High-load composite telegraph pole and pultrusion preparation method thereof

Abstract

The invention relates to the technical field of composite material preparation, and discloses a high-load composite material telegraph pole and a pultrusion preparation method thereof.The method comprises the steps of fiber configuration, resin matrix preparation, dipping, preforming, pultrusion and aftertreatment. Wherein the proportion of fibers for direct yarn feeding accounts for a high proportion of the total mass of the fibers, the fibers are distributed in the longitudinal direction of a product, the longitudinal reinforcing effect of the telegraph pole is guaranteed, the loading capacity and mechanical strength of the product are improved, meanwhile, the tension of the fibers is controlled through a tension control system, the stability of the fibers before dipping is guaranteed, and a fiber reinforcing system is optimized; the functional additive is added, and the functional additive comprises nano silicon dioxide subjected to plasma surface treatment and a silane coupling agent, so that the uniformity and dispersity of a resin matrix are improved, the interface bonding of fibers and resin is enhanced, and the overall performance of the composite material is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of composite material preparation, in particular to a high-load composite material pole and a pultrusion preparation method thereof. BACKGROUND

[0002] With the rapid development of new material technology in the power industry, traditional cement poles are gradually replaced by composite materials; in order to regulate the quality requirements of new pole products, the China Electricity Enterprise Association has developed standards to fill the technical standard gap in the field of composite material poles.

[0003] At present, in the pultrusion preparation process of the composite material pole, due to the difficulty in accurately controlling the distribution orientation of the reinforcing fiber and the combination effect of the resin matrix, the proportion of the directly fed fiber and the tension adjustment in the traditional method have defects, which may result in the failure of the reinforcing effect of the fiber in the longitudinal direction; the dispersion uniformity of the functional additives in the resin matrix and the compatibility with the resin are poor, which affects the bonding strength of the interface of the final composite material and the stability of the overall performance; in the impregnation and curing stage, there is a lack of accurate control means for the impregnation quality and the curing process, which is easy to cause defects in the product, affecting the mechanical load capacity and long-term durability of the pole.

[0004] Therefore, the present application provides a high-load composite material pole and a pultrusion preparation method thereof to solve the above problems. SUMMARY

[0005] In view of the deficiencies of the prior art, the present application provides a high-load composite material pole and a pultrusion preparation method thereof, which solves the problems of the failure of the reinforcing effect of the fiber in the longitudinal direction, the poor bonding strength of the interface of the composite material and the stability of the overall performance, and the influence of the mechanical load capacity and long-term durability of the pole.

[0006] To achieve the above purpose, the present application provides the following technical scheme: a pultrusion preparation method of a high-load composite material pole, the method comprising the following steps: Step one: fiber configuration, the reinforcing fiber is guided through the creel, wherein the proportion of the directly fed fiber accounts for more than 80% of the total mass of the fiber, and the directly fed fiber refers to the fiber distributed along the longitudinal direction of the product; Step two: resin matrix preparation, 60-80 parts of unsaturated polyester resin, 10-20 parts of epoxy resin, 1-3 parts of curing agent, 0.5-2 parts of accelerator, 3-8 parts of functional additive and 1-5 parts of flame retardant are mixed according to the weight ratio to prepare the resin matrix; Step three: impregnation, the prepared fiber is impregnated with the resin matrix through the resin impregnation tank; Step four: preforming and pultrusion, the impregnated fiber is passed through a preforming mold and then enters a pultrusion mold, and is cured and formed at a mold temperature of 120-160℃ and a pultrusion speed of 0.5-1.5m / min; Step five: post-processing, the pultrusion product is heated and cured, and cut to obtain a high-load composite pole.

[0007] Preferably, the reinforcing fiber used in step one is one or a combination of glass fiber, carbon fiber or basalt fiber, and the direct yarn feeding fiber is a unidirectional continuous fiber bundle, the mass ratio of which in the entire fiber reinforced system is controlled to be between 82% and 88%, and the remaining fiber is an axial reinforcing braid or felt material.

[0008] Preferably, the direct yarn feeding unidirectional continuous fiber has an elastic modulus higher than 70GPa, a single filament diameter in the range of 15-25 microns, and the fiber bundle needs to pass through a tension control system before entering the impregnation tank, with a tension control of 100-300N.

[0009] Preferably, the preparation method of the functional additive specifically includes: The nanometer silicon dioxide is placed in a plasma treatment chamber, treated under a nitrogen atmosphere at a power of 400-600W for 10-15 minutes, then dispersed in ethanol solvent with silane coupling agent KH-550 at a mass ratio of 2:1, mechanically stirred at 60℃ water bath for 2 hours, and finally dried, ground and sieved to obtain a powder with a particle size of 50-100 nanometers.

[0010] Preferably, the number of surface functional groups of the plasma-treated nanometer silicon dioxide increases by more than 20%, the amount of silane coupling agent KH-550 is 50% of the mass of nanometer silicon dioxide, and the addition amount of functional additive in the resin matrix is preferably 5-7 parts.

[0011] Preferably, the transducers of the ultrasonic auxiliary device in step three are uniformly arranged at the bottom and both sides of the impregnation tank, the ultrasonic frequency is set to 25-40kHz, and the power density is controlled to be 0.5-1.0W / cm 3 During the impregnation process, the resin temperature is maintained at 25-35℃.

[0012] Preferably, the temperature of the three independent temperature zones of the pultrusion mold in step four is accurately controlled to be 120-130℃, 140-150℃ and 150-160℃ respectively, and the temperature deviation of each zone is not more than ±2℃, and the internal pressure of the mold is maintained at 0.5-2MPa by a hydraulic system.

[0013] Preferably, the post-curing treatment in step five is carried out in a segmented programmable curing oven, and the curing program is as follows: Ramp from room temperature to 80-100°C at a rate of 2-3°C / min and hold at this temperature for 2-4 hours.

[0014] Preferably, the flame retardant is a compounded system of ammonium polyphosphate and aluminum hydroxide with a mass ratio of 1:1 to 1:2, the total amount of the flame retardant added accounts for 2-5% of the total mass of the resin matrix, and the particle size D90 of the flame retardant is less than 20 microns.

[0015] The high-load composite pole has a structure composed of a cured resin matrix composed of unsaturated polyester resin and epoxy resin and a reinforcing fiber covered by the matrix. The reinforcing fiber contains more than 80% of direct yarn feeding fibers distributed along the longitudinal direction of the product, the cured resin matrix uniformly disperses the plasma surface treated nano-silicon dioxide functional additive and the flame retardant component, and the cross section of the pole presents a dense and defect-free fiber reinforced composite structure.

[0016] Advantages Compared with the prior art, the present application provides a high-load composite pole and a pultrusion preparation method thereof, which has the following advantages: 1. In the present application, during the pultrusion preparation of the high-load composite pole, direct yarn feeding fibers are used, which have a high proportion of the total fiber mass and are distributed along the longitudinal direction of the product, ensuring the longitudinal reinforcement effect of the pole, improving the load capacity and mechanical strength of the product, and controlling the fiber tension through a tension control system to ensure the stability of the fiber before impregnation and optimize the fiber reinforcement system.

[0017] 2. In the present application, during the preparation of the resin matrix, functional additives are added, which include plasma surface treated nano-silicon dioxide and silane coupling agent, improving the uniformity and dispersibility of the resin matrix, enhancing the interface bonding between the fiber and the resin, thereby improving the overall performance of the composite material, and improving the flame retardant performance of the pole through the compounded system of flame retardants.

[0018] 3. In the present application, during the impregnation and pultrusion process, ultrasonic assisted impregnation and controlled pultrusion mold temperature are used to ensure that the fiber is fully impregnated with the resin matrix and forms a dense structure during the curing process, improving the quality and durability of the pole, and optimizing the curing effect of the resin matrix through the segmented programmed curing of the post-curing process, ensuring the final performance of the product. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 Flowchart of the pultrusion preparation method of the high-load composite pole of the present application. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0021] Embodiment 1: A pultrusion preparation method of a high-load composite telegraph pole, the method comprising the following steps: Step one: fiber arrangement, guiding the reinforcing fibers through the creel, wherein the proportion of directly fed fibers accounts for more than 80% of the total mass of the fibers, and the directly fed fibers refer to the fibers distributed along the longitudinal direction of the product; Step two: resin matrix preparation, mixing 60 parts of unsaturated polyester resin, 10 parts of epoxy resin, 1 part of curing agent, 0.5 parts of accelerator, 3 parts of functional additive, and 1 part of flame retardant by weight to prepare the resin matrix; Step three: impregnation, impregnating the arranged fibers through the resin impregnation tank to make the fibers fully impregnate the resin matrix; Step four: preforming and pultrusion, passing the impregnated fibers through the preforming mold and then into the pultrusion mold, and curing and forming under the conditions of a mold temperature of 120℃ and a pultrusion speed of 0.5m / min; Step five: post-treatment, heating and curing the pultrusion-formed product, and cutting to obtain the high-load composite telegraph pole.

[0022] The reinforcing fibers used in step one are one or a combination of glass fibers, carbon fibers, or basalt fibers, and the directly fed fibers are unidirectional continuous fiber bundles, the mass proportion of which in the entire fiber reinforcement system is controlled at 83%, and the remaining fibers are axially reinforced woven fabrics or felt materials.

[0023] The unidirectional continuous fibers directly fed have an elastic modulus higher than 70GPa, and a single filament diameter of 15 microns, and the fiber bundle needs to pass through a tension control system before entering the impregnation tank, and the tension is controlled at 100N.

[0024] The preparation method of the functional additive specifically comprises: The nanometer silicon dioxide is placed in a plasma treatment chamber, treated under a nitrogen atmosphere at a power of 400W for 10 minutes, then dispersed in an ethanol solvent at a mass ratio of 2:1 with silane coupling agent KH-550, mechanically stirred at 60℃ water bath for 2 hours, and finally dried, ground and sieved to obtain a powder with a particle size of 50 nanometers.

[0025] The quantity of surface functional groups of the plasma treated nano-silica is increased by more than 20%, the quantity of the silane coupling agent KH-550 is 50% of the mass of the nano-silica, and the quantity of the functional additive in the resin matrix is preferably 5 parts.

[0026] The transducers of the ultrasonic auxiliary device in step three are uniformly arranged at the bottom and both sides of the impregnation tank, the ultrasonic frequency is set to 25 kHz, and the power density is controlled to be 0.5 W / cm 3 The temperature of the resin during the impregnation process is maintained at 25℃.

[0027] The temperatures of the three independent temperature zones of the pultrusion die in step four are accurately controlled to be 120℃, 140℃ and 150℃ respectively, the temperature deviation of each zone is not more than ±2℃, and the internal pressure of the die is maintained at 0.5 MPa by a hydraulic system.

[0028] The post-curing treatment in step five is carried out in a segmented programmable curing oven, and the curing program is as follows: Rise from room temperature to 80℃ at a rate of 2℃ / min, and maintain at this temperature for 2 hours.

[0029] The flame retardant is a compounded system of ammonium polyphosphate and aluminum hydroxide, the mass ratio is 1:1, the total amount of the flame retardant added accounts for 2% of the total mass of the resin matrix, and the particle size D90 of the flame retardant is less than 20 microns.

[0030] The high-load composite pole includes a cured resin matrix composed of unsaturated polyester resin and epoxy resin, and a reinforcing fiber covered by the matrix. The reinforcing fiber contains more than 80% of direct yarn feeding fibers distributed along the longitudinal direction of the product, the cured resin matrix uniformly disperses nano-silica functional additives and flame retardant components after plasma surface treatment, and the cross section of the pole presents a dense and defect-free fiber reinforced composite structure.

[0031] Embodiment 2: Pultrusion preparation method of high-load composite pole, the method includes the following steps: Step one: fiber configuration, the reinforcing fiber is guided through the creel, the proportion of direct yarn feeding fiber accounts for more than 80% of the total mass of the fiber, and the direct yarn feeding refers to the fiber distributed along the longitudinal direction of the product; Step two: resin matrix preparation, 70 parts of unsaturated polyester resin, 15 parts of epoxy resin, 2 parts of curing agent, 1.3 parts of accelerator, 6 parts of functional additive and 3 parts of flame retardant are mixed according to weight parts to prepare the resin matrix; Step three: impregnation, the configured fiber is passed through the resin impregnation tank to make the fiber fully impregnate the resin matrix; Step four: preforming and pultrusion, the impregnated fiber is passed through a preforming mold and then enters a pultrusion mold, and is cured and formed at a mold temperature of 140℃ and a pultrusion speed of 1.0m / min; Step five: post-processing, the pultrusion product is heated and cured, and cut to obtain a high-load composite pole.

[0032] The reinforcing fiber used in step one is one or a combination of glass fiber, carbon fiber or basalt fiber, and the direct yarn feeding fiber is a unidirectional continuous fiber bundle, the mass ratio of which in the entire fiber reinforced system is controlled at 85%, and the remaining fiber is an axially reinforced woven fabric or felt material.

[0033] The unidirectional continuous fiber directly fed has an elastic modulus higher than 70GPa, and a single filament diameter of 20 microns, and the fiber bundle needs to pass through a tension control system before entering the impregnation tank, and the tension is controlled at 200N.

[0034] The preparation method of the functional aid agent specifically includes: The nanometer silicon dioxide is placed in a plasma treatment chamber, treated under a nitrogen atmosphere at a power of 500W for 13 minutes, then dispersed in ethanol solvent with silane coupling agent KH-550 at a mass ratio of 2:1, mechanically stirred at 60℃ water bath for 2 hours, and finally dried, ground and sieved to obtain a powder with a particle size of 75 nanometers.

[0035] The number of surface functional groups of the plasma-treated nanometer silicon dioxide increases by more than 20%, the amount of silane coupling agent KH-550 is 50% of the mass of nanometer silicon dioxide, and the addition amount of the functional aid agent in the resin matrix is preferably 6 parts.

[0036] The transducers of the ultrasonic auxiliary device in step three are uniformly arranged at the bottom and both sides of the impregnation tank, the ultrasonic frequency is set to 33kHz, and the power density is controlled at 0.75W / cm 3 The resin temperature is maintained at 30℃ during the impregnation process.

[0037] The pultrusion mold in step four has three independent temperature zones, and the temperatures of the three zones are accurately controlled at 125℃, 145℃ and 155℃ respectively, and the temperature deviation of each zone is not more than ±2℃, and the internal pressure of the mold is maintained at 1.3MPa by a hydraulic system.

[0038] The post-curing treatment in step five is carried out in a segmented programmable curing oven, and the curing program is as follows: Rise from room temperature to 90℃ at a rate of 2.5℃ / min, and keep at this temperature for 3 hours.

[0039] The flame retardant is a compounded system of ammonium polyphosphate and aluminum hydroxide, the mass ratio is 1:2, the total amount of the flame retardant is 3.5% of the total mass of the resin matrix, and the particle size D90 of the flame retardant is less than 20 microns.

[0040] The high-load composite pole comprises a cured resin matrix composed of unsaturated polyester resin and epoxy resin and a reinforcing fiber covered by the matrix. The reinforcing fiber contains more than 80% of direct yarn feeding fibers distributed along the longitudinal direction of the product, the cured resin matrix uniformly disperses plasma surface treated nano-silica functional additives and flame retardant components, and the cross section of the pole presents a dense and defect-free fiber reinforced composite structure.

[0041] Embodiment 3: Pultrusion preparation method of high-load composite pole, the method comprises the following steps: Step one: fiber configuration, the reinforcing fiber is guided through the creel, wherein the proportion of direct yarn feeding fiber is more than 80% of the total mass of the fiber, and the direct yarn feeding refers to the fiber distributed along the longitudinal direction of the product; Step two: resin matrix preparation, 80 parts of unsaturated polyester resin, 20 parts of epoxy resin, 3 parts of curing agent, 2 parts of accelerator, 8 parts of functional additives and 5 parts of flame retardant are mixed to prepare the resin matrix; Step three: impregnation, the configured fiber is impregnated with the resin matrix through the resin impregnation tank; Step four: preforming and pultrusion, the impregnated fiber is preformed through the preforming mold and then enters the pultrusion mold, and the curing forming is carried out under the conditions of mold temperature 160℃ and pultrusion speed 1.5m / min; Step five: post-processing, the pultrusion formed product is heated and cured, and then cut to obtain the high-load composite pole.

[0042] The reinforcing fiber used in step one is one or a combination of glass fiber, carbon fiber or basalt fiber, and the direct yarn feeding fiber is a unidirectional continuous fiber bundle, the mass proportion of which in the whole fiber reinforced system is controlled to be 87%, and the remaining fiber is an axially reinforced woven fabric or felt material.

[0043] The unidirectional continuous fiber of direct yarn feeding has an elastic modulus higher than 70GPa, and the single filament diameter is 25 microns, and the fiber bundle needs to pass through a tension control system before entering the impregnation tank, and the tension is controlled to be 300N.

[0044] The preparation method of the functional additive comprises: The nano-silica is placed in a plasma treatment chamber, treated for 15 minutes under a nitrogen atmosphere at a power of 600 W, then dispersed in an ethanol solvent at a mass ratio of 2:1 with a silane coupling agent KH-550, mechanically stirred for 2 hours in a 60°C water bath, and finally dried, ground and sieved to obtain a powder with a particle size of 100 nanometers.

[0045] The number of surface functional groups of the plasma-treated nano-silica is increased by more than 20%, the amount of the silane coupling agent KH-550 is 50% of the mass of the nano-silica, and the addition amount of the functional additive in the resin matrix is preferably 7 parts.

[0046] The ultrasonic auxiliary device in step three has transducers uniformly arranged at the bottom and both sides of the immersion tank, the ultrasonic frequency is set to 40 kHz, and the power density is controlled at 1.0 W / cm 3 The resin temperature is maintained at 35°C during the immersion process.

[0047] The temperatures of the three independent temperature zones of the pultrusion die in step four are accurately controlled at 130°C, 150°C and 160°C respectively, the temperature deviation of each zone is not more than ±2°C, and the internal pressure of the die is maintained at 2 MPa by a hydraulic system.

[0048] The post-curing treatment in step five is carried out in a segmented programmable curing oven, and the curing program is as follows: Rise from room temperature to 100°C at a rate of 3°C / min, and maintain at this temperature for 4 hours.

[0049] The flame retardant is a compounded system of ammonium polyphosphate and aluminum hydroxide, with a mass ratio of 1:2, the total amount of the flame retardant added accounts for 5% of the total mass of the resin matrix, and the particle size D90 of the flame retardant is less than 20 microns.

[0050] The high-load composite pole has a structure composed of a cured resin matrix composed of unsaturated polyester resin and epoxy resin, and a reinforcing fiber covered by the matrix; The reinforcing fiber contains more than 80% of direct yarn feeding fibers distributed along the longitudinal direction of the product, the cured resin matrix uniformly disperses the plasma surface treated nano-silica functional additive and the flame retardant component, and the cross section of the pole presents a dense and defect-free fiber reinforced composite structure.

[0051] Comparative Example 1, the difference between this comparative example and Example 1 is that no functional additive is added when preparing the resin matrix.

[0052] Comparative Example 2, the difference between this comparative example and Example 1 is that no flame retardant additive is added when preparing the resin matrix.

[0053] Comparative Example 3, the difference between this comparative example and Example 1 is that the reinforcing fibers in this comparative example are not treated with flame retardant.

[0054] Comparative Example 4, the difference between this comparative example and Example 1 is that the ultrasonic assisted impregnation process is not used in the preparation process of this comparative example.

[0055] The high load composite pole prepared in Examples 1-3 and Comparative Examples 1-4 is tested for performance, and the test items and test methods are as follows: The longitudinal tensile strength is tested by using an electronic universal testing machine, and the tensile speed is 2 mm / min; The bending performance is tested by using a three-point bending method, and the span-to-thickness ratio is 16:1, and the loading speed is 2 mm / min; The load capacity is tested by determining the ultimate load capacity of the pole through a static load test; The flame retardant performance is tested by using an oxygen index tester.

[0056] The test data of the high load composite poles prepared in Examples 1-3 and Comparative Examples 1-4 are recorded in the following table:

[0057] By comparing and analyzing the data in the table, it can be seen that the high load composite poles prepared by the process in Examples 1-3 have more excellent performance than the composite poles prepared by the process in Comparative Examples 1-4, which shows that by using the direct yarn feeding fiber configuration in the present application, the proportion of the direct yarn feeding fiber in the total fiber mass is relatively high, and the fiber is distributed along the longitudinal direction of the product, which ensures the longitudinal reinforcement effect of the pole and improves the load capacity and mechanical strength of the product. At the same time, the fiber tension is controlled by the tension control system to ensure the stability of the fiber before impregnation, and the fiber reinforcement system is optimized. By adding functional additives, including nano-silicon dioxide and silane coupling agent treated by plasma surface treatment, the uniformity and dispersity of the resin matrix are improved, and the interface bonding between the fiber and the resin is enhanced, thereby improving the overall performance of the composite material. And by using the compounding system of the flame retardant, the flame retardant performance of the pole is improved. By using ultrasonic assisted impregnation and controlled pultrusion die temperature, the fiber is fully impregnated with the resin matrix and forms a dense structure during the curing process, thereby improving the quality and durability of the pole.

[0058] By comparing and analyzing the relevant data in the table, it can be seen that the high load composite poles prepared by the molding process of the present application have excellent mechanical properties, load capacity and flame retardant performance. Therefore, it can be seen that the high load composite poles and the pultrusion preparation process provided by the present application have a wider market prospect and are more suitable for popularization.

[0059] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting; it is not intended to exclude myriad other embodiments of the present application that other inventors can develop based on the same general inventive concepts embodied by the described embodiments. That is, although the present application is described in terms of particular embodiments and implementations, it is to be understood that the terminology used is for the purpose of descriptive clarity and that it should be taken in a descriptive sense and not a limiting sense.

[0060] While the embodiments of the application have been shown and described herein, it is to be understood that the application is not limited to these embodiments. Rather, many modifications, changes, substitutions, and alterations can be made to the embodiments of the application without departing from the spirit and scope of the application as defined by the appended claims and their equivalents.

Claims

1. A pultrusion method for preparing high-load-bearing composite utility poles, characterized in that: The method includes the following steps: Step 1: Fiber configuration, the reinforcing fibers are guided through the yarn frame, wherein the proportion of fibers directly fed into the yarn accounts for more than 80% of the total fiber mass, and the directly fed yarn refers to fibers distributed along the longitudinal direction of the product; Step 2: Resin matrix preparation. By weight, mix 60-80 parts of unsaturated polyester resin, 10-20 parts of epoxy resin, 1-3 parts of curing agent, 0.5-2 parts of accelerator, 3-8 parts of functional additives and 1-5 parts of flame retardant to prepare a resin matrix. Step 3: Impregnation. Pass the prepared fibers through a resin impregnation tank to fully impregnate the resin matrix. Step 4: Preforming and pultrusion. The impregnated fibers are passed through a preforming mold and then into a pultrusion mold. They are cured and formed at a mold temperature of 120-160℃ and a pultrusion speed of 0.5-1.5m / min. Step 5: Post-processing. The pultruded product is heated and cured, then cut to obtain a high-load-bearing composite material utility pole.

2. The pultrusion preparation method for high-load composite material utility poles according to claim 1, characterized in that: The reinforcing fibers used in step one are one or more combinations of glass fiber, carbon fiber or basalt fiber, and the fibers directly fed into the yarn are unidirectional continuous fiber bundles, whose mass proportion in the entire fiber reinforcement system is controlled between 60% and 95%, and the remaining fibers are axially reinforced woven fabrics or felts.

3. The pultrusion preparation method for high-load composite material utility poles according to claim 2, characterized in that: The unidirectional continuous fiber that is directly fed has an elastic modulus higher than 70 GPa, a single filament diameter in the range of 15-25 micrometers, and the fiber bundle needs to pass through a tension control system before entering the impregnation tank, with the tension controlled between 100-300 N.

4. The pultrusion preparation method for high-load composite material utility poles according to claim 1, characterized in that: The preparation method of the functional additive specifically includes: Nano-silica was placed in a plasma treatment chamber and treated for 10-15 minutes under a nitrogen atmosphere with a power of 400-600W. Then, it was dispersed together with silane coupling agent KH-550 in an ethanol solvent at a mass ratio of 2:1 and mechanically stirred for 2 hours in a water bath at 60°C. Finally, it was dried, ground and sieved to obtain powder with a particle size of 50-100 nanometers.

5. The pultrusion preparation method for high-load composite material utility poles according to claim 4, characterized in that: The plasma-treated nano-silica has a surface functional group count that increases by more than 20%, the amount of silane coupling agent KH-550 is 50% of the mass of nano-silica, and the amount of functional additive added to the resin matrix is ​​preferably 5-7 parts.

6. The pultrusion preparation method for high-load composite material utility poles according to claim 1, characterized in that: In step three, the transducers of the ultrasonic-assisted device are evenly arranged at the bottom and sides of the impregnation tank, the ultrasonic frequency is set to 25-40kHz, and the power density is controlled at 0.5-1.0W / cm². 3 During the impregnation process, the resin temperature is maintained at 25-35℃.

7. The pultrusion preparation method for high-load composite material utility poles according to claim 1, characterized in that: In step four, the temperatures of the three independent temperature zones of the pultrusion die are precisely controlled at 120-130℃, 140-150℃ and 150-160℃ respectively, with the temperature deviation of each zone not exceeding ±2℃. The internal pressure of the die is maintained at 0.5-2MPa by the hydraulic system.

8. The pultrusion preparation method for high-load composite material utility poles according to claim 1, characterized in that: The post-curing process in step five is carried out in a segmented programmable curing oven, and the curing procedure is as follows: Heat the sample from room temperature to 80-100°C at a rate of 2-3°C / min, and hold it at this temperature for 2-4 hours.

9. The pultrusion preparation method for high-load composite material utility poles according to claim 1, characterized in that: The flame retardant is a compound system of ammonium polyphosphate and aluminum hydroxide, with a mass ratio of 1:1 to 1:

2. The total amount of the flame retardant added accounts for 2-5% of the total mass of the resin matrix, and the particle size D90 of the flame retardant is less than 20 micrometers.

10. A high-load-bearing composite material utility pole, used to implement the pultrusion preparation method of the high-load-bearing composite material utility pole according to any one of claims 1-9, characterized in that: Its structural composition includes a cured resin matrix composed of unsaturated polyester resin and epoxy resin, and reinforcing fibers coated by the matrix. The reinforcing fiber contains more than 68% by weight of direct-feed fibers that are directly distributed along the longitudinal direction of the product. The cured resin matrix contains nano-silica functional additives and flame retardant components that have undergone plasma surface treatment. The cross-section of the utility pole exhibits a dense and defect-free fiber-reinforced composite material structure.

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