Low-smoke halogen-free flame-retardant cable

Abstract

The utility model relates to cable manufacturing technical field discloses a low smoke halogen -free flame -retardant cable, including conductor core, the conductor core surrounds and is provided with a plurality of quantity halogen -free flame -retardant glass fiber band, the outer surface of conductor core is provided with first adhesive layer, the outer surface of first adhesive layer is provided with insulating layer. The utility model discloses a first adhesive layer that is set up on the outer surface of conductor core, and the first adhesive layer is bonded between conductor core and insulating layer, and the insulating layer has excellent heat resistance, electrical insulation and flame -retardant performance, and the second adhesive layer is bonded between insulating layer and shielding layer, and the shielding layer is used for isolating electromagnetic interference, and the third adhesive layer is bonded between shielding layer and flame -retardant filling layer, and the flame -retardant filling layer makes cable cross section more round, prevents the stress concentration of cable when bending or compression, and forms carbonization layer under the action of flame, delays the flame to spread to the inside, thereby can reach the effect that can fast self -extinguishing, reduces the risk of fire spread.

Description

Technical Field

[0001] This utility model relates to the field of cable manufacturing technology, specifically to a low-smoke halogen-free flame-retardant cable. Background Technology

[0002] Most existing flame-retardant cables use halogen-containing flame-retardant materials. While they can play a certain role in flame retardancy when burning, they release a large amount of toxic and harmful substances such as hydrogen halide gas and dioxins, along with dense smoke. This not only seriously threatens human health but also causes a sharp decrease in visibility at the fire scene, greatly affecting the efficiency of personnel evacuation and fire rescue, posing a significant safety hazard.

[0003] To address this issue, the industry has gradually developed low-smoke halogen-free flame-retardant cables. These cables reduce the generation of smoke and toxic gases by using halogen-free flame-retardant polyolefins in the insulation and sheath materials. While these cables have improved environmental performance to some extent, they still have shortcomings: the flame-retardant performance of existing low-smoke halogen-free materials is greatly affected by the formulation and process, and the performance of different batches of cables in combustion tests is unstable, with problems such as uneven thickness and unreasonable distribution of the flame-retardant layer. Utility Model Content

[0004] (a) Technical problems to be solved To address the shortcomings of existing technologies, this utility model provides a low-smoke, halogen-free flame-retardant cable with advantages such as rapid self-extinguishing and reduced risk of fire spread, thus solving the problems mentioned in the background section.

[0005] (II) Technical Solution To achieve the above objectives, this utility model provides the following technical solution: a low-smoke halogen-free flame-retardant cable, comprising a cable body, wherein a plurality of conductor cores are disposed in the center of the cable body, and a plurality of halogen-free flame-retardant glass fiber tapes are disposed around the conductor cores, a first adhesive layer is disposed on the outer surface of the conductor cores, an insulation layer is disposed on the outer surface of the first adhesive layer, a second adhesive layer is disposed on the outer surface of the insulation layer, a shielding layer is disposed on the outer surface of the second adhesive layer, a third adhesive layer is disposed on the outer surface of the shielding layer, and a flame-retardant filling layer is disposed on the outer surface of the third adhesive layer.

[0006] Preferably, a fourth adhesive layer is provided on the outer surface of the flame-retardant filler layer.

[0007] Preferably, the outer surface of the fourth adhesive layer is provided with an inner sheath layer.

[0008] The inner sheath layer is set on the outer surface of the fourth adhesive layer. The fourth adhesive layer uses a halogen-free hot melt adhesive with strong adhesion and achieves coating bonding through a hot extrusion process. Its main function is to firmly bond the inner sheath layer with the flame-retardant filler layer, preventing bulging or delamination of the sheath due to heat or stress, thereby enhancing the mechanical integrity of the cable. The inner sheath layer is usually made of low-smoke halogen-free polyolefin material extruded. As the first continuous protective layer inside the cable, it can effectively prevent the intrusion of moisture, dust, etc., and provide a uniform and flat base for the armor layer, avoiding mechanical damage to the internal insulation layer or filler by the metal armor.

[0009] Preferably, the outer surface of the inner sheath layer is provided with a fifth adhesive layer.

[0010] Preferably, the outer surface of the fifth adhesive layer is provided with an armor layer.

[0011] The fifth adhesive layer uses a flexible adhesive to ensure that the armor layer fits tightly against the inner sheath during the wrapping process, preventing armor loosening due to interlayer slippage, thereby improving tensile and compressive strength. The armor layer is set on the outer surface of the fifth adhesive layer. The armor layer is wrapped with steel tape or steel wire, and the thickness and wrapping angle are determined according to the cable application. Steel tape armor is suitable for general mechanical protection, while steel wire armor is more suitable for occasions requiring tensile strength. The armor layer can effectively prevent external mechanical impact, compression and rodent bites, and is especially suitable for high-risk locations such as tunnels, mines, and field power transmission.

[0012] Preferably, the outer surface of the armor layer is provided with a sixth adhesive layer.

[0013] Preferably, the outer surface of the sixth adhesive layer is provided with an outer sheath layer.

[0014] The sixth bonding layer uses halogen-free flame-retardant adhesive material to ensure a gapless bond between the outer sheath and the armor layer, thereby improving the overall sealing, moisture resistance, and flame retardancy of the cable. This prevents the sheath from bulging or peeling due to moisture or aging. The outer sheath layer is located on the outer surface of the sixth bonding layer and is the outermost protective layer of the cable. It is made of low-smoke halogen-free flame-retardant polyolefin material through extrusion molding, and its thickness is determined according to the rated voltage and mechanical strength requirements. The outer sheath not only has the characteristics of wear resistance, impact resistance, weather resistance, and UV aging resistance, but also produces a small amount of transparent smoke in a fire environment without releasing halogens or acidic gases, greatly reducing the harm to people and equipment and meeting the requirements for use in public places and high-rise buildings.

[0015] Compared with the prior art, this utility model provides a low-smoke halogen-free flame-retardant cable, which has the following beneficial effects: 1. This utility model features a first adhesive layer on the outer surface of the conductor core, which is bonded between the conductor core and the insulation layer. The insulation layer has excellent heat resistance, electrical insulation, and flame retardant properties. A second adhesive layer is bonded between the insulation layer and the shielding layer, which is used to isolate electromagnetic interference. A third adhesive layer is bonded between the shielding layer and the flame-retardant filler layer. The flame-retardant filler layer makes the cable cross-section more rounded, prevents stress concentration when the cable is bent or compressed, and forms a carbonized layer under the action of flame, which slows down the spread of flame inward. This allows for rapid self-extinguishing and reduces the risk of fire spread.

[0016] 2. This utility model provides strong mechanical protection through the armor layer set on the outer surface of the fifth adhesive layer, thereby effectively preventing damage from external impacts, squeezing, or rodent bites. In applications requiring tensile or compressive strength, it can significantly improve the service life and safety of the cable. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of the cable body of this utility model; Figure 2 This is a schematic diagram of the internal structure of the cable body of this utility model; Figure 3 This is a schematic diagram of the cross-section of the conductor core of this utility model; Figure 4 This is a schematic diagram of the radial cross-section of the cable body of this utility model.

[0018] The components are: 1. Cable body; 101. Conductor core; 102. Halogen-free flame-retardant fiberglass tape; 2. First adhesive layer; 3. Insulation layer; 4. Second adhesive layer; 5. Shielding layer; 6. Third adhesive layer; 7. Flame-retardant filler layer; 8. Fourth adhesive layer; 9. Inner sheath layer; 10. Fifth adhesive layer; 11. Armor layer; 12. Sixth adhesive layer; 13. Outer sheath layer. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0020] Please see Figure 1-4A low-smoke halogen-free flame-retardant cable includes a cable body 1. A plurality of conductor cores 101 are disposed in the center of the cable body 1. A plurality of halogen-free flame-retardant glass fiber tapes 102 are disposed around the conductor cores 101. A first adhesive layer 2 is disposed on the outer surface of the conductor cores 101. An insulation layer 3 is disposed on the outer surface of the first adhesive layer 2. A second adhesive layer 4 is disposed on the outer surface of the insulation layer 3. A shielding layer 5 is disposed on the outer surface of the second adhesive layer 4. A third adhesive layer 6 is disposed on the outer surface of the shielding layer 5. A flame-retardant filling layer 7 is disposed on the outer surface of the third adhesive layer 6. A fourth adhesive layer 8 is disposed on the outer surface of the flame-retardant filling layer 7. The conductor cores 101 are located in the innermost layer of the cable and are typically made of multiple strands of annealed copper wire or tin-plated copper wire tightly twisted together. The annealing process gives the copper wires good ductility and flexibility, enabling them to maintain stable conductivity during multiple bending and laying processes. Tin plating effectively prevents oxidation of the copper wire surface, improving corrosion resistance and weldability. The diameter and number of strands of the conductor cores 101 can be flexibly adjusted according to the rated current of the cable and the application. Halogen-free flame-retardant glass fiber tape 102 is uniformly wound around the outside of conductor core 101. The glass fiber tape is treated with halogen-free flame retardant. The glass fiber tape itself is non-combustible and has high strength and high melting point characteristics. It can form a strong skeleton structure in the environment of cable overheating or combustion, preventing the flame from spreading along the conductor. At the same time, the flexible winding method of glass fiber tape can absorb a certain mechanical stress and prevent the insulation layer 3 from being punctured by copper wire burrs during the extrusion process, playing a dual role of electrical isolation and flame retardancy. Insulation layer 3 is disposed on the outer surface of the first adhesive layer 2 and serves as a transition bonding layer between conductor core 101 and insulation layer 3. It is typically made of halogen-free flame-retardant hot melt adhesive or modified polyolefin adhesive. During the high-temperature extrusion process, this layer forms a melt-penetrating bond with insulation layer 3, ensuring that insulation layer 3 and the glass fiber tape on the surface of conductor core 101 are tightly bonded, thereby avoiding electric field concentration and partial discharge phenomena caused by interlayer voids or local peeling. Insulation layer 3 is an important component of the cable and is typically made of cross-linked polyolefin (XLPE) or low-smoke halogen-free polyolefin material. The cross-linked structure gives the material higher thermal decomposition temperature and electrical strength, and it can maintain stable performance under long-term operation at 90℃ and short-term overload at 250℃. Insulation layer 3 not only provides high dielectric strength to prevent breakdown between conductors, but also releases moisture and absorbs heat during combustion through inorganic flame retardants (such as magnesium hydroxide and aluminum hydroxide) in the material, thereby effectively preventing flame spread. The shielding layer 5 is disposed on the outer surface of the second adhesive layer 4. It is usually made of halogen-free flame-retardant adhesive material extruded and molded. Its main function is to enhance the adhesion between the insulation layer 3 and the shielding layer 5, and to prevent the shielding layer 5 from loosening, slipping or even bulging during the later twisting or wrapping process. At the same time, this layer can fill the small depressions and bumps, so that the shielding layer 5 fits more tightly, thereby improving the overall voltage resistance of the cable. The shielding layer 5 is generally formed by longitudinal wrapping of copper tape, copper wire braiding or aluminum-plastic composite tape wrapping. The single-layer or composite structure is selected according to the usage environment. The main function of the shielding layer 5 is to prevent electromagnetic leakage generated by the cable during operation from interfering with external equipment, and at the same time suppress the interference of external electromagnetic waves on internal signals. It is particularly suitable for power transmission, communication and control cables. The braiding density is usually controlled above 80% to ensure the balance between shielding effect and mechanical flexibility. The flame-retardant filler layer 7 is disposed between the third adhesive layer 6 and the fourth adhesive layer 8. The third adhesive layer 6 uses a halogen-free flame-retardant adhesive with good flexibility to ensure that the shielding layer 5 can be firmly embedded in the flame-retardant filler layer 7, avoiding wrinkling or misalignment of the shielding layer 5 due to shrinkage or loosening of the filler during long-term operation of the cable. At the same time, this layer can also serve as a stress buffer layer to reduce the damage to the shielding layer 5 caused by external mechanical impact. The flame-retardant filler layer 7 is usually composed of low-smoke halogen-free flame-retardant polyolefin material or flame-retardant rope, used to fill the gaps between the cables, making the cable cross-section more rounded and facilitating the uniform extrusion of the outer sheath. This layer can form a carbonized layer during combustion, effectively delaying flame penetration. At the same time, its flame-retardant formula contains smoke suppressants, which can significantly reduce smoke density and ensure good visibility conditions in a fire.

[0021] Specifically, such as Figure 2 and Figure 4 As shown, the outer surface of the fourth adhesive layer 8 is provided with an inner sheath layer 9.

[0022] Through the above technical solution, the inner sheath layer 9 is set on the outer surface of the fourth adhesive layer 8. The fourth adhesive layer 8 uses a halogen-free hot melt adhesive with strong adhesion and achieves encapsulation bonding through hot extrusion process. Its main function is to firmly bond the inner sheath layer 9 with the flame-retardant filler layer 7, and prevent bulging or delamination of the sheath due to heat or stress, thereby enhancing the mechanical integrity of the cable. The inner sheath layer 9 is usually extruded from low-smoke halogen-free polyolefin material. As the first continuous protective layer inside the cable, it can effectively prevent the intrusion of moisture, dust, etc., and provide a uniform and flat base for the armor layer 11, avoiding mechanical damage to the internal insulation layer 3 or filler by the metal armor.

[0023] Specifically, such as Figure 2 and Figure 4 As shown, a fifth adhesive layer 10 is provided on the outer surface of the inner sheath layer 9, and an armor layer 11 is provided on the outer surface of the fifth adhesive layer 10.

[0024] Through the above technical solution, the fifth adhesive layer 10 adopts an adhesive with a certain degree of flexibility to ensure that the armor layer 11 is tightly attached to the inner sheath layer 9 during the wrapping process, avoiding armor loosening due to interlayer slippage, thereby improving tensile and compressive strength. The armor layer 11 is set on the outer surface of the fifth adhesive layer 10. The armor layer 11 adopts steel tape wrapping or steel wire armor. The thickness and wrapping angle are determined according to the cable application. Steel tape armor is suitable for general mechanical protection, while steel wire armor is more suitable for occasions requiring tensile strength. The armor layer 11 can effectively prevent external mechanical impact, squeezing and rodent gnawing, and is especially suitable for high-risk places such as tunnels, mines, and field power transmission.

[0025] Specifically, such as Figure 2 and Figure 4 As shown, a sixth adhesive layer 12 is provided on the outer surface of the armor layer 11, and an outer sheath layer 13 is provided on the outer surface of the sixth adhesive layer 12.

[0026] Through the above technical solution, the sixth adhesive layer 12 adopts halogen-free flame-retardant adhesive material to ensure a gapless bond between the outer sheath layer 13 and the armor layer 11, thereby improving the overall sealing, moisture resistance and flame retardancy of the cable, and preventing the sheath from bulging or peeling due to moisture or aging. The outer sheath layer 13 is set on the outer surface of the sixth adhesive layer 12. The outer sheath layer 13 is the outermost protective layer of the cable. It is made of low-smoke halogen-free flame-retardant polyolefin material by extrusion molding. The thickness is determined according to the rated voltage and mechanical strength requirements. The outer sheath not only has the characteristics of wear resistance, impact resistance, weather resistance and UV aging resistance, but also produces a small amount of transparent smoke in the fire environment and does not release halogens and acid gases, which greatly reduces the harm to people and equipment and meets the use requirements of public places and high-rise buildings.

[0027] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A low-smoke halogen-free flame-retardant cable, comprising a cable body (1), characterized in that: The cable body (1) has a number of conductor cores (101) in the middle of its interior. A number of halogen-free flame-retardant glass fiber tapes (102) are arranged around the conductor cores (101). A first adhesive layer (2) is arranged on the outer surface of the conductor cores (101). An insulation layer (3) is arranged on the outer surface of the first adhesive layer (2). A second adhesive layer (4) is arranged on the outer surface of the insulation layer (3). A shielding layer (5) is arranged on the outer surface of the second adhesive layer (4). A third adhesive layer (6) is arranged on the outer surface of the shielding layer (5). A flame-retardant filling layer (7) is arranged on the outer surface of the third adhesive layer (6).

2. The low-smoke halogen-free flame-retardant cable according to claim 1, characterized in that: A fourth adhesive layer (8) is provided on the outer surface of the flame-retardant filler layer (7).

3. The low-smoke halogen-free flame-retardant cable according to claim 2, characterized in that: The outer surface of the fourth adhesive layer (8) is provided with an inner sheath layer (9).

4. The low-smoke halogen-free flame-retardant cable according to claim 3, characterized in that: The outer surface of the inner sheath layer (9) is provided with a fifth adhesive layer (10).

5. A low-smoke halogen-free flame-retardant cable according to claim 4, characterized in that: An armor layer (11) is provided on the outer surface of the fifth adhesive layer (10).

6. A low-smoke halogen-free flame-retardant cable according to claim 5, characterized in that: The outer surface of the armor layer (11) is provided with a sixth adhesive layer (12).

7. A low-smoke halogen-free flame-retardant cable according to claim 6, characterized in that: The outer surface of the sixth adhesive layer (12) is provided with an outer sheath layer (13).

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