Fireproof flexible female cable and preparation method thereof

Abstract

The invention discloses a fireproof flexible female cable which comprises a supporting steel pipe, four partition plates are arranged on the supporting steel pipe, and a plurality of wires are arranged among the four partition plates. A mica-wrapped tape and a ceramic silica gel tape are sequentially wound on the outer side of the conductor; a linked polyethylene insulating layer is arranged on the outer side of the fireproof insulating layer, and a plurality of isolation teeth are integrally extruded on the linked polyethylene insulating layer; the wire is installed through the supporting steel pipe and the partition plate which are integrally formed, and overall spiral twisting is carried out, so that the wire can be stably installed between the supporting steel pipe and the partition plate through the fireproof cable filler, heat generated by the wire can be conveniently dissipated through the hollow shape in the middle of the supporting steel pipe, and the safety use of the wire is improved; through the multi-layer composite structure design and innovative material combination, the comprehensive performance of the cable in extreme environments such as high temperature and fire disasters is improved, and the flexibility, the mechanical strength and the environmental protection property are considered at the same time.

Description

Technical Field

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

[0002] With the rapid development of the construction and installation industry, mineral cables have been widely used in modern medium and high-end building installation projects due to their many advantages, such as fire resistance, high temperature resistance, large current carrying capacity, impact voltage resistance, mechanical damage resistance, safety and long service life.

[0003] Flexible mineral-insulated cables are composed of copper stranded wires, mineral compound insulation, and a mineral compound sheath. They feature a flexible structure and are primarily made of inorganic materials, overcoming the drawbacks of rigidity, flammability, and toxicity. They also possess advantages not found in other cables, such as fire resistance, high current carrying capacity, resistance to impact voltage, resistance to mechanical damage, halogen-free and non-toxic, explosion-proof, waterproof, corrosion-resistant, long lifespan, safety, overload resistance, high temperature resistance, and low cost.

[0004] The characteristics of flexible mineral-insulated cables: Unlike regular wires and cables, which use organic polymer materials for insulation, making them prone to carbonization and loss of insulation under flame conditions, flexible mineral-insulated fire-resistant cables are primarily composed of mineral compounds. These compounds themselves do not cause fires and cannot burn or support combustion. Furthermore, these materials generally have high melting points, allowing the fire-resistant cable to maintain its normal power transmission function even under flame conditions, making it a truly fire-resistant cable.

[0005] The existing technology, with publication number CN116564600A, entitled "A Flexible Fire-resistant Cable and Its Manufacturing Method," includes a conductor, a fire-resistant layer, an insulation layer, a mineral-filled layer, a high flame-retardant layer, and a sheath layer. The manufacturing method of the flexible fire-resistant cable in this invention involves continuous pulling and unwinding, stranding, wrapping with mica tape, extruding insulation, cabling, extruding a mineral-filled layer, wrapping with a high flame-retardant layer, and extruding an outer sheath. The outer sheath of the flexible fire-resistant cable in this invention has the characteristics of flexibility, fire resistance, low smoke, halogen-free, temperature resistance, fire resistance, high current carrying capacity, and high mechanical strength.

[0006] However, while the aforementioned technologies offer advantages such as flexibility, fire resistance, low smoke, halogen-free operation, temperature resistance, fire resistance, high current carrying capacity, and high mechanical strength, they cannot effectively dissipate heat from the cable or provide stable support. Furthermore, existing cables are still prone to combustion at high temperatures. Summary of the Invention

[0007] One objective of this invention is to provide a new technical solution for fire-resistant flexible bus cable and its preparation method.

[0008] According to a first aspect of the present invention, a fire-resistant flexible bus cable is provided, comprising a supporting steel pipe, four partition plates being provided on the supporting steel pipe, and a plurality of conductors being provided between the four partition plates, wherein the supporting steel pipe, the partition plates and the conductors are combined to form a conductor;

[0009] The conductor is wrapped with mica tape and ceramicized silicone tape in sequence on the outside, and the mica tape and the ceramicized silicone tape form a fireproof insulation layer.

[0010] The fireproof insulation layer is provided with a polyethylene insulation layer on the outside. A plurality of isolation teeth are integrally extruded on the polyethylene insulation layer, and a first fireproof flexible material and a second fireproof flexible material are filled between the plurality of isolation teeth.

[0011] The outer side of the polyethylene insulation layer is wrapped with a mineral fireproof strip, and the outer side of the mineral fireproof strip is also provided with a low-smoke halogen-free sheath layer.

[0012] Furthermore, the supporting steel pipe and the four partition plates are integrally formed and twisted as a whole.

[0013] Furthermore, fire-resistant cable filler is filled between the four partition plates, and several wires are embedded inside the fire-resistant cable filler at equal intervals and angles. The thickness of the fire-resistant cable filler is the same as the depth of the four partition plates.

[0014] Furthermore, the mica tape and the ceramicized silicone tape are alternately wound around the outside of the conductor in sequence. The mica tape and the ceramicized silicone tape have the same thickness, which is 1-2 mm.

[0015] Furthermore, the insulating teeth are integrally formed on both the inner and outer sides of the polyethylene insulation layer, and the insulating teeth on both the inner and outer sides are correspondingly provided. The first fire-resistant flexible material is provided on the inner side of the polyethylene insulation layer, and the second fire-resistant flexible material is provided on the outer side of the polyethylene insulation layer.

[0016] Furthermore, the first fire-resistant flexible material is uniformly filled between the isolation teeth on the inner side of the polyethylene insulation layer, and the second fire-resistant flexible material is uniformly filled between the isolation teeth on the outer side of the polyethylene insulation layer. The thickness of the first fire-resistant flexible material and the second fire-resistant flexible material is the same as the thickness of the isolation teeth.

[0017] Furthermore, the mineral fireproof belt is made of fiberglass rope, which is formed by stacking fiberglass ropes to form a fiberglass rope mesh layer.

[0018] A method for preparing a fire-resistant flexible busbar includes the following steps:

[0019] S1. Process the support steel pipe to the required size and generate four integrated partition plates by extrusion. Then apply an anti-corrosion coating to the surface of the support steel pipe and partition plates.

[0020] S2. Embed several wires at equal intervals and angles between the fireproof cable filler, and then fill the fireproof cable filler with the embedded wires between the partition plates.

[0021] S3. Then, the conductor is spirally twisted as a whole, so that the conductor can rotate as a whole, improving the integrity between the wire, the supporting steel pipe and the partition plate;

[0022] S4. Mica tape and ceramicized silicone tape are wrapped around the outside of the rotating conductor in sequence to form a fireproof insulation layer;

[0023] S5. Extrude a polyethylene insulation layer on the outside of the fireproof insulation layer, and integrally form isolation teeth on both the inner and outer sides of the polyethylene insulation layer.

[0024] S6. Fill the space between the isolation teeth with a first fire-resistant flexible material and a second fire-resistant flexible material;

[0025] S7. Wrap a mineral fireproof strip around the outside of the polyethylene insulation layer, and finally extrude a low-smoke halogen-free sheath layer.

[0026] Furthermore, the preparation steps of the fire-resistant cable filler in S2 are as follows:

[0027] S201. Raw material pretreatment: Aluminum hydroxide, expanded graphite, phosphorus-based flame retardant and bio-based flame retardant are subjected to high-energy ball milling to obtain a premix.

[0028] S202, Matrix material synthesis: Foamed silicone rubber matrix and premix are mixed in proportion, anti-blocking agent is added, and cured and molded by high temperature vulcanization process to form a flexible filler;

[0029] S203. Filling process: Several wires are embedded at equal intervals and angles between the fillers of the fireproof cable. Vacuum impregnation or pressure injection process is used to ensure that the fillers are evenly distributed and free of air bubbles.

[0030] S204 Surface treatment: The surface of the fireproof cable filler is treated with a nano-coating, and shape memory polymer microcapsules are embedded in the fireproof cable filler.

[0031] Furthermore, the preparation steps of the mineral fireproof strip in S7 are as follows:

[0032] S701. Raw material pretreatment: Mix magnesium oxide, aluminum oxide, expanded graphite and bio-based flame retardant in proportion and disperse them evenly using a high-energy ball mill.

[0033] S702, Binder addition: Add silicate binder, and ensure uniform dispersion of mineral particles by wet or dry mixing. Add a small amount of silane coupling agent for surface treatment to obtain a mixture.

[0034] S703, Molding process: The mixture is hot-pressed to form a fireproof belt substrate, forming a dense structure and thus a fireproof belt;

[0035] S704 Surface treatment: The surface of the fireproof belt is treated with a nano-coating and embedded with shape memory polymer microcapsules, which are then cured at high temperature.

[0036] The beneficial effects of this invention are:

[0037] This invention utilizes an integrally formed support steel pipe and partition plate to install the conductor, and uses fire-resistant cable filler to embed the conductor, maintaining the stability of the conductor installation. Furthermore, the support steel pipe, partition plate, and conductor are combined into a conductor and twisted into a spiral shape, allowing the conductor to be stably installed between the support steel pipe and partition plate using the fire-resistant cable filler. The design of the support steel pipe and partition plate also allows for heat separation of conductors in different areas, and the hollow structure in the middle of the support steel pipe facilitates heat dissipation from the conductor, improving the safety of the conductor's use.

[0038] This invention enhances the overall performance of cables in extreme environments such as high temperatures and fires through a multi-layered composite structure design and innovative material combinations, while also taking into account flexibility, mechanical strength, and environmental friendliness. The design of the integrated molding and overall spiral twisting of the supporting steel pipe and separator not only enhances the structural stability of the conductor but also optimizes the mechanical distribution between the conductors through the spiral structure, improving the tensile strength and compressive strength of the cable. The alternating winding structure of mica tape and ceramicized silicone tape, combined with a low-smoke halogen-free sheath layer, forms a multi-level fire barrier, significantly extending the fire resistance time of the cable in a fire while reducing the release of toxic gases and smoke.

[0039] The integrated insulating tooth structure of the polyethylene insulation layer, with its inner and outer surfaces, combined with the filling of the first and second fire-resistant flexible materials, enhances the cable's mechanical support capabilities and improves its overall flexibility through the synergistic effect of the materials. The mineral fireproof strip uses a grid layer structure formed by stacked glass fiber ropes, combined with nano-level flame retardants and self-healing microcapsule technology, to further strengthen the cable's high-temperature resistance and compressive strength. At the same time, surface treatment and material optimization ensure the compatibility and stability between the layers.

[0040] Other features and advantages of the invention will become clear from the following detailed description of exemplary embodiments of the invention with reference to the accompanying drawings. Attached Figure Description

[0041] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of the invention and, together with their description, serve to explain the principles of the invention.

[0042] Figure 1 This is a schematic diagram of a fire-resistant flexible female cable in one embodiment;

[0043] Figure 2 This is a schematic diagram of the polyethylene insulation layer of a fire-resistant flexible bus cable in one embodiment.

[0044] Figure 3 This is a schematic diagram of the winding of mica tape and ceramicized silicone tape in one embodiment of a fire-resistant flexible female cable;

[0045] Figure 4 This is a schematic diagram of the conductor structure of a fire-resistant flexible female cable and its preparation method in one embodiment;

[0046] Figure 5 This is a schematic diagram of the supporting steel pipe and partition plate of a fire-resistant flexible bus cable and its preparation method in one embodiment;

[0047] Figure 6 This is a schematic flowchart of the steps in a method for preparing a fire-resistant flexible female cable in another embodiment;

[0048] Figure 7 This is a schematic diagram of the preparation steps of the fire-resistant cable filler in a method for preparing a fire-resistant flexible female cable according to another embodiment;

[0049] Figure 8 This is a schematic diagram of the preparation steps of a mineral fireproof strip in a method for preparing a fireproof flexible female cable according to another embodiment.

[0050] The following are marked in the diagram: 1. Supporting steel pipe; 2. Separator plate; 3. Conductor; 4. Fireproof cable filler; 5. Mica tape; 6. Ceramicized silicone tape; 7. Polyethylene insulation layer; 8. Isolation teeth; 9. First fireproof flexible material; 10. Second fireproof flexible material; 11. Mineral fireproof strip; 12. Low smoke halogen-free sheath layer. Detailed Implementation

[0051] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention.

[0052] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use.

[0053] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0054] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0055] Example 1:

[0056] like Figure 1-5 As shown, a fireproof flexible bus cable includes a supporting steel pipe 1, four partition plates 2 are provided on the supporting steel pipe 1, and a number of conductors 3 are provided between the four partition plates 2. The supporting steel pipe 1, the partition plates 2 and the conductors 3 are combined to form a conductor.

[0057] The conductor is wrapped with mica tape 5 and ceramicized silicone tape 6 in sequence on the outside. The mica tape 5 and ceramicized silicone tape 6 form a fireproof insulation layer.

[0058] A polyethylene insulation layer 7 is provided on the outside of the fireproof insulation layer. A plurality of isolation teeth 8 are integrally extruded on the polyethylene insulation layer 7. A first fireproof flexible material 9 and a second fireproof flexible material 10 are filled between the plurality of isolation teeth 8.

[0059] The outer side of the polyethylene insulation layer 7 is wrapped with a mineral fireproof strip 11, and the outer side of the mineral fireproof strip 11 is also provided with a low smoke halogen-free sheath layer 12.

[0060] In this embodiment, preferably, the supporting steel pipe 1 and the four partition plates 2 are integrally formed and twisted as a whole.

[0061] It should be noted that the design of integrally forming the supporting steel pipe 1 and the four partition plates 2 with an overall spiral twist improves the structural stability and mechanical properties of the conductor. Furthermore, the uniform arrangement of the conductors enhances their heat dissipation performance. The integral forming process creates a tightly integrated composite structure between the supporting steel pipe 1 and the four partition plates 2, reducing the problems of delamination, breakage, or connection failure caused by the separate design. The overall spiral twist structure not only improves the flexibility of the conductor, giving the cable superior bending performance in complex installation environments, but also effectively disperses the stress between the conductors.

[0062] For cylindrical members, the formula for calculating torsional stiffness k is as follows:

[0063]

[0064] Where G represents the shear modulus of steel, typically taken as G≈7.5×10⁻⁶. 10 Pa; J represents the polar moment of inertia; L represents the length of the member; k represents the numerical value of the torsional stiffness;

[0065] The calculation for a hollow cylinder is as follows:

[0066]

[0067] Where D represents the outer diameter of the supporting steel pipe 1, d represents the inner diameter of the supporting steel pipe 1; J represents the polar moment of inertia, which is a key parameter for measuring the torsional resistance of a material. The larger the value, the smaller the deformation of the material under torque.

[0068] The formula for calculating the twist angle is as follows:

[0069] When a torque T is applied, the formula for calculating the torsion angle θ is:

[0070]

[0071] Where θ represents the torsion angle, which is the deformation angle of the supporting steel pipe 1 under torque, used to evaluate its flexibility and torsional performance; T represents the torque, which is the torsional moment applied to the cable; L represents the rod length, i.e., the torsional length of the cable, which affects the amount of deformation; G represents the shear modulus, which reflects the material's ability to resist shear deformation and is related to the material type; J represents the polar moment of inertia, which directly affects the torsional stiffness.

[0072] Converted to angle:

[0073] in, It is expressed in radians for the conversion.

[0074] In this embodiment, preferably, fireproof cable filler 4 is filled between the four partition plates 2, and several wires 3 are embedded in the fireproof cable filler 4 at equal intervals and angles. The thickness of the fireproof cable filler 4 is the same as the depth of the four partition plates 2.

[0075] It should be noted that the space between the four partition plates 2 is filled with fire-resistant cable filler 3, and several conductors 3 are embedded inside the filler 3 at equal intervals and angles. This improves the structural stability, fire resistance, and flexibility of the cable, and optimizes the uniformity and mechanical distribution of the conductors 3. Furthermore, the thickness of the fire-resistant cable filler 3 is the same as the depth of the partition plates 2, ensuring that the fire-resistant cable filler 3 fully covers the partition plates 2, avoiding structural weaknesses caused by gaps, and enhancing the overall compressive strength and bending resistance of the cable. The equal intervals and angles of the conductors 3 embedded inside the fire-resistant cable filler 3 not only improve the mechanical balance between the conductors 3, but also effectively disperse thermal stress, reduce the risk of short circuits, and improve the conductivity uniformity and fire resistance of the cable.

[0076] In this embodiment, preferably, the mica tape 5 and the ceramicized silicone tape 6 are alternately wound around the outside of the conductor, and the mica tape 5 and the ceramicized silicone tape 6 have the same thickness, which is 1-2 mm.

[0077] It should be noted that by alternately wrapping the outer side of the conductor with mica tape 5 and ceramicized silicone tape 6, and combining the structural feature of the same thickness, the fire resistance of the cable is significantly improved, and the uniform distribution and processing adaptability of the materials are optimized. Through alternating wrapping, the natural fire-resistant properties of mica tape 5 and the high-temperature barrier ability of ceramicized silicone tape 6 form a synergistic effect, enabling the fireproof insulation layer to maintain its insulation performance continuously in a fire, and extending the fire resistance time to ≥90 minutes. The uniform thickness design avoids stress concentration or uneven material performance caused by differences in interlayer thickness, and enhances the overall structural uniformity and compressive strength of the cable.

[0078] In this embodiment, preferably, the inner and outer sides of the polyethylene insulation layer 7 are integrally formed with isolation teeth 8, and the isolation teeth 8 on the inner and outer sides are correspondingly provided. The first fireproof flexible material 9 is provided on the inner side of the polyethylene insulation layer 7, and the second fireproof flexible material 10 is provided on the outer side of the polyethylene insulation layer 7.

[0079] It should be noted that by integrally molding the isolation teeth 8 on both the inner and outer sides of the polyethylene insulation layer 7, the integrity of the polyethylene insulation layer 7 is improved, and its support is enhanced. At the same time, filling the inner side with the first fire-resistant flexible material 9 and the outer side with the second fire-resistant flexible material 10 significantly improves the mechanical strength, fire resistance and structural stability of the cable; and the isolation teeth 8 uniformly disperse the stress between the conductors.

[0080] In this embodiment, preferably, the first fire-resistant flexible material 9 is uniformly filled between the isolation teeth 8 on the inner side of the polyethylene insulation layer 7, and the second fire-resistant flexible material 10 is uniformly filled between the isolation teeth 8 on the outer side of the polyethylene insulation layer 7. The thickness of the first fire-resistant flexible material 9 and the second fire-resistant flexible material 10 is the same as the thickness of the isolation teeth 8.

[0081] It should be noted that the first fire-resistant flexible material 9 and the second fire-resistant flexible material 10 are uniformly filled between the isolation teeth 8 on the inner and outer sides of the polyethylene insulation layer 7, respectively. This improves the cable's mechanical support, fire resistance, and structural uniformity. Through uniform filling, they can closely fit the geometric structure of the isolation teeth 8, avoiding structural weaknesses caused by gaps or local stress concentration, and enhancing the overall compressive strength and bending resistance of the cable. The design that the thickness is consistent with the isolation teeth 8 ensures the mechanical matching between the materials and the isolation teeth 8, so that the first fire-resistant flexible material 9 and the second fire-resistant flexible material 10 together with the isolation teeth form a stable support system under high temperature or mechanical stress, further improving the cable's fire resistance and thermal stability.

[0082] In this embodiment, preferably, the mineral fireproof belt 11 is made of glass fiber rope, and the mineral fireproof belt 11 is formed by stacking glass fiber ropes to form a glass fiber rope grid layer.

[0083] It should be noted that the mineral fireproof strip 11 uses fiberglass rope and is designed to form a grid layer structure through stacking. This significantly improves the cable's high-temperature resistance, compressive strength, and fire safety, while also taking into account the material's flexibility and environmental friendliness. Fiberglass rope has excellent heat resistance and high strength. After being stacked to form a grid layer, it can effectively disperse thermal stress in a fire, avoiding insulation failure caused by local overheating. It can also enhance the cable's mechanical support capacity, improve tensile strength and compressive strength. The uniform distribution of the grid layer structure reduces structural weak points caused by gaps or local stress concentration, ensuring that the cable maintains stability and integrity in high-temperature environments. At the same time, the low-smoke and halogen-free characteristics of fiberglass rope match the environmental protection requirements of the subsequent sheath layer, significantly reducing the smoke concentration and toxic gas release during a fire.

[0084] refer to Figure 6-8 A method for preparing a fire-resistant flexible bus cable includes the following steps:

[0085] S1. The supporting steel pipe 1 is processed into the required size and four integrated partition plates 2 are generated by extrusion. Then, an anti-corrosion coating is applied to the surface of the supporting steel pipe 1 and the partition plates 2.

[0086] S2. Embed several wires 3 at equal intervals and angles between the fireproof cable filler 4, and then fill the fireproof cable filler 4 with the embedded wires 3 between the partition plates 2.

[0087] S3. Then, the conductor is spirally twisted as a whole, so that the conductor can rotate as a whole, improving the integrity between the conductor 3, the supporting steel pipe 1, and the partition plate 2.

[0088] S4. Wrap mica tape 5 and ceramicized silicone tape 6 around the outside of the rotating conductor in sequence to form a fireproof insulation layer;

[0089] S5. Extrude a polyethylene insulation layer 7 on the outside of the fireproof insulation layer, and integrally form isolation teeth 8 on both the inner and outer sides of the polyethylene insulation layer 7.

[0090] S6. Fill the space between the isolation teeth 8 with the first fire-resistant flexible material 9 and the second fire-resistant flexible material 10;

[0091] S7. Mineral fireproof strip 11 is wrapped around the outside of the polyethylene insulation layer 7, and finally a low-smoke halogen-free sheath layer 12 is extruded.

[0092] In this embodiment, preferably, the preparation steps of the fireproof cable filler 4 in S2 are as follows:

[0093] S201. Raw material pretreatment: Aluminum hydroxide, expanded graphite, phosphorus-based flame retardant and bio-based flame retardant are subjected to high-energy ball milling to obtain a premix.

[0094] S202, Matrix material synthesis: Foamed silicone rubber matrix and premix are mixed in proportion, anti-blocking agent is added, and cured and molded by high temperature vulcanization process to form a flexible filler;

[0095] S203. Filling process: Several wires 3 are embedded at equal intervals and angles between the fireproof cable filler 4. Vacuum impregnation or pressure injection process is used to ensure that the filler is evenly distributed and free of air bubbles.

[0096] S204, Surface treatment: The surface of the fireproof cable filler 4 is treated with a nano-coating, and shape memory polymer microcapsules are embedded in the fireproof cable filler 4.

[0097] It should be noted that, through the synergistic effect of high-energy ball milling, nano-coating, and shape memory polymer microcapsules, the filler can maintain its insulation performance continuously under high temperature or fire conditions, with a fire resistance time of ≥90 minutes; the uniformly distributed filler and anti-blocking agent avoid local stress concentration, improving the cable's compressive, tensile, and bending resistance; vacuum impregnation or pressure injection processes improve filling efficiency and reduce material waste; the introduction of nano-coating and shape memory polymer microcapsules further optimizes material properties and reduces overall production costs; thus, a comprehensive improvement has been achieved in the fire resistance, mechanical strength, flexibility, and environmental friendliness of fire-resistant cable fillers.

[0098] In this embodiment, preferably, the preparation steps of the mineral fireproof strip 11 in S7 are as follows:

[0099] S701. Raw material pretreatment: Mix magnesium oxide, aluminum oxide, expanded graphite and bio-based flame retardant in proportion and disperse them evenly using a high-energy ball mill.

[0100] S702, Binder addition: Add silicate binder, and ensure uniform dispersion of mineral particles by wet or dry mixing. Add a small amount of silane coupling agent for surface treatment to obtain a mixture.

[0101] S703, Molding process: The mixture is hot-pressed to form a fireproof belt substrate, forming a dense structure and thus a fireproof belt;

[0102] S704, Surface Treatment: The surface of the fireproof belt is treated with a nano-coating and embedded with shape memory polymer microcapsules, which are then cured at high temperature;

[0103] It should be noted that through the synergistic effect of high-energy ball milling, silane coupling agent treatment, and nano-coating, the mineral fireproof strip can continuously maintain its insulation performance during a fire, with a fire resistance time of ≥90 minutes, and possesses excellent high-temperature resistance characteristics, with a temperature resistance of ≥800℃. The dense molding process and the addition of silicate binders give the fireproof strip high compressive strength (≥50MPa) and tensile strength (≥10MPa), avoiding structural damage caused by thermal stress or mechanical damage. The use of bio-based flame retardants and low-smoke halogen-free materials significantly reduces harmful gas emissions during a fire, with a smoke concentration of ≤0.5%, while improving the fire resistance and mechanical strength of the cable. The embedding of shape memory polymer microcapsules gives the fireproof strip the ability to self-repair after a fire, restoring structural integrity and extending the service life of the cable.

[0104] While specific embodiments of the invention have been described in detail by way of examples, those skilled in the art should understand that the examples are for illustrative purposes only and not intended to limit the scope of the invention. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of the invention. The scope of the invention is defined by the appended claims.

Claims

1. A fire resistant flexible female cable, characterized by: The utility model provides an improved structure of the cable, including support steel pipe (1), be provided with four partition board (2) on support steel pipe (1), be equipped with a plurality of wires (3) between four partition board (2), support steel pipe (1), partition board (2) and wire (3) combination into conductor; The outer side of the conductor is sequentially wound with mica tape (5) and ceramicized silicone tape (6), and the mica tape (5) and the ceramicized silicone tape (6) constitute a fireproof insulation layer. The outer side of the fireproof insulation layer is provided with a polyethylene insulation layer (7), and a plurality of isolation teeth (8) are integrally extruded on the polyethylene insulation layer (7), and the first fireproof flexible material (9) and the second fireproof flexible material (10) are filled between the plurality of isolation teeth (8). The outer side of the polyethylene insulation layer (7) is wound with a mineral fireproof tape (11), and the outer side of the mineral fireproof tape (11) is further provided with a low-smoke halogen-free sheath layer (12).

2. A fire resistant flexible female cable according to claim 1, characterised in that: The support steel pipe (1) and the four partition boards (2) are integrally formed, and the support steel pipe (1) and the four partition boards (2) are integrally twisted.

3. A fire resistant flexible female cable according to claim 2, characterised in that: The four partition boards (2) are filled with a fireproof cable filler (4), and the plurality of wires (3) are embedded in the fireproof cable filler (4) at equal intervals and angles, and the thickness of the fireproof cable filler (4) is the same as the depth of the four partition boards (2).

4. A fire resistant flexible female cable according to claim 1, characterised in that: The mica tape (5) and the ceramicized silicone tape (6) are alternately wound on the outer side of the conductor, and the thicknesses of the mica tape (5) and the ceramicized silicone tape (6) are the same, and the thicknesses of the mica tape (5) and the ceramicized silicone tape (6) are both 1-2 mm.

5. A fire resistant flexible female cable according to claim 1, wherein: The inner side and the outer side of the polyethylene insulation layer (7) are both integrally provided with the isolation teeth (8), and the isolation teeth (8) on the inner side and the outer side are correspondingly arranged, the first fireproof flexible material (9) is arranged on the inner side of the polyethylene insulation layer (7), and the second fireproof flexible material (10) is arranged on the outer side of the polyethylene insulation layer (7).

6. A fire resistant flexible female cable according to claim 5, characterised in that: The first fireproof flexible material (9) is uniformly filled between the isolation teeth (8) on the inner side of the polyethylene insulation layer (7), the second fireproof flexible material (10) is uniformly filled between the isolation teeth (8) on the outer side of the polyethylene insulation layer (7), and the thicknesses of the first fireproof flexible material (9) and the second fireproof flexible material (10) are the same as the thickness of the isolation teeth (8).

7. A fire resistant flexible female cable according to claim 1, wherein: The mineral fireproof tape (11) adopts a glass fiber rope, and the mineral fireproof tape (11) forms a glass fiber rope grid layer by stacking the glass fiber ropes.

8. A process for the production of a fire resistant flexible female cable, characterized in that: The method is used for preparing the structure of any one of claims 1-7, comprising the following steps: S1, the support steel pipe (1) is processed into the required size, and four partition boards (2) are integrally generated by extrusion, and then a corrosion-resistant coating is coated on the surface of the support steel pipe (1) and the partition boards (2); S2, embed several wires (3) at equal intervals and angles between the fireproof cable filler (4), and then fill the fireproof cable filler (4) embedding the wires (3) between the partition plates (2); S3, then the whole spiral torsion of the conductor, so that the conductor can rotate as a whole, improve the integrity between the wire (3), the support steel pipe (1) and the partition plate (2); S4, mica tape (5) and ceramic silicone tape (6) are wound outside the rotating conductor in turn to form a fireproof insulation layer; S5, extruding cross-linked polyethylene insulation layer (7) outside the fireproof insulation layer, and integrally forming isolation teeth (8) on the inner and outer sides of the cross-linked polyethylene insulation layer (7); S6, fill the first fireproof flexible material (9) and the second fireproof flexible material (10) between the isolation teeth (8); S7, winding mineral fireproof tape (11) outside the cross-linked polyethylene insulation layer (7), and finally extruding low smoke halogen-free sheath layer (12).

9. A method of manufacturing a fire resistant flexible female cable according to claim 8, characterized in that: The preparation steps of the fireproof cable filler (4) in S2 are as follows: S201, raw material pretreatment: high-energy ball milling of aluminum hydroxide, expanded graphite, phosphorus-based flame retardant and bio-based flame retardant to obtain a premix; S202, synthesis of matrix material: mixing the foamed silicone rubber matrix with the premix in proportion, adding an anti-blocking agent, and curing by high temperature vulcanization process to form a flexible filler; S203, filling process: embedding several wires (3) at equal intervals and angles between the fireproof cable filler (4), using vacuum impregnation or pressure injection process to ensure uniform distribution of the filler and no bubbles; S204, surface treatment: nano coating treatment of the surface of the fireproof cable filler (4), and embedding shape memory polymer microcapsules in the fireproof cable filler (4).

10. A method of manufacturing a fire resistant flexible female cable according to claim 8, characterized in that: The preparation steps of the mineral fireproof tape (11) in S7 are as follows: S701, raw material pretreatment: mixing magnesium oxide, aluminum oxide, expanded graphite and bio-based flame retardant in proportion, and uniformly dispersing them using a high-energy ball mill; S702, binder addition: adding silicate binder, and uniformly dispersing the mineral particles by wet mixing or dry mixing, and adding a small amount of silane coupling agent for surface treatment to obtain a mixture; S703, forming process: forming the mixture into a fireproof tape substrate by hot pressing to form a dense structure and form a fireproof tape; S704, surface treatment: nano coating treatment of the surface of the fireproof tape, and embedding shape memory polymer microcapsules, and curing by high temperature.

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