High-strength high-molecular fiber and fishing net weaving process thereof

Abstract

The application discloses high-strength high-molecular fiber and a fishing net weaving process thereof, and belongs to the technical field of high-molecular fiber materials. The high-strength high-molecular fiber is an ultrahigh-molecular-weight polyethylene composite fiber, and has a core layer near-surface layer double-layer structure; the core layer is highly oriented ultrahigh-molecular-weight polyethylene; the near-surface layer is a flexible modified layer rich in SEBS; a hindered amine light stabilizer is distributed in the modified layer; the radial thickness of the near-surface layer is 0.2% to 8% of the diameter of a fiber finished product; the diameter of the fiber finished product is 0.05 to 0.5 mm; the breaking strength is greater than or equal to 28 cN / dtex; and the surface dynamic friction coefficient is 0.21 to 0.25. The modified layer is firmly combined and resistant to weaving friction, and is suitable for ocean fishing net weaving due to high strength and high surface friction.

Description

Technical Field

[0001] This invention belongs to the field of polymer fiber material technology, specifically relating to a high-strength ultra-high molecular weight polyethylene composite fiber and its preparation method, as well as a fishing net weaving process using this fiber. Background Technology

[0002] Ultra-high molecular weight polyethylene (UHMWPE) fiber is one of the highest strength-to-weight ratio high-performance fibers available today. It possesses excellent weather resistance, chemical corrosion resistance, low-temperature resistance, abrasion resistance, bending resistance, and impact resistance, making it widely used in aerospace, defense, marine engineering, and aquaculture. In the fisheries sector, UHMWPE fiber, with its high strength, low density, and seawater corrosion resistance, has become an important material for fishing gear and aquaculture facilities.

[0003] However, UHMWPE fibers still face several key technical bottlenecks in fishing net applications: First, the surface of UHMWPE fibers is smooth and lacks polar groups, with a surface dynamic friction coefficient of only about 0.15-0.19. During the net weaving process, the low coefficient of friction causes slippage and displacement between monofilaments, resulting in uneven net structure and unstable mesh size, severely affecting the overall strength and fishing efficiency of the net. Furthermore, this slippage can cause mesh deformation during subsequent use, further shortening the net's lifespan. Second, UHMWPE fibers exhibit creep deformation under long-term constant loads. When fishing nets are subjected to continuous loads such as seawater impact and dragging of catches, the fiber macromolecular chains undergo irreversible slippage along the axial direction, leading to a gradual increase in net size and a decrease in strength. This problem is particularly prominent in deep-sea aquaculture cages and large trawls. Third, although UHMWPE fibers have good weather resistance, long-term exposure to strong ultraviolet radiation in the ocean will still cause photo-oxidative aging on the surface, leading to the initiation and expansion of microcracks on the fiber surface, which will ultimately affect the long-term reliability of fishing nets.

[0004] To overcome the above problems, several modification schemes have been proposed in the prior art. The paper "Preparation and Characterization of Nano-SiC / Ultra-High Molecular Weight Polyethylene Composite Fibers" (Plastics, April 2015) uses gel spinning to prepare nano-SiC / UHMWPE composite fibers. After surface organic modification treatment of nano-SiC, it is blended with UHMWPE to reduce creep rate. However, in this scheme, the inorganic nanoparticles, after being blended with UHMWPE, penetrate the entire fiber cross-section, leading to a decrease in bulk strength. Patent CN105544180A uses a tannic acid-zinc oxide composite coating for surface modification via ultrasonic precipitation, forming a uniform zinc oxide nano-coating on the surface of ultra-high molecular weight polyethylene fibers to improve toughness. However, the functional coating adheres to the fiber surface and is difficult to effectively improve the bonding force between the fiber and the matrix. The paper "Research on Crosslinking Modification of Ultra-High Molecular Weight Polyethylene Fiber" (2013 National Polymer Academic Paper Conference) introduces initiators and crosslinking agents into ultra-high molecular weight polyethylene (UHMWPE) gel fibers during the extraction process to initiate a grafting-crosslinking reaction, thereby improving the heat resistance and creep resistance of UHMWPE fibers. However, this process involves initiators, crosslinking agents, and subsequent initiation reaction processes, making it complex and unsuitable for industrial application.

[0005] In summary, there is an urgent need to develop a product that can solve the problems of existing UHMWPE fibers, such as smooth and slippery surface and insufficient creep resistance, and apply it to fishing net weaving technology. Summary of the Invention

[0006] The purpose of this invention is to provide a high-strength polymer fiber and its fishing net weaving process. The technical solution to achieve the purpose of this invention is as follows.

[0007] In a first aspect, the present invention provides a high-strength polymer fiber having a double-layer structure of a core layer and a near-surface layer: the core layer is highly oriented ultra-high molecular weight polyethylene; the near-surface layer is a flexible modified layer enriched with SEBS, and the radial thickness of the near-surface layer is 0.2% of the finished fiber diameter. The radial thickness is 8%, measured from the outer surface of the fiber to the core, and the hindered amine light stabilizer is distributed within the modified layer; the polymer fiber diameter is 0.05 mm. 0.5 mm, fracture strength ≥ 28 cN / dtex, surface dynamic friction coefficient is 0.21 0.25.

[0008] The high-strength polymer fiber is prepared by a method comprising the following steps: (1) Ultra-high molecular weight polyethylene and spinning solvent are mixed to form a spinning gel solution, which is then subjected to twin-screw extrusion, spin extrusion and rapid cooling molding to obtain gel filaments that have not undergone high-ratio thermal stretching. (2) The gel fiber is directly introduced into the impregnation tank and immersed in the modified liquid for online impregnation; the impregnation temperature is 45-55℃ and the impregnation time is 4-10 min; during the impregnation process, xylene is used as both a SEBS solvent and an extraction medium to replace and extract the paraffin oil on the surface of the gel fiber, opening the surface diffusion channel, allowing SEBS macromolecules to penetrate and diffuse into the near-surface region of the fiber, and hindered amine light stabilizer is enriched in the near-surface region along with SEBS. (3) The wet gel filaments after impregnation are subjected to multi-stage hot stretching; the stretching temperature is 115-124℃ and the total stretching ratio is 45-60 times; during the hot stretching process, low-boiling-point xylene gradually evaporates and is discharged; after being replaced by xylene, the paraffin oil is squeezed and migrated to the fiber surface under the action of stretching deformation and is carried out with the exhaust system; the production is equipped with a condensation recovery system to recycle xylene; the core layer ultra-high molecular weight polyethylene molecular chains are highly oriented; the near-surface SEBS and UHMWPE macromolecular chain segments are locally physically entangled to form a strong bonding interface; (4) The high-strength polymer fiber is obtained by heat setting and winding.

[0009] Further, in step (1), the viscosity-average molecular weight of the ultra-high molecular weight polyethylene is 3.2 million to 4.2 million; the spinning solvent is selected from at least one of paraffin oil and decahydronaphthalene; in the spinning gel solution, the mass ratio of ultra-high molecular weight polyethylene to spinning solvent is (6-12):(88-94).

[0010] Furthermore, in step (1), the temperature of the twin-screw extrusion is 160-260℃; the cooling medium for the rapid cooling molding is a water bath or an oil bath, and the cooling temperature is 0-30℃.

[0011] Furthermore, the polymer mass fraction in the gel filament is 6%-12%; this mass fraction refers to the percentage of polymer mass in the gel filament, which contains a large amount of spinning solvent, and the macromolecules are in a swollen and relaxed state; the gel filament diameter is 0.5 mm. 3.0mm.

[0012] Further, in step (2), the SEBS is a styrene-ethylene-butene-styrene block copolymer with a styrene content of 28-33 wt%; the hindered amine light stabilizer is a 2,2,6,6-tetramethylpiperidine light stabilizer, preferably at least one of Tinuvin 770, Tinuvin 622, and Chimassorb 944.

[0013] Further, in step (2), the modified liquid contains, by mass fraction: SEBS 9-13 wt%, hindered amine light stabilizer 0.4-0.8 wt%, and the balance is xylene.

[0014] In step (2), the gel filament is not dried before impregnation and contains spinning solvent. The fiber macromolecules are in a swellable and relaxed state. During the online impregnation process, by controlling the impregnation time, xylene moderately swells the surface of the gel filament, and SEBS macromolecules penetrate and diffuse into the near-surface area of ​​the fiber. The hindered amine light stabilizer is enriched in the near-surface area along with SEBS.

[0015] Further, in step (3), the multi-stage thermal stretching is 2-5 stages of progressive stretching; the stretching temperature of each stage is independently 115-124℃, the temperature gradient between adjacent stages is 1-5℃; and the total stretching ratio is 45-60 times.

[0016] Furthermore, in step (3), the multi-stage hot stretching process is carried out in a multi-stage hot stretching oven; the hot stretching oven is equipped with an active air supply and exhaust system to promote the evaporation and discharge of the solvent; this process relies on impregnation Stretching coupling enables paraffin oil extraction and displacement. After thermal stretching, the total solvent residue in the fiber is ≤1000 ppm, of which xylene residue is ≤100 ppm and paraffin oil residue is ≤500 ppm, meeting the requirements for use in marine fishing nets.

[0017] Furthermore, in step (4), the heat setting temperature is 115-124℃ and the time is 1-10 min.

[0018] Furthermore, in step (4), the winding speed is 50-200 m / min.

[0019] Furthermore, in step (4), the finished diameter of the high-strength polymer fiber is 0.05-0.5 mm, which is suitable for subsequent processes such as twisting and warping in fishing net weaving.

[0020] Furthermore, the thickness of the near-surface SEBS-enriched flexible modified layer is 0.2%-8% of the fiber diameter, and is controlled by the impregnation temperature, impregnation time, and SEBS concentration in step (2).

[0021] On the other hand, the present invention provides a fishing net weaving process, which is woven from the aforementioned high-strength polymer fibers, and includes the following steps: S1. After combining one or more monofilaments of the high-strength polymer fiber, twist them on a twisting machine to obtain fishing net line; the twisting method is double twisting, and the twist degree is 30-180 twists / meter.

[0022] S2. The net yarn obtained in step S1 is warped on a warping machine according to the mesh size and width requirements of the fishing net design to form a warp layer; S3. The warp yarns after warping are fed into a net weaving machine to weave and make a fishing net sheet; the fishing net sheet is heat-set at a temperature of 110-130℃ for 1-10 minutes, then cooled and rolled up to obtain the finished fishing net.

[0023] By adopting the above technical solution, the present invention has the following beneficial effects: (1) This invention modifies the surface of the gel fiber by impregnating it with SEBS in the gel fiber stage. It utilizes the characteristic that the surface of the gel fiber can be moderately swollen by organic solvents to allow SEBS macromolecules to penetrate and diffuse into the near-surface area of ​​the fiber. Then, multi-stage thermal stretching is performed to achieve selective enrichment of SEBS only in the near-surface area of ​​the fiber. The core layer maintains the highly oriented structure of pure UHMWPE, which not only ensures the breaking strength of the fiber, but also achieves a firm bond of the modified layer.

[0024] (2) This invention constructs a flexible modified layer enriched with SEBS near the surface of the fiber, achieving a surface dynamic friction coefficient of 0.21-0.25. This effectively reduces slippage between monofilaments during fishing net weaving, improves the uniformity of the weaving structure and the stability of the mesh size, and meets the needs of fishing net weaving processing. When the fiber is subjected to axial tensile force, the stress is transmitted layer by layer from the outside to the inside. The SEBS-enriched modified layer near the surface of the fiber binds the amorphous chain segments in the near region of the fiber, while reducing stress concentration at micro-defects on the fiber surface and inhibiting chain-transmitted macromolecular slippage induced by surface chain slippage. Thus, the overall creep resistance of the fiber is improved under the condition that SEBS is only distributed in the near surface layer.

[0025] (3) This invention enriches the HALS light stabilizer along with SEBS in the near-surface layer of the fiber, which can effectively capture free radicals generated by ultraviolet light in the seawater environment, inhibit photo-oxidative aging of the fiber surface, and improve marine weather resistance. This invention does not add any inorganic nanofillers, avoiding stress defects and process complexity caused by nanoparticle agglomeration. The equipment modification cost is low, only requiring the addition of an impregnation tank after the spin-coagulation process and before the hot stretching process in the existing gel spinning production line, making it suitable for industrial promotion. Detailed Implementation

[0026] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0027] In the following examples, UHMWPE powder (viscosity-average molecular weight 3.5 million, gel spinning grade) was purchased from Shanghai Lianle Chemical Technology Co., Ltd.; SEBS (styrene-ethylene-butene-styrene block copolymer, styrene content 30wt%) was purchased from Baling Petrochemical; HALS (hindered amine light stabilizer, brand name Tinuvin 770) was purchased from BASF; xylene (analytical grade) was purchased from Sinopharm Chemical Reagent Co., Ltd.; and paraffin oil (industrial grade) was purchased from China Petroleum & Chemical Corporation.

[0028] Example 1 This embodiment provides a high-strength polymer fiber and its preparation method: (1) UHMWPE powder with a viscosity-average molecular weight of 3.5 million was mixed with paraffin oil at a mass ratio of 8:92 and melt-mixed at 230°C in a twin-screw extruder to prepare a uniform spinning gel solution. After extrusion through a spinneret, the extrudate was rapidly cooled and shaped in a 10°C water bath to obtain gel filaments that had not undergone high-ratio hot stretching. The polymer mass fraction in the gel filaments was approximately 8%.

[0029] (2) By mass fraction, 11wt% SEBS, 0.6wt% HALS and 88.4wt% xylene are heated and stirred at 50°C until completely dissolved to obtain a modified solution. The gel fiber obtained in step (1) is introduced directly into the impregnation tank containing the above modified solution without drying or pre-stretching, and impregnated at 50°C for 6 min.

[0030] (3) The wet gel fiber after impregnation was directly and continuously introduced into a three-stage hot stretching oven for hot stretching without intermediate drying. The three stretching temperatures were 118℃, 120℃ and 122℃, and the total stretching ratio was 50 times. After stretching, the total solvent residue of the fiber was about 820 ppm, of which paraffin oil residue was about 410 ppm and xylene residue was about 70 ppm.

[0031] (4) The stretched fiber was relaxed and heat-set at 120℃ for 5 min, and then wound at a speed of 100 m / min to obtain a SEBS near-surface modified UHMWPE composite high-strength fiber. The cross-section of the obtained fiber has a core-near-surface double-layer structure. After cryosectioning, the sample was observed by selective etching with tetrahydrofuran (THF) using scanning electron microscopy. The etching conditions were: soaking in pure THF at room temperature for 15 min, and an unetched blank control was set up to eliminate the size interference caused by slight swelling of THF. THF can selectively dissolve the SEBS phase, and the UHMWPE matrix only swells slightly and does not dissolve. The radial depth of the cavity left after the SEBS phase is etched is measured as the thickness of the modified layer. In Example 1, the radial depth was measured to be about 800 nm. The diameter of the finished fiber is 0.14 mm.

[0032] Example 2 The difference between this embodiment and Example 1 lies in the SEBS content in the modified solution and the impregnation conditions. Modified solution preparation: 9 wt% SEBS, 0.4 wt% HALS, and 90.6 wt% xylene were mixed by mass fraction and heated and stirred at 45°C until completely dissolved. Impregnation conditions: Impregnation temperature 45°C, impregnation time 10 min. The total stretching ratio of the multi-stage hot stretching was 45 times. The remaining steps and conditions were the same as in Example 1. The resulting fiber had a near-surface thickness of approximately 500 nm and a finished fiber diameter of 0.16 mm.

[0033] Example 3 The difference between this embodiment and Example 1 lies in the SEBS content in the modified solution and the impregnation conditions. Modified solution preparation: 13 wt% SEBS, 0.8 wt% HALS, and 86.2 wt% xylene were mixed by mass fraction and heated and stirred at 55°C until completely dissolved. Impregnation conditions: Impregnation temperature 55°C, impregnation time 4 min. The total stretching ratio of the multi-stage hot stretching was 60 times. The remaining steps and conditions were the same as in Example 1. The resulting fiber had a near-surface thickness of approximately 1.2 μm (i.e., 1200 nm) and a finished fiber diameter of 0.12 mm (i.e., 120 μm).

[0034] Example 4 The difference between this embodiment and Example 1 lies in the impregnation time; all other raw materials and process parameters are identical to those in Example 1. Impregnation conditions: impregnation temperature 50℃, impregnation time 4 min. The remaining processes, characterization, and performance testing methods are the same as in Example 1. The resulting fiber has a near-surface thickness of approximately 450 nm and a finished fiber diameter of 0.14 mm.

[0035] Example 5 The difference between this embodiment and Embodiment 1 lies in the impregnation time; all other raw materials and process parameters are identical to those in Embodiment 1. Impregnation conditions: impregnation temperature 50℃, impregnation time 10 min. The remaining processes, characterization, and performance testing methods are the same as in Embodiment 1.

[0036] Comparative Example 1 Comparative Example 1 consisted of unmodified pure UHMWPE fibers, prepared using the same gel spinning process as Example 1, but without the online impregnation modification step; the gel precursor fibers were directly subjected to multi-stage hot stretching and post-treatment. The resulting finished fiber had a diameter of 0.14 mm.

[0037] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that Comparative Example 2 uses a post-dip coating method to replace the online impregnation of gel-bonded fibers. The unmodified UHMWPE fibers obtained in Comparative Example 1 were immersed in the same SEBS-HALS-xylene modified solution as in Example 1, impregnated at 50°C for 6 minutes, and then dried in an oven at 120°C to remove xylene, resulting in post-dip coated modified UHMWPE fibers. The diameter of the resulting finished fibers was 0.14 mm.

[0038] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that the online impregnation stage of the gel fiber stage was replaced by a solution-blended SEBS modification route. UHMWPE powder with a viscosity-average molecular weight of 3.5 million was blended with SEBS at a mass ratio of 90:10 (i.e., SEBS content of 10 wt%), and then paraffin oil (solid content of 8 wt%) was added. The mixture was melt-blended at 230°C in a twin-screw extruder to prepare a spinning gel solution. After extrusion through a spinneret, the extrudate was rapidly cooled in a 10°C water bath to obtain gel fiber. The obtained gel fiber was not impregnated for modification and was directly subjected to multi-stage hot stretching (under the same stretching conditions as Example 1) and post-treatment (under the same heat setting conditions as Example 1) to obtain solution-blended SEBS-modified UHMWPE fiber. The diameter of the finished fiber was 0.14 mm. In this method, SEBS runs through the entire fiber cross-section.

[0039] Performance testing The fibers obtained in Examples 1-5 and Comparative Examples 1-3 were subjected to the following performance tests: (1) Fracture strength test The tensile strength of the fibers was tested according to GB / T 19975-2005 "Test Method for Tensile Properties of High-Strength Fiber Filaments". A single-fiber tensile tester was used, with a clamping distance of 250 mm and a tensile speed of 250 mm / min. Twenty samples were tested in each group, and the average value was taken.

[0040] (2) Test of surface dynamic friction coefficient The winch method was used, with the following test conditions: winding angle 180°, tension 10g, test speed 10mm / min, and fiber... Fiber abrasion; refer to ASTM D3412 / D3412M 13 (2020); each group was tested 10 times and the average value was taken.

[0041] (3) Adhesion test of modified layer (simulated weaving friction) Reciprocating friction tests were conducted using a braiding testing machine. Test conditions: monofilament clamping tension 0.3 cN / dtex, reciprocating stroke 15 mm, reciprocating speed 60 times / minute, and 500 reciprocating friction cycles. The rate of change of the surface dynamic friction coefficient before and after friction was measured to evaluate the adhesion of the modified layer.

[0042] (4) Creep resistance test A constant-temperature, constant-load monofilament creep test method was adopted. At room temperature (25℃), a constant load of 20% of the breaking strength was applied to the fiber, and the creep elongation was recorded over 100 hours. The arithmetic mean of 20 monofilament samples in each group was taken. This test adopts the experimental approach of constant-load creep testing for geosynthetics, with adaptive adjustments made for the monofilament samples.

[0043] (5) Near-surface thickness measurement Fiber samples were cryogenically frozen and ultrathinly sectioned to obtain cross-sectional sections with a thickness of less than 100 nm. These sections were then selectively etched in tetrahydrofuran (THF) for 15 min, with an unetched blank section as a control to eliminate interference from slight swelling of the THF. THF selectively dissolved only the SEBS phase, with only slight swelling of the UHMWPE matrix and no dissolution or destruction. Scanning electron microscopy (SEM) was used to observe the etched cross-sections, obtaining secondary electron images. After the SEBS phase was etched away, dark pores or voids were formed, while the UHMWPE matrix appeared as a continuous, bright skeleton. Slight grooves or tears at the edges of the pores could serve as indirect evidence of localized physical entanglement between SEBS and UHMWPE. The radial depth of the continuous SEBS void distribution area was measured from the fiber outer surface towards the core. When the SEBS voids disappeared and only the continuous UHMWPE matrix was visible, this radial depth was recorded as the modified layer thickness.

[0044] The test results are shown in Table 1.

[0045] Table 1 Performance test results of Examples 1-5 and Comparative Examples 1-3

[0046] The test results in Table 1 show that: (1) The tensile strength of the fibers obtained in Examples 1-5 all reached above 28 cN / dtex, which is slightly lower than that of the unmodified Comparative Example 1, but still meets the strength requirements of high-strength fibers for fishing nets. This shows that by performing online impregnation modification at the gel filament stage, SEBS is only enriched in the near-surface layer of the fiber, the core layer UHMWPE maintains a highly oriented structure, and the fiber body strength is not significantly damaged.

[0047] (2) Comparative Example 3 adopted the SEBS modification route of spinning solution blending. SEBS runs through the entire fiber cross section, and the breaking strength is only 23.7 cN / dtex, which is 24.8% lower than that of the unmodified Comparative Example 1, and cannot meet the strength requirements of high-strength fibers for fishing nets (≥28 cN / dtex). This shows that although solution blending of SEBS can improve surface friction properties and creep resistance to a certain extent, the bulk strength is sacrificed too much.

[0048] (3) The surface dynamic friction coefficient of the fibers obtained in Examples 1-5 was 0.21-0.25, which was significantly higher than 0.18 of Comparative Example 1 and comparable to Comparative Example 2 and Comparative Example 3, indicating that the flexible modified layer enriched by SEBS effectively improved the friction characteristics of the fiber surface.

[0049] (4) As can be seen from the friction coefficient retention rate after weaving friction, the retention rate of Examples 1-5 is all above 95%, while that of Comparative Example 2 is only 86.4% and that of Comparative Example 3 is 90.9%. This shows that the SEBS enriched modified layer prepared by the present invention has a strong bond, which is far superior to the physical adhesion of the post-dip coating method. At the same time, since SEBS has local physical entanglement with UHMWPE near the surface, the adhesion durability of its modified layer is better than that of the original solution blending method (in Comparative Example 3, SEBS runs through the entire cross section. Although the overall integrity is good, the interface bonding is mainly physical blending. After friction, the surface SEBS may still wear or migrate to a certain extent, so the retention rate is slightly lower than that of this application).

[0050] (5) The creep test results show that the creep elongation at 100 h (2.5-2.9%) of Examples 1-5 is significantly lower than that of Comparative Example 1 (3.8%) and Comparative Example 2 (3.5%), indicating that the SEBS near-surface entanglement modified layer plays a physical binding role on the amorphous chain segments of UHMWPE, effectively inhibiting the slippage of macromolecular chains and improving the fiber's anti-creep performance. The creep elongation at 2.5% of Comparative Example 3 is comparable to that of Example 3, but its fiber strength is seriously substandard.

[0051] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A high-strength polymer fiber, which is an ultra-high molecular weight polyethylene composite fiber, characterized in that, The fiber has a dual-layer structure consisting of a core layer and a near-surface layer: the core layer is highly oriented ultra-high molecular weight polyethylene; the near-surface layer is a flexible modified layer enriched with SEBS, and the radial thickness of the near-surface layer is 0.2% of the finished fiber diameter. The radial thickness is 8%, measured from the outer surface of the fiber to the core, and the hindered amine light stabilizer is distributed within the modified layer; the polymer fiber diameter is 0.05 mm. 0.5 mm, fracture strength ≥ 28 cN / dtex, surface dynamic friction coefficient is 0.21 0.

25.

2. The high-strength polymer fiber according to claim 1, characterized in that, Prepared by a method including the following steps: (1) Ultra-high molecular weight polyethylene and spinning solvent are mixed to form a spinning gel solution, which is then subjected to twin-screw extrusion, spin extrusion and rapid cooling molding to obtain gel filaments that have not undergone high-ratio thermal stretching. (2) The gel fiber is directly introduced into the impregnation tank and impregnated in the modification solution; the impregnation temperature is 45-55℃ and the impregnation time is 4-10 min; the modification solution contains, by mass fraction: SEBS 9-13 wt%, hindered amine light stabilizer 0.4-0.8 wt%, and the balance is xylene; (3) The wet gel fibers after impregnation are subjected to multi-stage thermal stretching; the stretching temperature is 115-124℃ and the total stretching ratio is 45-60 times. (4) The high-strength polymer fiber is obtained by heat setting and winding.

3. The high-strength polymer fiber according to claim 2, characterized in that, In step (1), the viscosity-average molecular weight of the ultra-high molecular weight polyethylene is 3.2 million to 4.2 million; the spinning solvent is selected from at least one of paraffin oil and decahydronaphthalene; in the spinning gel solution, the mass ratio of ultra-high molecular weight polyethylene to spinning solvent is (6-12):(88-94).

4. The high-strength polymer fiber according to claim 2, characterized in that, In step (2), the SEBS is a styrene-ethylene-butene-styrene block copolymer with a styrene content of 28-33 wt%; the hindered amine light stabilizer is a 2,2,6,6-tetramethylpiperidine light stabilizer.

5. The high-strength polymer fiber according to claim 2, characterized in that, In step (3), the multi-stage thermal stretching is 2-5 stages of progressive stretching; the stretching temperature of each stage is 115-124℃, and the temperature gradient between adjacent stages is 1-5℃; the total stretching ratio is 45-60 times.

6. The high-strength polymer fiber according to claim 2, characterized in that, In step (4), the heat setting temperature is 115-124℃ and the time is 1-10 min.

7. A fishing net weaving technique, characterized in that, The product is woven from high-strength polymer fibers as described in any one of claims 1-6, and includes the following steps: S1. After combining one or more monofilaments of the high-strength polymer fiber, twist them on a twisting machine to obtain fishing net line; the twisting method is double twisting, and the twist degree is 30-180 twists / meter; S2. The net yarn obtained in step S1 is warped on a warping machine according to the mesh size and width requirements of the fishing net design to form a warp layer; S3. The warp yarns after warping are fed into a net weaving machine to weave and make a fishing net sheet; the fishing net sheet is heat-set at a temperature of 110-130℃ for 1-10 minutes, then cooled and rolled up to obtain the finished fishing net.

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