Preparation process for b1-grade high flame-retardant NS-type fire-resistant cable

Abstract

A preparation process for a B1-grade high flame-retardant NS-type fire-resistant cable. On outer surfaces of copper conductors, overlap-wrapping is used and an insulating layer is extruded to obtain insulated cores; after a plurality of insulated cores are stranded into a cable, gaps within a cable core are filled with PP filler ropes for rounding; two layers of halogen-free flame-retardant tapes are wrapped around the outer surfaces of the cores and the fillers, argon arc welding is used to longitudinally wrap an aluminum tape and a corrugation treatment is performed to form an aluminum sheath; and finally, a ceramicized silicon rubber tape and a low-smoke halogen-free flame-retardant polyolefin sheathing material for low-heat-release cables are wrapped, thereby obtaining a finished cable.

Description

A manufacturing process for B1-grade high flame-retardant NS-type fire-resistant cables Technical Field

[0001] This invention belongs to the field of cable technology and relates to a manufacturing process for a B1-grade high flame-retardant NS-type fireproof cable. Background Technology

[0002] With the rapid development of urbanization in my country, traditional PVC and cross-linked polyethylene insulated cables are gradually becoming insufficient to meet the high fire resistance requirements of high-rise buildings and densely populated areas. Fire-resistant cables, due to their superior fire resistance, high temperature resistance, large current carrying capacity, resistance to impact voltage, resistance to mechanical damage, safety, and long service life, are used in high-rise buildings, airports, shopping malls, schools, and other locations to ensure the uninterrupted operation of critical fire-fighting electrical equipment such as fire pumps, fire elevators, local lighting, emergency evacuation guidance, security monitoring, smoke control and exhaust systems, and backup power supplies in the event of a fire. Simultaneously, their flexibility, corrosion resistance, high temperature resistance, fire resistance, explosion-proof properties, and non-combustible nature also make them suitable for use in dangerous, harsh, and high-temperature environments such as nuclear power plants, metallurgy, chemical plants, and mines.

[0003] However, the fire-resistant cables currently used in urban construction in China generally do not have the performance to withstand impact spray during combustion. Although they can maintain continuous power supply for a certain period of time under high-temperature combustion conditions, in actual fire rescue environments, there is still a risk of losing power transmission capacity due to the impact of building collapse caused by fire, high-pressure water jet spray, and other factors. In order to meet the high requirements for cable safety performance in my country's urbanization construction, there is still room for improvement in the safety performance of fire-resistant cables. Summary of the Invention

[0004] The purpose of this invention is to provide a manufacturing process for a B1-grade high flame-retardant NS-type fire-resistant cable. Compared with traditional fire-resistant cables, the B1-grade high flame-retardant NS-type fire-resistant cable, while meeting the same fire resistance performance, has the characteristics of impact and spray resistance, and has better safety performance. In the event of a fire, it can reduce the pressure on fire rescue and provide a greater chance for people to escape.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] A manufacturing process for a B1-grade high flame-retardant NS-type fire-resistant cable, the manufacturing process comprising the following steps:

[0007] Step 1: The copper rod is drawn and annealed to obtain copper wire, which is then stranded to obtain a copper conductor;

[0008] Step 2: An overlapping wrapping process is used on the outer surface of the copper conductor to wrap three layers of three-in-one phlogopite tape, and then an XLPE insulation layer is extruded to obtain the insulated wire core;

[0009] Step 3: Twist multiple insulated wire cores into a cable by twisting them together. Fill the gaps between the cable cores with high flame-retardant PP filler rope to make them round. Wrap two layers of halogen-free flame-retardant tape around the wire core and the outer surface of the filler by overlapping wrapping to obtain the cable core.

[0010] Step 4: The cable core is longitudinally wrapped with an aluminum strip using argon arc welding and then corrugated to obtain an aluminum sheath;

[0011] Step 5: Wrap two layers of ceramicized silicone rubber tape around the outer surface of the aluminum sheath using an overlapping wrapping method to obtain a silicone rubber wrapping layer;

[0012] Step 6: Evenly extrude the outer sheath material around the silicone rubber tape layer to form the outer sheath, thus obtaining the finished cable.

[0013] Furthermore, the copper rod mentioned in step one is a high-quality oxygen-free copper rod with a copper purity of 99.9%; the copper conductor includes copper conductor A and copper conductor B, and the cross-sectional area of ​​copper conductor A is 50 mm². 2 The cross-sectional area of ​​the copper conductor B is 25 mm². 2 The copper conductor A is made of 10 strands of copper wire with a diameter of 2.62±0.02mm; the copper conductor B is made of 7 strands of copper wire with a diameter of 2.10±0.02mm.

[0014] Furthermore, the overlap rate of the three-layer, three-in-one phlogopite tape wrapping described in step two is 15-30%.

[0015] Furthermore, the overlap rate of the two layers of halogen-free flame-retardant tape in step three is 15-25%.

[0016] Furthermore, in step five, the overlap rate of the two layers of ceramicized silicone rubber tape is 8-15%.

[0017] Furthermore, the method for preparing the ceramicized silicone rubber tape in step five is as follows:

[0018] Silicone rubber and silica are mixed in a specific mass ratio and then kneaded at 80-90℃ and 50-70 rpm for 15-25 minutes. Then, ceramic filler and flame retardant are added and kneaded at 90-110℃ and 80-100 rpm for 0.6-1 hours. After cooling, the mixture is passed through a two-roll mill 20-30 times. Then, vulcanizing agent is added and kneaded at 60-90℃ and 30-50 rpm for 10-20 minutes. The resulting mixture is then coated onto release paper with a coating thickness of 0.3-0.5 mm and cured at 120-140℃ for 1-3 hours to obtain ceramicized silicone rubber tape.

[0019] Furthermore, the mass ratio of the silicone rubber, silica, ceramicized filler, flame retardant, and vulcanizing agent is 8-12:2.5-3.5:3-5:1-1.5:0.2-0.3;

[0020] The method for preparing the ceramicized filler is as follows:

[0021] A 20wt% sodium silicate solution was prepared using sodium silicate and deionized water. Alumina, aluminum phosphate, zirconium oxide, and the 20wt% sodium silicate solution were mixed in a mass ratio of 1:0.1-0.3:0.3-0.7:2.7-3.3. Then, sodium dodecylbenzenesulfonate (2.5-3.5wt% of alumina) and silica sol (5-10wt% of alumina) were added. The ultrasonic frequency was set to 40-60kHz, and the ultrasonic power to 400-600W. The ultrasonic treatment lasted for 1 minute. 0.5-2.5h, while sonicating, add 0.05-0.15mol / L dilute hydrochloric acid solution and 0.05-0.15mol / L sodium hydroxide solution dropwise to adjust the pH to 9-10. After sonication, let stand for 0.5h, filter to obtain the coated product, rinse with deionized water, and dry at 90℃ for 3-5h to obtain the dried product. Place the dried product in a muffle furnace, heat to 1300-1400℃ at a rate of 5℃ / min, and hold for 6-10h to obtain the ceramicized filler.

[0022] Furthermore, the outer sheath material described in step six is ​​a low-smoke, halogen-free, flame-retardant polyolefin sheath material for low-heat-release cables.

[0023] Furthermore, the parameters of the extrusion equipment for the outer protective layer material described in step six are as follows: barrel zone 1 temperature is 137-141℃, barrel zone 2 temperature is 143-145℃, barrel zone 3 temperature is 147-151℃, barrel zone 4 temperature is 156-158℃, barrel zone 5 temperature is 162-164℃, barrel zone 6 temperature is 160-164℃, flange area temperature is 160-164℃, die zone 1 temperature is 165-167℃, die zone 2 temperature is 186-190℃, and die zone 3 temperature is 200-202℃.

[0024] Furthermore, the extrusion equipment uses a halogen-free, low-smoke screw with a low compression ratio of 1.1:1 and employs a tube-type extrusion die.

[0025] The beneficial effects of this invention are:

[0026] (1) In this invention, copper is wrapped with three-in-one mica tape and extruded with XLPE insulation layer to obtain insulated wire core. After multiple insulated wire cores are twisted into a cable, the gap between the cable cores is filled with high flame-retardant PP filler rope to make it round. Two layers of halogen-free flame-retardant tape are wrapped around the outside of the cable core and argon arc welded with longitudinal aluminum tape and corrugated to form an aluminum sheath, which ensures the sealing and mechanical strength of the aluminum sheath. Finally, ceramicized silicone rubber tape and low-smoke halogen-free flame-retardant polyolefin sheath material for low heat release cables are wrapped. The strength and stability of the cable are improved by multi-layer wrapping. When subjected to impact, the impact force can be dispersed to reduce damage to the internal insulated wire core. Furthermore, this multi-layer wrapping makes the cable have good sealing performance, which can effectively prevent moisture from entering the cable core. In the event of a fire, if a fire sprinkler system is activated, it can protect the internal cable core from water, ensuring that the cable can maintain good electrical performance in a humid environment.

[0027] (2) In the preparation process of the ceramicized silicone tape used in this invention, sodium silicate solution impregnates alumina, aluminum phosphate, and zirconium oxide. Sodium silicate solution and alumina generate aluminum silicate under high temperature sintering. At the same time, sodium dodecylbenzene sulfonate promotes the uniform dispersion of each material and the adhesion of silica sol, forming a ceramicized filler with aluminum silicate as the shell layer and aluminum phosphate and other materials. Aluminum phosphate will be converted into a stable ceramic phase at high temperature. Zirconia has high hardness and strength. The synergy of each material helps to form a ceramicized silicone tape with higher strength, denser structure, and better thermal insulation performance. In addition, the bending strength of ceramicized silicone is much greater than that of ordinary silicone rubber, and it increases significantly with the increase of temperature. The ceramicized filler is quickly burned into a hard and complete shell at high temperature. When water is sprayed under high temperature ablation, the sintered body of ceramicized silicone rubber does not crack, showing good thermal shock resistance. This ensures that the cable does not short-circuit or break under flame burning, thus ensuring the smooth operation of the line.

[0028] (3) In addition, the low-smoke halogen-free flame-retardant polyolefin sheath material for low heat release cables, as the outer sheath material, has a certain toughness and elasticity, and can absorb impact energy to a certain extent. The halogen-free flame-retardant tape can absorb a large amount of heat during the combustion process and form a carbon shell layer, isolate the air, and prevent the cable from burning further. The synergistic treatment of multi-layer wrapping makes the B1-grade high flame-retardant NS-type fireproof cable prepared by this invention, compared with traditional fireproof cables, meet the same fire resistance performance. At the same time, the B1-grade high flame-retardant NS-type fireproof cable has the characteristics of impact and spray resistance, and has better safety performance. It can reduce the pressure on fire rescue and provide greater opportunities for personnel to escape when a fire occurs. Detailed Implementation

[0029] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with embodiments, is provided below.

[0030] All copper rods in all embodiments and comparative examples of this invention were purchased directly from the market from Qingyuan Xinghai Copper Industry Co., Ltd.; all three-in-one phlogopite mica tapes were purchased directly from the market from Hubei Zhongtian Mica Products Co., Ltd.; all XLPE insulation materials were purchased directly from the market from Zhejiang Wanma Polymer Materials Group Co., Ltd.; all high flame-retardant PP filler ropes were purchased directly from the market from Guangdong Zhongzhi Keyi Cable Materials Co., Ltd.; all halogen-free flame-retardant tapes were purchased directly from the market from Yangzhou Tengfei Cable & Electrical Materials Co., Ltd.; all aluminum tapes were purchased directly from the market from Anhui Kaide Cable Materials Co., Ltd.; and all low-smoke halogen-free flame-retardant polyolefin outer sheath materials for low-heat release cables were purchased directly from the market from Shanghai Kaibo Cable Special Materials Co., Ltd.

[0031] Example 1

[0032] A manufacturing process for a B1-grade high flame-retardant NS-type fire-resistant cable, the manufacturing process of this embodiment includes the following steps:

[0033] Step 1: The copper rod is drawn and annealed to obtain copper wire, which is then stranded to obtain a copper conductor. In this embodiment, the copper rod is a high-quality oxygen-free copper rod with a copper purity of 99.9%. The copper conductor includes copper conductor A and copper conductor B, and the cross-sectional area of ​​copper conductor A is 50 mm². 2 The cross-sectional area of ​​copper conductor B is 25 mm². 2 Copper conductor A is made of 10 strands of copper wire with a diameter of 2.60 mm; copper conductor B is made of 7 strands of copper wire with a diameter of 2.08 mm.

[0034] Step 2: An overlapping wrapping process is performed on the outer surfaces of copper conductors A and B respectively, wrapping three layers of three-in-one phlogopite tape, and then extruding a layer of XLPE insulation to obtain insulated core A and insulated core B. In this embodiment, the wrapping direction of the three-in-one phlogopite tape on copper conductor A is left-handed, with a wrapping thickness and width of 0.14mm and 20mm respectively. The wrapping direction of the three-in-one phlogopite tape on copper conductor B is right-handed, with a wrapping thickness and width of 0.14mm and 15mm respectively. In this embodiment, the thickness of the extruded XLPE insulation layer on copper conductor A is 1mm, and the thickness of the extruded XLPE insulation layer on copper conductor B is 0.9mm.

[0035] Step 3: Twist 3 insulated wire cores A and 1 insulated wire core B to the right to form a cable. Fill the gaps between the cable cores with high flame-retardant PP filler rope to make it round. The outer diameter of the high flame-retardant PP filler rope is 8mm. Wrap two layers of halogen-free flame-retardant tape to the left side of the wire core and the filler outer surface to obtain the cable core. The wrapping thickness and width of the two layers of halogen-free flame-retardant tape are 0.17mm and 45mm, respectively.

[0036] Step 4: The cable core is longitudinally wrapped with an aluminum strip using argon arc welding and then corrugated to obtain an aluminum sheath. The corrugation pitch of the corrugation treatment is 11.5mm, and the longitudinal wrapping thickness of the aluminum sheath is 1mm.

[0037] Step 5: Wrap two layers of ceramicized silicone rubber tape around the outer surface of the aluminum sheath using an overlapping wrapping method to obtain a silicone rubber wrapping layer;

[0038] Step 6: Extrude the outer sheath material evenly around the silicone rubber tape layer to form the outer sheath. The extrusion thickness is 1mm to obtain the finished cable.

[0039] In step two, the overlap rate of the three-layer, three-in-one phlogopite tape in this embodiment is 15%.

[0040] In step three, the overlap rate of the two layers of halogen-free flame-retardant tape in this embodiment is 15%.

[0041] In step five, the overlap rate of the two layers of ceramicized silicone rubber tape in this embodiment is 8%.

[0042] The method for preparing the ceramicized silicone rubber tape in step five of this embodiment is as follows:

[0043] Silicone rubber and silica were mixed in a specific mass ratio and then kneaded at 80°C and 50 rpm for 15 minutes. Then, ceramic filler and flame retardant were added, and the mixture was kneaded at 90°C and 80 rpm for 0.6 hours. After cooling, the mixture was passed through a two-roll mill 20 times. Then, vulcanizing agent was added, and the mixture was kneaded at 60°C and 30 rpm for 10 minutes. The resulting mixture was then coated onto release paper with a coating thickness of 0.3 mm and cured at 120°C for 1 hour to obtain ceramicized silicone rubber tape.

[0044] In this embodiment, the mass ratio of silicone rubber, silica, ceramic filler, flame retardant, and vulcanizing agent is 8:2.5:3:1:0.2; the flame retardant and vulcanizing agent in this embodiment are decabromodiphenyl ethane and bis(2,5-diphenyl) sulfide, respectively.

[0045] The method for preparing the ceramicized filler in this embodiment is as follows:

[0046] A 20wt% sodium silicate solution was prepared using sodium silicate and deionized water. Alumina, aluminum phosphate, zirconium oxide, and the 20wt% sodium silicate solution were mixed in a mass ratio of 1:0.1:0.3:2.7. Then, 2.5wt% sodium dodecylbenzenesulfonate and 5wt% silica sol (based on the mass of alumina) were added. The ultrasonic frequency was set to 40kHz, the ultrasonic power to 400W, and the ultrasonic treatment lasted for 1.5 hours. Simultaneously, 0.05mol / L dilute hydrochloric acid and 0.05mol / L sodium hydroxide solutions were added dropwise to adjust the pH to 9. After ultrasonication, the mixture was allowed to stand for 0.5 hours, filtered, and the coated product was obtained. The product was rinsed with deionized water and dried at 90℃ for 3 hours to obtain the dried product. The dried product was placed in a muffle furnace and heated to 1300℃ at a rate of 5℃ / min, and held at that temperature for 6 hours to obtain the ceramicized filler.

[0047] In step six, the outer sheath material in this embodiment is a low-smoke, halogen-free, flame-retardant polyolefin sheath material for low-heat-release cables.

[0048] In step six, the parameters of the extrusion equipment for the outer protective layer material in this embodiment are as follows: barrel zone 1 temperature is 137°C, barrel zone 2 temperature is 143°C, barrel zone 3 temperature is 147°C, barrel zone 4 temperature is 156°C, barrel zone 5 temperature is 162°C, barrel zone 6 temperature is 160°C, flange area temperature is 160°C, die zone 1 temperature is 165°C, die zone 2 temperature is 186°C, and die zone 3 temperature is 200°C.

[0049] The extrusion equipment in this embodiment uses a halogen-free, low-smoke screw with a low compression ratio of 1.1:1 and an extrusion die of type tube extrusion.

[0050] Example 2

[0051] A manufacturing process for a B1-grade high flame-retardant NS-type fire-resistant cable, the manufacturing process of this embodiment includes the following steps:

[0052] Step 1: The copper rod is drawn and annealed to obtain copper wire, which is then stranded to obtain a copper conductor. In this embodiment, the copper rod is a high-quality oxygen-free copper rod with a copper purity of 99.9%. The copper conductor includes copper conductor A and copper conductor B, and the cross-sectional area of ​​copper conductor A is 50 mm². 2 The cross-sectional area of ​​copper conductor B is 25 mm². 2 Copper conductor A is made of 10 strands of copper wire with a diameter of 2.64 mm; copper conductor B is made of 7 strands of copper wire with a diameter of 2.12 mm.

[0053] Step 2: An overlapping wrapping process is performed on the outer surfaces of copper conductors A and B respectively, wrapping three layers of three-in-one phlogopite tape, and then extruding a layer of XLPE insulation to obtain insulated core A and insulated core B. In this embodiment, the wrapping direction of the three-in-one phlogopite tape on copper conductor A is left-handed, with a wrapping thickness and width of 0.14mm and 20mm respectively. The wrapping direction of the three-in-one phlogopite tape on copper conductor B is right-handed, with a wrapping thickness and width of 0.14mm and 15mm respectively. In this embodiment, the thickness of the extruded XLPE insulation layer on copper conductor A is 1mm, and the thickness of the extruded XLPE insulation layer on copper conductor B is 0.9mm.

[0054] Step 3: Twist 3 insulated wire cores A and 1 insulated wire core B to the right to form a cable. Fill the gaps between the cable cores with high flame-retardant PP filler rope to make it round. The outer diameter of the high flame-retardant PP filler rope is 8mm. Wrap two layers of halogen-free flame-retardant tape to the left side of the wire core and the filler outer surface to obtain the cable core. The wrapping thickness and width of the two layers of halogen-free flame-retardant tape are 0.17mm and 45mm, respectively.

[0055] Step 4: The cable core is longitudinally wrapped with an aluminum strip using argon arc welding and then corrugated to obtain an aluminum sheath. The corrugation pitch of the corrugation treatment is 11.5mm, and the longitudinal wrapping thickness of the aluminum sheath is 1mm.

[0056] Step 5: Wrap two layers of ceramicized silicone rubber tape around the outer surface of the aluminum sheath using an overlapping wrapping method to obtain a silicone rubber wrapping layer;

[0057] Step 6: Extrude the outer sheath material evenly around the silicone rubber tape layer to form the outer sheath. The extrusion thickness is 1mm to obtain the finished cable.

[0058] In step two, the overlap rate of the three-layer, three-in-one phlogopite tape in this embodiment is 30%.

[0059] In step three, the overlap rate of the two layers of halogen-free flame-retardant tape in this embodiment is 25%.

[0060] In step five, the overlap rate of the two layers of ceramicized silicone rubber tape wrapped in this embodiment is 15%.

[0061] The method for preparing the ceramicized silicone rubber tape in step five of this embodiment is as follows:

[0062] Silicone rubber and silica were mixed in a specific mass ratio and then kneaded at 70 rpm for 25 minutes at 90°C. Ceramicized filler and flame retardant were then added and kneaded at 100 rpm for 1 hour at 110°C. After cooling, the mixture was passed through a two-roll mill 30 times. A vulcanizing agent was then added and kneaded at 50 rpm for 20 minutes at 90°C. The resulting mixture was then coated onto release paper with a coating thickness of 0.5 mm and cured at 140°C for 3 hours to obtain a ceramicized silicone rubber tape.

[0063] In this embodiment, the mass ratio of silicone rubber, silica, ceramic filler, flame retardant, and vulcanizing agent is 12:3.5:5:1.5:0.3; the flame retardant and vulcanizing agent in this embodiment are decabromodiphenyl ethane and bis(2,5-diphenyl) sulfide, respectively.

[0064] The method for preparing the ceramicized filler in this embodiment is as follows:

[0065] A 20wt% sodium silicate solution was prepared using sodium silicate and deionized water. Alumina, aluminum phosphate, zirconium oxide, and the 20wt% sodium silicate solution were mixed in a mass ratio of 1:0.3:0.7:3.3. Then, 3.5wt% sodium dodecylbenzenesulfonate and 10wt% silica sol (based on the mass of alumina) were added. The ultrasonic frequency was set to 60kHz, the ultrasonic power to 600W, and the ultrasonic treatment lasted for 2.5 hours. Simultaneously, 0.15mol / L dilute hydrochloric acid and 0.15mol / L sodium hydroxide solutions were added dropwise to adjust the pH to 10. After ultrasonication, the mixture was allowed to stand for 0.5 hours, filtered, and the coated product was obtained. The product was rinsed with deionized water and dried at 90℃ for 5 hours to obtain the dried product. The dried product was placed in a muffle furnace and heated to 1400℃ at a rate of 5℃ / min, and held at that temperature for 10 hours to obtain the ceramicized filler.

[0066] In step six, the outer sheath material in this embodiment is a low-smoke, halogen-free, flame-retardant polyolefin sheath material for low-heat-release cables.

[0067] In step six, the parameters of the extrusion equipment for the outer protective layer material in this embodiment are as follows: barrel zone 1 temperature is 141°C, barrel zone 2 temperature is 145°C, barrel zone 3 temperature is 151°C, barrel zone 4 temperature is 158°C, barrel zone 5 temperature is 164°C, barrel zone 6 temperature is 164°C, flange area temperature is 164°C, die zone 1 temperature is 167°C, die zone 2 temperature is 190°C, and die zone 3 temperature is 202°C.

[0068] The extrusion equipment in this embodiment uses a halogen-free, low-smoke screw with a low compression ratio of 1.1:1 and an extrusion die of type tube extrusion.

[0069] Example 3

[0070] A manufacturing process for a B1-grade high flame-retardant NS-type fire-resistant cable, the manufacturing process of this embodiment includes the following steps:

[0071] Step 1: The copper rod is drawn and annealed to obtain copper wire, which is then stranded to obtain a copper conductor. In this embodiment, the copper rod is a high-quality oxygen-free copper rod with a copper purity of 99.9%. The copper conductor includes copper conductor A and copper conductor B, and the cross-sectional area of ​​copper conductor A is 50 mm². 2 The cross-sectional area of ​​copper conductor B is 25 mm². 2 Copper conductor A is made of 10 strands of copper wire with a diameter of 2.62 mm; copper conductor B is made of 7 strands of copper wire with a diameter of 2.10 mm.

[0072] Step 2: An overlapping wrapping process is performed on the outer surfaces of copper conductors A and B respectively, wrapping three layers of three-in-one phlogopite tape, and then extruding a layer of XLPE insulation to obtain insulated core A and insulated core B. In this embodiment, the wrapping direction of the three-in-one phlogopite tape on copper conductor A is leftward, with a wrapping thickness and width of 0.14mm and 20mm respectively. The wrapping direction of the three-in-one phlogopite tape on copper conductor B is rightward, with a wrapping thickness and width of 0.14mm and 15mm respectively. In this embodiment, the thickness of the extruded XLPE insulation layer on copper conductor A is 1mm, and the thickness of the extruded XLPE insulation layer on copper conductor B is 0.9mm.

[0073] Step 3: Twist 3 insulated wire cores A and 1 insulated wire core B to the right to form a cable. Fill the gaps between the cable cores with high flame-retardant PP filler rope to make it round. The outer diameter of the high flame-retardant PP filler rope is 8mm. Wrap two layers of halogen-free flame-retardant tape to the left side of the wire core and the filler outer surface to obtain the cable core. The wrapping thickness and width of the two layers of halogen-free flame-retardant tape are 0.17mm and 45mm, respectively.

[0074] Step 4: The cable core is longitudinally wrapped with an aluminum strip using argon arc welding and then corrugated to obtain an aluminum sheath. The corrugation pitch of the corrugation treatment is 11.5mm, and the longitudinal wrapping thickness of the aluminum sheath is 1mm.

[0075] Step 5: Wrap two layers of ceramicized silicone rubber tape around the outer surface of the aluminum sheath using an overlapping wrapping method to obtain a silicone rubber wrapping layer;

[0076] The method for preparing the ceramicized silicone rubber tape in step five of this embodiment is as follows:

[0077] Silicone rubber and silica were mixed in a specific mass ratio and then kneaded at 85°C and 60 rpm for 20 minutes. Then, ceramic filler and flame retardant were added and kneaded at 90-110°C and 90 rpm for 0.8 hours. After cooling, the mixture was passed through a two-roll mill 25 times. Then, vulcanizing agent was added and kneaded at 75°C and 40 rpm for 15 minutes. The resulting mixture was then coated onto release paper with a coating thickness of 0.4 mm and cured at 130°C for 2 hours to obtain ceramicized silicone rubber tape.

[0078] In this embodiment, the mass ratio of silicone rubber, silica, ceramic filler, flame retardant, and vulcanizing agent is 10:3:4:1.25:0.25; the flame retardant and vulcanizing agent in this embodiment are decabromodiphenyl ethane and bis(2,5-diphenyl) sulfide, respectively; the ceramic filler is composed of silica and alumina.

[0079] The method for preparing the ceramicized filler in this embodiment is as follows:

[0080] A 20wt% sodium silicate solution was prepared using sodium silicate and deionized water. Alumina, aluminum phosphate, zirconium oxide, and the 20wt% sodium silicate solution were mixed in a mass ratio of 1:0.2:0.5:3. Then, 3wt% sodium dodecylbenzenesulfonate and 7.5wt% silica sol were added. The ultrasonic frequency was set to 50kHz, the ultrasonic power to 500W, and the mixture was ultrasonicated for 2 hours. Simultaneously, 0.1mol / L dilute hydrochloric acid and 0.1mol / L sodium hydroxide solutions were added dropwise to adjust the pH to 9.5. After ultrasonication, the mixture was allowed to stand for 0.5 hours, filtered, and the coated product was obtained. The product was rinsed with deionized water and dried at 90℃ for 4 hours to obtain the dried product. The dried product was placed in a muffle furnace and heated to 1350℃ at a rate of 5℃ / min, and held at that temperature for 8 hours to obtain the ceramicized filler.

[0081] Step 6: Extrude the outer sheath material evenly around the silicone rubber tape layer to form the outer sheath. The extrusion thickness is 1mm to obtain the finished cable.

[0082] In step two, the overlap rate of the three-layer, three-in-one phlogopite tape in this embodiment is 22.5%.

[0083] In step three, the overlap rate of the two layers of halogen-free flame-retardant tape in this embodiment is 20%.

[0084] In step five, the overlap rate of the two layers of ceramicized silicone rubber tape wrapped in this embodiment is 11.5%.

[0085] In step six, the outer sheath material in this embodiment is a low-smoke, halogen-free, flame-retardant polyolefin sheath material for low-heat-release cables.

[0086] In step six, the parameters of the extrusion equipment for the outer protective layer material in this embodiment are as follows: barrel zone 1 temperature is 139°C, barrel zone 2 temperature is 144°C, barrel zone 3 temperature is 149°C, barrel zone 4 temperature is 157°C, barrel zone 5 temperature is 163°C, barrel zone 6 temperature is 162°C, flange area temperature is 162°C, die zone 1 temperature is 166°C, die zone 2 temperature is 188°C, and die zone 3 temperature is 201°C.

[0087] The extrusion equipment in this embodiment uses a halogen-free, low-smoke screw with a low compression ratio of 1.1:1 and an extrusion die of type tube extrusion.

[0088] Comparative Example 1

[0089] Based on Example 3, while keeping other conditions consistent, the steps of the preparation process are changed to:

[0090] Step 1: The copper rod is drawn and annealed to obtain copper wire, which is then stranded to obtain the copper conductor. The copper rod used in this comparative example is a high-quality oxygen-free copper rod with a copper purity of 99.9%. The copper conductor consists of copper conductor A and copper conductor B, with copper conductor A having a cross-sectional area of ​​50 mm². 2 The cross-sectional area of ​​copper conductor B is 25 mm². 2 Copper conductor A is made of 10 strands of copper wire with a diameter of 2.62 mm; copper conductor B is made of 7 strands of copper wire with a diameter of 2.10 mm.

[0091] Step 2: Apply an overlapping wrapping process to the outer surfaces of copper conductor A and copper conductor B respectively, wrapping three layers of three-in-one phlogopite tape, and extruding a layer of XLPE insulation layer to obtain insulated core A and insulated core B.

[0092] Step 3: Twist 3 insulated wire cores A and 1 insulated wire core B into a cable. Fill the gaps between the cable cores with high flame-retardant PP filler rope to make them round. Wrap two layers of halogen-free flame-retardant tape around the wire core and the filler outer surface in an overlapping wrapping manner to obtain the cable core.

[0093] Step 4: Two layers of ceramicized silicone rubber tape are wrapped around the outer surface of the cable core using an overlapping wrapping method to obtain a silicone rubber wrapping layer;

[0094] Step 5: Evenly extrude the outer sheath material around the silicone rubber tape layer to form the outer sheath, thus obtaining the finished cable.

[0095] Comparative Example 2

[0096] Based on Example 3, while keeping other conditions consistent, the steps of the preparation process are changed to:

[0097] Step 1: The copper rod is drawn and annealed to obtain copper wire, which is then stranded to obtain the copper conductor. The copper rod used in this comparative example is a high-quality oxygen-free copper rod with a copper purity of 99.9%. The copper conductor consists of copper conductor A and copper conductor B, with copper conductor A having a cross-sectional area of ​​50 mm². 2 The cross-sectional area of ​​copper conductor B is 25 mm². 2 Copper conductor A is made of 10 strands of copper wire with a diameter of 2.62 mm; copper conductor B is made of 7 strands of copper wire with a diameter of 2.10 mm.

[0098] Step 2: Apply an overlapping wrapping process to the outer surfaces of copper conductor A and copper conductor B respectively, wrapping three layers of three-in-one phlogopite tape, and extruding a layer of XLPE insulation layer to obtain insulated core A and insulated core B.

[0099] Step 3: Twist 3 insulated wire cores A and 1 insulated wire core B into a cable. Fill the gaps between the cable cores with high flame-retardant PP filler rope to make them round. Then, longitudinally wrap an aluminum strip with argon arc welding and perform corrugation treatment to obtain the cable core.

[0100] Step 4: Two layers of ceramicized silicone rubber tape are wrapped around the outer surface of the cable core using an overlapping wrapping method to obtain a silicone rubber wrapping layer;

[0101] Step 5: Evenly extrude the outer sheath material around the silicone rubber tape layer to form the outer sheath, thus obtaining the finished cable.

[0102] Comparative Example 3

[0103] Based on Example 3, while keeping other conditions consistent, the steps of the preparation process are changed to:

[0104] Step 1: The copper rod is drawn and annealed to obtain copper wire, which is then stranded to obtain the copper conductor. The copper rod used in this comparative example is a high-quality oxygen-free copper rod with a copper purity of 99.9%. The copper conductor consists of copper conductor A and copper conductor B, with copper conductor A having a cross-sectional area of ​​50 mm². 2 The cross-sectional area of ​​copper conductor B is 25 mm². 2 Copper conductor A is made of 10 strands of copper wire with a diameter of 2.62 mm; copper conductor B is made of 7 strands of copper wire with a diameter of 2.10 mm.

[0105] Step 2: Apply an overlapping wrapping process to the outer surfaces of copper conductor A and copper conductor B respectively, wrapping three layers of three-in-one phlogopite tape, and extruding a layer of XLPE insulation layer to obtain insulated core A and insulated core B.

[0106] Step 3: Twist 3 insulated wire cores A and 1 insulated wire core B into a cable. Fill the gaps between the cable cores with high flame-retardant PP filler rope to make them round. Wrap two layers of halogen-free flame-retardant tape around the wire core and the filler outer surface in an overlapping wrapping manner to obtain the cable core.

[0107] Step 4: The cable core is longitudinally wrapped with an aluminum strip using argon arc welding and then corrugated to obtain an aluminum sheath;

[0108] Step 5: Evenly extrude the outer sheath material onto the outer surface of the aluminum sheath to form the outer sheath, thus obtaining the finished cable.

[0109] Comparative Example 4

[0110] Based on Example 3, sodium dodecylbenzenesulfonate was removed from the preparation of the ceramic filler and replaced with an equal weight of 20wt% sodium silicate solution, while other conditions remained the same as in Example 3.

[0111] Comparative Example 5

[0112] Based on Example 3, the silica sol in the preparation of the ceramic filler was removed and replaced with an equal weight of 20wt% sodium silicate solution, while other conditions remained the same as in Example 3.

[0113] Comparative Example 6

[0114] Based on Example 3, the ceramicized filler was removed and replaced with an equal amount of filler, which consisted of aluminum silicate, aluminum phosphate and zirconium oxide in a mass ratio of 1:0.3:0.7.

[0115] Performance testing:

[0116] Using the cables prepared in Examples 1-3 and Comparative Examples 1-6 as samples, the flame spread (FS), peak heat release rate (HRR), and total heat release within 1200 s of exposure to fire (THR) of the cables were tested according to GB31248-2014. 1200 The combustion performance rating of the samples was tested by measuring the peak smoke production rate (SPR) and vertical flame spread (H). According to BS6387 "Fire resistance test method for cables to maintain line integrity under flame conditions", the test was conducted to determine whether the cable would break down after being subjected to impact vibration for 15 minutes under a flame of 950-1350℃. The test results are shown in Table 1 below.

[0117] Table 1

[0118] ;

[0119] Table 1 shows that the flame spread (FS), peak heat release rate (HRR), and total heat release within 1200 seconds of exposure to fire of the cable prepared by this invention are as follows: 1200The peak smoke production rate (SPR) and vertical flame spread (H) all meet the requirements of the B1 combustion performance level. At the same time, it was found that the samples of Examples 1-3 had no burning droplets / particles within 1200s after combustion, and the smoke toxicity level reached ZAs. Furthermore, the cable was not broken after being subjected to 15 minutes of impact vibration at a flame temperature of 950-1350℃. In Comparative Example 1, the removal of the aluminum strip weakened the overall performance; in Comparative Example 2, the removal of the flame-retardant strip reduced the cable's flame-retardant performance, making it prone to cracking at high temperatures and thus weakening its impact resistance; in Comparative Example 3, the removal of the ceramicized silicone rubber strip prevented it from being rapidly fired into a hard, complete shell at high temperatures like in this invention, thus weakening its performance. This demonstrates that the present invention, through multi-layer wrapping, synergistically improves the cable's performance. In Comparative Examples 4 and 5, the removal of sodium dodecylbenzenesulfonate and silica sol during the preparation of the ceramicized filler may lead to uneven component dispersion, agglomeration, or weakened adhesion, resulting in poor performance of the ceramicized filler. Comparative Example 6 simply combined aluminum silicate, aluminum phosphate, and zirconium oxide, while the present invention generates aluminum silicate by sintering sodium silicate solution and aluminum oxide at high temperatures, forming a ceramicized filler with aluminum silicate as the shell layer and covering aluminum phosphate and other materials. The resulting filler not only has improved performance but also forms a denser ceramicized structure at high temperatures, thus exhibiting superior performance compared to the cable prepared in Comparative Example 6. Therefore, compared with traditional fire-resistant cables, the B1-grade high flame-retardant NS-type fire-resistant cable prepared by this invention, while meeting the same fire resistance performance, has the characteristics of impact and spray resistance, and has better safety performance. It can reduce the pressure on fire rescue and provide greater opportunities for personnel to escape when a fire occurs.

[0120] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A manufacturing process for a B1-grade high flame-retardant NS-type fire-resistant cable, characterized in that: The preparation process includes the following steps: Step 1: The copper rod is drawn and annealed to obtain copper wire, which is then stranded to obtain a copper conductor; Step 2: An overlapping wrapping process is used on the outer surface of the copper conductor to wrap three layers of three-in-one phlogopite tape, and then an XLPE insulation layer is extruded to obtain the insulated wire core; Step 3: Twist multiple insulated wire cores into a cable by twisting them together. Fill the gaps between the cable cores with high flame-retardant PP filler rope to make them round. Wrap two layers of halogen-free flame-retardant tape around the wire core and the outer surface of the filler by overlapping wrapping to obtain the cable core. Step 4: The cable core is longitudinally wrapped with an aluminum strip using argon arc welding and then corrugated to obtain an aluminum sheath; Step 5: Wrap two layers of ceramicized silicone rubber tape around the outer surface of the aluminum sheath using an overlapping wrapping method to obtain a silicone rubber wrapping layer; Step 6: Evenly extrude the outer sheath material around the silicone rubber tape layer to form the outer sheath, thus obtaining the finished cable.

2. The manufacturing process of a B1-grade high flame-retardant NS-type fire-resistant cable according to claim 1, characterized in that: The copper rod mentioned in step one is a high-quality oxygen-free copper rod with a copper purity of 99.9%; the copper conductor includes copper conductor A and copper conductor B, and the cross-sectional area of ​​copper conductor A is 50 mm². 2 The cross-sectional area of ​​the copper conductor B is 25 mm². 2 The copper conductor A is made of 10 strands of copper wire with a diameter of 2.62±0.02mm; the copper conductor B is made of 7 strands of copper wire with a diameter of 2.10±0.02mm.

3. The manufacturing process of a B1-grade high flame-retardant NS-type fire-resistant cable according to claim 1, characterized in that: The overlap rate of the three-layer, three-in-one phlogopite tape wrapping in step two is 15-30%.

4. The manufacturing process of a B1-grade high flame-retardant NS-type fire-resistant cable according to claim 1, characterized in that: In step three, the overlap rate of the two layers of halogen-free flame-retardant tape is 15-25%.

5. The manufacturing process of a B1-grade high flame-retardant NS-type fire-resistant cable according to claim 1, characterized in that: The overlap rate of the two layers of ceramicized silicone rubber tapes in step five is 8-15%.

6. The manufacturing process of a B1-grade high flame-retardant NS-type fire-resistant cable according to claim 1, characterized in that: The method for preparing the ceramicized silicone rubber tape described in step five is as follows: Silicone rubber and silica are mixed in a specific mass ratio and then kneaded at 80-90℃ and 50-70 rpm for 15-25 minutes. Then, ceramic filler and flame retardant are added and kneaded at 90-110℃ and 80-100 rpm for 0.6-1 hours. After cooling, the mixture is passed through a two-roll mill 20-30 times. Then, vulcanizing agent is added and kneaded at 60-90℃ and 30-50 rpm for 10-20 minutes. The resulting mixture is then coated onto release paper with a coating thickness of 0.3-0.5 mm and cured at 120-140℃ for 1-3 hours to obtain ceramicized silicone rubber tape.

7. The manufacturing process of a B1-grade high flame-retardant NS-type fire-resistant cable according to claim 6, characterized in that: The mass ratio of the silicone rubber, silica, ceramic filler, flame retardant, and vulcanizing agent is 8-12:2.5-3.5:3-5:1-1.5:0.2-0.

3. The method for preparing the ceramicized filler is as follows: A 20wt% sodium silicate solution was prepared using sodium silicate and deionized water. Alumina, aluminum phosphate, zirconium oxide, and the 20wt% sodium silicate solution were mixed in a mass ratio of 1:0.1-0.3:0.3-0.7:2.7-3.

3. Then, sodium dodecylbenzenesulfonate (2.5-3.5wt% of alumina) and silica sol (5-10wt% of alumina) were added. The ultrasonic frequency was set to 40-60kHz, and the ultrasonic power to 400-600W. The ultrasonic treatment lasted for 1 minute. 0.5-2.5h, while sonicating, add 0.05-0.15mol / L dilute hydrochloric acid solution and 0.05-0.15mol / L sodium hydroxide solution dropwise to adjust the pH to 9-10. After sonication, let stand for 0.5h, filter to obtain the coated product, rinse with deionized water, and dry at 90℃ for 3-5h to obtain the dried product. Place the dried product in a muffle furnace, heat to 1300-1400℃ at a rate of 5℃ / min, and hold for 6-10h to obtain the ceramicized filler.

8. The manufacturing process of a B1-grade high flame-retardant NS-type fire-resistant cable according to claim 1, characterized in that: The outer sheath material described in step six is ​​a low-smoke, halogen-free, flame-retardant polyolefin sheath material for low-heat-release cables.

9. The manufacturing process of a B1-grade high flame-retardant NS-type fire-resistant cable according to claim 1, characterized in that: The parameters of the extrusion equipment for the outer protective layer material described in step six are as follows: barrel zone 1 temperature is 137-141℃, barrel zone 2 temperature is 143-145℃, barrel zone 3 temperature is 147-151℃, barrel zone 4 temperature is 156-158℃, barrel zone 5 temperature is 162-164℃, barrel zone 6 temperature is 160-164℃, flange area temperature is 160-164℃, die zone 1 temperature is 165-167℃, die zone 2 temperature is 186-190℃, and die zone 3 temperature is 200-202℃.

10. The manufacturing process of a B1-grade high flame-retardant NS-type fire-resistant cable according to claim 9, characterized in that: The extrusion equipment uses a halogen-free, low-smoke screw with a low compression ratio of 1.1:1 and employs a tube-type extrusion die.

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