Lightweight high-strength corrosion-resistant composite insulated electric pole and preparation method thereof

Abstract

The invention discloses a light high-strength corrosion-resistant composite insulated electric pole and a preparation method thereof, and belongs to the technical field of power transmission facilities. The electric pole is of a conical hollow structure, and an inner tough layer, a structural layer and an outer protective layer are sequentially compounded on a wall layer from inside to outside. The inner tough layer is made of a hyperbranched polyester modified epoxy vinyl ester-glass fiber composite material, so that the electric pole is endowed with excellent bending resilience performance; the structural layer is made of S glass fiber and T700 carbon fiber hybrid reinforced epoxy resin, so that high strength and rigidity are ensured; the outer protective layer is a fluorinated polyurethane / boron nitride composite coating, and provides long-acting weather resistance, corrosion resistance and insulation protection. According to the invention, through collaborative design of multi-layer materials and an integrated forming process, light weight, high mechanical strength, excellent insulativity and recoverability after bending of the electric pole are realized, and the electric pole is suitable for electric power line construction in a harsh environment.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of power transmission facilities, and particularly relates to a lightweight high-strength corrosion-resistant composite insulating pole and a preparation method thereof. BACKGROUND

[0002] In recent years, composite material poles have gradually been applied in power grid construction as a replacement for traditional power poles. Such products are usually made of resin matrix and reinforcing fibers, and exhibit certain advantages in terms of weight reduction and corrosion resistance improvement. The application range of composite materials in the field of power facilities is continuously expanding.

[0003] However, in the process of engineering practice and market verification, the existing composite material poles gradually expose several technical problems to be solved. Some products on the market have optimization space in terms of material ratio and structure design, resulting in that the mechanical properties and lightweight characteristics thereof fail to achieve the best balance. Some poles, although achieving the lightweight target, perform poorly in terms of bending strength and structural stiffness, especially in typhoon-prone areas and large-span line stringing scenarios, and the bearing capacity thereof is insufficient.

[0004] The problem of durability also deserves attention. Some poles using ordinary resin systems exhibit poor weather resistance during long-term outdoor use. After several years of wind and sun exposure, the pole body surface may appear to be powdery, discolored or even have micro-cracks, which not only affects the appearance, but also accelerates the material aging process. In areas with large temperature differences, the material thermal expansion coefficient matching problem may cause internal stress concentration, affecting the service life of the product.

[0005] In addition, the existing technology still has deficiencies in the depth development of the functionality of the pole. Most products only achieve basic insulation performance, but do not fully consider special needs such as anti-pollution flashover and lightning resistance. More importantly, the composite poles on the current market generally lack excellent elastic recovery characteristics. When encountering extreme weather such as strong winds, the pole body often produces permanent deformation after bending, which is an irreversible deformation that may not affect immediate use, but will bury safety hazards and force the operation and maintenance department to replace the pole in advance, increasing the use cost throughout the life cycle.

[0006] The existence of the above problems restricts the large-scale application of composite material poles in important power transmission lines and harsh environments. The power industry urgently needs a new type of composite pole solution that achieves a synergistic improvement in lightweight, structural strength, durability and functionality, to meet the higher requirements of modern power grid construction for reliability, economy and safety. SUMMARY

[0007] The present application is directed to the problems existing in the prior art, and provides a light high-strength corrosion-resistant composite insulating pole and a preparation method thereof, aiming to solve the technical bottlenecks of the existing composite pole, such as overweight, insufficient insulation reliability and lack of elastic recovery ability, and to realize lightweight transportation and installation of the pole in extreme environment, high reliability insulation and excellent structural toughness.

[0008] To achieve the above object, the technical scheme adopted by the present application is as follows: The first aspect of the present application provides a light high-strength corrosion-resistant composite insulating pole, comprising a pole body, the pole body is a conical hollow structure with increasing diameter from top to bottom, the top of the pole body is provided with a top mounting part for mounting insulators and fittings, and the bottom of the pole body is provided with a pole root connecting part fixed to the ground, the pole root connecting part is a flange structure provided with a connecting hole; the wall layer of the pole body is compounded with an inner toughness layer, a structural layer and an outer protective layer from inside to outside by an integrated forming process; The material of the inner toughness layer is an ultrabranched polyester modified epoxy vinyl ester-glass fiber composite material; the material of the structural layer is an S glass fiber-T700 carbon fiber hybrid reinforced epoxy resin composite material; and the material of the outer protective layer is a fluorinated polyurethane / boron nitride composite insulating coating material.

[0009] Further, the thickness of the inner toughness layer is 1.5-3.0 mm, the thickness of the structural layer is 8.0-15.0 mm, and the thickness of the outer protective layer is 0.2-0.5 mm.

[0010] Further, the inner toughness layer is prepared according to the following method: (1) 55-65 parts by mass of bisphenol A type epoxy vinyl ester resin and 5-8 parts of ultrabranched polyester are added to a reaction kettle, stirred and mixed to obtain an ultrabranched polymer modified resin matrix; (2) 3-5 parts of an epoxy-terminated polyether plasticizer, 7-9 parts of core-shell structure polyurethane-acrylate nano-elastic microspheres and 0.3-0.8 parts of a wetting dispersant are added to the above-mentioned ultrabranched polymer modified resin matrix, then the mixture is sheared and dispersed, 1.0-1.5 parts of diethylhexanoate peroxide and 0.2-0.4 parts of cobalt isooctoate are added to the dispersed mixture under stirring, and the stirring is continued to obtain an inner toughness layer composite glue solution; (3) The inner toughness layer composite glue solution is injected into a glue dipping tank, and E-CR glass fibers with a breaking elongation of ≥4.8% are used for infiltration; then the infiltrated fibers are circularly wound on a core mold at a winding angle of 85° to 90° to the designed thickness, and the inner toughness layer is formed after gelation after standing.

[0011] Further, the temperature of the stirring and mixing in step (1) is 70-80℃, and the time is 30-60 minutes.

[0012] The inner toughness layer of the electric pole is the core functional layer for realizing the bending resilience of the electric pole, and its technical basis lies in the construction of a multiscale coordinated energy dissipation system.

[0013] At the material design level, by introducing hyperbranched polyester into the epoxy vinyl ester resin system, the interaction between the highly branched three-dimensional structure and the linear molecular chain of the resin is utilized to significantly improve the toughness and energy dissipation capacity of the matrix. When the material is loaded, the system can effectively disperse stress and inhibit crack propagation, thereby realizing excellent bending resilience.

[0014] At the microscale, the core-shell structured polyurethane-acrylate nanometer elastic microspheres, as preset energy dissipation centers, are uniformly dispersed in the above-mentioned toughened resin matrix. The shell has good compatibility and interfacial bonding force with the resin matrix, ensuring effective stress transfer; the core acts as an efficient elastic energy storage unit. Under external force, these microspheres become a large number of stress concentration points, and the surrounding matrix first produces plastic yield and crazing to absorb the initial energy; as the load increases, the microspheres themselves undergo large elastic deformation, further dissipating energy. This process effectively prevents the unstable propagation of a single main crack, transforming the failure mode from brittle fracture to controlled ductile failure.

[0015] When the inner toughness layer is applied to an electric pole and subjected to overload bending such as strong wind, the pole wall material can enter a large strain state without irreversible damage through the above-mentioned multi-level energy dissipation mechanism. Once the load is removed, the stored elastic deformation energy drives the material to return to its original state, thereby realizing a 30-degree bending resilience engineering effect. This feature solves the problem of brittle fracture of traditional electric poles and the problem of permanent deformation of some composite materials, providing a breakthrough solution for the safety and reliability of electric poles in harsh working conditions.

[0016] Further, the structural layer is prepared by the following method: (1) bundle S glass fibers and T700 carbon fibers in a mass ratio of (70-85):(15-30) to form a hybrid fiber bundle; (2) mix and stir 45-55 parts of bisphenol A type epoxy resin, 10-20 parts of methyl tetrahydrophthalic anhydride, and 1-2 parts of silane coupling agent to obtain a structural layer impregnating glue solution; (3) pass the hybrid fiber bundle through the impregnating glue tank containing the structural layer impregnating glue solution, complete impregnation, and then wrap the outer surface of the inner toughness layer at a winding angle of 54° to 58°, and after heating and curing, form the structural layer.

[0017] Further, the stirring in step (2) is carried out at 50-60°C, and the stirring time is 20-40 minutes.

[0018] The structural layer adopts S glass fiber and T700 carbon fiber to be bundled and mixed according to a specific mass ratio. In this design, the high-strength and high-performance S glass fiber as the main body bears most of the load; and the high-modulus T700 carbon fiber as a rigid skeleton embedded therein can greatly improve the overall axial elastic modulus of the composite material. This combination can effectively inhibit the bending deformation of the pole body under extreme wind load. Pre-bundling the two fibers into a single strand ensures that different fibers will not produce uneven internal stress or separation due to modulus difference during subsequent winding and stress process, thereby ensuring efficient load transfer between the two fibers. This layer is laid through an optimized winding angle of 54° to 58°, so that the fiber direction is highly matched with the principal stress direction when the pole bears bending moment, thereby converting the axial mechanical properties of the hybrid fiber into high structural stiffness and stability of the overall pole.

[0019] Further, the outer protective layer is prepared by the following method: (1) 65-75 parts of fluorinated polyurethane acrylate resin, 15-25 parts of flaky boron nitride, 3-5 parts of nano silicon dioxide, 3-5 parts of composite light stabilizer and 2-4 parts of leveling agent are mixed together to obtain a premixed slurry; (2) The premixed slurry is ground and dispersed until the fineness is not greater than 25 μm to obtain an outer protective layer coating slurry; (3) The outer protective layer coating slurry is coated on the outer surface of the structural layer, and after curing, the outer protective layer is formed.

[0020] Further, the composite light stabilizer is compounded from a benzotriazole ultraviolet absorber and a hindered amine light stabilizer in a mass ratio of (1.5-2.5):1; and the leveling agent is a polyether modified polysiloxane leveling agent.

[0021] The outer protective layer uses fluorinated polyurethane acrylate resin with excellent weather resistance as the matrix, which itself has excellent anti-ultraviolet aging ability. The filler flaky boron nitride has a two-dimensional sheet structure, which is arranged parallel to the substrate during the curing process of the coating, overlaps each other, and forms a dense physical isolation layer. This structure can effectively prolong the penetration path of corrosive media (such as water vapor and salt mist), and together with its excellent dielectric strength, it forms an insulating barrier to prevent surface current leakage. At the same time, the addition of nano silicon dioxide improves the hardness and wear resistance of the coating, and fills the micro voids between the flaky boron nitride, making the protective layer more complete. This layer provides a smooth, hydrophobic, stain-resistant and insulating protective shell for the pole.

[0022] The second aspect of the present application provides a preparation method of the above-mentioned lightweight high-strength corrosion-resistant composite insulating pole, comprising the following steps: S1. Inner toughness layer forming: On a conical core mold, the inner toughness layer composite glue solution is used to infiltrate E-CR glass fibers, and is wound at an angle of 85-90° to the design thickness, and the inner toughness layer is formed after gelation; S2. Structure layer forming: On the outer surface of the inner toughness layer, the structure layer impregnation glue solution is used to infiltrate the hybrid fiber bundle composed of S glass fibers and T700 carbon fibers, and is cross-wound at an angle of 54-58° to the design thickness, forming a structure layer; S3. Rod root connection forming: At the designed position of the rod body bottom, short-cut fibers and resin are used for filling and compaction to form a solid flange base that can be cured together with the rod body; S4. Outer protective layer coating: The outer protective layer coating slurry is coated on the outer surface of the structure layer and flange base to a design thickness to form an outer protective layer; During this process, the top mounting area of the top end of the pole is shielded or cleaned up later to expose the surface of the structure layer; S5. Integrated curing: The pole after the above steps is subjected to programmed temperature curing, so that the materials of each layer are cured and integrated as a whole; S6. Post-processing: After curing, demolding is performed; the rod root connection is machined to form a connecting hole, and the top mounting part is surface treated and drilled and tapped; finally, the finished product pole is obtained after inspection.

[0023] Further, the programmed temperature curing process is as follows: first, the temperature is raised to 80-90°C at a rate of 1-2°C / min, and the initial curing is completed after 1-2 hours of holding; then, the temperature is raised to 130-150°C at a rate of 0.5-1°C / min, and the complete curing is completed after 3-5 hours of holding.

[0024] Compared with the prior art, the present application has the following beneficial effects: 1. Light weight and high strength: The hybrid reinforcement design of S glass fibers and T700 carbon fibers significantly reduces the self-weight of the pole while imparting excellent axial tensile strength and bending stiffness, facilitating transportation and installation, especially suitable for areas with limited construction conditions such as mountainous areas and soft foundations.

[0025] 2. Excellent elastic recovery: The inner toughness layer uses a hyperbranched polyester modified and nano-elastic microsphere composite toughening system to build a multi-level energy dissipation mechanism, allowing the pole to quickly recover to its original state after bending under strong wind overload, effectively avoiding permanent deformation and improving safety and reliability in extreme weather.

[0026] 3. Long-term corrosion resistance and weather resistance: The outer protective layer uses fluorinated polyurethane as the matrix, combined with flaky boron nitride and nano-silicon dioxide, to form a dense, hydrophobic, and ultraviolet-resistant insulating protective layer, significantly improving the service life of the pole in high-corrosion environments such as coastal areas, industrial areas, and saline-alkali soils.

[0027] 4. Excellent electrical insulation performance: The overall structure has stable insulation performance, and the outer protective layer has high volume resistivity, which can effectively prevent leakage, pollution flashover and lightning penetration phenomena, and is suitable for power grid construction in compact lines, lightning areas and urban dense areas.

[0028] 5. Structural function integration: Through three-layer composite design and integrated forming process, the synergistic performance of inner toughness, middle strength and outer protection is realized, and the technical contradiction between lightweight, stiffness, toughness and durability of traditional electric poles is solved.

[0029] 6. Outstanding environmental adaptability and economy: The product has good high and low temperature resistance, salt spray resistance, moisture resistance and other properties, and is maintenance-free or low-maintenance throughout its life cycle, and is suitable for various harsh environments and special engineering scenarios. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 A schematic diagram of a lightweight high-strength corrosion-resistant composite insulating electric pole of Example 1.

[0031] Figure 2 A schematic diagram of the pole body wall layer structure of Example 1.

[0032] Figure 3 A field test diagram of the bending resilience performance of the electric pole.

[0033] In the figure, 1 is the inner toughness layer, 2 is the structural layer, 3 is the outer protective layer, 4 is the pole body, 5 is the top mounting part, and 6 is the pole root connecting part. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present application will be described below in a clear and complete manner. Obviously, the described embodiments are only a part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application. In addition, it is worth noting that the raw materials involved in the present application are ordinary commercially available products unless otherwise specified.

[0035] Example 1 The present embodiment provides a lightweight high-strength corrosion-resistant composite insulating electric pole, as shown in Figure 1 The pole body 4 is a conical hollow structure with increasing diameter from top to bottom, and the top is provided with a top mounting part 5 for mounting insulators and fittings, and the bottom is provided with a pole root connecting part 6 fixed to the ground, which is a flange structure provided with a connecting hole; the wall layer of the pole body is composed of an inner toughness layer 1, a structural layer 2 and an outer protective layer 3 (from inside to outside) by integrated forming process. Figure 2); wherein the inner-toughness layer has a thickness of 2.0 mm, the structural layer has a thickness of 10.0 mm, and the outer-protection layer has a thickness of 0.3 mm; and the length of the pole is 12 m.

[0036] The method for preparing the pole is as follows: S1. Forming the inner-toughness layer: (1) 60 parts of bisphenol A type epoxy vinyl ester resin (MFE-700 series) and 6 parts of hyperbranched polyester (Boltorn™ H20) are added to a reaction kettle with stirring and heating device, and mechanical stirring is carried out at a speed of 300 rpm for 45 minutes at a temperature of 78°C until the system is uniform and transparent, to obtain a hyperbranched polymer modified resin matrix.

[0037] (2) The temperature of the modified resin matrix is reduced to 45°C, and then 4 parts of epoxy-terminated polyether plasticizer (HELOXY Modifier 61), 8 parts of core-shell structured polyurethane-acrylate nano-elastic microspheres (Kaneka KaneACE® MX 153), and 0.5 parts of polyether modified siloxane wetting dispersant (BYK-110) are sequentially added thereto; the above mixture is transferred to a high-speed shearing emulsifying disperser, and continuous dispersion is carried out at a speed of 3000 rpm for 50 minutes until the nano-elastic microspheres are uniformly dispersed. The uniformly dispersed mixture is transferred back to the stirred kettle, and 1.2 parts of diethyl hexanoate peroxide (Trigonox 21S) and 0.3 parts of cobalt isooctanoate (cobalt content 6%) are slowly added under stirring at a speed of 500 rpm, and stirring is continued for 20 minutes after the addition is completed, to obtain an inner-toughness layer composite sizing solution.

[0038] (3) The prepared inner-toughness layer composite sizing solution is injected into the impregnation tank of a fiber winding machine, and the temperature of the sizing solution is controlled to be 25±5°C. E-CR glass fiber untwisted roving (Jushi Group E6-ECR-2400tex) with a breaking elongation of 5.0% is selected, and the fiber is passed through the impregnation tank at a constant tension of 50 N to ensure that the fiber is fully impregnated. The impregnated fiber is wound on a conical steel core mold at a winding angle of 88° and at a surface temperature of 30°C, and the number of winding layers is controlled to make the thickness of the inner-toughness layer reach 2.0 mm. After winding is completed, the inner-toughness layer is allowed to naturally gel and set at room temperature for 35 minutes.

[0039] S2. Forming the structural layer: (1) S-2 glass fiber untwisted roving (AGY S-2 Glass 1125) and T700 grade carbon fiber (Toray T700SC-12K) are combined into a hybrid fiber bundle through a fiber buncher at a mass ratio of 80:20.

[0040] (2) 50 parts of bisphenol A type epoxy resin (E-51), 15 parts of methyltetrahydrophthalic anhydride, and 1.5 parts of silane coupling agent (KH-560) were added to another stirring kettle, stirred at a temperature of 55°C and a speed of 400 rpm for 35 minutes, and a uniform transparent structural layer impregnating glue solution was obtained.

[0041] (3) The structural layer impregnating glue solution was injected into the second glue tank, the glue temperature was controlled at 40±5°C, and the aforementioned hybrid fiber bundle passed through the glue tank at a constant tension of 60 N to complete the full impregnation. The impregnated hybrid fiber bundle was cross-wound on the outer surface of the gelled inner toughness layer at a winding angle of 56°, and the structural layer thickness was controlled to be 10.0 mm by controlling the number of winding layers.

[0042] S3. Rod root connection part forming: In the flange plate forming area pre-set at the bottom of the rod body, a short-cut carbon fiber (T700) with a length of 3-5 mm was mixed uniformly with the structural layer impregnating glue solution at a mass ratio of 2:1 to form a filler. The filler was filled into the mold cavity, and a compact solid flange plate matrix was formed by using a press to compact multiple times to remove air bubbles and match the shape of the rod body bottom.

[0043] S4. Outer protective layer coating: (1) 70 parts of fluorinated polyurethane acrylate photocuring resin (Sartomer CN9002F), 20 parts of flaky boron nitride (Momentive PT110, particle size D50=10 μm), 4 parts of nano silicon dioxide (Evonik AEROSIL 200, particle size 12 nm), 4 parts of composite light stabilizer (Tinuvin 1130 is 2.5 parts and Tinuvin 292 is 1.5 parts), and 3 parts of polyether modified polysiloxane leveling agent (BYK-333) were added to a batching tank, pre-dispersed at a speed of 1500 rpm for 15 minutes using a high-speed disperser, and a premixed slurry was obtained.

[0044] (2) The slurry was transferred to a basket-type sand mill, an equal amount of zirconium oxide grinding beads was added, and the slurry was ground at a speed of 1250 rpm for 1.5 hours until the slurry fineness was ≤20 μm, and an outer protective layer coating slurry was obtained.

[0045] (3) The coating slurry was uniformly coated on the outer surface of the structural layer and the flange plate matrix using a high-pressure airless spraying device, the spraying pressure was 15 MPa, the gun moving speed was 0.5 m / s, the single wet film thickness was controlled at 150 μm, and two spraying was performed to make the final dry film thickness reach 0.3 mm. Before spraying, a high-temperature resistant pressure-sensitive adhesive tape was used to tightly shield the top mounting area at the top end of the pole.

[0046] S5. Integrated curing: The pole semi-finished product after all the above steps are completed is pushed into a program-controlled curing oven together with the core mold. After the oven door is closed, the temperature is raised from room temperature to 85°C at a rate of 1.5°C / min, and kept constant at 85°C for 2 hours to complete the initial curing. Subsequently, the temperature is continuously raised to 145°C at a rate of 1.0°C / min, and kept constant at 145°C for 4 hours to complete the complete curing. After the curing process is completed, the heating power is turned off, and the pole is naturally cooled to below 60°C with the oven.

[0047] S6. Post-processing: The core mold is smoothly pulled out of the completely cured pole using a hydraulic ejector device, the shielding tape at the top end of the pole is removed, the top mounting portion area is polished to ensure a smooth surface, and then a numerical control drilling machine is used to process the mounting threaded hole. The flange base of the pole root connecting portion is machined: first, turning is performed to ensure the flatness of the end face, and then evenly distributed bolt connecting holes are drilled.

[0048] Finally, the finished pole is subjected to a water pressure test, an electrical performance test, and an appearance inspection, and is stored in the warehouse after passing the tests.

[0049] Comparative Example 1 The comparative example provides a composite insulating pole, which is different from Example 1 in that 6 parts of hyperbranched polyester are replaced by 6 parts of carboxyl-terminated liquid nitrile rubber when the inner toughness layer is formed, the amount of diethyl hexanoate peroxide is increased from 1.2 parts to 1.3 parts, and the amount of cobalt isooctoate is increased from 0.3 parts to 0.32 parts; the rest is the same as Example 1.

[0050] Comparative Example 2 The comparative example provides a composite insulating pole, which is different from Example 1 in that 8 parts of core-shell structure polyurethane-acrylate nano-elastic microspheres are replaced by 8 parts of hydrophilic fumed nano-silicon dioxide when the inner toughness layer is formed; the rest is the same as Example 1.

[0051] Comparative Example 3 The comparative example provides a composite insulating pole, which is different from Example 1 in that only one type of fiber, S-2 glass fiber, is used for impregnation and winding when the structural layer is formed; the rest is the same as Example 1.

[0052] Comparative Example 4 The comparative example provides a composite insulating pole, which differs from Example 1 in that the outer protective layer coating step is replaced by: uniformly spraying two coats of high-temperature curing type methyl silicone resin insulating paint (POWERSIL® 710 from Wacker Chemie) on the outer surfaces of the structural layer and the flange plate base, and controlling the total dry film thickness to be 0.3 mm. After the spraying is completed, the pole semi-finished product is placed in a curing oven for constant temperature curing at 150°C for 2 hours. Except for the material and curing process of the outer protective layer described above, the rest is the same as Example 1.

[0053] Performance test Test sample: the poles prepared in Example 1 and Comparative Examples 1-4.

[0054] Test method: 1. Whole pole mass: the complete pole is weighed.

[0055] 2. Longitudinal tensile strength: axial tensile test is performed on the pole segment sampled according to standard GB / T 1447.

[0056] 3. Longitudinal elastic modulus: three-point bending test is performed on the pole segment sampled according to standard GB / T 1449, and the elastic modulus is calculated from the load-displacement curve.

[0057] 4. Bending resilience performance: lateral load is applied to the tip of the pole, so that the tip displacement reaches the design value (corresponding to a pole body bending of about 30 degrees), and after unloading, the residual deformation is measured after 10 minutes of standing, and the resilience rate is calculated (resilience rate = (1 - residual deformation / total deformation) x 100%). The test site is shown in Figure 3 .

[0058] 5. Salt spray resistance: neutral salt spray test is performed on the sample according to standard GB / T 10125, and the surface is inspected and the insulation resistance is tested after 3000 hours.

[0059] 6. Volume resistivity: the volume resistivity of the outer protective layer material is tested in a constant temperature and humidity environment according to standard GB / T 1410.

[0060] The test results are shown in Table 1.

[0061] Table 1 Performance test results Note: *In Comparative Example 3, the rigidity was insufficient in the test, the bending deformation was too large, the interface between the fiber and the resin was slightly detached before reaching 30 degrees, resulting in irreversible damage, so the resilience rate was high but had lost practical significance.

[0062] The above test results show that the electric pole prepared in Example 1 has excellent comprehensive performance: while achieving lightweight (152 kg), the longitudinal tensile strength is as high as 976 MPa, with ultra-high stiffness, excellent elastic recovery ability and excellent insulation corrosion resistance.

[0063] The longitudinal tensile strength and bending resilience of Comparative Example 1 both significantly decreased. It is speculated that the reason is that the CTBN rubber phase and the resin matrix modulus are not matched, which becomes a weak point when stressed, not only reducing the overall strength, but also the plastic deformation characteristics of itself, which also leads to the material being unable to efficiently rebound. Comparative Example 2 also significantly decreased the longitudinal tensile strength and bending resilience. The reason may be that the rigid nano-silicon dioxide and the resin interface bonding place are prone to stress concentration, becoming a crack source, which causes the material to fail prematurely, severely degrading the material's carrying capacity and toughness. Comparative Example 3 sharply decreased the longitudinal tensile strength and elastic modulus. It is proved that T700 carbon fiber as a high-strength and high-modulus component bears the main load in the hybrid structure; only S glass fiber cannot provide sufficient axial tensile and anti-deformation ability, leading to structural failure of the electric pole. Comparative Example 4 is close to Example 1 in terms of longitudinal mechanical properties, but the insulation performance is severely degraded. This shows that the silicon resin paint of the outer protective layer is far inferior to the functionalized coating of the present application in terms of long-term insulation and environmental aging resistance, and cannot guarantee the safe operation of the power grid.

[0064] Finally, it should be noted that the above content is only used to illustrate the technical solutions of the present application, and is not a limitation on the protection scope of the present application. Simple modifications or equivalent replacements of the technical solutions of the present application made by those skilled in the art do not deviate from the essence and scope of the technical solutions of the present application.

Claims

1. A light weight high strength corrosion resistant composite insulator pole comprising a pole body, characterised in that, The rod body is a conical hollow structure with gradually increasing diameter from top to bottom, and is provided with a top mounting portion for mounting insulators and fittings at the top and a rod root connecting portion for fixing to the ground at the bottom, wherein the rod root connecting portion is a flange structure provided with connecting holes; the wall layer of the rod body is compounded with an inner toughness layer, a structure layer and an outer protective layer from inside to outside by an integrated forming process; The material of the inner toughness layer is an ultrabranched polyester modified epoxy vinyl ester-glass fiber composite material; The material of the structure layer is an S glass fiber-T700 carbon fiber hybrid reinforced epoxy resin composite material; and the material of the outer protective layer is a fluorinated polyurethane / boron nitride composite insulation coating material.

2. The lightweight high strength corrosion resistant composite utility pole of claim 1, wherein: The thickness of the inner toughness layer is 1.5-3.0 mm, the thickness of the structure layer is 8.0-15.0 mm, and the thickness of the outer protective layer is 0.2-0.5 mm.

3. The lightweight high strength corrosion resistant composite utility pole of claim 1, wherein: The inner toughness layer is prepared by the following method: (1) 55-65 parts of bisphenol A type epoxy vinyl ester resin and 5-8 parts of ultrabranched polyester are added to a reaction kettle, stirred and mixed to obtain an ultrabranched polymer modified resin matrix; (2) 3-5 parts of an epoxy-terminated polyether plasticizer, 7-9 parts of core-shell structure polyurethane-acrylate nano elastic microspheres and 0.3-0.8 parts of a wetting dispersant are added to the above-mentioned ultrabranched polymer modified resin matrix to obtain a mixture; then the mixture is sheared and dispersed; the dispersed mixture is added to 1.0-1.5 parts of diethyl peroxide and 0.2-0.4 parts of cobalt isooctanoate under stirring to obtain an inner toughness layer composite glue solution; (3) The inner toughness layer composite glue solution is injected into a dipping tank, and E-CR glass fibers with a breaking elongation of ≥4.8% are used for infiltration; Then the infiltrated fibers are circularly wound on a mandrel at a winding angle of 85° to 90° to a designed thickness, and the inner toughness layer is formed after gelation.

4. The lightweight, high-strength, corrosion-resistant composite utility pole of claim 3, wherein: The temperature of the stirring and mixing in step (1) is 70-80°C, and the time is 30-60 minutes.

5. The lightweight, high-strength, corrosion-resistant composite utility pole of claim 1, wherein: The structure layer is prepared by the following method: (1) S glass fibers and T700 carbon fibers are bundled at a mass ratio of (70-85):(15-30) to form a hybrid fiber bundle; (2) 45-55 parts of bisphenol A type epoxy resin, 10-20 parts of methyl tetrahydrophthalic anhydride and 1-2 parts of a silane coupling agent are mixed and stirred to obtain a structure layer impregnating glue solution; (3) The hybrid fiber bundle passes through a glue dipping tank containing the structure layer impregnating glue solution, and after impregnation, it is wound on the outer surface of the inner toughness layer at a winding angle of 54° to 58°, and the structure layer is formed after heating and curing.

6. The lightweight, high-strength, corrosion-resistant composite utility pole of claim 5, wherein: The stirring in step (2) is carried out at 50-60°C, and the stirring time is 20-40 minutes.

7. The lightweight, high-strength, corrosion-resistant composite utility pole of claim 1, wherein: The outer protective layer is prepared by the following method: (1) 65-75 parts of fluorinated polyurethane acrylate resin, 15-25 parts of flaky boron nitride, 3-5 parts of nano silicon dioxide, 3-5 parts of composite light stabilizer and 2-4 parts of leveling agent are mixed together to obtain a premixed slurry; (2) grinding and dispersing the premixed slurry until the fineness is not greater than 25 μm to obtain an outer protective layer coating slurry; (3) coating the outer protective layer coating slurry on the outer surface of the structural layer, and forming the outer protective layer after curing.

8. The lightweight, high-strength, corrosion-resistant composite utility pole of claim 7, wherein: The composite light stabilizer is compounded from a benzotriazole ultraviolet absorber and a hindered amine light stabilizer in a mass ratio of (1.5-2.5):1; and the leveling agent is a polyether-modified polysiloxane leveling agent.

9. The preparation method of the composite insulating pole according to any one of claims 1-8, comprising the following steps: S1. Inner toughness layer forming: on a conical core mold, the inner toughness layer composite glue solution is used to infiltrate E-CR glass fibers, and is circularly wound at a winding angle of 85° to 90° to a designed thickness, and the inner toughness layer is formed after gelation by standing; S2. Structure layer forming: on the outer surface of the inner toughness layer, the structure layer impregnating glue solution is used to infiltrate hybrid fiber bundles composed of S glass fibers and T700 carbon fibers, and is cross-wound at a winding angle of 54° to 58° to a designed thickness, to form a structure layer; S3. Pole root connecting part forming: at the designed position of the bottom of the pole body, short-cut fibers and resins are used for filling and compaction to form a solid flange disc base which can be cured together with the pole body; S4. Outer protective layer coating: the outer protective layer coating slurry is coated on the outer surface of the structure layer and the flange disc base to a designed thickness to form an outer protective layer; in this process, the top mounting part area at the top end of the pole is shielded or cleaned up later to expose the surface of the structure layer; S5. Integrated curing: the pole after the above steps is subjected to programmed temperature curing, so that the materials of each layer are cured and combined into a whole; S6. Post-processing: after curing, demolding is performed; the pole root connecting part is machined to form a connecting hole, and the top mounting part is surface treated and drilled and tapped; finally, the finished product pole is obtained after inspection.

10. The method of claim 9, wherein: The programmed temperature curing process is: first, the temperature is raised to 80-90℃ at a rate of 1-2℃ / min, and the initial curing is completed after 1-2 hours of heat preservation; then, the temperature is raised to 130-150℃ at a rate of 0.5-1℃ / min, and the complete curing is completed after 3-5 hours of heat preservation.

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