Coarse denier high strength ultrahigh molecular weight polyethylene fibers and apparatus and methods for their production

Abstract

This invention relates to an apparatus for preparing coarse denier high-strength ultra-high molecular weight polyethylene (UHMWPE) fibers. Along the material flow direction, it sequentially includes a swelling vessel, a homogenizing vessel, a single-screw extruder, a metering pump, a spinning assembly, a bundling component, and a drawing assembly. The spinning assembly includes a spinneret and a double-layer sleeve assembly connected in sequence. The spinneret includes several spinnerets with the same or different orifice diameters and several stirring propellers disposed on its top, with each stirring propeller connected to a corresponding spinneret. The double-layer sleeve assembly includes several double-layer sleeves, with each spinneret connected to a corresponding double-layer sleeve. The apparatus provided by this invention combines a single screw with moderate stirring and conveying, which can effectively reduce the breakage of macromolecular chains during conveying and reduce resin degradation after swelling. This solves the problem of low strength in existing coarse denier UHMWPE fibers. This invention also relates to a coarse denier high-strength UHMWPE fiber and its preparation method.

Description

Technical Field

[0001] This invention relates to the field of ultra-high molecular weight polyethylene fiber technology, and in particular to an apparatus and method for preparing coarse denier high-strength ultra-high molecular weight polyethylene fiber that is simple in process, highly efficient and energy-saving, as well as coarse denier high-strength ultra-high molecular weight polyethylene fiber obtained by the above-mentioned apparatus and method. Background Technology

[0002] Ultra-high molecular weight polyethylene (UHMWPE) fiber is one of the world's three major high-performance fibers. Due to its excellent mechanical properties, as well as its low density, good weather resistance, chemical corrosion resistance, low-temperature resistance, wear resistance, good bending resistance, good cut resistance, high specific energy absorption, low electrical conductivity, X-ray permeability, and certain water resistance, it is widely used in many fields such as national defense equipment, aerospace, marine engineering, safety protection, transportation, sports equipment, and biomedical materials. With the rapid development of aquatic science and technology in my country, the demand for alternative products of high-performance, especially high-mechanical-strength, fishing fibers and ropes is increasing. Developing high-strength, high-performance UHMWPE fibers and ropes plays a crucial role in reducing the material requirements of net cages and other equipment, saving raw materials, reducing the operational resistance of trawls and net cages / enclosures, improving the water filtration performance of net cages and equipment, and increasing the efficiency and quality of my country's ecological fisheries while reducing production costs.

[0003] Ultra-high molecular weight polyethylene (UHMWPE) fibers are typically produced using a gel spinning-high-drawing process. Chinese patent CN101575742A discloses a method for preparing UHMWPE fibers, but the resulting UHMWPE fibers have a single filament fineness of 0.5–1.5 denier. This low single filament fineness is unfavorable for use in composite materials. Chinese patent CN102154749B discloses a method for manufacturing coarse denier UHMWPE fiber yarn and the resulting fiber, but the strength of the produced UHMWPE fibers does not exceed 30 cN / dtex. Summary of the Invention

[0004] To address the problems of existing technologies, the present invention aims to provide an apparatus and method for preparing coarse denier high-strength ultra-high molecular weight polyethylene fibers, wherein the monofilament fineness of the prepared coarse denier high-strength ultra-high molecular weight polyethylene fibers is 1.8-3.0D and the strength is 35-45cN / dtex.

[0005] Therefore, in a first aspect, the present invention provides an apparatus for preparing high-strength ultra-high molecular weight polyethylene fibers, comprising, in sequence along the material flow direction, a swelling vessel, a homogenizing vessel, a single-screw extruder, a metering pump, a spinning assembly, a bundling component, and a drawing assembly. The spinning assembly includes a spinneret and a double-layer sleeve assembly connected in sequence. The spinneret includes several spinnerets with the same or different orifice diameters and several stirring propellers disposed on its top. The stirring propellers are connected to the spinnerets in a one-to-one correspondence. The double-layer sleeve assembly includes several double-layer sleeves, and the spinnerets are connected to the double-layer sleeves in a one-to-one correspondence.

[0006] Specifically, traditional equipment for preparing high-strength ultra-high molecular weight polyethylene (UHMWPE) fibers uses a twin-screw extruder to excessively shear and dissolve the raw material solution, leading to significant degradation of the macromolecular resin during transport. The equipment for preparing UHMWPE fibers provided by this invention combines a single-screw extruder with a stirring conveyor, effectively reducing the breakage of macromolecular chains in the raw material solution during transport and minimizing resin degradation after swelling.

[0007] In a specific embodiment of the present invention, preferably, the double-layer sleeve assembly is disposed in the tunnel, and the length H2 of the double-layer sleeve is less than the length of the tunnel;

[0008] Preferably, the length H2 of the double-layer sleeve is adjustable; and / or

[0009] Preferably, the middle part of the tunnel is provided with a gaseous fluid medium inlet, and the upper and / or lower parts of the tunnel are each independently provided with a mixing medium outlet; and / or

[0010] The traction assembly is a multi-stage traction assembly. Preferably, the traction assembly is a two-stage, three-stage, four-stage, five-stage, or six-stage traction assembly.

[0011] When the drawing assembly is a two-stage drawing assembly, the two-stage drawing heat box includes a first-stage drawing heat box and a second-stage drawing heat box. The first-stage drawing heat box consists of a first drawing heat box, a second drawing heat box, and a first-stage hot five-roll drawing machine. The second-stage drawing heat box consists of a third drawing heat box, a fourth drawing heat box, and a second-stage hot five-roll drawing machine. Alternatively, the first-stage drawing heat box consists of a first drawing heat box and a first-stage hot five-roll drawing machine, and the second-stage drawing heat box consists of a third drawing heat box and a second-stage hot five-roll drawing machine.

[0012] In a preferred embodiment of the present invention, the metering pump is connected to the inlet of the stirring propeller, and the bottom outlet of the stirring propeller is connected to the inlet of the spinneret; and / or

[0013] The stirring propeller is equipped with a stirring blade, the maximum diameter of which is 0.75-0.8D1, where D1 is the diameter of the spinneret; preferably, the stirring blade is a stainless steel propeller; and / or

[0014] The stirring propeller and the spinneret are arranged in a matrix or single row; and / or

[0015] The spinneret has a plurality of spinneret holes on its surface, the center-to-center distance between the spinneret holes being 3d-10d, preferably 3d-8d, more preferably 3d-5d; and / or, the inlet diameter of the spinneret hole being 1.5d-2.5d, where d is the diameter of the spinneret hole.

[0016] As a specific embodiment of the present invention, preferably, the double-layer sleeve includes an inner tube and an outer tube, and the inner tube and the outer tube are uniformly provided with a plurality of corresponding through holes on their tube walls. The inner tube and the outer tube can partially or completely close or open the through holes on their tube walls by changing their relative positions.

[0017] Preferably, the through hole is a rectangular slit with rounded corners or a round hole, the length of the slit is 0.75-0.85D1 and the width is 0.45-0.55D1, and the diameter of the round hole is 0.1D1, where D1 is the diameter of the spinneret.

[0018] Preferably, the total area of ​​the slit or the hole is 50%-75% of the surface area of ​​the double-layer sleeve.

[0019] In a specific embodiment of the present invention, preferably, the diameter of the inner tube is the same as the diameter D1 of the spinneret; and / or

[0020] The length H2 of the double-layer sleeve is 10D1-100D1, preferably 20D1-80D1, more preferably 20D1-60D1; and / or

[0021] The bundling component includes a guide roller disposed between the tunnel outlet and the traction assembly inlet; and / or

[0022] The double-layer sleeve is detachably connected to the spinneret; and / or

[0023] The device also includes a solvent recovery component.

[0024] In a specific embodiment of the present invention, preferably, the length H2 of the double-layered sleeve is adjustable; and the length H2 of the double-layered sleeve is 10D1-100D1, preferably 20D1-80D1, and more preferably 20D1-60D1. When the gel filament is in contact with the low-temperature medium, the length H2 of the double-layered sleeve is 20D1-40D1; when the gel filament is in contact with the high-temperature medium, the length H2 of the double-layered sleeve is 40D1-60D1.

[0025] Specifically, the device provided by the present invention is equipped with a double-layer sleeve with an adjustable length H2, which not only reduces the interference to the gel forming and crystallization processes, but also solves or alleviates the problem of low monofilament fineness and fiber breaking strength of coarse denier ultra-high molecular weight polyethylene fibers prepared by traditional processes by adjusting the temperature and flow rate of the fluid medium entering the buffer area and appropriately controlling the solvent content of the gel precursor fibers.

[0026] In a specific embodiment of the present invention, preferably, the flow rate of the gaseous medium entering the buffer area of ​​the double-layered sleeve is adjusted by rotating the inner tube clockwise or counterclockwise, or the outer tube clockwise or counterclockwise, or by rotating the inner tube and the outer tube simultaneously in opposite directions, thereby partially or completely closing or opening the through hole on the pipe wall of the double-layered sleeve; and / or

[0027] Within the buffer zone of the double-layered sleeve, the flow rate of the gaseous medium is 5% to 50% of the total flow rate of all materials therein.

[0028] Preferably, the temperature of the flowing gaseous medium is 0℃-30℃ or 100℃-150℃; and / or, the flowing gaseous medium is selected from compressible gaseous media, preferably selected from one or more of carbon dioxide, nitrogen, and saturated water vapor.

[0029] Specifically, the device provided by the present invention controls the flow rate of the gaseous medium entering the buffer zone by adjusting the opening of the slit or round hole set in the sleeve wall, based on the temperature and pressure of the flowing gaseous medium, thereby achieving the purpose of controlling the solvent content of the gel fiber bundle.

[0030] Therefore, in a second aspect, the present invention provides a method for preparing coarse denier high-strength ultra-high molecular weight polyethylene fibers using the above-described apparatus, comprising the following steps:

[0031] 1) Add ultra-high molecular weight polyethylene resin and a good solvent into a swelling vessel, and heat in a gradient manner to obtain a spinning solution by swelling;

[0032] 2) The spinning solution is mixed by a single screw extruder and metered by a metering pump to form a high viscoelastic gel. After the high viscoelastic gel enters the spinning assembly, it is stirred by a stirring propeller and then extruded by a spinneret. It then enters the buffer area in the double-layer sleeve and comes into contact with the gaseous fluid medium. Some of the solvent in the high viscoelastic gel flashes out to form gel filaments.

[0033] 3) After the gel filaments are bundled by the bundling component at the exit of the tunnel, the bundled gel filaments enter the drawing assembly. After solvent removal and multi-stage drawing in the drawing assembly, gel fibers are obtained.

[0034] 4) The gel fiber is stretched by the stretching assembly to obtain ultra-high molecular weight polyethylene fiber.

[0035] As a specific embodiment of the present invention, preferably, the ultra-high molecular weight polyethylene resin has a viscosity-average molecular weight of 3-5 million and an entanglement degree of 0.1-0.6; and / or

[0036] The good solvent is selected from one or more of decahydronaphthalene, tetrahydronaphthalene, and xylene; and / or

[0037] The mass ratio of the ultra-high molecular weight polyethylene resin to the good solvent is (6:94)-(10:90); and / or

[0038] The gradient heating process involves heating to 80-85°C, then gradually increasing the temperature at a rate of 5°C per hour to 95-98°C, and then maintaining the temperature for one hour.

[0039] As a specific embodiment of the present invention, preferably, the gaseous fluid medium is a low-temperature medium of 0℃-30℃ or a high-temperature medium of 100℃-150℃;

[0040] Preferably, the flowing gaseous medium is a low-temperature medium, and the ratio of the linear velocity of the gel filament on the guide roller to the extrusion velocity of the spinneret is 1-50, preferably 3-40, more preferably 6-30; the solvent content in the bundled gel filament is 70wt%-95wt%, preferably 75wt%-92wt%, more preferably 80wt%-90wt%; or

[0041] The flowing gaseous medium is a high-temperature medium, and the ratio of the linear velocity of the gel filament on the guide roller to the extrusion velocity of the spinneret is 1-40, preferably 2-35, and more preferably 5-30; the solvent content in the bundled gel filament is 20wt%-90wt%, preferably 30wt%-75wt%, and more preferably 40wt%-65wt%.

[0042] Preferably, the gelatin filaments and the bundled gelatin filaments generated by the low-temperature medium are subjected to multi-stage drawing in the drawing assembly with three to four temperature gradients. Simultaneously, the solvent within the bundled gelatin filaments comes into contact with the high-temperature medium in the drawing assembly and detaches from the fiber interior and surface, allowing for solvent recovery. Preferably, the three temperature gradients include a first stage of 98℃-100℃, a second stage of 108℃-110℃, and a third stage of 118℃-120℃; the four temperature gradients include a first stage of 98℃-100℃, a second stage of 108℃-110℃, a third stage of 118℃-120℃, and a fourth stage of 121℃-123℃. Alternatively, the gelatin filaments and the bundled gelatin filaments generated by the high-temperature medium... The filaments enter the drawing assembly with a two- to three-stage temperature gradient for multi-stage drawing. Simultaneously, the solvent within the bundled gel filaments comes into contact with the high-temperature medium within the drawing assembly and detaches from the fiber's interior and surface, allowing for solvent recovery. Preferably, the second-stage temperature gradient includes a first stage of 105℃-108℃ and a second stage of 135℃-139℃, or a first stage of 115℃-118℃ and a second stage of 143℃-145℃; the third-stage temperature gradient includes a first stage of 105℃-108℃, a second stage of 115℃-118℃, and a third stage of 135℃-139℃, or a first stage of 115℃-118℃, a second stage of 135℃-139℃, and a third stage of 143℃-145℃.

[0043] Preferably, when the gel filament is in contact with the low-temperature medium, the length H2 of the double-layer sleeve is 20D1-40D1, and when the gel filament is in contact with the high-temperature medium, the length H2 of the double-layer sleeve is 40D1-60D1.

[0044] As a specific embodiment of the present invention, preferably, the bundling component includes a guide roller disposed between the tunnel outlet and the traction assembly inlet; preferably, the ratio of the linear velocity of the guide roller to the extrusion velocity of the spinneret is 1-50, more preferably 3-40, and more preferably 6-30; and / or

[0045] The total draw ratio of the bundled gel filaments in the drawing assembly is 5-50 times, preferably 10-40 times, more preferably 18-30 times; and / or

[0046] The wet content of the gel fiber is 1wt%-10wt%, preferably 2wt%-7wt%, and more preferably 3wt%-5wt%.

[0047] In a preferred embodiment of the present invention, the stretching assembly is a constant temperature shaping hot stretching box.

[0048] Therefore, in a third aspect, the present invention provides a coarse denier high-strength ultra-high molecular weight polyethylene fiber obtained by the above-described apparatus or the above-described preparation method. Preferably, the ultra-high molecular weight polyethylene fiber has a coarse denier of 400-1600D, a single filament fineness of 1.8-3.0D, and a strength of 35-45cN / dtex.

[0049] Beneficial effects:

[0050] This invention addresses the shortcomings of traditional processes for preparing coarse denier ultra-high molecular weight polyethylene (UHMWPE) fibers, such as excessive shearing and dissolution of the raw material solution leading to significant degradation of the macromolecular resin during transport. It employs a single-screw extruder combined with moderate stirring during transport, effectively reducing macromolecular chain breakage and resin degradation after swelling. This solves the problem of low fineness and fiber breaking strength in coarse denier UHMWPE fibers prepared by traditional processes.

[0051] This device regulates the height of the double-layered sleeve for temperature control of the flowing gaseous medium, thereby adjusting the material's travel in the buffer zone. This not only reduces interference during gel forming and crystallization processes, but also addresses the challenges of low fineness and fiber breaking strength in coarse denier ultra-high molecular weight polyethylene fibers prepared by traditional processes by adjusting the temperature and flow rate of the fluid medium entering the buffer zone and appropriately controlling the solvent content of the gel precursor fibers. Attached Figure Description

[0052] Figure 1 This is a schematic diagram of the apparatus for preparing coarse denier high-strength UHMWPE fibers according to the present invention.

[0053] Figure 2 This is a top view of the right side of a single-row spinneret in a spinning assembly, and an enlarged view of some of the spinneret orifices.

[0054] Figure 3 This is a left view of the spinning assembly and a partial enlarged view of the double-layered sleeve.

[0055] The components are: 1-Swelling kettle; 2-Homogenizing kettle; 3-Single screw extruder; 4-Metering pump; 5-Spinning assembly; 51-Agitator propeller; 52-Spinneret; 6-Channel; 61-Double-layer sleeve; 7-Gaseous fluid medium inlet; 8-Mixed medium outlet; 9-Heated gaseous medium; 10-Nitrogen sealing inlet; 11-Guide roller; 12-First hot drawing box; 13-Second hot drawing box; 14-First-stage hot five-roller drawing machine; 15-Third hot drawing box; 16-Fourth hot drawing box; 17-Second-stage hot five-roller drawing machine; 18-Spinneret;

[0056] H1 - Center-to-center distance between spinnerets on the spinneret surface; H2 - Length of the double-layer sleeve; D1 - Diameter of the spinneret; D2 - Maximum diameter of the blade; d - Diameter of the spinneret orifice. Detailed Implementation

[0057] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments are merely illustrative of the invention and should not be considered as specific limitations thereof. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0058] (I) Testing Methods

[0059] Tensile strength: 15 samples were randomly selected from the prepared UHMWPE fibers and tested 10 times on an Instron universal drawing machine. The average value was taken to obtain the tensile strength of the UHMWPE fibers. The test standard was GB / T19975-2005 Test method for tensile properties of high-strength filaments.

[0060] The apparatus for preparing coarse denier high-strength ultra-high molecular weight polyethylene fiber provided by the present invention includes, in sequence along the material flow direction, a swelling vessel, a homogenizing vessel, a single-screw extruder with a screw diameter of 20-50 mm and a length-to-diameter ratio of 25:1-36:1, a metering pump, a spinning assembly, a bundling component, and a drawing assembly. The spinning assembly includes a spinneret and a double-layer sleeve assembly connected in sequence. The spinneret includes several spinnerets with the same or different orifice diameters and several stirring propellers disposed on its top. The stirring propellers are connected to the spinnerets one by one. The double-layer sleeve assembly includes several double-layer sleeves, and the spinnerets are connected to the double-layer sleeves one by one.

[0061] Specifically, the spinneret is equipped with a stirring propeller to further evenly distribute the gel solution. The use of a single-screw extruder avoids excessive shearing and dissolution of the raw material solution, preventing significant degradation of the macromolecular resin during transport. The combination of a single-screw extruder and stirring conveying effectively reduces the breakage of macromolecular chains in the raw material solution during transport and minimizes resin degradation after swelling. This solves the problem of low fineness and fiber breaking strength in coarse denier ultra-high molecular weight polyethylene fibers produced by traditional processes.

[0062] See Figure 1As shown, the apparatus for preparing coarse denier high-strength ultra-high molecular weight polyethylene fiber provided by the present invention includes, in sequence along the material flow direction, a swelling vessel 1, a homogenizing vessel 2, a single-screw extruder 3, a metering pump 4, a spinning assembly 5, a bundling component, and a pulling assembly. The spinning assembly 5 includes a spinneret and a double-layer sleeve assembly connected in sequence. The spinneret includes several spinnerets 52 with the same or different orifice diameters and several stirring propellers 51 disposed on its top. The stirring propellers 51 are connected to the spinnerets 52 in a one-to-one correspondence. The double-layer sleeve assembly includes several double-layer sleeves 61, and the spinnerets 52 are connected to the double-layer sleeves 61 in a one-to-one correspondence.

[0063] A double-layered sleeve assembly is installed inside the passageway 6, and the length H2 of the double-layered sleeve 61 is less than the length of the passageway 6. A gaseous fluid medium inlet 7 is provided in the middle of the passageway 6, and a mixed medium outlet 8 is provided at the upper and lower parts of the passageway 6, and a nitrogen sealing inlet 10 is also provided at the lower part of the passageway 6.

[0064] The bundling component is the guide roller 11 located between the outlet of the tunnel 6 and the inlet of the drawing assembly. The drawing assembly is a multi-stage drawing heat box. See also Figure 1 As shown, the multi-stage drawing box consists of a first-stage drawing box and a second-stage drawing box. The first-stage drawing box comprises a first drawing box 12, a second drawing box 13, and a first-stage hot five-roll drawing machine 14. The second-stage drawing box comprises a third drawing box 15, a fourth drawing box 16, and a second-stage hot five-roll drawing machine 17. Of course, depending on the needs of the manufacturing process, the multi-stage drawing box can also be a three-stage, four-stage, five-stage, or even higher-level drawing box.

[0065] When preparing coarse denier high-strength ultra-high molecular weight polyethylene (UHMWPE) fibers using the above-described apparatus, UHMWPE resin is added to a stirred, expanded vessel 1 containing solvent. Under stirring conditions, the mixture is heated to obtain a spinning solution. The spinning solution is then fed into a homogenizing vessel 2, followed by a single-screw extruder 3 and a metering pump 4, where it is mixed to form a high-viscoelastic gel. The high-viscoelastic gel enters the spinning assembly 5 and is extruded from the spinning assembly 5 into a buffer zone within a double-layered sleeve 61. In this zone, the high-viscoelastic gel contacts the gaseous fluid medium entering through the gaseous fluid medium inlet 7 of the channel 6, resulting in gel filaments. At the outlet of the channel 6, the gel filaments are bundled by guide rollers 11 and then enter a multi-stage drawing assembly for solvent recovery and gel filament drawing. The resulting coarse denier high-strength UHMWPE fibers enter the upper yarn holder 18 and are wound to obtain the finished coarse denier fibers.

[0066] In this process, after the gaseous fluid medium comes into contact with the high viscoelastic gel, it is discharged from the mixed medium outlet 8 and then undergoes gas-liquid separation. The gaseous medium exchanges heat with the heat exchanger to obtain the heated gaseous fluid medium 9, which then enters the first drawing heat box 12, the second drawing heat box 13, the third drawing heat box 15 and / or the fourth drawing heat box 16. The drawing ratio of the gel filament is controlled by the linear speed ratio set on the first-stage hot five-roll drawing machine 14 and / or the second-stage hot five-roll drawing machine 17.

[0067] The high viscoelastic gel enters the spinning assembly 5, where it is further stirred and propelled by the stirring propeller 51 before entering the spinneret 52.

[0068] See Figure 2 As shown, Figure 2 This is a top right view of the spinnerets arranged in a single row in the spinning assembly. The stirring propeller 51 is connected to the spinnerets 52 in a one-to-one correspondence and arranged in a single row. Several spinneret holes are provided on the surface of the spinneret 52, where d is the diameter of the spinneret hole, and the center-to-center distance H1 between the spinneret holes is 3d-10d; the inlet diameter of the spinneret holes is 1.5d-2.5d.

[0069] See Figure 3 As shown, Figure 3 This is a left view of the spinning assembly and a partial enlarged view of the double-layered sleeve. The double-layered sleeve includes an inner tube and an outer tube. The inner and outer tubes have a plurality of corresponding rectangular slits evenly distributed on their walls. By changing their relative positions, the inner and outer tubes can partially or completely close or open the slits on their walls. The length of the slits is 0.75-0.85D1, and the width is 0.45-0.55D1, where D1 is the diameter of the spinneret. The total area of ​​the slits or holes is 50%-75% of the surface area of ​​the double-layered sleeve. Furthermore, the diameter of the inner tube is the same as the diameter D1 of the spinneret, and the double-layered sleeve is detachably connected to the spinneret.

[0070] In this embodiment, the transition zone of the spinning assembly has a detachable double-layered sleeve arranged in a single row or matrix. The outer periphery of the sleeve is a gaseous medium with different temperatures and pressures. By adjusting the opening of the slits or holes set in the sleeve wall, the flow rate of the gaseous medium entering the buffer zone is controlled, thereby controlling the solvent content of the gel fiber bundle.

[0071] Example 1

[0072] 1.30 kg of ultra-high molecular weight polyethylene resin with a viscosity-average molecular weight of 4.2 million and an entanglement degree of 0.354 was added to a swelling vessel containing 20 L (17.92 kg) of solvent decahydronaphthalene with stirring. Under stirring, the mixture was heated to 80 °C and then gradually increased to 98 °C at a rate of 5 °C per hour, and stabilized for one hour to complete the preparation of the spinning solution. The spinning solution was then fed into a homogenizing vessel equipped with a self-circulating system, and then sequentially fed into a single-screw extruder (screw diameter of 20 mm and length-to-diameter ratio of 25:1). A metering pump mixes the gel to form a highly viscoelastic gel. The gel, stirred by the propeller in a stirring device, is extruded at a rate of 3.25 m / min through an 8-group matrix of 48-hole spinnerets with a spinneret diameter of 0.9 mm and a center-to-center spacing of 4.5 mm. It then enters the buffer zone of a double-layered tube, where it comes into contact with nitrogen gas at 135±1℃ entering through a slit outside the double-layered tube. At this point, the slit opening is 100%, the stroke (length) of the double-layered tube is 50D1, and the gel fiber is drawn 6.5 times. The gel fibers exiting the buffer zone are bundled at the outlet and then enter a two-stage drawing chamber for solvent recovery and further drawing of the gel fibers.

[0073] At this point, the two-stage drawing chambers consist of a first-stage drawing chamber and a second-stage drawing chamber. The first-stage drawing chamber is composed of a second-stage drawing chamber 13 and a hot five-roll drawing machine 14, while the second-stage drawing chamber is composed of a third-stage drawing chamber 15 and a hot five-roll drawing machine 17. At this time, the first-stage drawing chamber 12 and the fourth-stage drawing chamber 16 are in a deactivated state, and the yarn bundle undergoes only a process without heat treatment.

[0074] The temperature of the second drawing box 13 is 139±1℃, the temperature of the third drawing box 15 is 145±1℃, and the drawing ratio of the gel filament in the first and second drawing boxes is 3.0 times; thus, coarse denier high-strength UHMWPE fiber with a specification of 800D is obtained.

[0075] After the device was running stably, the solvent content of the bundled gel fiber at the tunnel outlet and the gel fiber after being drawn in the secondary drawing hot box were sampled and analyzed. The test results were 45.65wt% and 2.6wt%, respectively. The total draw ratio of the finished fiber that fell into the drum was 22 times, the single filament fineness was 2.1D, and the breaking strength was 38.42cN / dtex.

[0076] Example 2

[0077] 1.40 kg of ultra-high molecular weight polyethylene resin with a viscosity-average molecular weight of 4 million and an entanglement degree of 0.348 was added to a swelling vessel containing 20 L (17.92 kg) of solvent decahydronaphthalene with stirring. The mixture was heated to 80°C and then gradually increased to 98°C at a rate of 5°C per hour, stabilizing for one hour to complete the preparation of the spinning solution. The spinning solution was then introduced into a homogenizing vessel equipped with a self-circulating system, and subsequently fed into a single-screw extruder (screw diameter 20 mm and length-to-diameter ratio 25:1). A high-viscoelastic gel is formed by mixing with a pump. The gel, stirred by the propeller in a stirring device, is extruded at a rate of 3.00 m / min through a 42-hole spinneret arranged in a matrix of eight groups (1.0 mm diameter, 4.0 mm center-to-center spacing) into the buffer zone of a double-layered tube. There, it comes into contact with saturated water vapor at 100±1℃ entering through a slit outside the double-layered tube. At this point, the slit opening is 100%, the tube stroke is 40D1, and the gel fiber is drawn 12 times. The gel fibers exiting the buffer zone are bundled at the channel outlet and then enter a two-stage drawing chamber where solvent recovery and gel fiber drawing are performed using a steam azeotropic method.

[0078] At this point, the two-stage drawing chambers consist of a first-stage drawing chamber and a second-stage drawing chamber. The first-stage drawing chamber is composed of a first-stage drawing chamber 12 and a first-stage hot five-roll drawing machine 14. The second-stage drawing chamber is composed of a fourth-stage drawing chamber 16 and a second-stage hot five-roll drawing machine 17. At this time, the second-stage drawing chamber 13 and the third-stage drawing chamber 15 are in a non-operational state, and the yarn bundle undergoes only a process without heat treatment.

[0079] The saturated steam temperature of the first drawing heat box 12 is 108±1℃, and the saturated steam temperature of the fourth drawing heat box 16 is 118±1℃. The drawing ratio of the gel filament in the first and second drawing heat boxes is 2.1 times. Coarse denier high-strength UHMWPE fiber with a specification of 800D is obtained.

[0080] After the device was running stably, the solvent content of the bundled gel fiber at the tunnel outlet and the gel fiber after being stretched by saturated steam in the secondary hot box were sampled and analyzed. The test results were 61.28 wt% and 4.26 wt%, respectively. The total stretch ratio of the finished fiber that fell into the drum was 28 times, the single filament fineness was 2.5D, and the breaking strength was 40.73 cN / dtex.

[0081] Example 3

[0082] 1.50 kg of ultra-high molecular weight polyethylene resin with a viscosity-average molecular weight of 3.5 million and an entanglement degree of 0.329 was added to a swelling vessel containing 20 L (17.92 kg) of solvent decahydronaphthalene with stirring. The mixture was heated to 80 °C and then gradually increased to 98 °C at a rate of 5 °C per hour, and stabilized for one hour to complete the preparation of the spinning solution. The spinning solution was then fed into a homogenizing vessel equipped with a self-circulating system, and then sequentially fed into a single-screw extruder (screw diameter of 20 mm and length-to-diameter ratio of 25:1). A metering pump mixes the gel to form a highly viscoelastic gel. The gel, stirred by the propeller in a stirring device, is extruded at a rate of 2.8 m / min through 12 sets of 32-hole spinnerets arranged in a matrix of 1.1 mm orifices with a center-to-center spacing of 3.6 mm into the buffer zone of a double-layered tube. There, it comes into contact with nitrogen gas at 5±1℃ entering through a slit outside the double-layered tube. At this point, the slit opening is 100%, the double-layered tube stroke is 30D1, and the gel fiber nozzle draw is 15 times. The gel fibers exiting the buffer zone are bundled at the channel outlet and then enter a three-stage drawing chamber where solvent recovery and gel fiber drawing are performed using a steam azeotropic method.

[0083] At this point, the three-stage drawing heat box includes a first-stage drawing heat box, a second-stage drawing heat box, and a third-stage drawing heat box. The first and second-stage drawing heat boxes are composed of a first-stage drawing heat box 12, a second-stage drawing heat box 13, and a hot five-roll drawing machine 14. The third-stage drawing heat box is composed of a third-stage drawing heat box 15, a fourth-stage drawing heat box 16, and a hot five-roll drawing machine 17.

[0084] The first drawing chamber 12 has a saturated steam temperature of 100±1℃, the second drawing chamber 13 has a saturated steam temperature of 110±1℃, and the third and fourth drawing chambers 15 and 16 have a saturated steam temperature of 120±1℃. The drawing ratio of the gel filament in the three-stage drawing chamber is 1.8 times. Coarse denier high-strength UHMWPE fiber with a specification of 800D is obtained.

[0085] After the device was running stably, the solvent content of the bundled gel fiber at the tunnel outlet and the gel fiber after saturated steam drawing in the three-stage drawing hot box were sampled and analyzed. The test results were 89.43wt% and 2.31wt%, respectively. The total draw ratio of the finished fiber that fell into the drum was 30 times, the single filament fineness was 2.3D, and the breaking strength was 42.58cN / dtex.

[0086] Example 4

[0087] 1.20 kg of ultra-high molecular weight polyethylene resin with a viscosity-average molecular weight of 4.5 million and an entanglement degree of 0.364 was added to a swelling vessel containing 20 L (17.92 kg) of solvent decahydronaphthalene with stirring. The solution was heated to 80°C and then gradually increased to 98°C at a rate of 5°C per hour, stabilizing for one hour to complete the preparation of the spinning solution. The spinning solution was then introduced into a homogenizing vessel equipped with a self-circulating system, and then sequentially fed into a single-screw extruder (screw diameter 20 mm and length-to-diameter ratio 25:1). A high-viscoelastic gel is formed by mixing with a pump. The gel, stirred by the propeller in a stirring device, is extruded at a rate of 3.25 m / min through four sets of 48-hole spinnerets arranged in a single row with a spinneret diameter of 0.9 mm and a center-to-center spacing of 4.5 mm. It comes into contact with nitrogen gas at 135±1℃ entering through a slit outside the double-layered sleeve. At this point, the slit opening is 75%, the double-layered sleeve stroke is 40D1, and the gel fiber nozzle draw is 7.0 times. The gel fibers exiting the buffer zone are bundled at the channel outlet and then enter a two-stage drawing chamber for solvent recovery and gel fiber drawing.

[0088] At this point, the two-stage drawing chambers consist of a first-stage drawing chamber and a second-stage drawing chamber. The first-stage drawing chamber is composed of a second-stage drawing chamber 13 and a hot five-roll drawing machine 14, while the second-stage drawing chamber is composed of a third-stage drawing chamber 15 and a hot five-roll drawing machine 17. At this time, the first-stage drawing chamber 12 and the fourth-stage drawing chamber 16 are in a deactivated state, and the yarn bundle undergoes only a process without heat treatment.

[0089] The temperature of the second drawing box 13 is 141±1℃, the temperature of the third drawing box 15 is 145±1℃, and the drawing ratio of the gel filament in the first and second drawing boxes is 2.5 times; thus, coarse denier high-strength UHMWPE fiber with a specification of 400D is obtained.

[0090] After the device was running stably, samples were taken and analyzed for the solvent content of the bundled gel fiber at the tube outlet and the gel fiber after being drawn in the secondary hot box. The test results were 50.32wt% and 3.14wt%, respectively. The total draw ratio of the finished fiber that fell into the drum was 20 times, the single filament fineness was 2.1D, and the breaking strength was 35.46cN / dtex.

[0091] Example 5

[0092] 1.30 kg of ultra-high molecular weight polyethylene resin with a viscosity-average molecular weight of 4 million and an entanglement degree of 0.348 was added to a swelling vessel containing 20 L (17.92 kg) of solvent decahydronaphthalene with stirring. The mixture was heated to 80°C and then gradually increased to 98°C at a rate of 5°C per hour, stabilizing for one hour to complete the preparation of the spinning solution. The spinning solution was then introduced into a homogenizing vessel equipped with a self-circulating system, and subsequently fed into a single-screw extruder (screw diameter 20 mm and length-to-diameter ratio 25:1). A high-viscoelastic gel is formed by mixing with a pump. The gel, stirred by the propeller in a stirring device, is extruded at a rate of 2.8 m / min through four sets of 42-hole spinnerets arranged in a single row with 1.0 mm orifice diameters and a center-to-center spacing of 4.0 mm into the buffer zone of a double-layered tube. There, it comes into contact with saturated water vapor at 100±1℃ entering through a slit outside the double-layered tube. At this point, the slit opening is 60%, the double-layered tube stroke is 40D1, and the gel fiber is drawn 12 times. The gel fibers exiting the buffer zone are bundled at the channel outlet and then enter a two-stage drawing chamber where solvent recovery and gel fiber drawing are performed using a steam azeotropic method.

[0093] At this point, the two-stage drawing chambers consist of a first-stage drawing chamber and a second-stage drawing chamber. The first-stage drawing chamber is composed of a first-stage drawing chamber 12 and a first-stage hot five-roll drawing machine 14. The second-stage drawing chamber is composed of a fourth-stage drawing chamber 16 and a second-stage hot five-roll drawing machine 17. At this time, the second-stage drawing chamber 13 and the third-stage drawing chamber 15 are in a non-operational state, and the yarn bundle undergoes only a process without heat treatment.

[0094] The saturated steam temperature of the first drawing heat box 12 is 108±1℃, and the saturated steam temperature of the fourth drawing heat box 16 is 118±1℃. The drawing ratio of the gel filament in the first and second heat boxes is 2.4 times, and a coarse denier high-strength UHMWPE fiber with a specification of 400D is obtained.

[0095] After the device was running stably, the solvent content in the bundled gel fiber at the sleeve outlet and the gel fiber after being stretched by saturated steam in the secondary hot box was sampled and analyzed. The test results were 71.34 wt% and 5.31 wt%, respectively. The total stretch ratio of the finished fiber that fell into the drum was 32 times, the single filament fineness was 2.4D, and the breaking strength was 38.47 cN / dtex.

[0096] Example 6

[0097] 1.40 kg of ultra-high molecular weight polyethylene resin with a viscosity-average molecular weight of 4 million and an entanglement degree of 0.348 was added to a swelling vessel containing 20 L (17.92 kg) of solvent decahydronaphthalene with stirring. The mixture was heated to 80°C and then gradually increased to 98°C at a rate of 5°C per hour, and stabilized for one hour to complete the preparation of the spinning solution. The spinning solution was then fed into a homogenizing vessel equipped with a self-circulating system, and then sequentially fed into a single-screw extruder (screw diameter of 20 mm and length-to-diameter ratio of 25:1). A highly viscoelastic gel is formed by mixing with a metering pump. The gel, stirred by the propeller in a stirring device, is extruded at a rate of 2.6 m / min through six sets of 32-hole spinnerets arranged in a single row with a spinneret diameter of 1.1 mm and a center-to-center spacing of 3.6 mm. It comes into contact with nitrogen gas at 10±1℃ entering through a slit outside the double-layered sleeve. At this point, the slit opening is 60%, the double-layered sleeve stroke is 40D1, and the gel fiber nozzle draw is 14 times. The gel fibers exiting the buffer zone are bundled at the channel outlet and then enter a three-stage drawing chamber where solvent recovery and gel fiber drawing are performed using a steam azeotropic method.

[0098] At this point, the three-stage drawing heat box includes a first-stage drawing heat box, a second-stage drawing heat box, and a third-stage drawing heat box. The first and second-stage drawing heat boxes are composed of a first-stage drawing heat box 12, a second-stage drawing heat box 13, and a hot five-roll drawing machine 14. The third-stage drawing heat box is composed of a third-stage drawing heat box 15, a fourth-stage drawing heat box 16, and a hot five-roll drawing machine 17.

[0099] The saturated steam temperature of the first drawing heat box 12 is 100±1℃, the saturated steam temperature of the second drawing heat box 13 is 110±1℃, and the saturated steam temperature of the third and fourth drawing heat boxes 15 and 16 is 120±1℃. The draw ratio of the gel filament in the three-stage drawing heat box is 2.0 times. A coarse denier high-strength UHMWPE fiber with a specification of 400D is obtained.

[0100] After the device was running stably, the solvent content of the bundled gel fiber at the tunnel outlet and the gel fiber after being stretched by saturated steam in the three-stage hot box were sampled and analyzed. The test results were 78.27wt% and 3.12wt%, respectively. The total stretch ratio of the finished fiber that fell into the drum was 30 times, the single filament fineness was 1.9D, and the breaking strength was 38.68cN / dtex.

[0101] Example 7

[0102] 1.40 kg of ultra-high molecular weight polyethylene resin with a viscosity-average molecular weight of 3.5 million and an entanglement degree of 0.329 was added to a swelling vessel containing 20 L (17.92 kg) of solvent decahydronaphthalene with stirring. The mixture was heated to 80°C and then gradually increased to 98°C at a rate of 5°C per hour, stabilizing for one hour to complete the preparation of the spinning solution. The spinning solution was then introduced into a homogenizing vessel equipped with a self-circulating system, and subsequently fed into a single-screw extruder (screw diameter 20 mm and length-to-diameter ratio 25:1). A high-viscoelastic gel is formed by mixing with a pump. The gel, stirred by the propeller in a stirring device, is extruded at a rate of 2.4 m / min through a 42-hole spinneret arranged in a matrix of 12 groups with 1.0 mm orifice diameters and a center-to-center spacing of 4.0 mm. It then enters the buffer zone of a double-layered tube, where it comes into contact with nitrogen gas at 135±1℃ entering through a slit outside the double-layered tube. At this point, the slit opening is 50%, the double-layered tube stroke is 60D1, and the gel fiber nozzle draw is 8.0 times. The gel fibers exiting the buffer zone are bundled at the channel outlet and then enter a two-stage drawing chamber for solvent recovery and gel fiber drawing.

[0103] At this point, the two-stage drawing chambers consist of a first-stage drawing chamber and a second-stage drawing chamber. The first-stage drawing chamber is composed of a second-stage drawing chamber 13 and a hot five-roll drawing machine 14, while the second-stage drawing chamber is composed of a third-stage drawing chamber 15 and a hot five-roll drawing machine 17. At this time, the first-stage drawing chamber 12 and the fourth-stage drawing chamber 16 are in a deactivated state, and the yarn bundle undergoes only a process without heat treatment.

[0104] The temperature of the first drawing box 13 is 141±1℃, and the temperature of the third drawing box 15 is 147±1℃. The drawing ratio of the gel filament in the two-stage drawing boxes is 2.6 times, and a coarse denier high-strength UHMWPE fiber with a specification of 1200D is obtained.

[0105] After the device was running stably, the solvent content in the bundled gel fiber at the tunnel outlet and the gel fiber after being stretched in the second-stage hot box was sampled and analyzed. The test results were 55.61 wt% and 3.73 wt%, respectively. The total stretch ratio of the finished fiber that fell into the drum was 23 times, the single filament fineness was 2.4D, and the breaking strength was 32.62 cN / dtex.

[0106] Example 8

[0107] 1.30 kg of ultra-high molecular weight polyethylene resin with a viscosity-average molecular weight of 4.5 million and an entanglement degree of 0.364 was added to a swelling vessel containing 20 L (17.92 kg) of solvent decahydronaphthalene with stirring. The mixture was heated to 80°C and then gradually increased to 98°C at a rate of 5°C per hour, stabilizing for one hour to complete the preparation of the spinning solution. The spinning solution was then introduced into a homogenizing vessel equipped with a self-circulating system, and subsequently fed into a single-screw extruder (screw diameter 20 mm and length-to-diameter ratio 25:1) and metering system. The gel is mixed in a pump to form a highly viscoelastic gel. Under the agitation of the propeller in the stirrer, the gel is extruded at a rate of 2.4 m / min through 12 sets of 36-hole spinnerets arranged in a matrix with a spinneret diameter of 1.1 mm and a center-to-center spacing of 4.4 mm. It comes into contact with saturated water vapor at 105±1℃ entering through a slit outside the double-layered sleeve. At this point, the slit opening is 50%, the double-layered sleeve stroke is 60D1, and the gel fiber nozzle draw is 11 times. The gel fibers exiting the buffer zone are bundled at the channel outlet and then enter a two-stage drawing chamber where solvent recovery and gel fiber drawing are performed using a steam azeotropic method.

[0108] At this point, the two-stage drawing chambers consist of a first-stage drawing chamber and a second-stage drawing chamber. The first-stage drawing chamber is composed of a second-stage drawing chamber 12 and a first-stage hot five-roll drawing machine 14. The second-stage drawing chamber is composed of a fourth-stage drawing chamber 16 and a second-stage hot five-roll drawing machine 17. At this time, the second-stage drawing chamber 13 and the third-stage drawing chamber 15 are in a non-operational state, and the yarn bundle undergoes only a process without heat treatment.

[0109] The first drawing heat box 12 has a saturated steam temperature of 108±1℃, the fourth drawing heat box 16 has a saturated steam temperature of 118±1℃, and the gel filament is drawn 2.2 times in the two drawing heat boxes; thus, coarse denier high-strength UHMWPE fiber with a specification of 1200D is obtained.

[0110] After the device was running stably, the solvent content of the bundled gel fiber at the tunnel outlet and the gel fiber after being stretched by saturated steam in the second-stage hot box were sampled and analyzed. The test results were 71.34 wt% and 5.31 wt%, respectively. The total stretch ratio of the finished fiber that fell into the drum was 27 times, the single filament fineness was 2.2D, and the breaking strength was 33.81 cN / dtex.

[0111] Example 9

[0112] 1.50 kg of ultra-high molecular weight polyethylene resin with a viscosity-average molecular weight of 3.5 million and an entanglement degree of 0.329 was added to a swelling vessel containing 20 L (17.92 kg) of solvent decahydronaphthalene with stirring. The mixture was heated to 80 °C and then gradually increased to 98 °C at a rate of 5 °C per hour, and stabilized for one hour to complete the preparation of the spinning solution. The spinning solution was then fed into a homogenizing vessel equipped with a self-circulating system, and then sequentially fed into a single-screw extruder (screw diameter of 20 mm and length-to-diameter ratio of 25:1). A metering pump mixes the gel to form a highly viscoelastic gel. The gel, stirred by the propeller in a stirring device, is extruded at a rate of 2.8 m / min through 12 sets of 32-hole spinnerets arranged in a matrix with 1.1 mm orifice diameters and a center-to-center spacing of 4.4 mm into the buffer zone of a double-layered tube. There, it comes into contact with nitrogen gas at 5±1℃ entering through a slit outside the double-layered tube. At this point, the slit opening is 100%, the double-layered tube stroke is 30D1, and the gel fiber nozzle draw is 15 times. The gel fibers exiting the buffer zone are bundled at the channel outlet and then enter a three-stage drawing chamber where solvent recovery and gel fiber drawing are performed using a steam azeotropic method.

[0113] At this point, the three-stage drawing heat box includes a first-stage drawing heat box, a second-stage drawing heat box, and a third-stage drawing heat box. The first and second-stage drawing heat boxes are composed of a first-stage drawing heat box 12, a second-stage drawing heat box 13, and a hot five-roll drawing machine 14. The third-stage drawing heat box is composed of a third-stage drawing heat box 15, a fourth-stage drawing heat box 16, and a hot five-roll drawing machine 17.

[0114] The first drawing chamber 12 has a saturated steam temperature of 100±1℃, the second drawing chamber 13 has a saturated steam temperature of 110±1℃, and the third and fourth drawing chambers 15 and 16 have a saturated steam temperature of 120±1℃. The drawing ratio of the gel filament in the three-stage drawing chamber is 1.8 times. Coarse denier high-strength UHMWPE fiber with a specification of 800D is obtained.

[0115] After the device was running stably, the solvent content in the bundled gel fiber at the drawing outlet and the gel fiber after saturated steam drawing in the third-stage drawing hot box was sampled and analyzed. The test results were 72.36wt% and 3.54wt%, respectively. The total draw ratio of the finished fiber that fell into the drum was 30 times, the single filament fineness was 2.4D, and the breaking strength was 42.58cN / dtex.

[0116] In summary, the apparatus and preparation method provided by this invention, by combining a single screw with moderate stirring and conveying, and by setting up a double-layered sleeve buffer zone with different strokes after the raw material solution is extruded from the spinneret, can effectively reduce the breakage of macromolecular chains during the conveying process, reduce resin degradation after swelling, and also reduce interference in processes such as gel molding and crystallization. By adjusting the temperature and flow rate of the fluid medium entering the buffer zone and effectively controlling the solvent content of the gel filament, the difficulties of low fineness and fiber breaking strength of coarse denier ultra-high molecular weight polyethylene fibers prepared by traditional processes can be effectively solved and alleviated. Therefore, coarse denier high-strength UHMWPE fibers can be prepared in a shorter process flow, which not only greatly reduces the operating cost of the apparatus but also greatly reduces the equipment setup.

[0117] The above description of the embodiments is provided to enable those skilled in the art to understand and apply the present invention. It will be apparent to those skilled in the art that various modifications can be easily made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the embodiments described herein, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. An apparatus for producing a coarse denier high strength ultrahigh molecular weight polyethylene fiber, characterized by, Along the material flow direction, the assembly sequentially includes a swelling vessel, a homogenizing vessel, a single-screw extruder, a metering pump, a spinning assembly, a bundling component, and a drawing assembly. The spinning assembly includes a spinneret and a double-layer sleeve assembly connected in sequence. The spinneret includes several spinnerets with the same or different orifice diameters and several stirring propellers disposed on its top. The stirring propellers are connected to the spinnerets one by one. The double-layer sleeve assembly includes several double-layer sleeves, and the spinnerets are connected to the double-layer sleeves one by one.

2. The apparatus of claim 1, wherein, The double-layer sleeve assembly is installed inside the tunnel, and the length H2 of the double-layer sleeve is less than the length of the tunnel; Preferably, the length H2 of the double-layer sleeve is adjustable; and / or Preferably, the middle section of the tunnel is provided with a gaseous fluid medium inlet, the upper and / or lower sections of the tunnel are each independently provided with a mixing medium outlet, and the lower section of the tunnel is also provided with a nitrogen sealing inlet; and / or The traction assembly is a multi-stage traction assembly. Preferably, the traction assembly is a two-stage, three-stage, four-stage, five-stage, or six-stage traction assembly.

3. The apparatus of claim 1 or 2, wherein, The metering pump is connected to the inlet of the agitator, and the bottom outlet of the agitator is connected to the inlet of the spinneret; and / or The stirring propeller is equipped with a stirring blade, the maximum diameter of which is 0.75-0.8D1, where D1 is the diameter of the spinneret; preferably, the stirring blade is a stainless steel propeller; and / or The stirring propeller and the spinneret are arranged in a matrix or single row; and / or The spinneret has a plurality of spinneret holes on its surface, the center-to-center distance between the spinneret holes being 3d-10d, preferably 3d-8d, more preferably 3d-5d; and / or, the inlet diameter of the spinneret hole being 1.5d-2.5d, where d is the diameter of the spinneret hole.

4. The apparatus of any one of claims 1-3, wherein, The double-layer sleeve includes an inner tube and an outer tube. The inner tube and the outer tube are provided with a number of corresponding through holes evenly arranged on their tube walls. The inner tube and the outer tube can partially or completely close or open the through holes on their tube walls by changing their relative positions. Preferably, the through hole is a rectangular slit with rounded corners or a round hole, the length of the slit is 0.75-0.85D1 and the width is 0.45-0.55D1, and the diameter of the round hole is 0.1D1, where D1 is the diameter of the spinneret. Preferably, the total area of ​​the slit or hole is 50%-75% of the surface area of ​​the double-layer sleeve.

5. The apparatus of claim 4, wherein, The diameter of the inner tube is the same as the diameter D1 of the spinneret; and / or The length H2 of the double-layer sleeve is 10D1-100D1, preferably 20D1-80D1, more preferably 20D1-60D1; and / or The bundling component includes a guide roller disposed between the tunnel outlet and the traction assembly inlet; and / or The double-layer sleeve is detachably connected to the spinneret; and / or The device also includes a solvent recovery component.

6. The apparatus of claim 4, wherein, By rotating the inner tube clockwise or counterclockwise within the double-layered sleeve, or the outer tube clockwise or counterclockwise, or by rotating the inner and outer tubes simultaneously in opposite directions, the through-holes in the double-layered sleeve wall can be partially or completely closed or opened, thereby regulating the flow rate of the gaseous medium entering the buffer zone of the double-layered sleeve; and / or Within the buffer zone of the double-layered sleeve, the flow rate of the gaseous medium is 5% to 50% of the total flow rate of all materials therein. Preferably, the temperature of the flowing gaseous medium is 0℃-30℃ or 100℃-150℃; and / or, the flowing gaseous medium is selected from compressible gaseous media, preferably selected from one or more of carbon dioxide, nitrogen, and saturated water vapor.

7. A method for producing a coarse denier high strength ultrahigh molecular weight polyethylene fiber, characterized by, Using the apparatus according to any one of claims 1-6 includes the following steps: 1) Add ultra-high molecular weight polyethylene resin and a good solvent into a swelling vessel, and heat in a gradient manner to obtain a spinning solution by swelling; 2) The spinning solution is mixed by a single screw extruder and metered by a metering pump to form a high viscoelastic gel. After the high viscoelastic gel enters the spinning assembly, it is stirred by a stirring propeller and then extruded by a spinneret. It then enters the buffer area in the double-layer sleeve and comes into contact with the gaseous fluid medium. Some of the solvent in the high viscoelastic gel flashes out to form gel filaments. 3) After the gel filaments are bundled by the bundling component at the exit of the tunnel, the bundled gel filaments enter the drawing assembly. After solvent removal and multi-stage drawing in the drawing assembly, gel fibers are obtained. 4) The gel fiber is stretched by the stretching assembly to obtain ultra-high molecular weight polyethylene fiber.

8. The production method according to claim 7, characterized by, The ultra-high molecular weight polyethylene resin has a viscosity-average molecular weight of 3-5 million and an entanglement degree of 0.1-0.6; and / or The good solvent is selected from one or more of decahydronaphthalene, tetrahydronaphthalene, and xylene; and / or The mass ratio of the ultra-high molecular weight polyethylene resin to the good solvent is (6:94)-(10:90); and / or The gradient heating process involves heating to 80-85°C, then gradually increasing the temperature at a rate of 3-8°C per hour to 95-98°C, and then maintaining the temperature for one hour.

9. The production method according to claim 7 or 8, characterized by, The gaseous fluid medium is a low-temperature medium of 0℃-30℃ or a high-temperature medium of 100℃-150℃. Preferably, the flowing gaseous medium is a low-temperature medium, and the ratio of the linear velocity of the gel filament on the guide roller to the extrusion velocity of the spinneret is 1-50, preferably 3-40, more preferably 6-30; the solvent content in the bundled gel filament is 70wt%-95wt%, preferably 75wt%-92wt%, more preferably 80wt%-90wt%; or The flowing gaseous medium is a high-temperature medium, and the ratio of the linear velocity of the gel filament on the guide roller to the extrusion velocity of the spinneret is 1-40, preferably 2-35, and more preferably 5-30; the solvent content in the bundled gel filament is 20wt%-90wt%, preferably 30wt%-75wt%, and more preferably 40wt%-65wt%. Preferably, the gelatin filaments and the bundled gelatin filaments generated by the low-temperature medium are subjected to multi-stage drawing in a drawing assembly with three or four temperature gradients. Simultaneously, the solvent within the bundled gelatin filaments comes into contact with the high-temperature medium in the drawing assembly and detaches from the fiber interior and surface, allowing for solvent recovery. Preferably, the three temperature gradients include a first stage of 98℃-100℃, a second stage of 108℃-110℃, and a third stage of 118℃-120℃; the four temperature gradients include a first stage of 98℃-100℃, a second stage of 108℃-110℃, a third stage of 118℃-120℃, and a fourth stage of 121℃-123℃. Alternatively, the gelatin filaments and the bundled gelatin filaments generated by the high-temperature medium... The filaments enter the drawing assembly with a two- or three-stage temperature gradient for multi-stage drawing. Simultaneously, the solvent within the bundled gel filaments comes into contact with the high-temperature medium within the drawing assembly and detaches from the fiber's interior and surface, allowing for solvent recovery. Preferably, the two-stage temperature gradient includes a first stage of 105℃-108℃ and a second stage of 135℃-139℃, or a first stage of 115℃-118℃ and a second stage of 143℃-145℃. The three-stage temperature gradient includes a first stage of 105℃-108℃, a second stage of 115℃-118℃, and a third stage of 135℃-139℃, or a first stage of 115℃-118℃, a second stage of 135℃-139℃, and a third stage of 143℃-145℃. Preferably, when the gel filament is in contact with the low-temperature medium, the length H2 of the double-layer sleeve is 20D1-40D1, and when the gel filament is in contact with the high-temperature medium, the length H2 of the double-layer sleeve is 40D1-60D1.

10. The production method according to any one of claims 7 to 9, characterized by, The bundling component includes a guide roller disposed between the tunnel outlet and the traction assembly inlet. Preferably, the ratio of the linear velocity of the guide roller to the extrusion velocity of the spinneret is 1-50, more preferably 3-40, and more preferably 6-30; and / or The total draw ratio of the bundled gel filaments in the drawing assembly is 5-50 times, preferably 10-40 times, more preferably 18-30 times; and / or The wet content of the gel fiber is 1wt%-10wt%, preferably 2wt%-7wt%, and more preferably 3wt%-5wt%.

11. A coarse denier high-strength ultra-high molecular weight polyethylene fiber prepared by any one of the apparatuses of claims 1-6 or by any one of the preparation methods of claims 7-10, preferably, the ultra-high molecular weight polyethylene fiber is a coarse and high-strength ultra-high molecular weight polyethylene fiber with a denier of 1.8-3.0D and a strength of 35-45cN / dtex.

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