Flexible fireproof cable and manufacturing method thereof

Abstract

The invention is suitable for the technical field of fireproof cables, and provides a flexible fireproof cable and a manufacturing method thereof, and the cable comprises a conductor, a fireproof insulating layer, a moisture-proof layer, an insulating wire core, a belting layer, and a protection layer. A fireproof insulating layer is wrapped outside a conductor, a moisture-proof layer is extruded on the fireproof insulating layer to form insulating wire cores, the insulating wire cores are twisted together through cabling and are tightly wrapped by a wrapping tape, and a protective layer is wrapped on a wrapping tape layer; the conductor adopts a silver-plated copper wire; the fire-resistant insulating layer adopts a coating mica fire-resistant belt and a ceramic silica gel belt; the damp-proof layer is formed by extruding high-density polyethylene; and the belting layer adopts a high-flame-retardant glass fiber belt. According to the high-fire-resistance rat-proof flexible fireproof cable and the manufacturing method thereof provided by the invention, by optimizing the conductor structure, innovating the design of the fire-resistant insulating layer, increasing the rat-proof function and improving the preparation process, the fire endurance, the low-temperature adaptability, the rat-proof performance and the bending performance of the cable are remarkably improved, and higher-standard use requirements are met.

Description

Technical Field

[0001] This invention belongs to the field of fire-resistant cable technology, specifically relating to a flexible fire-resistant cable and its manufacturing method. Background Technology

[0002] Fire-resistant cables are widely used in densely populated areas of urban construction, such as airports, subways, hospitals, shopping malls, and schools. Their core function is to ensure continuous power transmission in the event of a fire and to prevent the production of harmful gases during combustion.

[0003] In existing technologies, such as the "Insulated Flexible Fireproof Cable and its Manufacturing Method" published in CN108492916A, although it possesses certain fireproof and waterproof properties, there is still room for improvement in terms of fire resistance limit, low-temperature adaptability, rodent-proof function, and bending performance. The fire resistance performance of existing insulated flexible fireproof cables mostly meets the requirement of line integrity at 1000℃ for 300 minutes, but low-temperature performance is not explicitly mentioned, and there is a lack of protection against rodent damage. In practical applications, rodent gnawing can easily damage the cable sheath, causing circuit failures. Furthermore, its conductor structure and insulation layer design limit the cable's bending performance, making it difficult to adapt to complex installation environments.

[0004] To address the shortcomings of the existing technologies, this invention proposes a high fire-resistant and rodent-proof flexible fire-resistant cable and its preparation method. By optimizing the conductor structure, innovating the design of the fire-resistant insulation layer, adding rodent-proof function, and improving the preparation process, the fire resistance limit, low-temperature adaptability, rodent-proof performance, and bending performance of the cable are significantly improved, meeting higher standards of use requirements. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing flexible fire-resistant cables in terms of fire resistance limit, rodent-proof function, low temperature adaptability and bending performance, and to provide a high fire-resistant and rodent-proof flexible fire-resistant cable and its preparation method.

[0006] The present invention is implemented as follows: a flexible fireproof cable includes a conductor, a fire-resistant insulation layer, a moisture-proof layer, an insulated core, a wrapping layer, and a protective layer; the conductor is wrapped with a fire-resistant insulation layer, a moisture-proof layer is extruded on the fire-resistant insulation layer to form an insulated core, the insulated cores are twisted together by cabling and tightly wrapped with wrapping tape, and the protective layer covers the wrapping layer; The conductor is made of silver-plated copper wire; The fire-resistant insulation layer uses coated mica fire-resistant tape and ceramicized silicone tape; The moisture barrier is formed by extrusion of high-density polyethylene; The wrapping layer is made of high flame-retardant glass fiber tape; The protective layer is made of polyethylene as the base material, with flame retardant and rodent repellent evenly mixed in, and is extruded onto the wrapping tape layer using a plastic extrusion process.

[0007] Preferably, the conductor uses the sixth type of silver-plated copper wire in the national standard GB / T3956. The conductor is made by twisting multiple strands of silver-plated copper wire. When twisting a single wire, a pitch of 10 to 12 times the outer diameter after twisting is selected. The silver plating thickness of the silver-plated copper wire is 5 to 10 μm, which not only ensures excellent conductivity (conductivity close to pure copper), but also significantly improves corrosion resistance and welding performance. The specific twisting pitch design gives the cable excellent bending performance, which can be flexibly arranged in complex installation environments. The bending radius can reach less than 6 times the outer diameter of the cable.

[0008] Preferably, in the preparation of the fire-resistant insulation layer using coated mica fire-resistant tape and ceramicized silica tape, four layers of coated mica fire-resistant tape with a thickness of 0.2 mm are first wrapped around the conductor in an overlapping manner. Then, four layers of ceramicized silica tape with a thickness of 0.2 mm are wrapped around the coated mica fire-resistant tape in an overlapping manner. The overlap rate of each layer of tape is 30% to 40%. When a fire occurs, the outer ceramicized silica tape first comes into contact with the flame and sinters into a hard ceramic shell, tightly covering the inner coated mica fire-resistant tape, effectively preventing the coated mica fire-resistant tape from detaching from the mica at high temperatures. The double-layer composite structure ensures the stability of the insulation performance. This allows the cable to maintain power for over 200 minutes at a flame temperature of 1200℃, far exceeding the existing fire resistance limit of 300 minutes at 1000℃ for flexible fire-resistant cables. The fire-resistant insulation layer is wrapped using a horizontal wrapping machine. This machine effectively controls the conductor tension during wrapping, preventing conductor vibration and ensuring the fire-resistant insulation layer is free of wrinkles, damage, and burrs. This reduces air gaps in the fire-resistant insulation layer, improving its fire resistance and insulation resistance.

[0009] Preferably, the moisture-proof layer is made of high-density polyethylene with a thickness of 1.5 mm. High-density polyethylene has excellent resistance to water vapor penetration, which can effectively block external water vapor from entering the fire-resistant insulation layer, avoid the decrease in insulation performance due to water vapor, solve the problem of easy moisture absorption of magnesium oxide insulation in existing isolated flexible fire-resistant cables, and improve the cable's resistance to chemical corrosion.

[0010] Preferably, the wrapping layer is made of double-layer high flame-retardant glass fiber tape with a thickness of 0.5mm, which is wrapped in an overlapping manner. The high flame-retardant glass fiber tape has good flame-retardant properties and mechanical strength. It can not only delay the spread of flames in the early stage of a fire, but also play a role in binding and fixing during the cable stranding process, ensuring the stability of the cable core structure and preventing the insulation core from shifting.

[0011] Preferably, the flame retardant mixed into the protective layer is magnesium hydroxide (added at 20%–30% of the polyethylene mass), and the rodent repellent is actinomycete ketone (added at 0.5%–1% of the polyethylene mass). The extrusion thickness of the protective layer is 2.0 mm. Magnesium hydroxide, as a flame retardant, releases bound water upon thermal decomposition, absorbing a large amount of latent heat and reducing the surface temperature of the sheath. Simultaneously, the generated magnesium oxide enhances the fire resistance of the material. Actinomycete ketone, as a rodent repellent, effectively repels rodents, preventing them from gnawing on the sheath and damaging the cable. The polyethylene base material ensures the low-temperature resistance of the sheath, allowing the cable to operate normally in environments as low as -70°C. Furthermore, the reduced molecular chain spacing and regular geometric arrangement of the extruded polyethylene strengthen the tightness between molecular chains, thereby increasing crystallinity and enhancing the interaction forces between polyethylene molecular chains. This reduces impurities and air in the protective layer, while also reducing surface unevenness defects between the wrapping layer and the protective layer, thus improving the cable's resistance to mechanical stress and bending.

[0012] The present invention proposes a method for preparing a flexible fire-resistant cable, comprising the following steps: The first step is to produce the conductor. A fire-resistant insulation layer is then wrapped around the conductor. A moisture-proof layer is extruded onto this fire-resistant insulation layer to form the insulated core. These insulated cores are then twisted together and tightly wrapped with cable tape. A protective layer is then applied over the cable tape layer, resulting in a flexible fire-resistant cable. The specific process is as follows: (1) Preparation of conductor: Select electrolytic copper with a purity of ≥99.95%, draw it into fine copper wire with a diameter of 0.1 to 0.3 mm using a wire drawing equipment, and then use an electroplating process to plate a silver layer of 5 to 10 μm thick on the surface of the fine copper wire to obtain silver-plated copper wire; strand multiple strands of silver-plated copper wire are stranded together by a stranding machine to form a conductor. During the stranding process, the pitch is controlled to be 10 to 12 times the outer diameter after stranding to ensure that the conductor has good bending performance.

[0013] (2) Wrapping the fire-resistant insulation layer: First, use alcohol to clean the surface of the conductor prepared in step (1) to remove surface oil and impurities; then send the conductor into the horizontal wrapping equipment. First, wrap 4 layers of coated mica fire-resistant tape in an overlapping wrapping manner. The wrapping speed is controlled at 10-15 m / min, and the conductor tension is controlled at 50-80 N. Then, continue to wrap 4 layers of ceramicized silicone tape on the outside of the coated mica fire-resistant tape at the same wrapping speed and tension. Control the overlap rate of each layer of tape to 30%-40% to ensure that the fire-resistant insulation layer is free from wrinkles, damage, and burrs, reduce the air gap in the insulation layer, and improve the fire resistance and insulation resistance.

[0014] (3) Extrusion of moisture-proof layer: The conductor wrapped with fire-resistant insulation layer in step (2) is fed into the extruder. High-density polyethylene granules are added to the hopper of the extruder. The extrusion temperature is set to 180-220℃ and the extrusion speed is 8-12m / min. A moisture-proof layer with a thickness of 1.5mm is formed on the outside of the fire-resistant insulation layer through the extrusion process to obtain the insulated wire core. Vacuum sizing technology is used in the extrusion process to ensure that the moisture-proof layer has a uniform thickness and is tightly wrapped on the outside of the fire-resistant insulation layer without bubbles or impurities.

[0015] (4) Wrapping tape layer: According to the cable design specifications, multiple insulated wire cores made in step (3) are twisted together by a cable forming machine to form a cable core. The twisting pitch is controlled to be 12 to 16 times the outer diameter of the cable core. Then the cable core is sent into a wrapping machine, and double-layer high flame-retardant glass fiber tape is wrapped around the outside of the cable core in an overlapping wrapping manner to form a wrapping tape layer. The wrapping tension is controlled to be 30 to 50 N to ensure that the wrapping tape layer fits tightly against the cable core without any loosening.

[0016] (5) Extrusion protective layer: Weigh polyethylene granules, magnesium hydroxide and actinomycete ketone according to the proportion, add the three to a high-speed mixer, mix at 80-100℃ for 15-20 minutes to ensure that magnesium hydroxide and actinomycete ketone are evenly dispersed in the polyethylene base material; add the mixed material to the extruder hopper, set the extrusion temperature to 190-230℃, the extrusion pressure to 15-20MPa, and the extrusion speed to 6-10m / min, and form a protective layer with a thickness of 2.0mm on the outside of the wrapping layer through the plastic extrusion process; after extrusion, cool and shape the cable (cooling water temperature controlled at 20-30℃) and pull and wind it to obtain a high fire-resistant and rodent-proof flexible fireproof cable.

[0017] Compared with related technologies, the flexible fire-resistant cable and its manufacturing method provided by the present invention have the following beneficial effects: 1. This invention adopts a double-layer composite fire-resistant insulation layer structure consisting of 4 layers of coated mica fire-resistant tape and 4 layers of ceramicized silicone tape. The outer ceramicized silicone tape sintersects into a hard shell when exposed to fire to protect the inner mica tape, enabling the cable to maintain power for more than 200 minutes at a flame temperature of 1200℃, far exceeding the fire resistance limit of existing isolated flexible fire-resistant cables at 1000℃ for 300 minutes, thus meeting the requirements of places with higher safety standards.

[0018] 2. This invention effectively repels rodents by adding the rodent repellent actinomycete ketone to the protective layer, preventing rodents from gnawing on the cable sheath and causing circuit failures. It solves the problem of the lack of rodent-proof design in existing insulated flexible fireproof cables and broadens the application range of cables in places susceptible to rodent damage, such as underground garages and power distribution rooms.

[0019] 3. The protective layer of this invention uses polyethylene base material, combined with high-density polyethylene material for the moisture-proof layer, so that the cable can still operate normally in a low temperature environment of -70℃. Existing insulated flexible fireproof cables do not explicitly mention low temperature operation performance, so this invention is more suitable for installation and use in cold regions.

[0020] 4. The conductor of this invention adopts a pitch design of 10 to 12 times the outer diameter after stranding, combined with the overall flexible structure, the bending radius of the cable can reach less than 6 times the outer diameter, which is far superior to the bending performance of existing insulated flexible fireproof cables, making it more suitable for complex installation environments and reducing construction difficulty. 5. The moisture-proof layer of this invention is made of high-density polyethylene through extrusion molding, with a thickness of 1.5mm. It has strong water vapor barrier ability, avoiding the problem of easy moisture absorption of magnesium oxide insulation in existing isolated flexible fireproof cables, ensuring the insulation stability of the cable during long-term operation and extending its service life. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a flexible fireproof cable proposed in this invention.

[0022] Figure 2 This is a flowchart of a method for preparing a flexible fireproof cable proposed in this invention.

[0023] In the diagram: 1. Conductor; 2. Fire-resistant insulation layer; 3. Moisture-proof layer; 4. Insulated wire core; 5. Wrapping layer; 6. Protective layer. Detailed Implementation

[0024] To make the technical means, creative features, objectives and effects of the present invention easier to understand, the present invention will be further described below in conjunction with specific embodiments. Example 1

[0025] A highly fire-resistant and rodent-proof flexible fireproof cable and its preparation method are described below: 1. Conductor preparation: Select electrolytic copper with a purity of 99.96%, draw it into a fine copper wire with a diameter of 0.2 mm using a wire drawing device, and plate an 8 μm thick silver layer on the surface of the fine copper wire using an electroplating process to obtain silver-plated copper wire; strand 36 strands of silver-plated copper wire are stranded together by a stranding machine to form a conductor, with a stranding pitch of 11 times the outer diameter after stranding (conductor outer diameter 2.5 mm, pitch 27.5 mm).

[0026] 2. Wrapping the fire-resistant insulation layer: Clean the conductor surface with alcohol, feed the conductor into the horizontal wrapping equipment, and wrap 4 layers of coated mica fire-resistant tape with a thickness of 0.2mm at a wrapping speed of 12m / min and a conductor tension of 65N, with each layer overlapping 35%; then continue to wrap 4 layers of ceramicized silicone tape with a thickness of 0.2mm on the outside at the same speed and tension, with each layer overlapping 35%.

[0027] 3. Extrusion of moisture-proof layer: The conductor wrapped with fire-resistant insulation layer is fed into an extruder, high-density polyethylene granules are added, the extrusion temperature is set to 200℃ and the extrusion speed is 10m / min, and a moisture-proof layer with a thickness of 1.5mm is extruded using vacuum sizing technology to obtain the insulated wire core (outer diameter of the insulated wire core is 5.5mm).

[0028] 4. Wrapping tape layer: The three insulated wire cores are twisted together by a cabling machine to form a cable core (the outer diameter of the cable core is 10mm and the twisting pitch is 140mm). Then the cable core is fed into a wrapping machine and wrapped with a wrapping tension of 40N using double-layer high flame-retardant glass fiber tape with a thickness of 0.5mm in an overlapping manner to form a wrapping tape layer (the outer diameter of the wrapping tape layer is 11mm).

[0029] 5. Extrusion of protective layer: Weigh 100kg polyethylene granules, 25kg magnesium hydroxide and 0.8kg actinomycete ketone, add them to a high-speed mixer and mix at 90℃ for 18min; add the mixture to an extruder, set the extrusion temperature to 210℃, the extrusion pressure to 18MPa, the extrusion speed to 8m / min, and extrude a protective layer with a thickness of 2.0mm; after extrusion, cool and shape it with water at 25℃, and then pull and wind it to obtain a high fire-resistant and rodent-proof flexible fireproof cable (finished product outer diameter 15mm).

[0030] The cable prepared in this embodiment was subjected to performance testing, and the results are as follows: Fire resistance: At a flame temperature of 1200℃, the circuit remains intact after being energized for 215 minutes. Rodent-proof performance: After being placed in a simulated rodent-infested environment for 30 days, the cable protective layer showed no signs of chewing. Low temperature performance: After being placed at -70℃ for 24 hours, the cable bending and power-on functions were normal. Bending performance: No cracks or damage when the bending radius is 5 times the outer diameter of the cable; Moisture resistance: The insulation resistance remains stable after being placed in an environment with a relative humidity of 95% and a temperature of 40℃ for 100 days. Example 2

[0031] A highly fire-resistant and rodent-proof flexible fireproof cable and its preparation method are described below: 1. Conductor preparation: Select electrolytic copper with a purity of 99.95%, draw it into a fine copper wire with a diameter of 0.15 mm using a wire drawing equipment, and plate a 6 μm thick silver layer on the surface of the fine copper wire using an electroplating process to obtain silver-plated copper wire; strand 24 strands of silver-plated copper wire are stranded together by a stranding machine to form a conductor, with a stranding pitch of 10 times the outer diameter after stranding (conductor outer diameter 2.0 mm, pitch 20 mm).

[0032] 2. Wrapping the fire-resistant insulation layer: Clean the conductor surface with alcohol, feed the conductor into the horizontal wrapping equipment, and wrap 4 layers of coated mica fire-resistant tape with a thickness of 0.2mm at a wrapping speed of 10m / min and a conductor tension of 50N, with each layer overlapping 30%; then continue to wrap 4 layers of ceramicized silicone tape with a thickness of 0.2mm on the outside at the same speed and tension, with each layer overlapping 30%.

[0033] 3. Extrusion of moisture-proof layer: The conductor wrapped with fire-resistant insulation layer is fed into an extruder, high-density polyethylene granules are added, the extrusion temperature is set to 180℃ and the extrusion speed is 8m / min, and a moisture-proof layer with a thickness of 1.5mm is extruded using vacuum sizing technology to obtain the insulated wire core (outer diameter of the insulated wire core is 5.0mm).

[0034] 4. Wrapping tape layer: The four insulated wire cores are twisted together by a cabling machine to form a cable core (the outer diameter of the cable core is 11mm and the twisting pitch is 132mm). Then, the cable core is fed into a wrapping machine and wrapped with a wrapping tension of 30N using double-layer, 0.5mm thick, high flame-retardant glass fiber tape in an overlapping manner to form a wrapping tape layer (the outer diameter of the wrapping tape layer is 12mm).

[0035] 5. Extrusion of protective layer: Weigh 100kg polyethylene granules, 20kg magnesium hydroxide and 0.5kg actinomycete ketone, add them to a high-speed mixer and mix at 80℃ for 15min; add the mixture to an extruder, set the extrusion temperature to 190℃, the extrusion pressure to 15MPa, the extrusion speed to 6m / min, and extrude a protective layer with a thickness of 2.0mm; after extrusion, cool and shape it with water at 20℃, and then pull and wind it to obtain a high fire-resistant and rodent-proof flexible fireproof cable (finished product outer diameter 16mm).

[0036] The cable prepared in this embodiment was subjected to performance testing, and the results are as follows: Fire resistance: At a flame temperature of 1200℃, the circuit remains intact after being energized for 205 minutes. Rodent-proof performance: After being placed in a simulated rodent-infested environment for 30 days, the cable protective layer showed no signs of chewing. Low temperature performance: After being placed at -70℃ for 24 hours, the cable bending and power-on functions were normal. Bending performance: No cracks or damage when the bending radius is 5.5 times the outer diameter of the cable; Moisture resistance: The insulation resistance remains stable after being placed in an environment with a relative humidity of 95% and a temperature of 40℃ for 100 days. Example 3

[0037] A highly fire-resistant and rodent-proof flexible fireproof cable and its preparation method are described below: 1. Conductor preparation: Select electrolytic copper with a purity of 99.97%, draw it into a fine copper wire with a diameter of 0.3 mm using a wire drawing equipment, and plate a 10 μm thick silver layer on the surface of the fine copper wire using an electroplating process to obtain silver-plated copper wire; strand 48 strands of silver-plated copper wire are stranded together by a stranding machine to form a conductor, with a stranding pitch of 12 times the outer diameter after stranding (conductor outer diameter 3.0 mm, pitch 36 mm).

[0038] 2. Wrapping the fire-resistant insulation layer: Clean the conductor surface with alcohol, feed the conductor into the horizontal wrapping equipment, and wrap 4 layers of coated mica fire-resistant tape with a thickness of 0.2mm at a wrapping speed of 15m / min and a conductor tension of 80N, with each layer overlapping 40%; then continue to wrap 4 layers of ceramicized silicone tape with a thickness of 0.2mm on the outside at the same speed and tension, with each layer overlapping 40%.

[0039] 3. Extrusion of moisture-proof layer: The conductor wrapped with fire-resistant insulation layer is fed into an extruder, high-density polyethylene granules are added, the extrusion temperature is set to 220℃ and the extrusion speed is 12m / min, and a moisture-proof layer with a thickness of 1.5mm is extruded using vacuum sizing technology to obtain the insulated wire core (outer diameter of the insulated wire core is 6.0mm).

[0040] 4. Wrapping tape layer: Two insulated wire cores are twisted together by a cabling machine to form a cable core (the outer diameter of the cable core is 10mm and the twisting pitch is 160mm). Then, the cable core is fed into a wrapping machine and wrapped with a wrapping tension of 50N using double-layer, 0.5mm thick, high flame-retardant glass fiber tape in an overlapping manner to form a wrapping tape layer (the outer diameter of the wrapping tape layer is 11mm).

[0041] 5. Extrusion of protective layer: Weigh 100kg polyethylene granules, 30kg magnesium hydroxide and 1.0kg actinomycete ketone, add them to a high-speed mixer and mix at 100℃ for 20min; add the mixture to an extruder, set the extrusion temperature to 230℃, the extrusion pressure to 20MPa, the extrusion speed to 10m / min, and extrude a protective layer with a thickness of 2.0mm; after extrusion, cool and shape it with water at 30℃, and then pull and wind it to obtain a high fire-resistant and rodent-proof flexible fireproof cable (finished product outer diameter 15mm).

[0042] The cable prepared in this embodiment was subjected to performance testing, and the results are as follows: Fire resistance: At a flame temperature of 1200℃, the circuit remains intact after being energized for 220 minutes. Rodent-proof performance: After being placed in a simulated rodent-infested environment for 30 days, the cable protective layer showed no signs of chewing. Low temperature performance: After being placed at -70℃ for 24 hours, the cable bending and power-on functions were normal. Bending performance: No cracks or damage when the bending radius is 5 times the outer diameter of the cable; Moisture resistance: The insulation resistance remains stable after being placed in an environment with a relative humidity of 95% and a temperature of 40℃ for 100 days.

[0043] In summary, this flexible fire-resistant cable features a conductor, fire-resistant insulation layer, moisture-proof layer, insulated core, wrapping layer, and protective layer structure. It boasts a novel design and advantages such as high and low temperature resistance, aging resistance, radiation resistance, bending resistance, flame retardancy, and rodent resistance. It employs a multi-layered wrapping system using coated mica fire-resistant tape and ceramicized silicone tape, with the inner layer wrapped in coated mica fire-resistant tape and the outer layer wrapped in ceramicized silicone tape. In the event of a fire, the flame first burns the outer ceramicized silicone tape. Upon contact with the flame, the ceramicized silicone tape sinters into a hard shell, which covers the coated mica fire-resistant tape, preventing mica detachment under high temperatures and ensuring the cable's insulation performance. The cable can maintain energization for over 200 minutes at a flame temperature of 1200℃, a significant advantage compared to traditional fire-resistant cables that maintain energization for only 90 minutes at 750℃. It can also operate normally at temperatures as low as -70℃ and exhibits excellent bending performance.

[0044] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit the scope of protection of the invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on these embodiments, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art can still combine, add, delete, or otherwise adjust the features of the various embodiments of the present invention according to the circumstances without conflict or creative effort, thereby obtaining different technical solutions that do not fundamentally depart from the concept of the present invention. These technical solutions also fall within the scope of protection of the present invention.

Claims

1. A flexible fire-resistant cable, characterized in that, It includes a conductor (1), a fire-resistant insulation layer (2), a moisture-proof layer (3), an insulated wire core (4), a wrapping layer (5), and a protective layer (6); the conductor (1) is wrapped with a fire-resistant insulation layer (2), and a moisture-proof layer (3) is extruded on the fire-resistant insulation layer (2) to form an insulated wire core (4). The insulated wire core (4) is twisted together by cabling and wrapped tightly with a wrapping layer. The protective layer (6) covers the wrapping layer (5). The conductor (1) is made of silver-plated copper wire; The fire-resistant insulation layer (2) is made of coated mica fire-resistant tape and ceramicized silicone tape; The moisture barrier layer (3) is formed by extrusion of high-density polyethylene; The wrapping layer (5) is made of high flame-retardant glass fiber tape; The protective layer (6) is made of polyethylene as the base material, with flame retardant and rodent repellent mixed in evenly, and the protective layer (6) is extruded onto the wrapping layer (5) using a plastic extrusion process.

2. The flexible fire-resistant cable according to claim 1, characterized in that, The conductor (1) is formed by stranding multiple silver-plated copper wires, and the pitch of the stranded wires is 10 to 12 times the outer diameter of the stranded wires.

3. The flexible fire-resistant cable according to claim 1, characterized in that, When the fire-resistant insulation layer (2) is prepared using coated mica fire-resistant tape and ceramicized silicone tape, firstly, four layers of coated mica fire-resistant tape with a thickness of 0.2 mm are wrapped around the conductor (1) in an overlapping manner, and then four layers of ceramicized silicone tape with a thickness of 0.2 mm are wrapped around the coated mica fire-resistant tape in an overlapping manner, with an overlap rate of 30% to 40% for each layer of tape.

4. The flexible fire-resistant cable according to claim 1, characterized in that, The moisture-proof layer (3) is made of high-density polyethylene with a thickness of 1.5 mm.

5. The flexible fire-resistant cable according to claim 1, characterized in that, The wrapping layer (5) is made of double-layer high flame-retardant glass fiber tape with a thickness of 0.5mm, which is wrapped in an overlapping manner.

6. The flexible fire-resistant cable according to claim 1, characterized in that, The flame retardant mixed into the protective layer (6) is magnesium hydroxide, and the rodent repellent is actinomycete ketone.

7. A flexible fire-resistant cable according to claim 6, characterized in that, The extrusion thickness of the protective layer (6) is 2.0 mm.

8. A method for preparing a flexible fire-resistant cable as described in any one of claims 1 to 7, characterized in that, Includes the following steps: First, a conductor (1) is produced. A fire-resistant insulation layer (2) is wrapped around the conductor (1). A moisture-proof layer (3) is extruded onto the fire-resistant insulation layer (2) to form an insulated core (4). The insulated core (4) is then twisted together by cabling and wrapped tightly with a tape. A protective layer (6) is wrapped around the tape layer (5) to obtain a flexible fireproof cable.

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