069] In this invention, the hot drawing roller is located inside the preheating and drying drawing box, and the two are at the same temperature in the later stages.

[0070] According to the present invention, the draw ratio of the hot drawing machine is 1-1.5 times, preferably 1-1.2 times.

[0071] According to the present invention, the temperature of the stretching heat box is 100-140°C, preferably 120-130°C.

[0072] According to the present invention, the stretching ratio of the stretching heat box is 1-2 times, preferably 1.2-1.5 times.

[0073] According to the present invention, the multi-stage stretching includes primary stretching, secondary stretching and tertiary stretching; the total stretching ratio of the multi-stage stretching is 7-10 times.

[0074] According to the present invention, the first-stage stretching ratio is 3-6 times, preferably 4-5 times; the first-stage stretching temperature is 138-142℃, preferably 140-142℃.

[0075] According to the present invention, the secondary stretching ratio is 1.2-1.6 times, preferably 1.3-1.5 times; the secondary stretching temperature is 142-145℃, preferably 143-144℃.

[0076] According to the present invention, the three-stage stretching ratio is 1-1.4 times, preferably 1.05-1.2 times; the three-stage stretching temperature is 144-148℃, preferably 145-148℃.

[0077] A second aspect of the present invention provides an ultra-high molecular weight polyethylene coarse denier fiber obtained by the aforementioned method.

[0078] According to the present invention, the solvent content of the ultra-high molecular weight polyethylene coarse denier fiber is 900-14500ppm, the single filament fineness is 1-51dtex, the breaking strength is ≥30cN / dtex, and the Young's modulus is ≥1200cN / dtex.

[0079] In this invention, the solvent content increases the linear density of the fiber, thereby increasing the weight per unit length of the fiber. Later, the solvent in the fiber will slowly evaporate, causing a decrease in the fiber linear density. Higher solvent content makes it easier to obtain coarse denier fibers with large monofilament fineness; however, solvent content is only one factor influencing monofilament fineness.

[0080] Furthermore, the solvent content of the ultra-high molecular weight polyethylene coarse denier fiber is 3000-10000ppm, the single filament fineness is 1.5-3.8dtex, the breaking strength is ≥35cN / dtex, and the Young's modulus is ≥1300cN / dtex.

[0081] Figure 1The diagram shows the structure of the fiber spinning system. Metering pump 1 meters the polyethylene spinning solution, which is then extruded through a specific spinneret. The extruded gel filaments enter a coagulation bath 2 for rapid cooling. The cooled gel filaments undergo two cooling processes: a guide wire cold drawing machine 3, a guide wire drying cold box 4, and a cold drawing machine 5. After these two cooling processes, the gel filaments flow through a guide wire machine 6 and into a preheating channel 7 for preheating. They then flow through a guide wire machine 8 into a preheating drying drawing box 9, pass through a cold drawing machine 10, and enter a drawing hot box 11 for drawing and solvent removal. The removed gel filaments flow through a cold drawing machine 12 into an oiling machine 13 for oiling, and are then wound in a winding machine 14 to obtain the precursor fiber. The prepared precursor fiber undergoes multi-stage stretching to ultimately produce ultra-high molecular weight polyethylene coarse denier fiber.

[0082] The present invention will be described in detail below through embodiments.

[0083] Method for detecting the diameter of gel filaments: The equipment used is a Caikang CKC2000 microscope with a 10x eyepiece and DL-3000 particle size analysis software. Gel filament samples were taken from the nozzle outlet, coagulation bath outlet, guide drying cold box outlet, preheating tunnel outlet, preheating drying drawing box outlet, drawing hot box outlet, winding outlet, and finished fiber winding outlet. The diameter of the single filament was measured under a 250x field of view.

[0084] Method for detecting the mass ratio of ultra-high molecular weight polyethylene (UHMWPE) to solvent in gel filaments: Take 100g samples of bundled gel filaments at the nozzle outlet, coagulation bath outlet, guide drying cold box outlet, preheating tunnel outlet, preheating drying drawing box outlet, drawing hot box outlet, winding outlet, and finished fiber winding outlet. Dry the samples under vacuum conditions at 140℃ (temperature higher than the glass transition point of polyethylene, which would cause polyethylene to melt and the internal solvent to not easily volatilize, leading to distorted measurement results) for 3 hours. After drying, remove the samples, cool them to room temperature, and weigh them, recording the weight as m1. The solvent content is 100-m1, calculated according to the following formula.

[0085] Solvent:

[0086] Method for testing the fineness of single filaments of gel filaments and ultra-high molecular weight polyethylene coarse denier fibers: The test is conducted according to GB / T / 19975-2005. The fineness of the single filament is calculated by measuring the linear density of the bundled filaments. The fineness of the single filament is calculated as: fineness of the bundled filaments obtained by the test / number of holes in the spinneret.

[0087] The solvent content was detected by measuring the mass ratio of ultra-high molecular weight polyethylene to solvent in the gel fiber, and the average value was taken from three measurements.

[0088] The testing methods for the breaking strength and Young's modulus of ultra-high molecular weight polyethylene coarse denier fibers are as follows: GB / T19975-2005 method shall be used for testing.

[0089] Ultra-high molecular weight polyethylene (average particle size 250 μm, viscosity-average molecular weight 4.25 million g / mol) was purchased from Shanghai Lianle Company.

[0090] The solvent was decahydronaphthalene (≥98% industrial grade, cis:trans ratio 2:8), purchased from Zhongneng Chemical Company;

[0091] Deionized water and nitrogen were both purchased from the external pipeline network of Nanjing Chemical Company.

[0092] Example 1

[0093] The spinneret has an aspect ratio of 6:1, 70 holes, and a single hole diameter of 1.5 mm. Based on the total mass of the spinning solution, the content of ultra-high molecular weight polyethylene is 6 wt%, and the solvent content is 94 wt%. The swelling temperature of the ultra-high molecular weight polyethylene is 98℃; the melt temperature is 145℃; the component pressure is 1.25 MPa; the extrusion ratio of the nozzle is 5 times; and the nozzle extrusion rate is 3.25 m / min.

[0094] The temperature of the gel filaments when they are drawn out of the gel bath is 10℃, the outlet temperature of the air knife is -10℃, the outlet air velocity of the air knife is 50m / s, the draw ratio of the cold drawing machine is 0.8 times, preheating is carried out in the preheating tunnel at a temperature of 100℃, the temperature of the preheating drying drawing box is 130℃, the draw ratio of the hot drawing machine is 1.1 times, the temperature of the drawing hot box is 140℃, and the draw ratio of the drawing hot box is 1.2 times, thus obtaining the precursor fiber.

[0095] The raw yarn is then subjected to a multi-stage stretching process. The first stage stretching ratio is 4 times and the first stage stretching temperature is 140℃; the second stage stretching ratio is 1.5 times and the second stage stretching temperature is 144℃; the third stage stretching ratio is 1.05 times and the third stage stretching temperature is 145℃.

[0096] The analytical results of gel filaments / raw filaments / ultra-high molecular weight polyethylene coarse denier fibers are shown in Table 1.

[0097] Table 1

[0098]

[0099] Example 2

[0100] The spinneret has an aspect ratio of 6:1, 70 holes, and a single hole diameter of 1.5 mm. Based on the total mass of the spinning solution, the content of ultra-high molecular weight polyethylene is 6 wt%, and the solvent content is 94 wt%. The swelling temperature of the ultra-high molecular weight polyethylene is 98℃; the melt temperature is 145℃; the component pressure is 1.25 MPa; the extrusion ratio of the nozzle is 20 times; and the nozzle extrusion rate is 3.25 m / min.

[0101] The temperature of the gel filaments when they are drawn out of the gel bath is 20℃, the outlet temperature of the air knife is 10℃, the outlet air velocity of the air knife is 80m / s, the draw ratio of the cold drawing machine is 1, preheating is carried out in the preheating tunnel at a temperature of 70℃, the temperature of the preheating drying drawing box is 60℃, the draw ratio of the hot drawing machine is 1.1, the temperature of the drawing hot box is 120℃, and the draw ratio of the drawing hot box is 1.6, thus obtaining the precursor fiber.

[0102] The raw yarn is then subjected to a multi-stage stretching process. The first stage stretching ratio is 5 times and the first stage stretching temperature is 140℃; the second stage stretching ratio is 1.6 times and the second stage stretching temperature is 144℃; the third stage stretching ratio is 1.2 times and the third stage stretching temperature is 145℃.

[0103] The analytical results of gel filaments / raw filaments / ultra-high molecular weight polyethylene coarse denier fibers are shown in Table 2.

[0104] Table 2

[0105]

[0106] Example 3

[0107] The spinneret has an aspect ratio of 6:1, 70 holes, and a single hole diameter of 1.2 mm. Based on the total mass of the spinning solution, the content of ultra-high molecular weight polyethylene is 6 wt%, and the solvent content is 94 wt%. The swelling temperature of the ultra-high molecular weight polyethylene is 98℃; the melt temperature is 145℃; the component pressure is 1.25 MPa; the extrusion ratio of the nozzle is 8 times; and the nozzle extrusion rate is 3.25 m / min.

[0108] The temperature of the gel filaments when they are drawn out of the gel bath is 10℃, the outlet temperature of the air knife is 0℃, the outlet air velocity of the air knife is 60m / s, the draw ratio of the cold drawing machine is 0.9, preheating is carried out in the preheating tunnel at a temperature of 80℃, the temperature of the preheating drying drawing box is 120℃, the draw ratio of the hot drawing machine is 1.2, the temperature of the drawing hot box is 140℃, and the draw ratio of the drawing hot box is 1.5, thus obtaining the precursor fiber.

[0109] The raw yarn is then subjected to a multi-stage stretching process. The first stage stretching ratio is 4.5 times and the first stage stretching temperature is 140℃; the second stage stretching ratio is 1.5 times and the second stage stretching temperature is 144℃; the third stage stretching ratio is 1.1 times and the third stage stretching temperature is 145℃.

[0110] The analytical results of gel filaments / raw filaments / ultra-high molecular weight polyethylene coarse denier fibers are shown in Table 3.

[0111] Table 3

[0112]

[0113] Example 4

[0114] The spinneret has an aspect ratio of 3:1, 70 holes, and a single hole diameter of 2 mm. Based on the total mass of the spinning solution, the content of ultra-high molecular weight polyethylene is 6 wt%, and the solvent content is 94 wt%. The swelling temperature of the ultra-high molecular weight polyethylene is 98℃; the melt temperature is 145℃; the component pressure is 1.23 MPa; the nozzle stretch ratio is 5 times; and the nozzle extrusion rate is 3.25 m / min.

[0115] The temperature of the gel filaments when they are drawn out of the gel bath is 10℃, the outlet temperature of the air knife is -10℃, the outlet air velocity of the air knife is 70m / s, the draw ratio of the cold drawing machine is 0.8, preheating is carried out in the preheating tunnel at a temperature of 100℃, the temperature of the preheating drying drawing box is 135℃, the draw ratio of the hot drawing machine is 1.1, the temperature of the drawing hot box is 140℃, and the draw ratio of the drawing hot box is 1.2, thus obtaining the precursor filaments.

[0116] The raw yarn is then subjected to a multi-stage stretching process. The first stage stretching ratio is 4 times and the first stage stretching temperature is 140℃; the second stage stretching ratio is 1.4 times and the second stage stretching temperature is 144℃; the third stage stretching ratio is 1.05 times and the third stage stretching temperature is 145℃.

[0117] The analytical results of gel filaments / raw filaments / ultra-high molecular weight polyethylene coarse denier fibers are shown in Table 4.

[0118] Table 4

[0119]

[0120] Example 5

[0121] The spinneret has an aspect ratio of 6:1, 70 holes, and a single hole diameter of 1.5 mm. Based on the total mass of the spinning solution, the content of ultra-high molecular weight polyethylene is 6 wt%, and the solvent content is 94 wt%. The swelling temperature of the ultra-high molecular weight polyethylene is 98℃; the melt temperature is 145℃; the component pressure is 1.25 MPa; the extrusion ratio of the nozzle is 5 times; and the nozzle extrusion rate is 3.25 m / min.

[0122] The temperature of the gel filaments when they are drawn out of the gel bath is 30℃, the air velocity of the air knife is 50m / s, the air temperature of the air knife is -10℃, the draw ratio of the cold drawing machine is 0.8, the preheating is carried out in the preheating tunnel at a temperature of 100℃, the temperature of the preheating drying drawing box is 130℃, the draw ratio of the hot drawing machine is 1.1, the temperature of the drawing hot box is 140℃, and the draw ratio of the drawing hot box is 1.2, thus obtaining the precursor fiber.

[0123] The raw yarn is then subjected to a multi-stage stretching process. The first stage stretching ratio is 4 times and the first stage stretching temperature is 140℃; the second stage stretching ratio is 1.5 times and the second stage stretching temperature is 144℃; the third stage stretching ratio is 1.05 times and the third stage stretching temperature is 145℃.

[0124] The analytical results of gel filaments / raw filaments / ultra-high molecular weight polyethylene coarse denier fibers are shown in Table 5.

[0125] Table 5

[0126]

[0127] Example 6

[0128] The spinneret has an aspect ratio of 6:1, 70 holes, and a single hole diameter of 1.5 mm. Based on the total mass of the spinning solution, the content of ultra-high molecular weight polyethylene is 6 wt%, and the solvent content is 94 wt%. The swelling temperature of the ultra-high molecular weight polyethylene is 98℃; the melt temperature is 145℃; the component pressure is 1.25 MPa; the extrusion ratio of the nozzle is 5 times; and the nozzle extrusion rate is 3.25 m / min.

[0129] The temperature of the gel filaments when they are drawn out of the gel bath is 10℃, the outlet temperature of the air knife is -10℃, the outlet air velocity of the air knife is 120m / s, the draw ratio of the cold drawing machine is 0.8, preheating is carried out in the preheating tunnel at a temperature of 100℃, the temperature of the preheating drying drawing box is 130℃, the draw ratio of the hot drawing machine is 1.1, the temperature of the drawing hot box is 140℃, and the draw ratio of the drawing hot box is 1.2, thus obtaining the precursor fiber.

[0130] The raw yarn is then subjected to a multi-stage stretching process. The first stage stretching ratio is 4 times and the first stage stretching temperature is 140℃; the second stage stretching ratio is 1.5 times and the second stage stretching temperature is 144℃; the third stage stretching ratio is 1.05 times and the third stage stretching temperature is 145℃.

[0131] The analytical results of gel filaments / raw filaments / ultra-high molecular weight polyethylene coarse denier fibers are shown in Table 6.

[0132] Table 6

[0133]

[0134] Example 7

[0135] The spinneret has an aspect ratio of 6:1, 70 holes, and a single hole diameter of 1.5 mm. Based on the total mass of the spinning solution, the content of ultra-high molecular weight polyethylene is 6 wt%, and the solvent content is 94 wt%. The swelling temperature of the ultra-high molecular weight polyethylene is 98℃; the melt temperature is 145℃; the component pressure is 1.25 MPa; the extrusion ratio of the nozzle is 10 times; and the nozzle extrusion rate is 3.25 m / min.

[0136] The temperature of the gel filaments when they are drawn out of the gel bath is 10℃, the outlet temperature of the air knife is -10℃, the outlet air velocity of the air knife is 50m / s, the draw ratio of the cold drawing machine is 0.8 times, preheating is carried out in the preheating tunnel at a temperature of 100℃, the temperature of the preheating drying drawing box is 130℃, the draw ratio of the hot drawing machine is 1.1 times, the temperature of the drawing hot box is 140℃, and the draw ratio of the drawing hot box is 1.2 times, thus obtaining the precursor fiber.

[0137] The raw yarn is then subjected to a multi-stage stretching process. The first stage stretching ratio is 4 times and the first stage stretching temperature is 140℃; the second stage stretching ratio is 1.5 times and the second stage stretching temperature is 144℃; the third stage stretching ratio is 1.05 times and the third stage stretching temperature is 145℃.

[0138] The analytical results of gel filaments / raw filaments / ultra-high molecular weight polyethylene coarse denier fibers are shown in Table 7.

[0139] Table 7

[0140]

[0141]

[0142] Example 8

[0143] The spinneret has an aspect ratio of 6:1, 70 holes, and a single hole diameter of 1.5 mm. Based on the total mass of the spinning solution, the content of ultra-high molecular weight polyethylene is 6 wt%, and the solvent content is 94 wt%. The swelling temperature of the ultra-high molecular weight polyethylene is 98℃; the melt temperature is 140℃; the component pressure is 1.25 MPa; the extrusion ratio of the nozzle is 10 times; and the nozzle extrusion rate is 3.25 m / min.

[0144] The temperature of the gel filaments when they are drawn out of the gel bath is 10℃, the outlet temperature of the air knife is -10℃, the outlet air velocity of the air knife is 50m / s, the draw ratio of the cold drawing machine is 0.8 times, preheating is carried out in the preheating tunnel at a temperature of 100℃, the temperature of the preheating drying drawing box is 130℃, the draw ratio of the hot drawing machine is 1.1 times, the temperature of the drawing hot box is 140℃, and the draw ratio of the drawing hot box is 1.2 times, thus obtaining the precursor fiber.

[0145] The raw yarn is then subjected to a multi-stage stretching process. The first stage stretching ratio is 4 times and the first stage stretching temperature is 140℃; the second stage stretching ratio is 1.5 times and the second stage stretching temperature is 144℃; the third stage stretching ratio is 1.05 times and the third stage stretching temperature is 145℃.

[0146] The analytical results of gel filaments / raw filaments / ultra-high molecular weight polyethylene coarse denier fibers are shown in Table 8.

[0147] Table 8

[0148]

[0149]

[0150] Comparative Example 1

[0151] The spinneret has an aspect ratio of 6:1, 70 holes, and a single hole diameter of 1.5 mm. Based on the total mass of the spinning solution, the content of ultra-high molecular weight polyethylene is 6 wt%, and the solvent content is 94 wt%. The swelling temperature of the ultra-high molecular weight polyethylene is 98℃; the melt temperature is 145℃; the component pressure is 1.25 MPa; the extrusion ratio of the nozzle is 5 times; and the nozzle extrusion rate is 3.25 m / min.

[0152] The temperature of the gel filaments when they are drawn out of the gel bath is 10°C. They are then preheated in the preheating tunnel at 100°C. The temperature of the preheating drying drawing box is 130°C. The drawing ratio of the hot drawing machine is 1.1 times. The temperature of the drawing hot box is 140°C. The drawing ratio of the drawing hot box is 1.2 times, and the raw filaments are obtained.

[0153] The raw yarn is then subjected to a multi-stage stretching process. The first stage stretching ratio is 4 times and the first stage stretching temperature is 140℃; the second stage stretching ratio is 1.5 times and the second stage stretching temperature is 144℃; the third stage stretching ratio is 1.05 times and the third stage stretching temperature is 145℃.

[0154] The analytical results of gel filaments / raw filaments / ultra-high molecular weight polyethylene coarse denier fibers are shown in Table 9.

[0155] Table 9

[0156]

[0157] Fiber entanglement occurs in the preheating chamber of the tunnel. Solvent on the fiber surface is carried to the drafting rollers, and due to the surface tension of the solvent on the rollers, occasional broken filaments become entangled, causing entanglement and fiber breakage. Simultaneously, the lack of secondary cooling leads to a significant increase in residual solvent in the fiber, failing to meet application requirements and reducing solvent recovery rates.

[0158] Comparative Example 2

[0159] The spinneret has an aspect ratio of 6:1, 70 holes, and a single hole diameter of 1.5 mm. Based on the total mass of the spinning solution, the content of ultra-high molecular weight polyethylene is 6 wt%, and the solvent content is 94 wt%. The swelling temperature of the ultra-high molecular weight polyethylene is 98℃; the melt temperature is 145℃; the component pressure is 1.25 MPa; the extrusion ratio of the nozzle is 5 times; and the nozzle extrusion rate is 3.25 m / min.

[0160] The air knife has an outlet air velocity of 50 m / s and an outlet air temperature of -10℃. The cold drawing machine has a draw ratio of 0.8. Preheating is carried out in the preheating tunnel at a temperature of 100℃. The preheating and drying drawing box has a temperature of 130℃. The hot drawing machine has a draw ratio of 1.1. The drawing hot box has a temperature of 140℃ and a draw ratio of 1.2, thus obtaining the raw yarn.

[0161] The raw yarn is then subjected to a multi-stage stretching process. The first stage stretching ratio is 4 times and the first stage stretching temperature is 140℃; the second stage stretching ratio is 1.5 times and the second stage stretching temperature is 144℃; the third stage stretching ratio is 1.05 times and the third stage stretching temperature is 145℃.

[0162] Normal production is impossible. The gel fibers have extremely low tension under high temperature conditions. Affected by the high-speed airflow of the air knife, the gel fibers break directly and cannot maintain the stretching conditions.

[0163] Comparative Example 3

[0164] The spinneret has an aspect ratio of 6:1, 70 holes, and a single hole diameter of 1.5 mm. Based on the total mass of the spinning solution, the content of ultra-high molecular weight polyethylene is 6 wt%, and the solvent content is 94 wt%. The swelling temperature of the ultra-high molecular weight polyethylene is 98℃; the melt temperature is 145℃; the component pressure is 1.25 MPa; the extrusion ratio of the nozzle is 5 times; and the nozzle extrusion rate is 3.25 m / min.

[0165] The temperature of the gel filaments when they are drawn out of the gel bath is 10℃, the air velocity of the air knife is 50m / s, the air temperature of the air knife is -10℃, the draw ratio of the cold drawing machine is 0.8, the temperature of the drawing hot box is 140℃, and the draw ratio of the drawing hot box is 1.2, thus obtaining the precursor filaments.

[0166] The raw yarn is then subjected to a multi-stage stretching process. The first stage stretching ratio is 4 times and the first stage stretching temperature is 140℃; the second stage stretching ratio is 1.5 times and the second stage stretching temperature is 144℃; the third stage stretching ratio is 1.05 times and the third stage stretching temperature is 145℃.

[0167] The device could not operate stably, and the gel filaments were directly broken. The main reason was that the gel filaments were not softened and were in a "skin-core" structure. The inside was not dissolved, which caused the gel filaments to break once they were stretched in the subsequent stretching chamber.

[0168] The properties of the ultra-high molecular weight polyethylene coarse denier fibers prepared in the examples and comparative examples were tested, and the results are shown in Table 10.

[0169] Table 10

[0170] Solvent content (ppm) Fracture strength (cN / dtex) Young's modulus (cN / dtex) Example 1 5000 34.1 1330 Example 2 3500 35.3 1315 Example 3 4800 33.6 1302 Example 4 14000 29.8 1205 Example 5 7000 33.5 1258 Example 6 4800 34.7 1305 Example 7 900 36.8 1360 Example 8 1200 35.1 1325 Comparative Example 1 15000 28.9 1159 Comparative Example 2 - - - Comparative Example 3 - - -

[0171] "-" indicates that the preparation was unsuccessful and could not be detected.

[0172] Compared with the comparative examples, the ultra-high molecular weight polyethylene coarse denier fiber monofilaments prepared by the present invention have large fineness and good mechanical properties.

[0173] Comparing Example 1 and Example 4, when a coarser spinneret aperture is used, the fineness of the single filament can still be improved, but the amount of solvent residue in the fiber also increases, and the spinnability of the fiber decreases.

[0174] Comparing Example 1 and Example 5, the high temperature of the condensation bath is not conducive to the rapid precipitation of solvent, which will increase the solvent residue in the raw yarn and subsequent finished fiber. The fineness of the single filament can meet the requirements, but the high solvent residue will result in poor spinnability of the product, increased solvent loss, and reduced performance indicators, which is not conducive to maximizing product cost.

[0175] Comparing Example 1 and Example 6, the increased speed of the air knife is beneficial for solvent recovery. The increased air speed increases the precipitation and evaporation of solvent on the fiber surface, which is beneficial for improving the product's breaking strength. However, if the air speed is too high, it will increase the fiber variation rate, which will lead to a decrease in product quality indicators.

[0176] Comparing Example 1 and Example 7, increasing the nozzle stretching ratio reduces the mass ratio of solvent to ultra-high molecular weight polyethylene in the resulting coarse denier fiber, resulting in less solvent content in the fiber, which is beneficial for solvent recovery. However, increasing the nozzle stretching ratio also reduces the fiber fineness, which is not conducive to obtaining monofilaments with high fineness.

[0177] Comparing Example 7 and Example 8, lowering the spinning melt temperature is not conducive to the rapid flash evaporation of the solvent, resulting in an increase in the solvent content in the gel filaments. The mass ratio of solvent to ultra-high molecular weight polyethylene in the obtained coarse denier fibers increases, and the final solvent residue in the fibers increases.

[0178] Comparative Example 1 did not have a second cooling step, Comparative Example 2 did not have a first cooling step, and Comparative Example 3 did not have a preheating step.

[0179] The results in the table show that the two-stage cooling and preheating process of this invention allows the "skin-core" structure of the fiber to appear and then be eliminated during the preparation process. This causes the solvent in the gel filament to continuously precipitate out during the preparation process, avoiding fiber breakage and fuzzing caused by the "skin-core" structure of the gel filament. The resulting ultra-high molecular weight polyethylene coarse denier fiber has a large single filament fineness, low solvent content, and good mechanical properties, while also enabling solvent recycling.

[0180] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A process for the production of a coarse denier fiber of ultra-high molecular weight polyethylene, characterized in that, The spinning solution is extruded by the device to obtain gel filaments; the gel filaments are cooled twice, and then preheated, drawn, oiled and wound to obtain the raw yarn; the raw yarn is drawn in multiple stages to obtain the ultra-high molecular weight polyethylene coarse denier fiber; The device comprises a double-screw extruder, a metering pump, a spinning box and a spinneret; The extrusion process comprises: the spinning solution becomes a molten melt through the double-screw extruder, is accurately metered by the metering pump, flows through the spinning box, and is finally extruded from the spinneret; The temperature of the molten melt is 140-150℃; The twice cooling comprises first cooling and second cooling, the first cooling is solution cooling, and the second cooling is cold air cooling; The solution cooling is performed in a coagulation bath tank, and the temperature of the gel filaments when drawn out of the coagulation bath tank is ≤40℃; The cold air cooling is performed in a godet cold drawing machine, a godet drying cold box and a cold drawing machine, and the godet drying cold box is provided with an air knife; The air temperature of the air knife is -10℃ to -5℃.

2. The production method according to claim 1, wherein, The spinning solution comprises ultra-high molecular weight polyethylene and a solvent.

3. The production method according to claim 2, wherein The content of the ultra-high molecular weight polyethylene is 5-10wt% and the content of the solvent is 90-95wt% based on the total mass of the spinning solution.

4. The production method according to claim 3, wherein The content of the ultra-high molecular weight polyethylene is 6-7wt% and the content of the solvent is 93-94wt% based on the total mass of the spinning solution.

5. The production method according to claim 2, wherein, The viscosity-average molecular weight of the ultra-high molecular weight polyethylene is 100 million-1000 million g / mol.

6. The production method according to claim 5, wherein The viscosity-average molecular weight of the ultra-high molecular weight polyethylene is 400 million-500 million g / mol.

7. The production method according to claim 2, wherein The solvent is selected from compounds containing benzene rings.

8. The production method according to claim 7, wherein The boiling point of the solvent is 180-200℃.

9. The production method according to claim 8, wherein The boiling point of the solvent is 185-195℃.

10. The production method according to claim 2, wherein, The solvent is selected from at least one of decalin, tetralin and toluene.

11. The production method according to claim 10, wherein The solvent is decalin.

12. The method of producing according to claim 1, wherein, The temperature of the molten melt is 145-148℃.

13. The method of producing according to claim 1, wherein, The single-hole diameter of the spinneret is 0.5-2mm.

14. The production method according to claim 13, wherein The single-hole diameter of the spinneret is 1.2-1.5mm.

15. The method of producing according to claim 1, wherein, The length-diameter ratio of the spinneret is 4-10:

1.

16. The method of making according to claim 15, wherein, The length-diameter ratio of the spinneret is 6-8:

1.

17. The method of producing according to claim 1, wherein, The spinneret is provided with a nozzle, and the draw ratio of the nozzle is 5-20 times.

18. The method of making according to claim 17, wherein, The spinneret is provided with a nozzle, and the draw ratio of the nozzle is 10-15 times.

19. The method of producing according to claim 1, wherein, The extrusion rate is 2.5-5m / min.

20. The method of making according to claim 19, wherein, The extrusion rate is 3-3.5m / min.

21. The method of producing according to claim 1, wherein, The solution cooling is performed in a coagulation bath tank, and the temperature of the gel filaments when drawn out of the coagulation bath tank is ≤20℃.

22. The method of producing according to claim 1, wherein, The air speed of the air knife is 50-100m / s.

23. The method of making according to claim 22, wherein, The air speed of the air knife is 70-75m / s.

24. The method of producing according to claim 1, wherein, The draw ratio of the cold drawing machine is 0.8-1.2 times.

25. The method of manufacturing according to claim 24, wherein, The draw ratio of the cold drawing machine is 0.9-1 times.

26. The method of making according to any one of claims 1-25, wherein, The preheating is performed in a preheating duct, and the preheating temperature is 40-100℃.

27. The method of manufacturing according to claim 26, wherein, The preheating is performed in a preheating duct, and the preheating temperature is 70-80℃.

28. The method of making according to any one of claims 1-25, wherein, The drawing is performed in a preheating drying drawing box and a drawing hot box, and the drawing machine in the preheating drying drawing box is a hot drawing machine provided with a hot drawing roller.

29. The method of making according to claim 28, wherein, The temperature of the preheating drying draft box is 60-150℃.

30. The method of manufacturing according to claim 29, wherein, The temperature of the preheating drying draft box is 100-140℃.

31. The method of manufacturing according to claim 28, wherein, The draft ratio of the hot draft machine is 1-1.5 times.

32. The method of manufacturing according to claim 31, wherein, The draft ratio of the hot draft machine is 1-1.2 times.

33. The method of manufacturing according to claim 28, wherein, The temperature of the draft hot box is 100-140℃.

34. The method of manufacturing according to claim 33, wherein, The temperature of the draft hot box is 120-130℃.

35. The method of manufacturing according to claim 28, wherein, The draft ratio of the draft hot box is 1-2 times.

36. The method of manufacturing according to claim 35, wherein, The draft ratio of the draft hot box is 1.2-1.5 times.

37. The method of making according to any one of claims 1-25, wherein, The multi-stage draft includes a first-stage draft, a second-stage draft and a third-stage draft; the total draft ratio of the multi-stage draft is 7-10 times.

38. The method of manufacturing according to claim 37, wherein, The first-stage draft ratio is 3-6 times; the temperature of the first-stage draft is 138-142℃.

39. The method of manufacturing according to claim 38, wherein, The first-stage draft ratio is 4-5 times; the temperature of the first-stage draft is 140-142℃.

40. The method of manufacturing according to claim 37, wherein, The second-stage draft ratio is 1.2-1.6 times; the temperature of the second-stage draft is 142-145℃.

41. The method of manufacturing according to claim 40, wherein, The second-stage draft ratio is 1.3-1.5 times; the temperature of the second-stage draft is 143-144℃.

42. The method of manufacturing according to claim 37, wherein, The third-stage draft ratio is 1-1.4 times; the temperature of the third-stage draft is 144-148℃.

43. The method of manufacturing according to claim 42, wherein, The third-stage draft ratio is 1.05-1.2 times; the temperature of the third-stage draft is 145-148℃.

44. A method for preparing the ultra-high molecular weight polyethylene coarse denier fiber according to any one of claims 1-43.

45. The ultra-high molecular weight polyethylene coarse denier fiber of claim 44, wherein, The solvent content of the ultra-high molecular weight polyethylene coarse denier fiber is 900-14500 ppm, the single fiber fineness is 1-5 dtex, the breaking strength is ≥30 cN / dtex, and the Young's modulus is ≥1200 cN / dtex.

46. The ultra-high molecular weight polyethylene coarse denier fiber of claim 45, wherein, The solvent content of the ultra-high molecular weight polyethylene coarse denier fiber is 3000-10000 ppm, the single fiber fineness is 1.5-3.8 dtex, the breaking strength is ≥35 cN / dtex, and the Young's modulus is ≥1300 cN / dtex.

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