Low-smoke halogen-free flame-retardant fire-resistant cable and production method thereof

Abstract

The invention relates to the technical field of cables, in particular to a low-smoke halogen-free flame-retardant fire-resistant cable and a production method thereof. The cable comprises a stranded conductor, a glass fiber tape, an inner sheath, a toothed sleeve, an oxygen barrier layer, a halogen-free low-smoke high-flame-retardant tape and an outer sheath which are sequentially sleeved from inside to outside. The invention aims to provide the low-smoke halogen-free flame-retardant fire-resistant cable so as to solve the problems that when the oxygen barrier layer is extruded, the oxygen barrier material of the oxygen barrier layer is not uniformly distributed, so that the surface fire-proof and heat-insulating effects are not uniform, and the part with less filler is easier to burn and crack than the part with more filler; the invention aims to provide the production method of the low-smoke halogen-free flame-retardant fire-resistant cable so as to effectively slow down fire spreading in the combustion process and achieve the functions of fire prevention, heat insulation and flame retardance.

Description

Technical Field

[0001] The present invention relates to the technical field of cables, and in particular to a low-smoke, halogen-free, flame-retardant and fire-resistant cable and a production method thereof. Background Art

[0002] With the continuous acceleration of economic construction, the number of various large-scale industrial facilities, high-rise commercial buildings, underground buildings and residential houses has gradually increased. The urban population is becoming more and more dense, the functions are becoming more and more complex, the total amount of cables used in scenes such as subways, hospitals, and airports is increasing, and the density of laying is also increasing. With the frequent occurrence of electrical fire accidents, the flame retardant problem of wires and cables has gradually attracted everyone's attention.

[0003] At present, the implementation standard of flame-retardant cables in China is mainly based on GB / T19666-2005 "General Rules for Flame-retardant and Fire-resistant Wires and Cables". In the flame-retardant performance experimental method standard, the current commonly used cable specifications of ZA-YJV-0.6 / 1kV-4×50+1×25mm2 and performance were verified many times. The qualified rate of multiple structural verification tests was extremely low. From the results of multiple structural verifications, it is difficult to meet the current market demand. As a result, the existing cables can resist fire and flame, and have insulation and heat insulation when burned, but they cannot effectively slow down the spread of fire, resulting in a large range of fire when burned, which is difficult to effectively control.

[0004] Therefore, how to design a low-smoke, halogen-free, flame-retardant and fire-resistant cable and a production method thereof that can solve the above-mentioned technical problems is a technical problem that needs to be solved. Summary of the invention

[0005] In order to solve the above problems, the first object of the present invention is to provide a low-smoke halogen-free flame-retardant and fire-resistant cable, so as to solve the problem that when the oxygen insulation material of the oxygen insulation layer is unevenly distributed when the oxygen insulation layer is extruded, the fireproofing and heat insulation effect on the surface thereof is uneven, and the part with less filler is more likely to burn and rupture than the part with more filler; the second object of the present invention is to provide a production method of a low-smoke halogen-free flame-retardant and fire-resistant cable, so as to effectively slow down the spread of fire during the combustion process and achieve the functions of fireproofing, heat insulation and flame retardancy.

[0006] To achieve the above-mentioned first object, the present invention adopts the following technical scheme: comprising a stranded conductor, a glass fiber tape, an inner sheath, a tooth sleeve, an oxygen-isolating layer, a halogen-free low-smoke high-flame-retardant tape and an outer sheath which are sequentially sleeved from the inside to the outside;

[0007] The twisted conductor is composed of three power line cores, one neutral line core and one ground line twisted together; the inside of the twisted conductor is filled with minerals; the power line core, the neutral line core and the ground line core have the same structure, and are sequentially covered with conductors, silicone tapes and insulation layers from the inside to the outside;

[0008] The outer periphery of the insulating layer is sequentially covered with the glass fiber tape, the inner sheath, the tooth sleeve, the oxygen isolation layer, the halogen-free low-smoke high flame retardant tape and the outer sheath;

[0009] The outer peripheral wall of the gear sleeve is integrally provided with a plurality of blocking teeth equidistantly along its circumference;

[0010] Furthermore, the thickness of the silicone tape is 1.55-1.65 mm;

[0011] Furthermore, the thickness of the insulating layer is 0.81-0.89 mm;

[0012] Furthermore, the thickness of the glass fiber tape is 1.1-1.9 mm;

[0013] Furthermore, the thickness of the inner sheath is 1.5-1.7 mm;

[0014] Furthermore, the thickness of the gear sleeve is 0.85-10.0 mm;

[0015] Furthermore, the thickness of the oxygen barrier layer is 1.55-1.65 mm;

[0016] Furthermore, the thickness of the halogen-free, low-smoke, high-flame-retardant tape is 2.0-3.0 mm;

[0017] Furthermore, the thickness of the outer sheath is 1.5-1.7 mm.

[0018] Furthermore, the material of the insulating layer is refractory mica;

[0019] Furthermore, the inner sheath is made of environmentally friendly Teflon;

[0020] Furthermore, the material of the gear sleeve is radiation cross-linked flame-retardant polyolefin;

[0021] Furthermore, the material of the oxygen barrier layer is a mixture of magnesium hydroxide and sodium silicate;

[0022] Furthermore, the material of the halogen-free, low-smoke, highly flame-retardant tape is a low-smoke, halogen-free, flame-retardant material;

[0023] Furthermore, the outer sheath is made of polyvinyl chloride.

[0024] To achieve the above-mentioned second objective, the present invention adopts the following technical solutions:

[0025] Step 1: Wrap the silicone material around the outer layer of the conductor to form a silicone tape;

[0026] Step 2: continuously extruding the insulating material around the outer periphery of the silicone tape to form an insulating layer;

[0027] Step 3: Twist three power cores with silicone tape wrapped outside the conductor and an insulating layer, one neutral core with silicone tape wrapped outside the conductor and an insulating layer, and one ground wire with silicone tape wrapped outside the conductor and an insulating layer into a twisted conductor, and then extrude glass fiber material on the outside of the insulating layer to form a glass fiber tape;

[0028] Step 4: Extruding an environmentally friendly Teflon material around the outer periphery of the glass fiber tape to form an inner sheath;

[0029] Step 5: Extruding the radiation cross-linked flame retardant polyolefin material on the outside of the inner sheath to form a tooth sleeve;

[0030] Step 6: squeeze the oxygen-isolating material onto the outside of the tooth sleeve to form an oxygen-isolating layer;

[0031] Step 7: Extruding a low-smoke, halogen-free flame-retardant material on the outer side of the outer coating of the galvanized steel wire to form a halogen-free, low-smoke, high-flame-retardant belt;

[0032] Step 8: Extrude the polyvinyl chloride material around the periphery of the halogen-free, low-smoke, high-flame-retardant tape to form an outer sheath.

[0033] Wherein, in step 1, the extrusion is performed by an extruder, and a tension regulator is installed on the die base of the extruder;

[0034] Wherein, in step 1, the thickness of the silicone tape is 1.55-1.65 mm.

[0035] Wherein, in step 2, the material of the insulating layer is refractory mica;

[0036] Wherein, in step 2, the extrusion is carried out by an extruder, and a feed guide plate and a cavity are installed on the die base of the extruder;

[0037] Wherein, in step 2, the extrusion temperature is 480-530°C.

[0038] Wherein, in step 3, the extrusion is performed by cold extrusion;

[0039] Wherein, in step three, the thickness of the glass fiber tape is 1.1-1.9 mm.

[0040] Wherein, in step 4, the thickness of the inner sheath is 1.5-1.7 mm;

[0041] Wherein, in step 4, the material of the inner sheath is environmentally friendly Teflon;

[0042] Wherein, in step 4, the extrusion is carried out by tube extrusion.

[0043] Wherein, in step 5, the material of the gear sleeve is radiation cross-linked flame-retardant polyolefin;

[0044] Wherein, in step 5, during the extrusion of the gear sleeve, the extruder uses a 6-tooth gear-shaped mold;

[0045] Wherein, in step five, the thickness of the tooth sleeve is 0.85-10.0 mm.

[0046] Wherein, in step six, the material of the oxygen barrier layer is a mixture of magnesium hydroxide and sodium silicate;

[0047] Wherein, in step 6, the thickness of the oxygen barrier layer is 1.55-1.65 mm;

[0048] Wherein, in step six, the extrusion method adopts a tube extrusion method;

[0049] Among them, in step six, before the oxygen barrier material is extruded, the oxygen barrier material is pre-mixed.

[0050] Among them, in step six, the premixing treatment is carried out according to the following steps: magnesium hydroxide and sodium silicate with a mass ratio of 25:13 are stirred in a mixer at a stirring pressure of 1.4 MPa and the viscosity of the oxygen barrier material is controlled to be 690-900 Pa·S.

[0051] Wherein, in step seven, the material of the halogen-free, low-smoke, high-flame-retardant tape is a low-smoke, halogen-free, flame-retardant material;

[0052] Wherein, in step 7, the thickness of the halogen-free, low-smoke, high-flame-retardant tape is 2.0-3.0 mm;

[0053] Wherein, in step seven, the extrusion is carried out using a 120 type extruder.

[0054] Wherein, in step eight, the material of the outer sheath is polyvinyl chloride;

[0055] Wherein, in step eight, the thickness of the outer sheath is 1.5-1.7 mm.

[0056] The present invention has the following beneficial effects:

[0057] 1. The present invention provides an oxygen-isolating layer and extrude the oxygen-isolating layer outside the inner sheath. The oxygen-isolating layer and the oxygen-isolating material are hardened and crusted when heated to 400 to 480°C, thereby blocking the flame, absorbing heat and decomposing. Magnesium hydroxide and sodium silicate are decomposed by heat to release bound water. On the one hand, the decomposition releases a large amount of water to dilute the oxygen on the surface of the combustion object. The active magnesium oxide generated by the decomposition adheres to the surface of the combustible material to prevent the entry of combustible gas, heat and oxygen, and further prevent the combustion. On the other hand, the decomposed magnesium oxide has good fire resistance, achieves the effect of fireproofing and heat insulation, realizes the ability to reduce the spread of the flame of the outer sheath, and realizes oxygen isolation and flame retardancy.

[0058] 2. The present invention arranges 6 barrier teeth at equal intervals on the surface of the tooth sleeve so that the oxygen-isolating layer can be evenly arranged between the 6 barrier teeth, thereby avoiding uneven distribution of the oxygen-isolating material during movement or filling, thereby affecting the oxygen-isolating and heat-insulating effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 It is a schematic diagram of the present invention.

[0060] Description of reference numerals:

[0061] 1- stranded conductor, 11- power line core, 111- conductor, 112- silicone tape, 113- insulation layer, 12- neutral line core, 13- ground wire;

[0062] 2- Fiberglass tape;

[0063] 3-Inner sheath;

[0064] 4-tooth sleeve, 41-blocking tooth;

[0065] 5- oxygen barrier layer;

[0066] 6-Halogen-free, low-smoke, high flame retardant tape;

[0067] 7- Outer sheath. DETAILED DESCRIPTION

[0068] Embodiment 1

[0069] See also Figure 1 As shown, the scheme includes a stranded conductor 1, a glass fiber tape 2, an inner sheath 3, a tooth sleeve 4, an oxygen barrier layer 5, a halogen-free low-smoke high flame retardant tape 6 and an outer sheath 7 which are sequentially sleeved from the inside to the outside;

[0070] The twisted conductor 1 is composed of three power cores 11, a neutral core 12 and a grounding wire 13 twisted together; the inside of the twisted conductor 1 is filled with minerals; the power core 11, the neutral core 12 and the grounding wire 13 have the same structure, and are sequentially covered with a conductor 111, a silicone tape 112 and an insulating layer 113 from the inside to the outside;

[0071] The outer periphery of the insulating layer 113 is sequentially covered with the glass fiber tape 2, the inner sheath 3, the tooth sleeve 4, the oxygen barrier layer 5, the halogen-free low-smoke high flame retardant tape 6 and the outer sheath 7;

[0072] The outer peripheral wall of the gear sleeve 4 is integrally provided with a plurality of blocking teeth 41 at equal intervals along its circumferential direction;

[0073] The preparation method of this embodiment comprises the following steps:

[0074] Step 1: Wrap the silicone material around the outer layer of the conductor 111 to form a silicone tape 112, wherein the thickness of the silicone tape 112 is 1.55-1.65 mm;

[0075] Step 2: continuously extruding the insulating material around the outer periphery of the silicone tape 112 to form an insulating layer 113, wherein the thickness of the insulating layer 113 is 0.81-0.89 mm;

[0076] Step 3: three power cores 11 with silicone tape 112 and insulation layer 113 wrapped outside the conductor 111, one neutral core 12 with silicone tape 112 and insulation layer 113 wrapped outside the conductor 111, and one ground wire 13 with silicone tape 112 and insulation layer 113 wrapped outside the conductor 111 are twisted into a twisted conductor 1, and then a glass fiber tape 2 is cold-extruded on the outside to form a glass fiber tape 2 layer, wherein the thickness of the glass fiber tape 2 is 1.1-1.9 mm;

[0077] Step 4: Use an extrusion tube method to continuously extrude the environmentally friendly Teflon around the outer periphery of the glass fiber tape 2 to form an insulating layer 113; the thickness of the inner sheath 3 is 1.5-1.7 mm;

[0078] Step 5: Extruding the radiation cross-linked flame-retardant polyolefin material on the outside of the inner sheath 3, wherein during the extrusion of the gear sleeve 4, the extruder uses a 6-tooth tooth-shaped mold; the thickness of the gear sleeve 4 is 0.85-10.0 mm;

[0079] Step six: extrude the oxygen-insulating material onto the outer side of the gear sleeve 4 to form an oxygen-insulating layer 5; the thickness of the oxygen-insulating layer 5 is 1.55-1.65 mm; before the extrusion operation step, the oxygen-insulating material is pre-mixed, wherein the pre-mixing is performed according to the following steps, magnesium hydroxide and sodium silicate with a mass ratio of 25:13 are stirred at a stirring pressure of 1.4 MPa in a mixer and the viscosity of the oxygen-insulating material is controlled to be 690-900 Pa·S.

[0080] Step 7: Use a 120-type extruder to extrude the low-smoke halogen-free flame-retardant material onto the outside of the galvanized steel wire outer layer to form a halogen-free, low-smoke, high-flame-retardant belt 6, wherein the thickness of the halogen-free, low-smoke, high-flame-retardant belt 6 is 2.0-3.0 mm.

[0081] Step 8: Extruding polyvinyl chloride material around the periphery of the halogen-free, low-smoke, high-flame-retardant tape 6 to form an outer sheath 7, wherein the thickness of the outer sheath 7 is 1.5-1.7 mm.

[0082] The conductor 111 is made of copper;

[0083] The material of the insulating layer 113 is refractory mica;

[0084] The material of the inner sheath 3 is environmentally friendly Teflon;

[0085] The material of the gear sleeve 4 is radiation cross-linked flame-retardant polyolefin;

[0086] The material of the oxygen barrier layer 5 is a mixture of magnesium hydroxide and sodium silicate;

[0087] The material of the halogen-free, low-smoke, high-flame-retardant belt 6 is a low-smoke, halogen-free, flame-retardant material;

[0088] The material of the outer sheath 7 is polyvinyl chloride.

[0089] Embodiment 2

[0090] To achieve the above-mentioned second objective, the present invention adopts the following technical solutions:

[0091] Step 1: Wrap the silicone material around the outer layer of the conductor 111 to form a silicone tape 112;

[0092] Step 2: continuously extruding the insulating material around the outer periphery of the silicone tape 112 to form an insulating layer 113;

[0093] Step 3: three power cores 11 with silicone tape 112 and insulation layer 113 wrapped around the conductor 111, one neutral core 12 with silicone tape 112 and insulation layer 113 wrapped around the conductor 111, and one ground wire 13 with silicone tape 112 and insulation layer 113 wrapped around the conductor 111 are twisted into a twisted conductor 1, and then glass fiber material is extruded on the outside of the insulation layer 113 to form a glass fiber tape 2;

[0094] Step 4: Extruding an environmentally friendly Teflon material around the outer periphery of the glass fiber tape 2 to form an inner sheath 3;

[0095] Step 5: Extruding the radiation cross-linked flame-retardant polyolefin material on the outside of the inner sheath 3 to form a tooth sleeve 4;

[0096] Step 6: Extruding the oxygen-isolating material on the outer side of the gear sleeve 4 to form an oxygen-isolating layer 5;

[0097] Step 7: extruding a low-smoke, halogen-free flame-retardant material on the outer side of the outer coating of the galvanized steel wire to form a halogen-free, low-smoke, high-flame-retardant belt 6;

[0098] Step 8: Extrude the polyvinyl chloride material around the outer periphery of the halogen-free, low-smoke, high-flame-retardant tape 6 to form an outer sheath 7.

[0099] Wherein, in step 1, the extrusion is performed by an extruder, and a tension regulator is installed on the die base of the extruder;

[0100] Wherein, in step 1, the thickness of the silicone tape 112 is 1.55-1.65 mm.

[0101] In step 2, the material of the insulating layer 113 is refractory mica;

[0102] Wherein, in step 2, the extrusion is carried out by an extruder, and a feed guide plate and a cavity are installed on the die base of the extruder;

[0103] Wherein, in step 2, the extrusion temperature is 480-530°C.

[0104] Wherein, in step 3, the extrusion is performed by cold extrusion;

[0105] Wherein, in step three, the thickness of the glass fiber tape 2 is 1.1-1.9 mm.

[0106] Wherein, in step 4, the thickness of the inner sheath 3 is 1.5-1.7 mm;

[0107] Wherein, in step 4, the material of the inner sheath 3 is environmentally friendly Teflon;

[0108] Wherein, in step 4, the extrusion is carried out by tube extrusion.

[0109] Wherein, in step 5, the material of the gear sleeve 4 is radiation cross-linked flame-retardant polyolefin;

[0110] Wherein, in step 5, during the extrusion of the gear sleeve 4, the extruder uses a 6-tooth gear-shaped mold;

[0111] Wherein, in step five, the thickness of the gear sleeve 4 is 0.85-10.0 mm.

[0112] Wherein, in step six, the material of the oxygen barrier layer 5 is a mixture of magnesium hydroxide and sodium silicate;

[0113] Wherein, in step six, the thickness of the oxygen barrier layer 5 is 1.55-1.65 mm;

[0114] Wherein, in step six, the extrusion method adopts a tube extrusion method;

[0115] Among them, in step six, before the oxygen barrier material is extruded, the oxygen barrier material is pre-mixed.

[0116] Among them, in step six, the premixing treatment is carried out according to the following steps: magnesium hydroxide and sodium silicate with a mass ratio of 25:13 are stirred in a mixer at a stirring pressure of 1.4 MPa and the viscosity of the oxygen barrier material is controlled to be 690-900 Pa·S.

[0117] Among them, in step seven, the material of the halogen-free, low-smoke, high-flame-retardant tape 6 is a low-smoke, halogen-free, flame-retardant material;

[0118] Wherein, in step 7, the thickness of the halogen-free, low-smoke, high-flame-retardant tape 6 is 2.0-3.0 mm;

[0119] Wherein, in step seven, the extrusion is carried out using a 120 type extruder.

[0120] Wherein, in step eight, the material of the outer sheath 7 is polyvinyl chloride;

[0121] Wherein, in step eight, the thickness of the outer sheath 7 is 1.5-1.7 mm.

[0122] The above description is only a specific implementation mode of the present invention, and does not limit the patent scope of the present invention. Any equivalent structural transformation made by using the contents of the present invention description and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A low-smoke, halogen-free, flame-retardant and fire-resistant cable, characterized by: It comprises a twisted conductor (1), a glass fiber tape (2), an inner sheath (3), a tooth sleeve (4), an oxygen-isolating layer (5), a halogen-free, low-smoke, high-flame-retardant tape (6), and an outer sheath (7) which are sequentially sleeved from the inside to the outside; The twisted conductor (1) is composed of three power line cores (11), a neutral line core (12) and a ground line (13) twisted together; the interior of the twisted conductor (1) is filled with minerals; the power line core (11), the neutral line core (12) and the ground line (13) have the same structure, and are sequentially covered with a conductor (111), a silicone tape (112) and an insulating layer (113) from the inside to the outside; The outer periphery of the insulating layer (113) is sequentially covered with the glass fiber tape (2), the inner sheath (3), the tooth sleeve (4), the oxygen isolation layer (5), the halogen-free low-smoke high flame retardant tape (6) and the outer sheath (7); The outer peripheral wall of the gear sleeve (4) is integrally provided with a plurality of blocking teeth (41) at equal intervals along its circumferential direction; The thickness of the silicone tape (112) is 1.55-1.65 mm; The thickness of the insulating layer (113) is 0.81-0.89 mm; The thickness of the glass fiber tape (2) is 1.1-1.9 mm; The thickness of the inner sheath (3) is 1.5-1.7 mm; The thickness of the gear sleeve (4) is 0.85-10.0 mm; The thickness of the oxygen barrier layer (5) is 1.55-1.65 mm; The thickness of the halogen-free, low-smoke, high-flame-retardant tape (6) is 2.0-3.0 mm; The thickness of the outer sheath (7) is 1.5-1.7 mm.

2. A low-smoke, halogen-free, flame-retardant and fire-resistant cable according to claim 1, characterized in that: the conductor (111) is made of copper; The material of the insulating layer (113) is refractory mica; The material of the inner sheath (3) is environmentally friendly Teflon; The material of the gear sleeve (4) is radiation cross-linked flame-retardant polyolefin; The material of the oxygen barrier layer (5) is a mixture of magnesium hydroxide and sodium silicate; The material of the halogen-free, low-smoke, highly flame-retardant belt (6) is a low-smoke, halogen-free, flame-retardant material; The material of the outer sheath (7) is polyvinyl chloride.

3. A method for producing a low-smoke, halogen-free, flame-retardant and fire-resistant cable according to any one of claims 1 to 2, characterized in that: It includes the following steps: Step 1: Wrapping a silicone material around the outer layer of the conductor (111) to form a silicone tape (112); Step 2: continuously extruding an insulating material around the outer periphery of the silicone tape (112) to form an insulating layer (113); Step 3: three power line cores (11) with a silicone tape (112) and an insulating layer (113) wrapped around the conductor (111), a neutral line core (12) with a silicone tape (112) and an insulating layer (113) wrapped around the conductor (111), and a grounding line (13) with a silicone tape (112) and an insulating layer (113) wrapped around the conductor (111) are twisted into a twisted conductor (1), and then glass fiber material is extruded on the outside of the insulating layer (113) to form a glass fiber tape (2); Step 4: Extruding an environmentally friendly Teflon material around the outer periphery of the glass fiber tape (2) to form an inner sheath (3); Step 5: Extruding the radiation cross-linked flame-retardant polyolefin material onto the outer side of the inner sheath (3) to form a toothed sleeve (4); Step 6: Extruding an oxygen-isolating material onto the outer side of the tooth sleeve (4) to form an oxygen-isolating layer (5); Step 7: Extruding a low-smoke, halogen-free flame-retardant material onto the outer side of the outer coating of the galvanized steel wire to form a halogen-free, low-smoke, highly flame-retardant belt (6); Step 8: Extruding a polyvinyl chloride material around the outer periphery of the halogen-free, low-smoke, high-flame-retardant tape (6) to form an outer sheath (7).

4. The method for producing a low-smoke, halogen-free, flame-retardant and fire-resistant cable according to claim 3, characterized in that: In step 1, the extrusion is performed by an extruder, and a tension regulator is installed on the die base of the extruder; In step 1, the thickness of the silicone tape (112) is 1.55-1.65 mm; In step 2, the material of the insulating layer (113) is refractory mica; In step 2, the extrusion is carried out by an extruder, and a feed guide plate and a cavity are installed on the die base of the extruder; In step 2, the extrusion temperature is 480-530°C.

5. The method for producing a low-smoke, halogen-free, flame-retardant and fire-resistant cable according to claim 3, characterized in that: In step 3, the extrusion bag is cold extruded; In step 3, the thickness of the glass fiber tape (2) is 1.1-1.9 mm; In step 4, the thickness of the inner sheath (3) is 1.5-1.7 mm; In step 4, the material of the inner sheath (3) is environmentally friendly Teflon; In step 4, the extrusion is performed by tube extrusion.

6. The method for producing a low-smoke, halogen-free, flame-retardant and fire-resistant cable according to claim 3, characterized in that: In step 5, the material of the gear sleeve (4) is radiation cross-linked flame-retardant polyolefin; In step 5, during the extrusion of the gear sleeve (4), the extruder uses a 6-tooth gear-shaped mold; In step 5, the thickness of the gear sleeve (4) is 0.85-10.0 mm; In step 6, the material of the oxygen barrier layer (5) is a mixture of magnesium hydroxide and sodium silicate; In step 6, the thickness of the oxygen barrier layer (5) is 1.55-1.65 mm; In step six, the extrusion method is a tube extrusion method; In step six, the oxygen barrier material is pre-mixed before the extrusion process.

7. The method for producing a low-smoke, halogen-free, flame-retardant and fire-resistant cable according to claim 3, characterized in that: In step six, the premixing treatment is carried out according to the following steps: magnesium hydroxide and sodium silicate with a mass ratio of 25:13 are stirred in a mixer at a stirring pressure of 1.4 MPa and the viscosity of the oxygen barrier material is controlled to be 690-900 Pa·S.

8. The method for producing a low-smoke, halogen-free, flame-retardant and fire-resistant cable according to claim 3, characterized in that: In step 7, the material of the halogen-free, low-smoke, highly flame-retardant tape (6) is a low-smoke, halogen-free, flame-retardant material; In step 7, the thickness of the halogen-free, low-smoke, high-flame-retardant tape (6) is 2.0-3.0 mm; In step seven, the extrusion is carried out using a 120-type extruder.

9. The method for producing a low-smoke, halogen-free, flame-retardant and fire-resistant cable according to claim 3, characterized in that: In step eight, the material of the outer sheath (7) is polyvinyl chloride; In step eight, the thickness of the outer sheath (7) is 1.5-1.7 mm.

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