A high-temperature-resistant cable core wrapping tape based on a layered structure of p-anf film and a preparation method thereof

Abstract

This invention relates to the field of cable core wrapping material preparation technology, and particularly to a layered high-temperature resistant cable core wrapping material based on a p-ANFs film and its preparation method. The cable core wrapping material comprises a multi-layered composite structure arranged sequentially from top to bottom: the first layer is a p-ANFs film with uniformly distributed aramid nanofibers; the second layer is a uniformly dense finished mica paper; and the third layer is a mesh-like glass fiber cloth. The layered high-temperature resistant cable core wrapping material based on a p-ANFs film composite mica / glass fiber cloth prepared by this invention has advantages such as lightweight, high temperature resistance, high compressive strength, high tensile strength, and environmentally friendly processing, effectively avoiding the problem of mica paper dust shedding, and has a wide range of applications.

Description

Technical Field

[0001] This invention belongs to the field of cable core wrapping material preparation technology, specifically a layered high-temperature resistant cable core wrapping material based on p-ANFs film and its preparation method. Background Technology

[0002] Traditional cable core insulation materials typically use polymers such as polyethylene (PE), cross-linked polyethylene (XLPE), and cross-linked polyolefin (EPR). These materials meet the insulation protection requirements of the cable core to a certain extent. However, with the continuous development of power transmission and industrial applications, cables are required to operate under higher temperatures and more extreme conditions, and have a longer service life. This places higher demands on the high-temperature resistance of the cable core insulation. p-ANFs film, due to its excellent high-temperature stability, excellent mechanical properties and chemical stability, flame retardancy, oxidation resistance, and high insulation, is considered a potential excellent high-temperature insulation material. However, existing preparation methods suffer from cumbersome processes, high costs, and low production efficiency. Mica paper, an insulating material composed of layers of fine mica flakes, possesses excellent heat resistance, insulation, and mechanical strength, especially performing well under high temperature and high pressure environments. It also exhibits excellent chemical stability and corrosion resistance, but suffers from problems such as easy peeling and powdering of the composite layer. Fiberglass cloth is an inorganic non-metallic material mainly composed of glass fiber and short-thread needle-punched nonwoven fabric. It possesses characteristics such as weather resistance, chemical corrosion resistance, high insulation, antistatic properties, high strength, and good mechanical properties. Combining these three elements not only promises to meet the performance requirements of high-temperature cable core wrapping but also overcomes the shortcomings of traditional manufacturing methods, improving production efficiency and demonstrating high practical value and market potential. Summary of the Invention

[0003] To address the problems of traditional insulating tape materials, such as high density, poor temperature resistance, general flame retardancy, easy shedding and powdering, and cumbersome processes and high costs, this invention provides a layered high-temperature resistant cable core tape based on p-ANFs film and its preparation method.

[0004] This invention is achieved through the following technical solution:

[0005] A layered high-temperature resistant cable core wrapping based on p-ANFs film includes a multi-layer composite structure arranged from top to bottom. The first layer is a p-ANFs film with uniformly arranged aramid nanofibers, the second layer is a uniform and dense finished mica paper, and the third layer is a mesh-like glass fiber cloth.

[0006] A method for preparing a layered high-temperature resistant cable core wrapping based on p-ANFs film includes the following steps:

[0007] Step 1: Stir and disperse silica gel in toluene to prepare an adhesive, and brush the adhesive evenly onto the surface of mica paper and pre-dry it to obtain pretreated mica paper;

[0008] Step 2: Attach the fiberglass cloth to the pretreated mica paper, and then perform the first drying process using pressure to obtain the mica paper / fiberglass cloth composite layer.

[0009] Step 3: The para-aramid nanofiber dispersion is coated onto the mica surface of the mica paper / glass fiber cloth composite layer, and after a second drying treatment, a composite material with p-ANFs film is obtained.

[0010] Step 4: Hot-press the composite material with p-ANFs film to obtain a layered high-temperature resistant cable core wrapping based on p-ANFs film.

[0011] Preferably, in step 1, the silicone is a white, high-temperature resistant, insulating, flame-retardant RTV adhesive silicone, and the dispersion volume ratio of silicone to methanol is 1:(2.5-3); the adhesive coating thickness is 30-40 μm.

[0012] Preferably, in step 1, the temperature during pre-drying is 85–95°C and the time is 10–15 min.

[0013] Preferably, in step 2, the temperature during the first drying process is 120-125°C and the time is 2-2.5 hours.

[0014] Preferably, in step 3, the para-aramid nanofiber dispersion is prepared as follows:

[0015] First, an alkaline solution, para-aramid fibers, and dimethyl sulfoxide are stirred and mixed to obtain dispersion A; wherein the mass ratio of para-aramid fibers to dimethyl sulfoxide is 2-3:200-300, the concentration of solute in the alkaline solution is 0.3-0.6 g / mL, and the ratio of alkaline solution to para-aramid fibers is 1-2 mL:2-3 g; the solute in the alkaline solution is one or a mixture of sodium hydroxide and potassium hydroxide.

[0016] Dispersion A was uniformly dispersed in deionized water, and then allowed to stand and filtered to obtain para-aramid nanofiber dispersion B; wherein the volume ratio of water to dispersion A was 1000-1500:50-100; and the concentration of para-aramid nanofiber dispersion was 1%-1.5%.

[0017] Preferably, in step 3, the thickness of the p-ANFs film is 80-120 μm.

[0018] Preferably, in step 3, the temperature during the second drying process is 90–110°C and the time is 1–1.5 h.

[0019] Preferably, in step 4, during hot pressing, the hot pressing temperature is 180–200°C, the pressure is 8–10 MPa, and the hot pressing time is 10–15 min.

[0020] Application of a layered high-temperature resistant cable core wrapping based on p-ANFs film in high-voltage power transmission engineering. This cable core wrapping exhibits a power frequency breakdown strength exceeding 30 kV / mm, a limiting oxygen index exceeding 40%, and a volume resistivity exceeding 10 Ω·cm. 14 Ω·m, withstands high temperatures above 180℃.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] This invention relates to a layered high-temperature resistant cable core wrapping tape based on p-ANFs film and its preparation method, including steps such as bonding p-ANFs film with mica / glass fiber cloth, drying and shaping, and hot pressing. While ensuring high insulation, high temperature resistance, high flame retardancy, high strength, and high modulus performance, the process has the advantages of being green, environmentally friendly, non-toxic, harmless, simple, and efficient.

[0023] Firstly, p-ANFs membranes possess excellent high-temperature resistance and superior insulation properties, maintaining stable performance in high-temperature environments and effectively isolating dielectrics, thereby improving the safety and reliability of power cables. A layered reinforced cable core wrapping material based on p-ANFs membranes combined with mica / glass fiber cloth is constructed. Mica is in the middle layer, preventing powder shedding during application and providing strong corona resistance; the aramid nanofiber membrane on the surface increases density, improves insulation strength, and forms a protective film to prevent mica shedding; the glass fiber cloth at the bottom layer provides strength support and is also a good insulating, flame-retardant, and anti-static material, enhancing the overall temperature resistance and insulation of the cable core wrapping material. This layered high-temperature resistant cable core wrapping based on p-ANFs membranes solves the problems of poor performance and pollution hazards of existing commercially available cable core wrapping materials, achieving a temperature resistance rating of H (above 180℃). Compared to traditional materials, this high-temperature cable core wrapping better meets the power transmission requirements in high-temperature operating environments, offering a longer service life and lower maintenance costs.

[0024] Secondly, the innovative use of micron-porous metal mesh for flat pressing and a self-designed porous copper plate for heavy pressing in the hot-pressing drying process ensures air permeability and heat conduction rate, greatly improving the drying efficiency and surface smoothness of the cable core wrapping material. This also solves the adhesion problem between the fiberglass cloth and mica paper, and significantly enhances the interlayer bonding force of the layered structure. The selection of the drying temperature range, the coating thickness of the aramid nanofibers, the amount of silica gel, and the hot-pressing temperature and time are all the result of long-term process optimization. The drying temperature minimizes the preparation cycle while saving energy; furthermore, it is simpler and more efficient than existing technologies, helping to reduce production costs, improve production efficiency, and promote technological upgrading and product quality improvement in related industries.

[0025] Furthermore, the layered high-temperature cable core wrapping material based on p-ANFs film has low density and excellent mechanical properties. It is lightweight, flexible, and highly processable, which helps to reduce the overall weight of the cable, improve the transportation efficiency of the cable, and increase the durability of power equipment. Its high weather resistance and heat aging resistance can maintain stable performance during long-term use and extend the service life of the cable.

[0026] Furthermore, the aramid fibers, silica gel, and toluene used in the preparation process are all conventional pharmaceutical reagents, and the mica paper and fiberglass cloth are commercially available finished products that are non-toxic, inexpensive, and readily available. The equipment used is all conventional instruments and equipment, which lays the foundation for the commercialization of the process technology products protected by the invention, reduces costs, and improves market competitiveness.

[0027] In summary, the layered high-temperature resistant cable core wrapping tape based on p-ANFs film and its preparation method have advantages such as lightweight, high temperature resistance, excellent electrical insulation performance, outstanding mechanical strength, good flame retardant performance, environmental friendliness, and long-term stability. The product has significant technological advantages and economic benefits, and will play a positive role in promoting the development of related industries. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure of a layered high-temperature resistant cable core wrapping material based on p-ANFs film composite mica / glass fiber cloth according to the present invention.

[0029] Figure 2 The process flow of the method for preparing a layered high-temperature resistant cable core wrapping material based on p-ANFs film composite mica / glass fiber cloth according to the present invention is shown in the figure.

[0030] Figure 3 This is a SEM image of a layered high-temperature resistant cable core wrapping material based on p-ANFs film composite mica / glass fiber cloth, according to the present invention. Detailed Implementation

[0031] The present invention will be further described in detail below with reference to specific embodiments. These descriptions are for explanation purposes only and are not intended to limit the scope of the invention.

[0032] This invention discloses a layered high-temperature resistant cable core wrapping based on p-ANFs film, with reference to... Figure 1 The composite structure comprises a multi-layered structure arranged from top to bottom. The first layer is a p-ANFs membrane with uniformly distributed aramid nanofibers; the second layer is a uniformly dense finished mica paper; and the third layer is a mesh-like glass fiber cloth. This composite structure has outstanding advantages such as lightweight, high-temperature resistance, excellent electrical insulation properties, outstanding mechanical strength, good flame retardancy, environmental friendliness, and long-term stability. The mica paper in the second layer and the glass fiber cloth in the third layer are bonded together using an adhesive prepared with silicone.

[0033] This invention also discloses a method for preparing a layered high-temperature resistant cable core wrapping based on p-ANFs film, referring to... Figure 2 This includes the following steps:

[0034] Step 1: Disperse the silica gel in toluene at a volume ratio of 1:(2.5~3), stir evenly, brush it onto the surface of mica paper, and pre-dry it in a forced-air drying oven at 85~95℃ for 10~15min;

[0035] Step 2: Fiberglass cloth is attached to pre-dried mica paper and subjected to a first drying process under the pressure of a porous metal plate to obtain a mica paper / fiberglass cloth composite layer. During the first drying process, the temperature is 120–125℃ and the time is 2–2.5 hours. The porous metal plate is a self-made perforated copper plate; the A4-sized copper plate has 30–40 holes with a diameter of 4mm. The porous metal plate ensures the flatness of the fiberglass cloth and mica paper during the first drying process, and its high thermal conductivity allows for uniform heating of the paper surface, which helps to accelerate the drying time and improve drying efficiency.

[0036] Step 3: A 1% to 1.5% para-aramid nanofiber dispersion is coated onto the mica surface of the mica paper / glass fiber cloth composite layer. Then, the composite material with the p-ANFs film is subjected to a second drying treatment by flat pressing with a 2000 to 2300 mesh micron-pore metal mesh to obtain the composite material with the p-ANFs film.

[0037] The preparation of the para-aramid nanofiber dispersion is as follows:

[0038] First, an alkaline solution, para-aramid fibers, and dimethyl sulfoxide are stirred at a stirring speed of 4000–8000 r / min for 24–48 h to obtain dispersion A. The mass ratio of para-aramid fibers to dimethyl sulfoxide is 2–3:200–300, the concentration of solute in the alkaline solution is 0.3–0.6 g / mL, and the ratio of alkaline solution to para-aramid fibers is 1–2 mL:2–3 g. The solute in the alkaline solution is one or a mixture of sodium hydroxide and potassium hydroxide.

[0039] According to the volume ratio of 1000-1500:50-100, dispersion A is further uniformly dispersed in deionized water for solvent replacement, and then dissolved in a dissolving machine at a speed of 300-400 r / min for 2-3 h. Then, the uniformly dispersed aramid nanofiber dispersion is filtered through a 2800 mesh filter for 2-3 h to obtain para-aramid nanofiber dispersion B with a concentration of 1.5%.

[0040] The thickness of the p-ANFs film is 80-120 μm; during the second drying process, the temperature is 90-110℃ and the time is 1-1.5 h; the micro-nano porous metal mesh can also play a role in ensuring the smoothness of the paper surface and improving the drying efficiency.

[0041] Step 4: Place the composite material with p-ANFs film in a flat vulcanizing machine and hot press it at 180-200℃ and 8-10 MPa for 10-15 minutes to obtain a layered high-temperature resistant cable core wrapping based on p-ANFs film.

[0042] Figure 3 The image shows a SEM image of a layered high-temperature resistant cable core wrapping material based on p-ANFs film composite mica / glass fiber cloth according to the present invention. It can be seen that the p-ANFs film, mica paper and glass fiber cloth are uniformly bonded together to form a stable composite layered structure.

[0043] Example 1

[0044] Step 1: Disperse the silica gel in toluene at a volume ratio of 1:3, stir evenly, brush it onto the surface of mica paper, and pre-dry it in a forced-air drying oven at 85°C for 10 minutes.

[0045] Step 2: Fiberglass cloth is attached to pre-dried mica paper and further dried at 120°C for 2 hours under the heavy pressure of a porous metal plate to obtain a mica paper / fiberglass cloth composite layer.

[0046] Step 3: A 1.5% para-aramid nanofiber dispersion is coated onto the mica surface of the mica paper / glass fiber cloth composite layer. Then, it is flat-pressed through a 2000-mesh microporous metal mesh and dried at 90°C for 1 hour to obtain a composite material with a p-ANFs film. At this time, the thickness of the p-ANFs film is 120 μm.

[0047] The preparation of the para-aramid nanofiber dispersion is as follows:

[0048] An alkaline solution, para-aramid fibers, and dimethyl sulfoxide were added sequentially to a reaction vessel at a ratio of 2 ml: 3 g: 200 g. The mixture was subjected to chemical pyrolysis reaction at a stirring speed of 4000 r / min for 24 h to prepare aramid nanofiber dispersion A. The alkaline solution was a potassium hydroxide solution with a concentration of 0.5 g / ml.

[0049] Dispersion A was further uniformly dispersed in deionized water at a ratio of 80ml:1000ml for solvent replacement, and then disintegrated at a speed of 300r / min for 3h using a disintegrator. The uniformly dispersed aramid nanofiber dispersion was then filtered through a 2800 mesh filter for 3h to obtain para-aramid nanofiber dispersion B with a concentration of 1.5%.

[0050] Step 4: Place the composite material with p-ANFs film in a flat vulcanizing machine and further hot-press it for 10 minutes at 180°C and 8 MPa pressure to obtain a layered cable core wrapping based on p-ANFs film.

[0051] The cable core wrapping prepared in Example 1 does not delaminate or shed powder, has a power frequency breakdown strength of 35.2 kV / mm, a limiting oxygen index of 43%, a breaking stress of 45.7 MPa, and a volume resistivity of 9.7 × 10⁻⁶. 14 Ω·m, with a temperature resistance rating of H (above 180℃), is a layered high-temperature resistant cable core wrapping material based on p-ANFs film.

[0052] Example 2

[0053] Step 1: Disperse the silica gel in toluene at a volume ratio of 1:3, stir evenly, brush it onto the surface of mica paper, and pre-dry it in a forced-air drying oven at 90°C for 10 minutes.

[0054] Step 2: Fiberglass cloth is attached to pre-dried mica paper and further dried at 120°C for 2 hours under the heavy pressure of a porous metal plate to obtain a mica paper / fiberglass cloth composite layer.

[0055] Step 3: A 1.1% para-aramid nanofiber dispersion is coated onto the mica surface of the mica paper / glass fiber cloth composite layer. Then, it is dried at 90°C for 1.4 hours by flat pressing through a 2000-mesh microporous metal mesh to obtain a composite material with a p-ANFs film. At this time, the thickness of the p-ANFs film is 90 μm.

[0056] The preparation of the para-aramid nanofiber dispersion is as follows:

[0057] An alkaline solution, para-aramid fibers, and dimethyl sulfoxide were added sequentially to a reaction vessel at a ratio of 2 ml: 2.2 g: 200 g. The mixture was subjected to chemical pyrolysis reaction at a stirring speed of 4000 r / min for 24 h to prepare aramid nanofiber dispersion A. The alkaline solution was a potassium hydroxide solution with a concentration of 0.5 g / ml.

[0058] Dispersion A was further uniformly dispersed in deionized water at a ratio of 80ml:1000ml, solvent replacement was performed, and the dispersion was dissolved at a speed of 300r / min for 3h using a dissolving machine. Then, the uniformly dispersed aramid nanofiber dispersion was filtered through a 2800 mesh filter for 3h to obtain para-aramid nanofiber dispersion B with a concentration of 1.1%.

[0059] Step 4: Place the composite material with p-ANFs film in a flat vulcanizing machine and further hot-press it for 10 minutes at 190°C and 9 MPa pressure to obtain a layered cable core wrapping based on p-ANFs film.

[0060] The cable core wrapping prepared in Example 2 does not delaminate or shed powder, has a power frequency breakdown strength of 31.3 kV / mm, a limiting oxygen index of 47%, a breaking stress of 55.2 MPa, and a volume resistivity of 8.9 × 10⁻⁶. 14 Ω·m, with a temperature resistance rating of H (above 180℃), is a layered high-temperature resistant cable core wrapping material based on p-ANFs film.

[0061] Example 3

[0062] Step 1: Disperse the silica gel in toluene at a volume ratio of 1:3, stir evenly, brush it onto the surface of mica paper, and pre-dry it in a forced-air drying oven at 90°C for 12 minutes.

[0063] Step 2: Fiberglass cloth is attached to pre-dried mica paper and further dried at 120°C for 2.5 hours under the heavy pressure of a porous metal plate to obtain a mica paper / fiberglass cloth composite layer.

[0064] Step 3: A 1.0% concentration of para-aramid nanofiber dispersion is coated onto the mica surface of the mica paper / glass fiber cloth composite layer, and then dried at 100°C for 1 hour by flat pressing through a 2300-mesh microporous metal mesh to obtain a composite material with a p-ANFs film; at this time, the thickness of the p-ANFs film is 80 μm.

[0065] The preparation of the para-aramid nanofiber dispersion is as follows:

[0066] An alkaline solution, para-aramid fibers, and dimethyl sulfoxide were added sequentially to a reaction vessel at a ratio of 2 ml: 2 g: 200 g. The mixture was subjected to chemical pyrolysis reaction at a stirring speed of 4000 r / min for 24 h to prepare aramid nanofiber dispersion A. The alkaline solution was a potassium hydroxide solution with a concentration of 0.5 g / ml.

[0067] According to the ratio of 80ml:1000ml, the aramid nanofiber dispersion A was further uniformly dispersed in deionized water for solvent replacement, and then disintegrated for 3h at a speed of 300r / min using a disintegrator. The uniformly dispersed aramid nanofiber dispersion was then filtered through a 2800 mesh filter for 3h to obtain para-aramid nanofiber dispersion B with a concentration of 1.0%.

[0068] Step 4: Place the composite material with p-ANFs film in a flat vulcanizing machine and further hot-press it for 10 minutes at 200℃ and 10MPa pressure to obtain a layered cable core wrapping based on p-ANFs film.

[0069] The cable core wrapping prepared in Example 3 does not delaminate or shed powder, has a power frequency breakdown strength of 37.6 kV / mm, a limiting oxygen index of 48%, a breaking stress of 57.6 MPa, and a volume resistivity of 8.6 × 10⁻⁶. 14 Ω·m, with a temperature resistance rating of H (above 180℃), is a layered high-temperature resistant cable core wrapping material based on p-ANFs film.

[0070] Example 4

[0071] Step 1: Disperse the silica gel in toluene at a volume ratio of 1:3, stir evenly, brush it onto the surface of mica paper, and pre-dry it in a forced-air drying oven at 90°C for 12 minutes.

[0072] Step 2: Fiberglass cloth is attached to pre-dried mica paper and further dried at 120°C for 2 hours under the heavy pressure of a porous metal plate to obtain a mica paper / fiberglass cloth composite layer.

[0073] Step 3: A 1.3% para-aramid nanofiber dispersion is coated onto the mica surface of the mica paper / glass fiber cloth composite layer. Then, it is dried at 110°C for 1 hour by flat pressing through a 2000-mesh microporous metal mesh to obtain a composite material with a p-ANFs film. At this time, the thickness of the p-ANFs film is 110 μm.

[0074] The preparation of the para-aramid nanofiber dispersion is as follows:

[0075] An alkaline solution, para-aramid fibers, and dimethyl sulfoxide were added sequentially to a reaction vessel at a ratio of 2 ml: 2.6 g: 200 g. The mixture was subjected to chemical pyrolysis reaction at a stirring speed of 4000 r / min for 24 h to prepare aramid nanofiber dispersion A. The alkaline solution was a potassium hydroxide solution with a concentration of 0.5 g / ml.

[0076] According to the ratio of 80ml:1000ml, the aramid nanofiber dispersion A was further uniformly dispersed in deionized water for solvent replacement, and then disintegrated at a speed of 300r / min for 3h using a disintegrator. The uniformly dispersed aramid nanofiber dispersion was then filtered through a 2800 mesh filter for 3h to obtain para-aramid nanofiber dispersion B with a concentration of 1.3%.

[0077] Step 4: The composite material with p-ANFs film is placed in a flat vulcanizing machine and further hot-pressed for 12 minutes at 200°C and 10 MPa pressure to obtain a layered cable core wrapping based on p-ANFs film.

[0078] The cable core wrapping prepared in Example 4 does not delaminate or shed powder, has a power frequency breakdown strength of 35.4 kV / mm, a limiting oxygen index of 45%, a breaking stress of 61.8 MPa, and a volume resistivity of 8.3 × 10⁻⁶. 14 Ω·m, with a temperature resistance rating of H (above 180℃), is a layered high-temperature resistant cable core wrapping material based on p-ANFs film.

[0079] Example 5

[0080] Step 1: Disperse the silica gel in toluene at a volume ratio of 1:3, stir evenly, brush it onto the surface of mica paper, and pre-dry it in a forced-air drying oven at 95°C for 15 minutes.

[0081] Step 2: Fiberglass cloth is attached to pre-dried mica paper and further dried at 120°C for 2 hours under the heavy pressure of a porous metal plate to obtain a mica paper / fiberglass cloth composite layer.

[0082] Step 3: A 1.2% concentration of para-aramid nanofiber dispersion is coated onto the mica surface of the mica paper / glass fiber cloth composite layer. Then, it is dried at 110°C for 1.5 hours by flat pressing through a 2000-mesh microporous metal mesh to obtain a composite material with a p-ANFs film. At this time, the thickness of the p-ANFs film is 100 μm.

[0083] The preparation of the para-aramid nanofiber dispersion is as follows:

[0084] An alkaline solution, para-aramid fibers, and dimethyl sulfoxide were added sequentially to a reaction vessel at a ratio of 2 ml: 2.4 g: 200 g. The mixture was subjected to chemical pyrolysis reaction at a stirring speed of 4000 r / min for 24 h to prepare aramid nanofiber dispersion A. The alkaline solution was a potassium hydroxide solution with a concentration of 0.5 g / ml.

[0085] According to the ratio of 80ml:1000ml, the aramid nanofiber dispersion A was further uniformly dispersed in deionized water for solvent replacement, and then disintegrated at a speed of 300r / min for 3h using a disintegrator. The uniformly dispersed aramid nanofiber dispersion was then filtered through a 2800 mesh filter for 3h to obtain para-aramid nanofiber dispersion B with a concentration of 1.2%.

[0086] Step 4: Place the composite material with p-ANFs film in a flat vulcanizing machine and further hot-press it for 15 minutes at 200℃ and 10MPa pressure to obtain a layered cable core wrapping based on p-ANFs film.

[0087] The cable core wrapping prepared in Example 5 does not delaminate or shed powder, has a power frequency breakdown strength of 36.2 kV / mm, a limiting oxygen index of 43%, a breaking stress of 56.3 MPa, and a volume resistivity of 8.7 × 10⁻⁶. 14 Ω·m, with a temperature resistance rating of H (above 180℃), is a layered high-temperature resistant cable core wrapping material based on p-ANFs film.

[0088] Table 1 shows the technical parameters of the cable core wrapping tapes prepared in Examples 1-5. Analysis reveals that the cable core wrapping tapes prepared using the process route provided by this invention do not delaminate or shed powder; they exhibit high power frequency breakdown strength, all exceeding 30 kV / mm; good flame retardant properties, with limiting oxygen index exceeding 40%; good mechanical strength, with fracture stress exceeding 45 MPa; and excellent insulation performance, with volume resistivity exceeding 10 Ω·cm. 14 Ω·m; Temperature rating H, can withstand temperatures above 180℃.

[0089] Table 1 Technical parameters of cable core wrapping in implementation cases

[0090]

[0091] This invention is based on a layered structure of p-ANFs film composite mica / glass fiber cloth high-temperature resistant cable core wrapping tape, with aramid layer wrapping mica scales to prevent powder shedding and make the performance more stable; compared with traditional cable core wrapping tape, it has higher temperature resistance, electrical insulation performance, flame retardant performance and mechanical strength, which meets the working environment and application scenarios of rail locomotives, nuclear power and other applications.

[0092] This invention also discloses the application of a layered high-temperature resistant cable core wrapping based on p-ANFs film in high-voltage power transmission engineering. This cable core wrapping exhibits a power frequency breakdown strength exceeding 30 kV / mm, a limiting oxygen index exceeding 40%, and a volume resistivity exceeding 10 Ω·cm. 14 Ω·m, withstands high temperatures above 180℃.

[0093] The above description is merely a preferred embodiment of the present invention and is not intended to limit the technical solution of the present invention in any way. Those skilled in the art should understand that, without departing from the spirit and principles of the present invention, the technical solution can be modified and replaced in several simple ways, and these modifications and replacements are all within the scope of protection covered by the claims.

Claims

1. A method based on p A method for preparing a layered high-temperature resistant cable core wrapping tape with an ANFs film, characterized in that... The high-temperature resistant cable core wrapping based on p~ANFs film consists of a multi-layered composite structure arranged from top to bottom. The first layer is composed of uniformly arranged aramid nanofibers. p The first layer is an ANFs membrane, the second layer is a uniform and dense finished mica paper, and the third layer is a mesh-like glass fiber cloth. The method for preparing the cable core wrapping includes the following steps: Step 1: Stir and disperse silica gel in toluene to prepare an adhesive, and brush the adhesive evenly onto the surface of mica paper and pre-dry it to obtain pretreated mica paper; The pre-drying temperature is 85~95℃ and the time is 10~15min; Step 2: Fiberglass cloth is attached to pretreated mica paper and dried for the first time under the pressure of a porous metal plate to obtain a mica paper / fiberglass cloth composite layer. During the first drying process, the temperature is 120~125℃ and the time is 2~2.5h. Step 3: The para-aramid nanofiber dispersion is coated onto the mica surface of the mica paper / glass fiber cloth composite layer. Then, the composite material with the p-ANFs film is subjected to a second drying treatment by flat pressing with a 2000-2300 mesh micron-pore metal mesh to obtain the desired product. p Composite materials with ~ANFs membranes; During the second drying process, the temperature is 90~110℃ and the time is 1~1.5h. Step 4, for those with p The composite material based on the ~ANFs membrane was hot-pressed to obtain a product based on... p ~ANFs membrane layered structure high temperature resistant cable core wrapping.

2. The method based on claim 1 p A method for preparing a layered high-temperature resistant cable core wrapping tape with an ANFs film, characterized in that... In step 1, the silicone is a white, high-temperature resistant, insulating, and flame-retardant RTV adhesive silicone, and the dispersion volume ratio of silicone to methanol is 1:(2.5~3); the adhesive coating thickness is 30~40μm.

3. The method based on claim 1 p A method for preparing a layered high-temperature resistant cable core wrapping tape with an ANFs film, characterized in that... In step 3, the preparation of the para-aramid nanofiber dispersion is as follows: First, an alkaline solution, para-aramid fibers, and dimethyl sulfoxide are stirred and mixed to obtain dispersion A; wherein the mass ratio of para-aramid fibers to dimethyl sulfoxide is 2~3:200~300, the concentration of solute in the alkaline solution is 0.3~0.6g / mL, and the ratio of alkaline solution to para-aramid fibers is 1~2mL:2~3g; the solute in the alkaline solution is one or a mixture of sodium hydroxide and potassium hydroxide. Dispersion A was uniformly dispersed in deionized water, and then allowed to stand and filtered to obtain para-aramid nanofiber dispersion B; wherein the volume ratio of water to dispersion A was 1000~1500:50~100, and the concentration of para-aramid nanofiber dispersion was 1%~1.5%.

4. The method based on claim 1 p A method for preparing a layered high-temperature resistant cable core wrapping tape with an ANFs film, characterized in that... In step 3, p The thickness of the ~ANFs membrane is 80~120μm.

5. The method for preparing a layered high-temperature resistant cable core wrapping based on p~ANFs film according to claim 1, characterized in that, In step 4, during hot pressing, the hot pressing temperature is 180~200℃, the pressure is 8~10Mpa, and the hot pressing time is 10~15min.

6. The application of the high-temperature resistant cable core wrapping tape based on a layered structure of p-ANFs film obtained by the preparation method of the layered structure high-temperature resistant cable core wrapping tape based on p-ANFs film as described in any one of claims 1 to 5 in high-voltage power transmission engineering, characterized in that, The cable core wrapping has a power frequency breakdown strength exceeding 30 kV / mm, a limiting oxygen index exceeding 40%, and a volume resistivity exceeding 10. 14 Ω·m, withstands high temperatures above 180℃.

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