A lightweight, high-strength, corrosion-resistant composite insulating pole and its preparation method

Abstract

This invention discloses a lightweight, high-strength, corrosion-resistant composite insulated pole and its manufacturing method, belonging to the technical field of power transmission facilities. The pole adopts a conical hollow structure, with its wall layers sequentially composited from the inside out as an inner toughening layer, a structural layer, and an outer protective layer. The inner toughening layer uses a hyperbranched polyester-modified epoxy vinyl ester-glass fiber composite material, giving the pole excellent bending resilience. The structural layer uses a hybrid epoxy resin reinforced with S glass fiber and T700 carbon fiber to ensure high strength and stiffness. The outer protective layer is a fluorinated polyurethane / boron nitride composite coating, providing long-term weather resistance, corrosion resistance, and insulation protection. This invention, through multi-layer material synergistic design and integrated molding process, achieves lightweight, high mechanical strength, excellent insulation, and bend recovery of the pole, making it suitable for power line construction in harsh environments.

Description

Technical Field

[0001] This invention belongs to the field of power transmission facility technology, specifically relating to a lightweight, high-strength, corrosion-resistant composite insulating pole and its preparation method. Background Technology

[0002] In recent years, composite material poles have been increasingly used in power grid construction as an alternative to traditional power poles. These products are typically made of a resin matrix combined with reinforcing fibers, demonstrating advantages in weight reduction and improved corrosion resistance. The application of composite materials in power facilities is continuously expanding.

[0003] However, in engineering practice and market validation, existing composite material poles have gradually revealed several technical challenges that urgently need to be addressed. Currently, some products on the market have room for optimization in material proportions and structural design, resulting in an inability to achieve an optimal balance between mechanical properties and lightweight characteristics. While some poles have achieved lightweight goals, they exhibit insufficient bending strength and structural stiffness, particularly in typhoon-prone areas and long-span overhead power lines, where insufficient load-bearing capacity has become apparent.

[0004] Durability is also a concern. Some utility poles using ordinary resin systems exhibit poor weather resistance during long-term outdoor use. After years of exposure to wind and sun, the pole surface may show signs of powdering, fading, or even microcracks, which not only affects the appearance but also accelerates the material aging process. In regions with drastic temperature variations, mismatches in the material's coefficient of thermal expansion can lead to internal stress concentration, affecting the product's lifespan.

[0005] Furthermore, existing technologies still fall short in terms of in-depth development of pole functionality. Most products only achieve basic insulation performance, but do not adequately consider special requirements such as anti-pollution flashover and lightning protection. More concerning is that composite poles currently on the market generally lack excellent elastic recovery characteristics. When encountering extreme weather such as strong winds, the pole body often bends and undergoes permanent deformation. Even if this irreversible deformation does not affect immediate use, it can create safety hazards, forcing maintenance departments to replace the pole prematurely and increasing the total life-cycle cost.

[0006] The aforementioned issues have hindered the large-scale application of composite material poles in critical transmission lines and harsh environments. The power industry urgently needs a new composite pole solution that achieves synergistic improvements in lightweighting, structural strength, durability, and functionality to meet the higher demands of modern power grid construction for reliability, economy, and safety. Summary of the Invention

[0007] This invention addresses the problems existing in the prior art by providing a lightweight, high-strength, corrosion-resistant composite insulating pole and its preparation method. It aims to solve the technical bottlenecks of existing composite poles, such as excessive weight, insufficient insulation reliability, and lack of elastic recovery capability, and to achieve lightweight transportation and installation, high-reliability insulation, and excellent structural toughness of the pole in extreme environments.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0009] The first aspect of this invention provides a lightweight, high-strength, corrosion-resistant composite insulating pole, comprising a pole body, wherein the pole body is a conical hollow structure with a gradually increasing diameter from top to bottom, the top of which is provided with a top mounting part for installing insulators and fittings, and the bottom of which is provided with a pole root connection part fixed to the ground, the pole root connection part being a flange structure with connection holes; the wall layer of the pole body is composited from the inside out with an inner toughness layer, a structural layer and an outer protective layer through an integrated molding process;

[0010] The inner toughening layer is made of hyperbranched polyester-modified epoxy vinyl ester-glass fiber composite material; the structural layer is made of S glass fiber-T700 carbon fiber hybrid reinforced epoxy resin composite material; and the outer protective layer is made of fluorinated polyurethane / boron nitride composite insulating coating material.

[0011] Furthermore, 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.

[0012] Furthermore, the inner toughness layer is prepared according to the following method:

[0013] (1) By mass, 55-65 parts of bisphenol A type epoxy vinyl ester resin and 5-8 parts of hyperbranched polyester are added to a reaction vessel and stirred to obtain a resin matrix modified by hyperbranched polymer.

[0014] (2) Add 3-5 parts of terminal epoxy polyether plasticizer, 7-9 parts of core-shell structured polyurethane-acrylate nanoelastic microspheres and 0.3-0.8 parts of wetting and dispersing agent to the above hyperbranched polymer modified resin matrix; then shear and disperse the above mixture; add 1.0-1.5 parts of diethylhexanoate peroxide and 0.2-0.4 parts of cobalt isooctanoate to the dispersed mixture under stirring, and continue stirring to obtain the inner toughness layer composite adhesive;

[0015] (3) The inner toughness layer composite adhesive is injected into the impregnation tank and impregnated with E-CR glass fiber with an elongation at break of ≥4.8%; then the impregnated fiber is wound circumferentially on the mandrel at a winding angle of 85° to 90° to the designed thickness, and the inner toughness layer is formed after static gelation.

[0016] Furthermore, the mixing temperature in step (1) is 70-80℃ and the time is 30-60 minutes.

[0017] The inner toughness layer of the pole is the core functional layer that enables the pole to resist bending and rebound. Its technical basis lies in the construction of a multi-scale collaborative energy dissipation system.

[0018] At the materials design level, by introducing hyperbranched polyester into the epoxy vinyl ester resin system, the interaction between its highly branched three-dimensional structure and the linear molecular chains of the resin significantly improves the toughness and energy dissipation capacity of the matrix. When the material is under load, this system can effectively disperse stress and inhibit crack propagation, thereby achieving excellent flexural resilience.

[0019] At the microscale, core-shell structured polyurethane-acrylate nanoelastic microspheres are uniformly dispersed within the aforementioned toughened resin matrix, serving as pre-designed energy dissipation centers. The outer shell exhibits excellent compatibility and interfacial bonding with the resin matrix, ensuring effective stress transfer; the core acts as a highly efficient elastic energy storage unit. Under external forces, these microspheres become numerous stress concentration points, causing the surrounding matrix to initially exhibit plastic yielding and crazes, absorbing initial energy. As the load increases, the microspheres themselves undergo significant elastic deformation, further dissipating energy. This process effectively prevents the unstable propagation of a single master crack, transforming the failure mode from brittle fracture to controllable ductile failure.

[0020] When this internal toughening layer is applied to the pole and subjected to overload bending such as strong winds, the pole wall material can enter a high-strain state without irreversible damage through the aforementioned multi-stage energy dissipation mechanism. Once the load is removed, the stored elastic deformation energy drives the material to return to its original shape, thus achieving the engineering effect of springing back after bending 30 degrees. This characteristic solves the problems of brittle fracture in traditional poles and permanent deformation in some composite materials, providing a breakthrough solution for the safety and reliability of poles under harsh conditions.

[0021] Furthermore, the structural layer is prepared according to the following method:

[0022] (1) S glass fiber and T700 carbon fiber are bundled together at a mass ratio of (70-85):(15-30) to form a mixed fiber bundle;

[0023] (2) Mix 45-55 parts of bisphenol A type epoxy resin, 10-20 parts of methyltetrahydrophthalic anhydride and 1-2 parts of silane coupling agent to obtain structural layer impregnation solution.

[0024] (3) The mixed fiber bundle is passed through an impregnation tank containing the structural layer impregnation solution. After impregnation, it is wound around the outer surface of the inner toughness layer at a winding angle of 54° to 58°. After heating and curing, the structural layer is formed.

[0025] Furthermore, the stirring in step (2) is carried out at 50-60°C for 20-40 minutes.

[0026] The structural layer employs a hybrid of S-glass fiber and T700 carbon fiber bundled in a specific mass ratio. In this design, the high-strength, cost-effective S-glass fiber acts as the main component, bearing the majority of the load; while the high-modulus T700 carbon fiber is embedded within as a rigid skeleton, significantly enhancing the overall axial elastic modulus of the composite material. This combination effectively suppresses the bending deformation of the pole under extreme wind loads. Pre-bundling the two types of fibers into single strands ensures that during subsequent winding and stress application, the different fibers will not experience uneven internal stress or separation due to modulus differences, thus guaranteeing efficient load transfer between the two fibers. This layer utilizes an optimized winding angle of 54° to 58° to ensure that the fiber direction is highly matched to the principal stress direction when the pole is subjected to bending moment, thereby transforming the axial mechanical properties of the hybrid fibers into high structural stiffness and stability of the pole as a whole.

[0027] Furthermore, the outer protective layer is prepared according to the following method:

[0028] (1) Mix 65-75 parts of fluorinated polyurethane acrylate resin, 15-25 parts of flake boron nitride, 3-5 parts of nano silica, 3-5 parts of composite light stabilizer and 2-4 parts of leveling agent together to obtain a premixed slurry.

[0029] (2) Grind and disperse the premixed slurry until the fineness is no greater than 25 μm to obtain the outer protective coating slurry;

[0030] (3) The outer protective layer coating slurry is applied to the outer surface of the structural layer and cured to form the outer protective layer.

[0031] Furthermore, the composite light stabilizer is composed of a benzotriazole ultraviolet absorber and a hindered amine light stabilizer in a mass ratio of (1.5-2.5):1; the leveling agent is a polyether-modified polysiloxane leveling agent.

[0032] The outer protective layer uses fluorinated polyurethane acrylate resin with excellent weather resistance as the matrix, which itself possesses excellent resistance to ultraviolet aging. The filler, lamellar boron nitride, has a two-dimensional lamellar structure that arranges parallel to the substrate and overlaps each other during the coating curing process, forming a dense physical barrier layer. This structure effectively extends the penetration path of corrosive media (such as water vapor and salt spray), and due to its excellent dielectric strength, it together forms an insulating barrier to prevent surface current leakage. At the same time, the addition of nano-silica improves the hardness and wear resistance of the coating and fills the microscopic gaps between the lamellar boron nitride, making the protective layer more complete. This layer provides the pole with a smooth, hydrophobic, dirt-resistant, and stable insulating protective shell.

[0033] The second aspect of this invention provides a method for preparing the aforementioned lightweight, high-strength, corrosion-resistant composite insulating pole, comprising the following steps:

[0034] S1. Inner toughness layer forming: On a conical mandrel, E-CR glass fiber is impregnated with the inner toughness layer composite adhesive and wound circumferentially at a winding angle of 85° to 90° to the designed thickness, and the inner toughness layer is formed by static gelation.

[0035] S2. Structural layer forming: Outside the inner toughness layer, a hybrid fiber bundle composed of S glass fiber and T700 carbon fiber is impregnated with structural layer impregnation adhesive and cross-wound at a winding angle of 54° to 58° to the designed thickness to form a structural layer;

[0036] S3. Forming of the root connection: At the designed position at the bottom of the rod, short-cut fibers and resin are filled, piled up and compacted to form a solid flange base that can be cured together with the rod.

[0037] S4. Coating of outer protective layer: Apply outer protective layer coating slurry to the outer surface of the structural layer and flange substrate to the designed thickness to form an outer protective layer; during this process, the top mounting area at the top of the pole is shielded or subsequently cleaned to expose the surface of the structural layer;

[0038] S5. Integrated curing: The pole that has undergone the above steps is cured by programmed temperature increase, so that the materials of each layer are cured and bonded into a whole;

[0039] S6. Post-processing: After curing, demolding is performed; the pole root connection is machined to form connection holes, and the top mounting part is surface treated and drilled and tapped; finally, the finished pole is obtained after inspection.

[0040] Furthermore, the programmed temperature rise curing process is as follows: first, the temperature is raised to 80-90℃ at a rate of 1-2℃ / min, and held for 1-2 hours to complete the initial curing; then, the temperature is raised to 130-150℃ at a rate of 0.5-1℃ / min, and held for 3-5 hours to complete the full curing.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] 1. Combining lightweight and high strength: Through the hybrid reinforcement design of S glass fiber and T700 carbon fiber, the weight of the pole is significantly reduced while giving it excellent axial tensile strength and bending stiffness, which facilitates transportation and installation, and is especially suitable for areas with limited construction conditions such as mountainous areas and soft foundations.

[0043] 2. Excellent elastic recovery capability: The inner toughness layer adopts a composite toughening system of hyperbranched polyester modification and nano-elastic microspheres to construct a multi-level energy dissipation mechanism, which enables the pole to quickly return to its original shape after bending under strong wind overload, effectively avoiding permanent deformation and improving safety and reliability under extreme weather conditions.

[0044] 3. Long-lasting corrosion resistance and weather resistance: The outer protective layer uses fluorinated polyurethane as the base material, combined with flake boron nitride and nano-silica to form a dense, hydrophobic, and UV-resistant insulating protective layer, which significantly improves the service life of the pole in highly corrosive environments such as coastal areas, industrial areas, and saline-alkali land.

[0045] 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, flashover and lightning breakdown. It is suitable for power grid construction in compact lines, lightning-prone areas and densely populated urban areas.

[0046] 5. Integrated structure and function: Through a three-layer composite design and integrated molding process, the synergistic performance of internal toughness, medium strength and external protection is achieved, which solves the technical contradiction that traditional poles cannot balance between lightweight, rigidity, toughness and durability.

[0047] 6. Excellent environmental adaptability and economy: The product has good resistance to high and low temperatures, salt spray, and moisture. It requires no or requires little maintenance throughout its entire life cycle and is suitable for a variety of harsh environments and special engineering scenarios. Attached Figure Description

[0048] Figure 1 This is a schematic diagram of the structure of a lightweight, high-strength, corrosion-resistant composite insulating pole according to Example 1.

[0049] Figure 2 This is a schematic diagram of the rod wall structure in Example 1.

[0050] Figure 3 This is a field test diagram of the bending rebound performance of the utility pole.

[0051] In the diagram, 1-inner toughness layer, 2-structural layer, 3-outer protective layer, 4-rod body, 5-top mounting part, 6-rod root connection part. Detailed Implementation

[0052] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. In addition, it is worth noting that the raw materials involved in the present invention are all commercially available products unless otherwise specified.

[0053] Example 1

[0054] This embodiment provides a lightweight, high-strength, corrosion-resistant composite insulating pole, such as... Figure 1 As shown, the rod includes a rod body 4, which is a conical hollow structure with a gradually increasing diameter from top to bottom. The top of the rod body has a top mounting part 5 for installing insulators and fittings, and the bottom has a rod root connection part 6 fixed to the ground. The rod root connection part is a flange structure with connection holes. The wall of the rod body is composed of an inner toughness layer 1, a structural layer 2, and an outer protective layer 3, formed by an integrated molding process from the inside out. Figure 2 The inner toughness layer has a thickness of 2.0 mm, the structural layer has a thickness of 10.0 mm, and the outer protective layer has a thickness of 0.3 mm; the pole length is 12 m.

[0055] The method for preparing the pole is as follows:

[0056] S1. Inner toughness layer molding:

[0057] (1) By mass, 60 parts of bisphenol A type epoxy vinyl ester resin (MFE-700 series) and 6 parts of hyperbranched polyester (Boltorn™ H20) were added to a reactor equipped with a stirring and heating device. The mixture was mechanically stirred at 300 rpm for 45 minutes at 78°C until the system was homogeneous and transparent, thus obtaining a resin matrix modified by hyperbranched polymer.

[0058] (2) The temperature of the modified resin matrix was lowered to 45°C, and then 4 parts of terminal epoxy polyether plasticizer (HELOXY Modifier 61), 8 parts of core-shell structured polyurethane-acrylate nanoelastic microspheres (Kaneka KaneACE® MX 153), and 0.5 parts of polyether modified siloxane wetting and dispersing agent (BYK-110) were added sequentially. The mixture was transferred to a high-speed shear emulsifying disperser and dispersed at 3000 rpm for 50 minutes until the nanoelastic microspheres were uniformly dispersed. The uniformly dispersed mixture was transferred back to the mixing tank, and 1.2 parts of diethylhexanoate peroxide (Trigonox 21S) and 0.3 parts of cobalt isooctanoate (cobalt content 6%) were slowly added while stirring at 500 rpm. After the addition was complete, stirring was continued for 20 minutes to obtain the inner toughness layer composite adhesive.

[0059] (3) Inject the prepared inner toughness layer composite adhesive solution into the impregnation tank of the fiber winding machine, and control the adhesive solution temperature at 25±5℃. Select E-CR glass fiber untwisted roving with a breaking elongation of 5.0% (Jushi Group E6-ECR-2400tex), and pass it through the impregnation tank with a constant tension of 50 N to ensure that the fiber is fully impregnated. Wrap the impregnated fiber in a conical steel core mold with a winding angle of 88° at a surface temperature of 30℃, and control the number of winding layers to achieve an inner toughness layer thickness of 2.0 mm. After winding, let it stand at room temperature for 35 minutes to allow it to naturally gel and set.

[0060] S2. Structural layer forming:

[0061] (1) S-2 glass fiber roving (AGY S-2 Glass 1125) and T700 grade carbon fiber (TorayT700SC-12K) are combined into a mixed fiber bundle by a fiber bundler at a mass ratio of 80:20.

[0062] (2) By mass, 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) are added to another mixing vessel and stirred at 400 rpm for 35 minutes at 55°C to obtain a uniform and transparent structural layer impregnation solution.

[0063] (3) Inject the structural layer impregnation solution into the second impregnation tank, control the solution temperature to 40±5℃, and allow the aforementioned hybrid fiber bundle to pass through the impregnation tank with a constant tension of 60 N to complete the impregnation. The impregnated hybrid fiber bundle is then cross-wound at a winding angle of 56° on the outer surface of the gelled inner toughness layer. By controlling the number of winding layers, the thickness of the structural layer reaches 10.0 mm.

[0064] S3. Shaft root connection forming:

[0065] In the pre-designed flange forming area at the bottom of the rod, using a dedicated mold cavity, short-cut carbon fiber (T700) with a length of 3-5 mm is mixed evenly with the above-mentioned structural layer impregnation adhesive at a mass ratio of 2:1 to form a filler. The filler is filled into the mold cavity and compacted multiple times using a press to remove air bubbles, forming a dense, solid flange base that fits the shape of the bottom of the rod.

[0066] S4. Outer protective layer coating:

[0067] (1) By mass, 70 parts of fluorinated polyurethane acrylate photocurable resin (Sartoma CN9002F), 20 parts of flake boron nitride (Momentive PT110, particle size D50=10 μm), 4 parts of nano silica (EvonikAEROSIL 200, particle size 12 nm), 4 parts of composite light stabilizer (of which Tinuvin 1130 is 2.5 parts and Tinuvin 292 is 1.5 parts) and 3 parts of polyether modified polysiloxane leveling agent (BYK-333) are added to the mixing tank and pre-dispersed for 15 minutes at 1500 rpm using a high-speed disperser to obtain a premixed slurry.

[0068] (2) Transfer the slurry to a basket mill, add an equal volume of zirconium oxide grinding beads, and circulate and grind at a speed of 1250 rpm for 1.5 hours until the fineness of the slurry is ≤20 μm when sampled and tested, and the outer protective coating slurry is obtained.

[0069] (3) High-pressure airless spraying equipment was used to uniformly coat the coating slurry onto the outer surface of the structural layer and the flange substrate. The spraying pressure was 15 MPa, the spray gun moving speed was 0.5 m / s, and the single-pass wet film thickness was controlled at 150 μm. Two passes were sprayed to achieve a final dry film thickness of 0.3 mm. Before spraying, the top mounting area of ​​the pole was tightly masked with high-temperature pressure-sensitive tape.

[0070] S5. Integrated curing:

[0071] The semi-finished pole, along with the core mold, after completing all the above steps, is pushed into a programmable temperature-controlled curing oven. After closing the oven door, the temperature is increased from room temperature to 85°C at a rate of 1.5°C / min and maintained at 85°C for 2 hours to complete the initial curing. Subsequently, the temperature is increased to 145°C at a rate of 1.0°C / min and maintained at 145°C for 4 hours to complete the full curing. After the curing process is complete, the heating power is turned off, allowing the pole to cool naturally with the oven to below 60°C.

[0072] S6. Post-processing:

[0073] Using a hydraulic ejector, the mandrel is smoothly extracted from the fully cured pole. The masking tape at the top of the pole is removed, and the top mounting area is ground to ensure a smooth surface. Then, CNC drilling machines are used to machine the mounting threaded holes. The flange base of the pole root connection is machined: first, turning is performed to ensure a flat end face, and then evenly distributed bolt holes are drilled.

[0074] Finally, the finished poles undergo hydrostatic testing, electrical performance testing, and visual inspection. Once they pass the inspection, they are put into storage.

[0075] Comparative Example 1

[0076] This comparative example provides a composite insulated pole, which differs from Example 1 in that: when the inner toughening layer is formed, 6 parts of hyperbranched polyester are replaced with 6 parts of carboxyl-terminated liquid nitrile rubber, and the amount of diethylhexanoate peroxide is increased from 1.2 parts to 1.3 parts, and the amount of cobalt isooctanoate is increased from 0.3 parts to 0.32 parts; the rest are the same as in Example 1.

[0077] Comparative Example 2

[0078] This comparative example provides a composite insulated pole, which differs from Example 1 in that: when the inner toughening layer is formed, 8 parts of core-shell structured polyurethane-acrylate nanoelastic microspheres are replaced with 8 parts of hydrophilic fumed silica nanospheres; all other aspects are the same as in Example 1.

[0079] Comparative Example 3

[0080] This comparative example provides a composite insulated pole, which differs from Example 1 in that only S-2 glass fiber is used for impregnation and winding during the structural layer forming process; the rest is the same as Example 1.

[0081] Comparative Example 4

[0082] This comparative example provides a composite insulated pole, differing from Example 1 in that the outer protective layer coating step is replaced by uniformly spraying two coats of high-temperature curing methyl silicone resin insulating varnish (Wacker Chemicals' POWERSIL® 710) onto the outer surfaces of the structural layer and flange substrate, controlling the total dry film thickness to be 0.3 mm. After spraying, the pole semi-finished product is placed in a curing oven and cured at 150°C for 2 hours. Except for the material and curing process of the outer protective layer, everything else is the same as in Example 1.

[0083] Performance testing

[0084] Test samples: poles prepared in Example 1 and Comparative Examples 1-4.

[0085] Test method:

[0086] 1. Overall pole mass: Weigh the complete pole.

[0087] 2. Longitudinal tensile strength: In accordance with standard GB / T 1447, axial tensile tests were conducted on samples taken from pole sections.

[0088] 3. Longitudinal modulus of elasticity: Referring to standard GB / T 1449, samples were taken from pole segments for three-point bending tests, and the modulus of elasticity was calculated through load-displacement curves.

[0089] 4. Bending Rebound Performance: A lateral load is applied to the tip of the pole, causing the tip displacement to reach the design value (corresponding to a pole bending of approximately 30 degrees). After unloading, the pole is allowed to stand for 10 minutes, and the residual deformation is measured. The rebound rate is calculated (Rebound rate = (1 - Residual deformation / Total deformation) × 100%). The test site is as follows... Figure 3 As shown.

[0090] 5. Salt spray resistance: Refer to standard GB / T 10125, conduct a neutral salt spray test on the sample, and check the surface and test the insulation resistance after 3000 hours.

[0091] 6. Volume resistivity: The volume resistivity of the outer protective layer material was tested under constant temperature and humidity conditions in accordance with standard GB / T 1410.

[0092] The test results are shown in Table 1.

[0093] Table 1 Performance Test Results

[0094]

[0095] Note: *Comparative Example 3 suffered from insufficient stiffness and excessive bending deformation during the test. It did not reach 30 degrees before the fiber and resin interface became slightly debonded, resulting in irreversible damage. Therefore, although the resilience rate was high, it had lost its practical significance.

[0096] The test results above show that the pole prepared in Example 1 has excellent comprehensive performance: while achieving lightweight (152kg), the longitudinal tensile strength is as high as 976 MPa, and it also has ultra-high stiffness, excellent elastic recovery ability and insulation and corrosion resistance.

[0097] Comparative Example 1 shows a significant decrease in both longitudinal tensile strength and flexural resilience. The presumed reason is the mismatch in modulus between the CTBN rubber phase and the resin matrix, making it a weak point under stress. This not only reduces overall strength but also hinders efficient material resilience due to its inherent plastic deformation characteristics. Comparative Example 2 also shows a significant decrease in both longitudinal tensile strength and flexural resilience. This may be because stress concentration easily occurs at the interface between rigid nano-silica and the resin, becoming a crack initiation point and prematurely causing material failure, severely degrading the material's load-bearing capacity and toughness. Comparative Example 3 shows a sharp decrease in both longitudinal tensile strength and elastic modulus. This demonstrates that T700 carbon fiber, as a high-strength, high-modulus component, bears the main load in the hybrid structure; S-glass fiber alone cannot provide sufficient axial tensile and deformation resistance, leading to structural failure of the pole. Comparative Example 4 shows longitudinal mechanical properties similar to Example 1, but severely degraded insulation performance. This indicates that the silicone resin varnish of the outer protective layer is far inferior to the functionalized coating of this invention in terms of long-term insulation and resistance to environmental aging, failing to guarantee the safe operation of the power grid.

[0098] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, and is not intended to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions made by those skilled in the art to the technical solution of the present invention do not depart from the essence and scope of the technical solution of the present invention.

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 by an integrated forming process from inside to outside; The inner toughness layer is prepared by the following method: (1) 55-65 parts by mass of bisphenol A type epoxy vinyl ester resin and 5-8 parts of hyperbranched polyester are added to a reaction kettle and stirred and mixed to obtain a hyperbranched 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 hyperbranched 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 glue dipping tank, and E-CR glass fibers with a breaking elongation of ≥4.8% are used for dipping; Then the dipped fibers are wound on a mandrel at a winding angle of 85° to 90° to a designed thickness in a circumferential direction, and the inner toughness layer is formed after gelation and standing; 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; 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 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 structure layer, and the outer protective layer is formed after curing.

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: In the preparation method of the inner toughness layer, the temperature of the stirring and mixing in step (1) is 70-80℃, and the time is 30-60 minutes.

4. The lightweight high strength corrosion resistant composite utility pole of claim 1, wherein: In the preparation method of the structure layer, the stirring in step (2) is carried out at 50-60℃, and the stirring time is 20-40 minutes.

5. The lightweight, high-strength, corrosion-resistant composite utility pole of claim 1, wherein: The composite light stabilizer is compounded by 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.

6. The method for preparing the composite insulator pole according to any one of claims 1-5, comprising the following steps: S1. Inner toughness layer forming: on a conical core mold, inner toughness layer composite glue solution is used to soak E-CR glass fibers, and the soaked fibers are 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: outside the inner toughness layer, structure layer impregnation glue solution is used to soak hybrid fiber bundles composed of S glass fibers and T700 carbon fibers, and the soaked fibers are cross-wound at a winding angle of 54° to 58° to a designed thickness, and the structure layer is formed; 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 stacking and compaction, and a solid flange plate base that can be cured together with the pole body is formed; S4. Outer protective layer coating: outer protective layer coating slurry is coated on the outer surface of the structure layer and the flange plate base to a designed thickness, and the outer protective layer is formed; 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.

7. The method of claim 6, wherein: The programmed temperature curing process is: first, the temperature is raised to 80-90℃ at a rate of 1-2℃ / min, and 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 complete curing is completed after 3-5 hours of heat preservation.

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