Method for improving thermal stability of industrial polyethylene fiber fabric

Abstract

The invention provides a method for improving the thermal stability of an industrial polyethylene fiber fabric, which comprises the following steps: A) blending a polyethylene raw material, a photoinitiator and an auxiliary cross-linking agent to obtain a mixture; b) performing melt spinning on the mixture to obtain polyethylene fibers; c) drafting and weaving the polyethylene fiber to obtain a polyethylene fiber fabric; and D) performing ultraviolet irradiation on the polyethylene fiber fabric to obtain the modified polyethylene fiber fabric. The method has the core advantages that the operation process is simple and convenient, the treatment effect is remarkable and efficient, and the thermal stability of the polyethylene fiber fabric is remarkably improved from multiple aspects by finely regulating and controlling the blending system and the ultraviolet irradiation condition, so that the limitation of the polyethylene fiber fabric on the application of the fabric textile is solved, and the application prospect is wide. And a reliable scheme is provided for industrial development of common polyethylene fiber fabrics.

Description

Technical Field

[0001] The invention belongs to the technical field of material manufacturing, and in particular relates to a method for improving the thermal stability of industrial polyethylene fiber fabrics. Background Art

[0002] Polyethylene fiber is a polymer material with excellent physical properties and chemical stability. It is widely used in many industrial fields such as automobiles, aerospace, and electronic appliances. Due to its unique properties, polyethylene fiber has become an indispensable material in many fields, providing strong support for industrial development. However, although polyethylene fiber performs well at room temperature, its performance faces huge challenges in high temperature environments. Although ultra-high molecular weight polyethylene fiber has excellent thermal stability, its expensive cost is undoubtedly not suitable for industrialization in the textile field, and the low-cost medium molecular weight polyethylene fiber has poor thermal stability, which greatly limits its further development and application in the fabric field. Therefore, improving the thermal stability of ordinary medium molecular weight polyethylene fiber fabrics and solving their problems in industrialization have become an urgent problem to be solved.

[0003] In order to overcome this problem, researchers have conducted a lot of exploration and research. They tried to start with changing the molecular structure of polyethylene fibers, and enhance their thermal stability by adjusting parameters such as the length and branching degree of the molecular chain. However, this method often requires complex synthesis processes and expensive costs, and the effect is not always satisfactory. In addition, researchers have also tried the method of adding heat stabilizers. Heat stabilizers inhibit the occurrence of thermal degradation by reacting with unstable groups in polyethylene fibers. Although this method improves the thermal stability of polyethylene fibers to a certain extent, the type and amount of heat stabilizers need to be precisely controlled, otherwise it may have a negative impact on other properties of the fiber. UV cross-linking modification is very suitable for the modification of polyethylene fibers. Although researchers have made some progress, the existing methods still have problems such as limited effect, complex operation, high cost, and difficulty in industrialization, which are difficult to meet the needs of practical applications. Therefore, developing an efficient and practical method to improve the thermal stability of polyethylene fiber fabrics and solve industrialization problems has become a major challenge in the field of materials science. Summary of the invention

[0004] The purpose of the present invention is to provide a method for improving the thermal stability of industrial polyethylene fiber fabrics. The method of the present invention can effectively improve the thermal stability of polyethylene fiber fabrics in a high temperature environment while significantly shortening the production cycle to meet industrial needs.

[0005] The present invention provides a method for improving the thermal stability of industrial polyethylene fiber fabrics, comprising the following steps:

[0006] A) blending a polyethylene raw material, a photoinitiator and an auxiliary crosslinking agent to obtain a mixture;

[0007] B) melt spinning the mixture to obtain polyethylene fibers;

[0008] C) drawing and weaving the polyethylene fiber to obtain a polyethylene fiber fabric;

[0009] D) irradiating the polyethylene fiber fabric with ultraviolet light to obtain a modified polyethylene fiber fabric.

[0010] Preferably, the density of the polyethylene raw material is 0.90-0.96 g / cm 3 The polyethylene raw material is a medium molecular weight polyethylene, and the number average molecular weight of the polyethylene raw material is 100,000 to 500,000.

[0011] Preferably, the photoinitiator is benzophenone, and the mass concentration of the photoinitiator in the mixture is 2-4 wt %.

[0012] Preferably, the auxiliary cross-linking agent is triallyl isocyanurate, and the mass concentration of the auxiliary cross-linking agent in the mixture is 1 to 2 wt %.

[0013] Preferably, the blending in step A) is solution blending or dry blending;

[0014] The solution blending comprises the following steps:

[0015] The polyethylene raw material, the photoinitiator and the auxiliary cross-linking agent are stirred in anhydrous ethanol in the dark, and then the anhydrous ethanol is removed by distillation under reduced pressure to obtain a mixture;

[0016] The dry mixing comprises the following steps:

[0017] The polyethylene material is crushed to obtain polyethylene particles, and then the polyethylene particles, a photoinitiator and an auxiliary cross-linking agent are stirred and mixed to obtain a mixture.

[0018] Preferably, the melt spinning temperature is 150-200°C.

[0019] Preferably, the stretching ratio in step C) is 1 to 4 times.

[0020] Preferably, the illumination intensity of the ultraviolet light is 1500-2500 mW / cm 2 ; The irradiation time of the polyethylene fiber fabric under ultraviolet light is 15 to 60 seconds.

[0021] Preferably, the gel content of the modified polyethylene fiber fabric is greater than 70%.

[0022] Preferably, before obtaining the polyethylene fiber fabric, it is produced under UV protection.

[0023] The present invention provides a method for improving the thermal stability of industrial polyethylene fiber fabrics, which aims to significantly improve the thermal tolerance of polyethylene fiber fabrics under high temperature extreme conditions, improve production efficiency, and solve industrialization problems. First, medium molecular weight polyethylene is used as a substrate, and then a photoinitiator and an auxiliary crosslinking agent are introduced to efficiently blend with the polyethylene matrix to construct a potential reactive network. Under the precise control of the melt spinning technology, the uniformly mixed fiber precursor is processed into a polyethylene fiber with uniform morphology. Then, drafting is performed to further improve the parallelism and straightness of the fiber, and further improve the strength and stability of the fiber, thereby improving the strength and durability of the fabric. The obtained polyethylene fiber is stored and woven in a dark place, and then the woven grey cloth is crosslinked and modified by ultraviolet irradiation technology. In this step, the photoinitiator is activated under ultraviolet light, and a chemical crosslinking reaction is induced between the crosslinking agent and the polyethylene molecular chain inside the fiber to form a stable three-dimensional network structure, thereby significantly enhancing the thermal stability of the fiber; between the fibers, crosslinking between nodes is induced, the internal force is strengthened, and the heat resistance and dimensional stability are improved as a whole. At the same time, irradiation of the fabric can improve the cross-linking efficiency while ensuring the cross-linking effect, solve the problem of poor cross-linking effect caused by too fast spinning speed during the spinning stage, thereby improving the efficiency in actual production and solving the problem of industrialization. After this treatment process, the polyethylene fiber fabric exhibits excellent physical and mechanical properties and excellent chemical stability under high temperature conditions, effectively overcoming the limitations of traditional polyethylene fibers that are easy to degrade and have reduced performance under high temperature conditions, and industrial production is also easy to achieve. This strategy has greatly expanded the application of ordinary polyethylene fibers in the field of textiles, and industrial applications have been well solved. The core advantages of the present invention lie in the simplicity of its operating process and the significance and efficiency of the treatment effect. By finely controlling the blending system and ultraviolet irradiation conditions, the thermal stability of polyethylene fiber fabrics is significantly improved from multiple levels, thereby solving its limitations in fabric textile applications and providing a reliable solution for the industrial development of ordinary polyethylene fiber fabrics. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0025] Figure 1is the structural formula of benzophenone (BP) and triallyl isocyanurate (TAIC) in the present invention;

[0026] Figure 2 This is a diagram of the reaction mechanism of BP and TAIC ultraviolet light-induced cross-linked polyethylene fibers in the present invention;

[0027] Figure 3 This is an ultra-depth micrograph of the polyethylene fiber before and after modification in Example 1 of the present invention. DETAILED DESCRIPTION

[0028] The present invention provides a method for improving the thermal stability of industrial polyethylene fiber fabrics, comprising the following steps:

[0029] A) blending a polyethylene raw material, a photoinitiator and an auxiliary crosslinking agent to obtain a mixture;

[0030] B) melt spinning the mixture to obtain polyethylene fibers;

[0031] C) drawing and weaving the polyethylene fiber to obtain a polyethylene fiber fabric;

[0032] D) irradiating the polyethylene fiber fabric with ultraviolet light to obtain a modified polyethylene fiber fabric.

[0033] The core of the present invention is to improve the high temperature resistance of ordinary medium molecular weight polyethylene fiber fabrics while reducing the impact of the modification process on the entire production process, greatly shortening the production cycle and meeting industrial needs. Through low-cost modification technology, the temperature limitation in its traditional application is overcome, thereby broadening its application scope in high temperature environments, and through the ultraviolet irradiation technology of weaving first and then irradiating, its production efficiency is improved. This not only enhances the comprehensive performance of medium molecular weight polyethylene fiber fabrics and shortens the entire production cycle, but also provides strong support for its industrial application and development in the field of textiles, which is of great significance for promoting the progress of materials science and the diversification of industrial applications.

[0034] In the present invention, the polyethylene raw material is preferably medium molecular weight polyethylene, and the number average molecular weight of the medium molecular weight polyethylene is preferably 100000-500000; the density is preferably 0.90-0.96 g / cm 3Compared with high molecular weight polyethylene, medium molecular weight polyethylene production technology is more mature, raw materials and processing costs are lower, so the production cost is lower, more suitable for general industrial applications. At the same time, medium molecular weight polyethylene fiber is easier to process than high molecular weight polyethylene fiber. Due to the moderate molecular weight, better products can be formed at lower processing temperatures. Compared with high molecular weight polyethylene, medium molecular weight polyethylene has a lower melting temperature and can be stably melt-spun at a lower temperature, which can avoid the thermal polymerization reaction of the allyl group of the cross-linking agent. In the spinning operation process, because the medium molecular weight polyethylene has a shorter molecular chain, good tensile properties and is easy to form fibers, the spinning speed can be very fast, and the speed of the winding machine can be set very high. At the same time, the melt fluidity of medium molecular weight polyethylene is better, the design of the spinneret and the setting of the stretching equipment are relatively simple, and the production efficiency is high. The stretching process of high molecular weight polyethylene is more complicated, and the fiber needs to go through a slower and more delicate cooling process to maintain the orientation and structural stability of the molecular chain, while the spinning process of medium molecular weight polyethylene is smoother, and the cooling and curing process is also faster. In terms of technology, no additional cooling treatment is required, and the cooling speed is faster. After the fiber is solidified, it can maintain a good shape while ensuring a short overall production cycle. The post-processing of medium molecular weight polyethylene fibers in spinning and weaving, such as heat setting and stretching, can be completed under relatively conventional conditions. The fiber orientation and strength are relatively stable, which saves resources in actual production while ensuring the stability and durability of fiber fabric products.

[0035] In the present invention, the photoinitiator is preferably benzophenone (BP), and the mass concentration of the photoinitiator in the mixture is preferably 2 to 4 wt %, more preferably 3 to 4 wt %.

[0036] In the photoinitiator system of the present invention, the effect of a single photoinitiator is often limited by the limited number of crosslinking nodes formed by the free radicals between polyethylene macromolecules, and the initiation efficiency is difficult to maximize. Therefore, the present invention creatively introduces an auxiliary crosslinking agent to significantly enhance the efficiency and depth of the crosslinking reaction. The auxiliary crosslinking agent is preferably triallyl isocyanurate (TAIC), which contains two or more unsaturated bonds and can efficiently participate in the photocrosslinking process. Compared with other auxiliary crosslinking agents such as isopropyl cyanurate (TAC), trimethylolpropane triacrylate (TMPTA) and pentaerythritol triallyl propionate (PETA), TAIC not only performs well in crosslinking efficiency, but also has better thermal stability and deep penetration, ensuring the uniformity and depth of the crosslinking reaction. The mass concentration of the auxiliary crosslinking agent in the mixture is preferably 1 to 2wt%, more preferably 1.5 to 2wt%.

[0037] In the present invention, the photoinitiator acts as a "trigger" for the cross-linking reaction, and its molecular structure can efficiently absorb ultraviolet light energy, which is then converted into chemical energy to stimulate the generation of highly active free radicals. These free radicals not only directly act on the polyethylene molecular chain, causing its chain segments to break and expose new reaction sites, but also actively interact with the auxiliary cross-linking agent molecules to further induce the generation of more free radicals and form a free radical chain reaction. In this process, the auxiliary cross-linking agent not only accelerates the generation and transfer of free radicals, but also promotes the uniformity and depth of the cross-linking reaction through its unique molecular structure, effectively avoiding the problem of excessive or insufficient local cross-linking. With the continuous collision and recombination between free radicals, the originally two-dimensional linear polyethylene molecular chain gradually transforms into a complex three-dimensional network structure. This structural transformation significantly enhances the key properties of the fiber material, such as thermal stability, mechanical strength and chemical corrosion resistance.

[0038] In the present invention, the polyethylene raw material, the photoinitiator and the auxiliary cross-linking agent may be blended in solution or in dry form.

[0039] The solution blending comprises the following steps:

[0040] The polyethylene raw material, the photoinitiator and the auxiliary cross-linking agent are stirred in anhydrous ethanol in the dark to ensure the stability of the photosensitive component, and then the anhydrous ethanol is removed by reduced pressure distillation at 55° C. to promote the uniform distribution of BP and TAIC molecules in the polyethylene raw material matrix to obtain a mixture.

[0041] Specifically, first, accurately weigh the required mass of BP and TAIC under strict light-proof conditions; second, dissolve them in a slightly excess of anhydrous ethanol solvent, and this step is carried out in a flask wrapped with tin foil to completely isolate the influence of light; then, finely crush the polyethylene particles into powder, and accurately weigh an appropriate amount and add it to the above flask; then, stir the mixture for half an hour at room temperature to ensure that the components are initially dispersed evenly; finally, in order to further promote the deep mixing between BP, TAIC and polyethylene powder, transfer the stirred mixture to a 55°C oil bath for vacuum distillation for 2 hours. In this process, the ethanol solvent is effectively removed, and the BP and TAIC molecules are fully penetrated and evenly distributed in the polyethylene powder. This step not only provides good lighting conditions for subsequent UV cross-linking, but also significantly improves the uniformity and efficiency of the cross-linking reaction, ensuring that the polyethylene fiber can show better comprehensive properties after cross-linking modification.

[0042] The dry mixing preferably comprises the following steps:

[0043] The polyethylene material is crushed to increase the surface area of ​​the polyethylene material to obtain polyethylene particles, and then the polyethylene particles, a photoinitiator and an auxiliary cross-linking agent are stirred and mixed to obtain a mixture.

[0044] After obtaining the mixture, the present invention performs melt spinning on the mixture to obtain polyethylene fibers.

[0045] In the present invention, the temperature of the melt spinning is preferably 150-200° C., more preferably 160-180° C. At this spinning temperature, both the polymer melt state and the activity of the crosslinking agent are ensured. The molten polyethylene mixture is extruded from the spinneret and wound and collected at a constant rate, and the light-shielding condition is maintained throughout the process to prevent the pre-crosslinking effect.

[0046] After obtaining the polyethylene fibers, the present invention stretches and weaves the polyethylene fibers to obtain polyethylene fiber fabrics.

[0047] In the present invention, the drafting ratio is preferably 1 to 4 times, more preferably 2 to 3 times; the weaving is a commonly used manufacturing method in the art, and the present invention will not be described in detail here.

[0048] After the polyethylene fiber fabric is obtained, the invention further irradiates it to make it cross-linked, and the illumination intensity of the ultraviolet light irradiation is preferably 1500-2500 mW / cm 2 , more preferably 1800 to 2200 mW / cm 2 , such as 1500mW / cm 2 , 1600mW / cm 2 , 1700mW / cm 2 , 1800mW / cm 2 , 1900mW / cm 2 , 2000mW / cm 2 , 2100mW / cm 2 , 2200mW / cm 2 , 2300mW / cm 2 , 2400mW / cm 2 , 2500mW / cm 2 , preferably a range value with any of the above values ​​as the upper limit or lower limit; the irradiation time of the polyethylene fiber fabric under ultraviolet light is preferably 15 to 60 seconds, more preferably 20 to 50 seconds.

[0049] In the present invention, the ultraviolet light irradiation cross-linking preferably uses LED ultraviolet lamp as the irradiation light source. Specifically, although the mercury lamp can provide high-intensity ultraviolet radiation, its high energy consumption, significant heat generation and environmental hazards of mercury emission are not conducive to the sustainability and environmental protection of the polyethylene fiber cross-linking process, so it is excluded. Metal halide lamps are known for their uniformity of spectral distribution and high energy conversion efficiency. However, their high purchase cost and relatively short service life limit their wide application in large-scale industrial production, and they are also not suitable as the light source of the present invention. Although tritium lamps have specific uses, their light output intensity is insufficient and it is difficult to meet the needs of efficient cross-linking of polyethylene fibers, so they are not an ideal choice. In contrast, LED ultraviolet lamps have the significant advantages of excellent energy efficiency, ultra-long service life, low heat generation and environmental protection. Its high photoelectric conversion efficiency ensures sufficient ultraviolet energy required for the cross-linking reaction, while avoiding the energy consumption and environmental protection problems of traditional light sources. More importantly, the surface light source design of the LED UV lamp perfectly meets the cross-linking requirements of fiber fabric materials, ensuring that the light can be evenly and fully irradiated to the fiber surface, promoting the uniformity and depth of the cross-linking reaction while ensuring the cross-linking efficiency.

[0050] After the fibers are woven into fabrics, they are irradiated and cross-linked. The double cross-linking inside the fibers and between the fiber nodes ensures the heat resistance and dimensional stability of the fabric. Different from directly irradiating and cross-linking the fibers before spinning, the irradiation after weaving not only changes the internal structure of the fibers at the fiber level and improves the high temperature resistance of the fibers, but also cross-links the nodes between the fibers at the level between the fibers, strengthens the overall structure, and improves the dimensional stability. Compared with direct irradiation of the fibers for photoinitiation, the irradiation after weaving increases the amount of photoinitiator in the raw material ratio to ensure that there are enough active free radicals to initiate the reaction in the irradiation regulation link. In terms of production efficiency, it also avoids the problem of poor cross-linking effect caused by direct irradiation cross-linking of the fibers and the high-speed movement of the fiber winding. Irradiation cross-linking of the woven fabric can ensure sufficient cross-linking at a speed that can be produced continuously. For example, in the shaping section after weaving, adding ultraviolet light tubes in the shaping machine oven can achieve a satisfactory cross-linking effect at a fabric speed of 20m / min. Weaving the fibers into fabrics and then cross-linking them by irradiation can shorten the entire process and improve the efficiency of ultraviolet irradiation to meet the needs of industrial production. Because the fibers are in a state of high-speed movement in actual production, the residence time of the fibers under the irradiation of the light source is too short to guarantee the basic irradiation effect of ultraviolet light. After being woven into fabrics, the arrangement of the fibers on the plane can undoubtedly maximize the use of ultraviolet light energy. At the same time, the irradiation efficiency can be significantly improved by irradiating with a double-sided LED ultraviolet light source. The irradiation time of the fabric under the light source is 15s to 60s, which can better match the speed of the fabric in post-processing and meet the needs of industrial production.

[0051] The present invention proposes a method for improving the thermal stability of industrial polyethylene fiber fabrics, aiming to significantly improve the thermal stability of polyethylene fiber fabrics while greatly improving production efficiency. This method irradiates the fabric after fiber weaving by precisely controlling the ultraviolet light cross-linking system, which not only strengthens the molecular structure of the fiber and promotes the formation of a three-dimensional network structure, but also strengthens the interaction between the fibers, thereby achieving a qualitative leap in thermal stability. Its beneficial effects are reflected in three aspects: first, it significantly improves the high temperature resistance of the fiber fabric and broadens the application field; second, it enhances the mechanical strength and durability of the fiber fabric and extends the service life; third, it improves the processing performance and reduces the energy consumption and cost in the production process; fourth, it improves production efficiency and greatly improves the industrialization process. In summary, this treatment method provides strong technical support for the upgrading and industrial application of polyethylene fiber fabrics, and has significant economic and social benefits.

[0052] In order to further illustrate the present invention, a method for improving the thermal stability of industrial polyethylene fiber fabric provided by the present invention is described in detail below in conjunction with embodiments, but it should not be construed as limiting the scope of protection of the present invention.

[0053] Example 1

[0054] 2 wt% benzophenone (BP) and 1 wt% triallyl isocyanurate (TAIC) were blended with polyethylene powder particles, melt-spun, and drawn to make a fabric. The fabric was then exposed to light at an intensity of 2000 mW / cm 2 The modified polyethylene fiber fabric was prepared by irradiating with an LED ultraviolet light source for 30 seconds.

[0055] The morphology of the polyethylene fiber fabric in Example 1 was observed before and after modification. The results are as follows: Figure 3 As shown by Figure 3 It can be seen that the modified fibers are improved in regularity and the connections between the fibers are closer, which effectively enhances the overall heat resistance and dimensional stability of the fabric. In actual use, the fibers also have stronger durability and better performance. At the same time, the modification has no effect on the surface morphology of the fibers.

[0056] Example 2

[0057] 4wt% benzophenone (BP) and 2wt% triallyl isocyanurate (TAIC) were blended with polyethylene powder particles, melt-spun, and drawn to make a fabric. 2 The modified polyethylene fiber fabric was prepared by irradiating with an LED ultraviolet light source for 30 seconds.

[0058] Example 3

[0059] 4wt% benzophenone (BP) and 2wt% triallyl isocyanurate (TAIC) were blended with polyethylene powder particles, melt-spun, and drawn to make a fabric. 2 The modified polyethylene fiber fabric was prepared by irradiating and cross-linking with an LED ultraviolet light source for 40 seconds.

[0060] Example 4

[0061] 4wt% benzophenone (BP) and 2wt% triallyl isocyanurate (TAIC) were blended with polyethylene powder particles, melt-spun, and drawn to make a fabric. 2 The modified polyethylene fiber fabric was prepared by irradiating with an LED ultraviolet light source for 30 seconds.

[0062] The crosslinking degree of the modified polyethylene fiber fabrics prepared in Examples 1 to 4 was measured, and the maximum strain was measured at different temperatures and stresses before and after stretching, and the dimensional change rate was measured at different temperatures to measure the thermal stability. The creep resistance and thermal stability properties obtained are shown in Table 1.

[0063] In Table 1, the stress-strain test was completed by a DMA Q800 dynamic thermal mechanical analyzer, the mode was selected as DMACreep (creep), the program was set to start heating from 30°C, and then increase the temperature to 130°C or 150°C at a rate of 10°C / min, and then keep it at this temperature for 1 minute, and then stretch it at the set stress for 5 minutes, and then relax it for 1 minute. The strain during the recording process was plotted into a curve.

[0064] In Table 1, the thermal stability test is reflected by the dimensional change rate. The test steps are as follows: after measuring the size of a certain length (100-150 mm) of modified polyethylene fiber fabric, fix both ends on a 20*20 cm transparent glass plate with clips, and then place the glass plate in an oven at 130°C or 150°C. After 5 minutes, take it out and measure its length, and calculate its dimensional change rate.

[0065] Table 1 Strain test of modified polyethylene fiber fabrics prepared in Examples 1 to 4

[0066]

[0067] It can be seen from the test results that the crosslinking degree of the modified polyethylene fiber fabric is above 70%. At the same time, the unmodified polyethylene fiber fabric in the control test broke at a high temperature of 130°C and a stress of 5MPa. The modified polyethylene fiber still has good creep resistance and good thermal stability at high temperatures of 130°C and 150°C. At the same time, the movement speed of the fabric at 10m / min can well ensure the crosslinking effect, which can well solve the problem of poor production rate and industrialization problem.

[0068] At a high temperature of 130°C, the modified polyethylene fiber fabric had no obvious appearance changes, while the modified polyethylene fiber fabric shrank in size and became harder. At a high temperature of 150°C, the original polyethylene fiber fabric shrank into a ball, while the cross-linked polyethylene fiber fabric had a small change in size and no obvious change in appearance.

[0069] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for improving the thermal stability of industrial polyethylene fiber fabrics, comprising the following steps: A) blending a polyethylene raw material, a photoinitiator and an auxiliary crosslinking agent to obtain a mixture; B) melt spinning the mixture to obtain polyethylene fibers; C) drawing and weaving the polyethylene fiber to obtain a polyethylene fiber fabric; D) irradiating the polyethylene fiber fabric with ultraviolet light to obtain a modified polyethylene fiber fabric.

2. The method according to claim 1, characterized in that The density of the polyethylene raw material is 0.90-0.96 g / cm 3 The polyethylene raw material is a medium molecular weight polyethylene, and the number average molecular weight of the polyethylene raw material is 100,000 to 500,000.

3. The method according to claim 1, characterized in that The photoinitiator is benzophenone, and the mass concentration of the photoinitiator in the mixture is 2-4 wt %.

4. The method according to claim 1, characterized in that: The auxiliary cross-linking agent is triallyl isocyanurate, and the mass concentration of the auxiliary cross-linking agent in the mixture is 1-2 wt %.

5. The method according to claim 1, characterized in that The blending in step A) is solution blending or dry blending; The solution blending comprises the following steps: The polyethylene raw material, the photoinitiator and the auxiliary cross-linking agent are stirred in anhydrous ethanol in the dark, and then the anhydrous ethanol is removed by distillation under reduced pressure to obtain a mixture; The dry mixing comprises the following steps: The polyethylene material is crushed to obtain polyethylene particles, and then the polyethylene particles, a photoinitiator and an auxiliary cross-linking agent are stirred and mixed to obtain a mixture.

6. The method according to claim 1, characterized in that The temperature of the melt spinning is 150-200°C.

7. The method according to claim 1, characterized in that The drafting ratio in the step C) is 1 to 4 times.

8. The method according to claim 1, characterized in that The illumination intensity of the ultraviolet light irradiation is 1500-2500 mW / cm 2 ; The irradiation time of the polyethylene fiber fabric under ultraviolet light is 15 to 60 seconds.

9. The method according to claim 1, characterized in that: The gel content of the modified polyethylene fiber fabric is greater than 70%.

10. The method according to claim 1, characterized in that Before obtaining the polyethylene fiber fabric, it is produced under UV protection.

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