Preparation process of B1-grade high-flame-retardant NS type fireproof cable

Abstract

The invention relates to a B1-grade high-flame-retardant NS type fireproof cable preparation technology, and belongs to the technical field of cables. According to the preparation technology of the B1-level high-flame-retardant NS type fireproof cable, after the insulated wire cores wrap copper and are stranded into the cable, gaps of the cable core are filled with PP filling ropes to be round, the cable core is wrapped with two layers of halogen-free flame-retardant belts, the cable core is longitudinally wrapped with an aluminum belt through argon arc welding, and the aluminum sheath is formed through embossing treatment; and finally, the ceramic silicone rubber tape and the low-smoke halogen-free flame-retardant polyolefin sheath material for the low-heat-release cable are lapped, so that the finished cable is obtained, the sealing performance, the fire resistance, the impact resistance and other performance of the cable are improved through treatment of multi-layer lapping, ceramic silicone rubber tape preparation and the like, the same fire resistance performance is met, and meanwhile the service life of the cable is prolonged. The B1-level high-flame-retardant NS type fireproof cable has the characteristics of impact resistance and spraying resistance, has better safety performance, and can relieve pressure for fire rescue and strive for greater opportunities for personnel escape when a fire occurs.

Description

Technical Field

[0001] The invention belongs to the technical field of cables and relates to a preparation process of a B1-level highly flame-retardant NS type fireproof cable. Background Art

[0002] With the rapid development of urbanization in my country, traditional polyvinyl chloride and cross-linked polyethylene insulated cables have gradually failed to meet the high requirements for cable fire resistance in high-rise buildings and crowded places. Fire-resistant cables are used in high-rise buildings, airports, shopping malls, schools and other places to ensure the uninterrupted operation of important fire-fighting electrical equipment such as fire pumps, fire elevators, local lighting, emergency evacuation instructions, security monitoring, fire prevention, smoke exhaust systems and self-contained power supplies in the event of a fire. At the same time, due to its good flexibility, corrosion resistance, high temperature resistance, fire prevention, explosion prevention, non-combustion and other characteristics, it is also used in dangerous, harsh and high-temperature environments such as nuclear power plants, metallurgy, chemical industry, and mines.

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

[0004] The purpose of the present invention is to provide a process for preparing a B1-class high-flame-retardant NS type fireproof cable. Compared with traditional fireproof cables, the prepared B1-class high-flame-retardant NS type fireproof cable has the characteristics of impact resistance and spray resistance while meeting the same fire resistance performance. It has better safety performance and can reduce the pressure on fire rescue when a fire occurs, and provide greater opportunities for people to escape.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A preparation process of a B1-grade highly flame-retardant NS-type fireproof cable, the preparation process comprising the following steps:

[0007] Step 1: The copper rod is subjected to wire drawing and annealing to obtain copper wire, and then subjected to a wire stranding process to obtain a copper conductor;

[0008] Step 2: Using overlapping wrapping process on the outer surface of the copper conductor, wrapping three layers of three-in-one phlogopite tape, and extruding a layer of XLPE insulation layer to obtain an insulated wire core;

[0009] Step 3: twist multiple insulated wire cores into a cable by twisting, fill the gaps between the cable cores with highly flame-retardant PP filling ropes to make them round, and wrap two layers of halogen-free flame-retardant tapes around the outer surfaces of the wire cores and the fillings by overlapping wrapping to obtain a cable core;

[0010] Step 4: longitudinally wrap the cable core with a layer of aluminum tape by argon arc welding and perform corrugation treatment to obtain an aluminum sheath;

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

[0012] Step 6: Uniformly extrude the outer sheath material onto the outer periphery of the silicone rubber tape layer as an outer sheath to obtain a finished cable.

[0013] Furthermore, in step 1, the copper rod is a high-quality oxygen-free copper rod with a copper purity of 99.9%; the copper conductor comprises a copper conductor A and a copper conductor B, and the cross-sectional area of ​​the copper conductor A is 50 mm 2 , the cross-sectional area of ​​the copper conductor B is 25mm 2 ; The copper conductor A is obtained by 10 copper strands with a diameter of 2.62±0.02mm; the copper conductor B is obtained by 7 copper strands with a diameter of 2.10±0.02mm.

[0014] Furthermore, the overlapping rate of the three-layer three-in-one phlogopite tapes in step 2 is 15-30%.

[0015] Furthermore, in step 3, the overlapping rate of the two layers of halogen-free flame retardant tapes is 15-25%.

[0016] Furthermore, in step 5, the overlapping rate of the two layers of ceramic silicone rubber tapes is 8-15%.

[0017] Furthermore, the preparation method of the ceramic silicone rubber belt in step 5 is:

[0018] After mixing silicone rubber and white carbon black according to the mass ratio, kneading at 80-90°C and 50-70rmp for 15-25min, then adding ceramic filler and flame retardant, kneading at 90-110°C and 80-100rmp for 0.6-1h, passing through an open mill for 20-30 times after cooling, then adding vulcanizing agent, kneading at 60-90°C and 30-50rmp for 10-20min, and coating the obtained mixture on release paper through a coater with a coating thickness of 0.3-0.5mm, and curing at 120-140°C for 1-3h to obtain a ceramic silicone rubber belt.

[0019] Furthermore, the mass ratio of the silicone rubber, white carbon black, ceramic filler, flame retardant and vulcanizer is 8-12:2.5-3.5:3-5:1-1.5:0.2-0.3;

[0020] The preparation method of the ceramic filler is:

[0021] Sodium silicate and deionized water are used to prepare a sodium silicate solution with a concentration of 20wt%, and aluminum oxide, aluminum phosphate, zirconium oxide and 20wt% sodium silicate solution are mixed according to a mass ratio of 1:0.1-0.3:0.3-0.7:2.7-3.3, and then 2.5-3.5wt% of sodium dodecylbenzene sulfonate and 5-10wt% of silica sol are added to the mass of aluminum oxide. The ultrasonic frequency is set to 40-60kHz, the ultrasonic power is 400-600W, and the ultrasonic is 1 .5-2.5h, while ultrasonicating, add 0.05-0.15mol / L dilute hydrochloric acid solution and 0.05-0.15mol / L sodium hydroxide solution to adjust the pH to 9-10, let it stand for 0.5h after the ultrasonication, filter to obtain the coated product, rinse with deionized water, dry at 90℃ for 3-5h to obtain the dry product, put the dry product into a muffle furnace, heat to 1300-1400℃ at a rate of 5℃ / min, and keep it warm for 6-10h to obtain a ceramic filler.

[0022] Furthermore, the outer sheath material 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 of the outer sheath material in step six are as follows: the temperature of barrel zone 1 is 137-141°C, the temperature of barrel zone 2 is 143-145°C, the temperature of barrel zone 3 is 147-151°C, the temperature of barrel zone 4 is 156-158°C, the temperature of barrel zone 5 is 162-164°C, the temperature of barrel zone 6 is 160-164°C, the temperature of flange area is 160-164°C, the temperature of die zone 1 is 165-167°C, the temperature of die zone 2 is 186-190°C, and the temperature of die zone 3 is 200-202°C.

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

[0025] Beneficial effects of the present invention:

[0026] (1) The present invention wraps a three-in-one phlogopite tape around the copper and extrude an XLPE insulation layer to obtain an insulated core. After multiple insulated cores are twisted into a cable, the gaps between the cable cores are filled and rounded with a high flame retardant PP filling rope. Two layers of halogen-free flame retardant tape are wrapped around the outside of the cable core, and an aluminum tape is longitudinally wrapped by argon arc welding and corrugated to form an aluminum sheath, thereby ensuring the sealing and mechanical strength of the aluminum sheath. Finally, a ceramic silicone rubber tape and a 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 impacted, the impact force can be dispersed to reduce damage to the internal insulating core. Furthermore, this multi-layer wrapping makes the cable have good sealing properties and can effectively prevent moisture from invading the cable core. In the event of a fire, if a fire sprinkler system is activated, the internal cable core can be protected from the influence of water, thereby ensuring that the cable can still maintain good electrical properties in a humid environment.

[0027] (2) During the preparation process of the ceramic silicone tape used in the present invention, sodium silicate solution infiltrates aluminum oxide, aluminum phosphate, and zirconium oxide. The sodium silicate solution and aluminum oxide generate aluminum silicate under high-temperature sintering. At the same time, sodium dodecylbenzene sulfonate is used to promote the uniform dispersion of various materials and the adhesion of silica sol to form a ceramic filler with aluminum silicate as a shell layer covering aluminum phosphate and other materials. Aluminum phosphate will be converted into a stable ceramic phase under high temperature conditions. Zirconium oxide has high hardness and strength. The various materials work together to help form a ceramic silicone tape with higher strength, denser structure, and better thermal insulation performance. In addition, the bending strength of ceramic silicone is much greater than that of ordinary silicone rubber, and it increases significantly with the increase of temperature. The ceramic 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 the ceramic silicone rubber does not explode, showing good thermal shock resistance, thereby preventing the cable from short-circuiting or disconnecting under flame burning, thereby ensuring the smoothness of the line.

[0028] (3) In addition, the low-smoke halogen-free flame-retardant polyolefin sheath material for low-heat-release cables used as the outer sheath material has 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 to isolate the air and hinder further combustion of the cable, etc. The coordinated treatment of multi-layer wrapping makes the B1-level high flame-retardant NS-type fireproof cable prepared by the present invention have the characteristics of impact resistance and spray resistance compared with traditional fireproof cables while meeting the same fire resistance performance. It has better safety performance and can reduce the pressure on fire rescue when a fire occurs, and provide greater opportunities for people to escape. DETAILED DESCRIPTION

[0029] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of the present invention are described in detail below in combination with the embodiments.

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

[0031] Example 1

[0032] A preparation process of a B1-grade high flame-retardant NS-type fireproof cable, the preparation process of this embodiment comprises the following steps:

[0033] Step 1: The copper rod is subjected to wire drawing and annealing to obtain copper wire, and then subjected to a wire stranding process to obtain a copper conductor; the copper rod of this embodiment 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 50mm 2 , the cross-sectional area of ​​copper conductor B is 25mm 2 ; Copper conductor A is obtained by 10 stranded copper wires with a diameter of 2.60 mm; copper conductor B is obtained by 7 stranded copper wires with a diameter of 2.08 mm;

[0034] Step 2: The outer surfaces of the copper conductor A and the copper conductor B are respectively wrapped with three layers of three-in-one phlogopite tapes by an overlapping wrapping process, and a layer of XLPE insulation layer is extruded to obtain an insulated core A and an insulated core B; the wrapping direction of the three-in-one phlogopite tape wrapped around the copper conductor A of this embodiment is left-handed wrapping, and the wrapping thickness and width are 0.14 mm and 20 mm, respectively; the wrapping direction of the three-in-one phlogopite tape wrapped around the copper conductor B is forward-handed wrapping, and the wrapping thickness and width are 0.14 mm and 15 mm, respectively; the thickness of the extruded XLPE insulation layer of the copper conductor A of this embodiment is 1 mm, and the thickness of the extruded XLPE insulation layer of the copper conductor B is 0.9 mm;

[0035] Step 3: Twist 3 insulated cores A and 1 insulated core B to the right to form a cable by twisting, fill the gap between the cable cores with a high flame retardant PP filling rope to make it round, the filling outer diameter of the high flame retardant PP filling rope is 8mm, and wrap two layers of halogen-free flame retardant tape to the left on the outer surface of the core and the filling surface in an overlapping wrapping manner to obtain a cable core, wherein the wrapping thickness and width of the two layers of halogen-free flame retardant tape are 0.17mm and 45mm respectively;

[0036] Step 4: longitudinally wrap a layer of aluminum tape on the cable core by argon arc welding and perform corrugation to obtain an aluminum sheath, wherein the corrugation pitch of the corrugation is 11.5 mm and the longitudinal wrapping thickness of the aluminum sheath is 1 mm;

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

[0038] Step 6: Extrude the outer sheath material evenly around the silicone rubber tape layer as the outer sheath with a thickness of 1 mm to obtain a finished cable.

[0039] In step 2, the overlapping rate of the three-layer three-in-one phlogopite tape of this embodiment is 15%.

[0040] In step 3, the overlapping rate of the two layers of halogen-free flame retardant tapes in this embodiment is 15%.

[0041] In step 5, the overlapping rate of the two layers of ceramic silicone rubber belts in this embodiment is 8%.

[0042] In step 5, the preparation method of the ceramic silicone rubber belt of this embodiment is:

[0043] After mixing silicone rubber and white carbon black according to the mass ratio, kneading at 80°C and 50 rpm for 15 minutes, ceramic filler and flame retardant were added, kneading at 90°C and 80 rpm for 0.6 hours, and after cooling, thinning was passed 20 times on an open mixing mill. Then, vulcanizing agent was added, and kneading was carried out at 60°C and 30 rpm for 10 minutes. The obtained mixture was coated on release paper by a coater with a coating thickness of 0.3 mm, and cured at 120°C for 1 hour to obtain a ceramic silicone rubber belt.

[0044] The mass ratio of silicone rubber, white carbon black, ceramic filler, flame retardant and vulcanizing agent in this embodiment is 8:2.5:3:1:0.2; the flame retardant and vulcanizing agent in this embodiment are decabromodiphenylethane and dipentadienyl vulcanizing agent respectively;

[0045] The preparation method of the ceramic filler of this embodiment is:

[0046] Sodium silicate and deionized water are used to prepare a sodium silicate solution with a concentration of 20wt%, and alumina, aluminum phosphate, zirconium oxide and 20wt% of the sodium silicate solution are mixed in a mass ratio of 1:0.1:0.3:2.7, and then 2.5wt% of sodium dodecylbenzene sulfonate and 5wt% of silica sol are added to the alumina mass. The ultrasonic frequency is set to 40kHz, the ultrasonic power is set to 400W, and the ultrasonic wave is performed for 1.5h. While the ultrasonic wave is performed, 0.05mol / L of dilute hydrochloric acid solution and 0.05mol / L of sodium hydroxide solution are added dropwise to adjust the pH to 9. After the ultrasonic wave is completed, the mixture is allowed to stand for 0.5h, and the coated product is obtained by filtration, which is rinsed with deionized water and dried at 90°C for 3h to obtain a dry product. The dry product is placed in a muffle furnace, heated to 1300°C at a rate of 5°C / min, and kept warm for 6h to obtain a ceramic filler.

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

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

[0049] The extrusion screw of the extrusion equipment of this embodiment adopts a 1.1:1 low compression ratio halogen-free and low-smoke screw, and adopts a tube extrusion die.

[0050] Example 2

[0051] A preparation process of a B1-grade high flame-retardant NS-type fireproof cable, the preparation process of this embodiment comprises the following steps:

[0052] Step 1: The copper rod is subjected to wire drawing and annealing to obtain copper wire, and then subjected to a wire stranding process to obtain a copper conductor; the copper rod of this embodiment 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 50mm 2 , the cross-sectional area of ​​copper conductor B is 25mm 2 ; Copper conductor A is obtained by 10 stranded copper wires with a diameter of 2.64 mm; copper conductor B is obtained by 7 stranded copper wires with a diameter of 2.12 mm;

[0053] Step 2: The outer surfaces of the copper conductor A and the copper conductor B are respectively wrapped with three layers of three-in-one phlogopite tapes by an overlapping wrapping process, and a layer of XLPE insulation layer is extruded to obtain an insulated core A and an insulated core B; the wrapping direction of the three-in-one phlogopite tape wrapped around the copper conductor A of this embodiment is left-handed wrapping, and the wrapping thickness and width are 0.14 mm and 20 mm, respectively; the wrapping direction of the three-in-one phlogopite tape wrapped around the copper conductor B is forward-handed wrapping, and the wrapping thickness and width are 0.14 mm and 15 mm, respectively; the thickness of the extruded XLPE insulation layer of the copper conductor A of this embodiment is 1 mm, and the thickness of the extruded XLPE insulation layer of the copper conductor B is 0.9 mm;

[0054] Step 3: Twist 3 insulated cores A and 1 insulated core B to the right to form a cable by twisting, fill the gap between the cable cores with a high flame retardant PP filling rope to make it round, the filling outer diameter of the high flame retardant PP filling rope is 8mm, and wrap two layers of halogen-free flame retardant tape to the left on the outer surface of the core and the filling surface in an overlapping wrapping manner to obtain a cable core, wherein the wrapping thickness and width of the two layers of halogen-free flame retardant tape are 0.17mm and 45mm respectively;

[0055] Step 4: longitudinally wrap a layer of aluminum tape on the cable core by argon arc welding and perform corrugation to obtain an aluminum sheath, wherein the corrugation pitch of the corrugation is 11.5 mm and the longitudinal wrapping thickness of the aluminum sheath is 1 mm;

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

[0057] Step 6: Extrude the outer sheath material evenly around the silicone rubber tape layer as the outer sheath with a thickness of 1 mm to obtain a finished cable.

[0058] In step 2, the overlapping rate of the three-layer three-in-one phlogopite tape of this embodiment is 30%.

[0059] In step 3, the overlapping rate of the two layers of halogen-free flame retardant tapes in this embodiment is 25%.

[0060] In step 5, the overlapping rate of the two layers of ceramic silicone rubber belts in this embodiment is 15%.

[0061] In step 5, the preparation method of the ceramic silicone rubber belt of this embodiment is:

[0062] After mixing silicone rubber and white carbon black according to the mass ratio, kneading at 90°C and 70 rpm for 25 minutes, ceramic filler and flame retardant were added, kneading at 110°C and 100 rpm for 1 hour, and after cooling, thinning was passed 30 times on an open mixing mill. Then, vulcanizing agent was added, and kneading was carried out at 90°C and 50 rpm for 20 minutes to obtain the mixture, which was coated on release paper by a coater with a coating thickness of 0.5 mm, and cured at 140°C for 3 hours to obtain a ceramic silicone rubber belt.

[0063] The mass ratio of silicone rubber, white carbon black, ceramic filler, flame retardant and vulcanizing agent in this embodiment is 12:3.5:5:1.5:0.3; the flame retardant and vulcanizing agent in this embodiment are decabromodiphenylethane and dipentadienyl vulcanizing agent respectively;

[0064] The preparation method of the ceramic filler of this embodiment is:

[0065] Sodium silicate and deionized water are used to prepare a sodium silicate solution with a concentration of 20wt%, and alumina, aluminum phosphate, zirconium oxide and 20wt% of the sodium silicate solution are mixed in a mass ratio of 1:0.3:0.7:3.3, and then 3.5wt% of sodium dodecylbenzene sulfonate and 10wt% of silica sol are added to the alumina mass. The ultrasonic frequency is set to 60kHz, the ultrasonic power is set to 600W, and the ultrasonic wave is performed for 2.5h. While the ultrasonic wave is performed, 0.15mol / L of dilute hydrochloric acid solution and 0.15mol / L of sodium hydroxide solution are added dropwise to adjust the pH to 10. After the ultrasonic wave is completed, the mixture is allowed to stand for 0.5h, and the coated product is obtained by filtration, which is rinsed with deionized water and dried at 90°C for 5h to obtain a dry product. The dry product is placed in a muffle furnace, heated to 1400°C at a rate of 5°C / min, and kept warm for 10h to obtain a ceramic filler.

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

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

[0068] The extrusion screw of the extrusion equipment of this embodiment adopts a 1.1:1 low compression ratio halogen-free and low-smoke screw, and adopts a tube extrusion die.

[0069] Example 3

[0070] A preparation process of a B1-grade high flame-retardant NS-type fireproof cable, the preparation process of this embodiment comprises the following steps:

[0071] Step 1: The copper rod is subjected to wire drawing and annealing to obtain copper wire, and then subjected to a wire stranding process to obtain a copper conductor; the copper rod of this embodiment 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 50mm 2 , the cross-sectional area of ​​copper conductor B is 25mm 2 ; Copper conductor A is obtained by 10 stranded copper wires with a diameter of 2.62 mm; copper conductor B is obtained by 7 stranded copper wires with a diameter of 2.10 mm;

[0072] Step 2: The outer surfaces of the copper conductor A and the copper conductor B are respectively wrapped with three layers of three-in-one phlogopite tapes by an overlapping wrapping process, and a layer of XLPE insulation layer is extruded to obtain an insulated core A and an insulated core B; the wrapping direction of the three-in-one phlogopite tape wrapped around the copper conductor A of this embodiment is left-handed wrapping, and the wrapping thickness and width are 0.14 mm and 20 mm, respectively; the wrapping direction of the three-in-one phlogopite tape wrapped around the copper conductor B is forward-handed wrapping, and the wrapping thickness and width are 0.14 mm and 15 mm, respectively; the thickness of the extruded XLPE insulation layer of the copper conductor A of this embodiment is 1 mm, and the thickness of the extruded XLPE insulation layer of the copper conductor B is 0.9 mm;

[0073] Step 3: Twist 3 insulated cores A and 1 insulated core B to the right to form a cable by twisting, fill the gap between the cable cores with a high flame retardant PP filling rope to make it round, the filling outer diameter of the high flame retardant PP filling rope is 8mm, and wrap two layers of halogen-free flame retardant tape to the left on the outer surface of the core and the filling surface in an overlapping wrapping manner to obtain a cable core, wherein the wrapping thickness and width of the two layers of halogen-free flame retardant tape are 0.17mm and 45mm respectively;

[0074] Step 4: longitudinally wrap a layer of aluminum tape on the cable core by argon arc welding and perform corrugation to obtain an aluminum sheath, wherein the corrugation pitch of the corrugation is 11.5 mm and the longitudinal wrapping thickness of the aluminum sheath is 1 mm;

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

[0076] In step 5, the preparation method of the ceramic silicone rubber belt of this embodiment is:

[0077] After mixing silicone rubber and white carbon black according to the mass ratio, kneading at 85°C and 60 rpm for 20 min, ceramic filler and flame retardant were added, kneading at 90-110°C and 90 rpm for 0.8 h, and after cooling, thinning was passed on an open mill for 25 times, and vulcanizing agent was added, and kneading was carried out at 75°C and 40 rpm for 15 min. The obtained mixture was coated on release paper by a coater with a coating thickness of 0.4 mm, and cured at 130°C for 2 h to obtain a ceramic silicone rubber belt.

[0078] The mass ratio of silicone rubber, white carbon black, ceramic filler, flame retardant and vulcanizer in this embodiment is 10:3:4:1.25:0.25; the flame retardant and vulcanizer in this embodiment are decabromodiphenylethane and dipentadienyl vulcanizer respectively; the ceramic filler is composed of silicon dioxide, aluminum oxide

[0079] The preparation method of the ceramic filler of this embodiment is:

[0080] Sodium silicate and deionized water are used to prepare a sodium silicate solution with a concentration of 20wt%, and alumina, aluminum phosphate, zirconium oxide and 20wt% of the sodium silicate solution are mixed in a mass ratio of 1:0.2:0.5:3, and then 3wt% of sodium dodecylbenzene sulfonate and 7.5wt% of silica sol are added. The ultrasonic frequency is set to 50kHz, the ultrasonic power is set to 500W, and the ultrasonic wave is performed for 2h. While the ultrasonic wave is performed, 0.1mol / L of dilute hydrochloric acid solution and 0.1mol / L of sodium hydroxide solution are added dropwise to adjust the pH to 9.5. After the ultrasonic wave is completed, the mixture is allowed to stand for 0.5h, and the coated product is obtained by filtration. The mixture is rinsed with deionized water, and dried at 90°C for 4h to obtain a dry product. The dry product is placed in a muffle furnace, heated to 1350°C at a rate of 5°C / min, and kept warm for 8h to obtain a ceramic filler.

[0081] Step 6: Extrude the outer sheath material evenly around the silicone rubber tape layer as the outer sheath with a thickness of 1 mm to obtain a finished cable.

[0082] In step 2, the overlapping rate of the three-layer three-in-one phlogopite tape of this embodiment is 22.5%.

[0083] In step 3, the overlapping rate of the two layers of halogen-free flame retardant tapes in this embodiment is 20%.

[0084] In step 5, the overlapping rate of the two layers of ceramic silicone rubber belts in this embodiment is 11.5%.

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

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

[0087] The extrusion screw of the extrusion equipment of this embodiment adopts a 1.1:1 low compression ratio halogen-free and low-smoke screw, and adopts a tube extrusion die.

[0088] Comparative Example 1

[0089] On the basis of Example 3, keeping other conditions the same, the steps of the preparation process are changed to:

[0090] Step 1: The copper rod is subjected to wire drawing and annealing to obtain copper wire, and then subjected to a wire stranding process to obtain a copper conductor; the copper rod of this comparative example 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 50mm 2 , the cross-sectional area of ​​copper conductor B is 25mm 2 ; Copper conductor A is obtained by 10 stranded copper wires with a diameter of 2.62 mm; copper conductor B is obtained by 7 stranded copper wires with a diameter of 2.10 mm;

[0091] Step 2: Using overlapping wrapping process, wrap three layers of three-in-one phlogopite tape on the outer surface of the copper conductor A and the copper conductor B, and extrude a layer of XLPE insulation layer to obtain the insulated wire core A and the insulated wire core B;

[0092] Step 3: Twist three insulated cores A and one insulated core B into a cable by twisting, fill the gaps between the cable cores with highly flame-retardant PP filling ropes to make them round, and wrap two layers of halogen-free flame-retardant tapes around the outer surfaces of the cores and the filling ropes by overlapping wrapping to obtain a cable core;

[0093] Step 4: Wrap two layers of ceramic silicone rubber tape on the outer surface of the cable core in an overlapping wrapping manner to obtain a silicone rubber tape layer;

[0094] Step 5: Uniformly extrude the outer sheath material onto the outer periphery of the silicone rubber tape layer as an outer sheath to obtain a finished cable.

[0095] Comparative Example 2

[0096] On the basis of Example 3, keeping other conditions the same, the steps of the preparation process are changed to:

[0097] Step 1: The copper rod is subjected to wire drawing and annealing to obtain copper wire, and then subjected to a wire stranding process to obtain a copper conductor; the copper rod of this comparative example 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 50mm 2 , the cross-sectional area of ​​copper conductor B is 25mm 2 ; Copper conductor A is obtained by 10 stranded copper wires with a diameter of 2.62 mm; copper conductor B is obtained by 7 stranded copper wires with a diameter of 2.10 mm;

[0098] Step 2: Using overlapping wrapping process, wrap three layers of three-in-one phlogopite tape on the outer surface of the copper conductor A and the copper conductor B, and extrude a layer of XLPE insulation layer to obtain the insulated wire core A and the insulated wire core B;

[0099] Step 3: Twist three insulated cores A and one insulated core B into a cable by twisting, fill the gaps between the cable cores with highly flame-retardant PP filling ropes to make them round, and longitudinally wrap a layer of aluminum tape by argon arc welding and perform corrugation treatment to obtain a cable core;

[0100] Step 4: Wrap two layers of ceramic silicone rubber tape on the outer surface of the cable core in an overlapping wrapping manner to obtain a silicone rubber tape layer;

[0101] Step 5: Uniformly extrude the outer sheath material onto the outer periphery of the silicone rubber tape layer as an outer sheath to obtain a finished cable.

[0102] Comparative Example 3

[0103] On the basis of Example 3, keeping other conditions the same, the steps of the preparation process are changed to:

[0104] Step 1: The copper rod is subjected to wire drawing and annealing to obtain copper wire, and then subjected to a wire stranding process to obtain a copper conductor; the copper rod of this comparative example 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 50mm 2 , the cross-sectional area of ​​copper conductor B is 25mm 2 ; Copper conductor A is obtained by 10 stranded copper wires with a diameter of 2.62 mm; copper conductor B is obtained by 7 stranded copper wires with a diameter of 2.10 mm;

[0105] Step 2: Using overlapping wrapping process, wrap three layers of three-in-one phlogopite tape on the outer surface of the copper conductor A and the copper conductor B, and extrude a layer of XLPE insulation layer to obtain the insulated wire core A and the insulated wire core B;

[0106] Step 3: Twist three insulated cores A and one insulated core B into a cable by twisting, fill the gaps between the cable cores with highly flame-retardant PP filling ropes to make them round, and wrap two layers of halogen-free flame-retardant tapes around the outer surfaces of the cores and the filling ropes by overlapping wrapping to obtain a cable core;

[0107] Step 4: longitudinally wrap the cable core with a layer of aluminum tape by argon arc welding and perform corrugation treatment to obtain an aluminum sheath;

[0108] Step 5: Extrude the outer sheath material evenly on the outer surface of the aluminum sheath as the outer sheath to obtain a finished cable.

[0109] Comparative Example 4

[0110] On the basis of Example 3, the sodium dodecylbenzene sulfonate in the preparation of the ceramic filler was removed and replaced with an equal weight of 20 wt % sodium silicate solution. Other conditions were consistent with those in Example 3.

[0111] Comparative Example 5

[0112] On the basis of Example 3, the silica sol in the preparation of the ceramic filler was removed and replaced with an equal weight of 20 wt % sodium silicate solution. Other conditions were the same as those in Example 3.

[0113] Comparative Example 6

[0114] On the basis of Example 3, the ceramic filler is removed and replaced with a filler of equal weight, wherein the filler is composed of aluminum silicate, aluminum phosphate and zirconium oxide in a mass ratio of 1:0.3:0.7.

[0115] Performance Test:

[0116] The cables prepared in Examples 1-3 and Comparative Examples 1-6 were used as samples, and the flame spread (FS), peak heat release rate (HRR peak), and total heat release within 1200s of fire (THR 1200 ), smoke production rate peak (SPR peak) and vertical flame spread H, the combustion performance level of the sample was tested; according to BS6387 "Fire resistance test method for cables to maintain line integrity under flame conditions", the cable was tested to see if it was broken after being subjected to knocking and vibration for 15 minutes under a flame of 950-1350℃; the test results are shown in Table 1 below.

[0117] Table 1

[0118]

[0119] As shown in Table 1, the flame spread (FS), peak heat release rate (HRR peak), and total heat release within 1200s of fire (THR 1200), the peak value of the smoke production rate (SPR peak) and the vertical flame spread H all meet the requirements of the B1 combustion performance grade. At the same time, it is measured that after the samples of Examples 1-3 are burned, there are no burning drips / particles within 1200s, the smoke toxicity level reaches ZAs, and the cable is not broken down after being subjected to knocking and vibration for 15min under a flame of 950-1350℃. In Comparative Example 1, the aluminum tape was removed, and the overall performance was weakened; in Comparative Example 2, the flame retardant tape was removed, the flame retardant performance of the cable decreased, and it was easy to break at high temperature, so the impact resistance was weakened; in Comparative Example 3, the ceramic silicone rubber tape was removed, and it could not be quickly fired into a hard and complete shell at high temperature like the present invention, so the performance was weakened; it shows that the present invention has synergistically improved the performance of the cable through multi-layer wrapping; in Comparative Examples 4 and 5, sodium dodecylbenzene sulfonate and silica sol were removed in the preparation process of the ceramic filler, which may cause uneven dispersion of components, agglomeration or weakened adhesion, thereby causing the performance of the ceramic filler to deteriorate. Comparative Example 6 only simply combines aluminum silicate, aluminum phosphate and zirconium oxide, while the present invention generates aluminum silicate by sintering sodium silicate solution and aluminum oxide at high temperature to form a ceramic filler with aluminum silicate as the shell layer coated with aluminum phosphate and other materials. The obtained filler not only has improved performance, but can also form a denser ceramic structure at high temperature, so the performance is better than the cable prepared by Comparative Example 6. Therefore, compared with traditional fireproof cables, the B1-class high flame-retardant NS-type fireproof cable prepared by the present invention has the characteristics of impact resistance and spray resistance while meeting the same fire resistance performance. It has better safety performance and can reduce the pressure on fire rescue when a fire occurs, and create a greater opportunity for people to escape.

[0120] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A B1 grade high flame retardant NS type fireproof cable preparation process, characterized by: The preparation process comprises the following steps: Step 1: The copper rod is subjected to wire drawing and annealing to obtain copper wire, and then subjected to a wire stranding process to obtain a copper conductor; Step 2: Using overlapping wrapping process on the outer surface of the copper conductor, wrapping three layers of three-in-one phlogopite tape, and extruding a layer of XLPE insulation layer to obtain an insulated wire core; Step 3: twist multiple insulated wire cores into a cable by twisting, fill the gaps between the cable cores with highly flame-retardant PP filling ropes to make them round, and wrap two layers of halogen-free flame-retardant tapes around the outer surfaces of the wire cores and the fillings by overlapping wrapping to obtain a cable core; Step 4: longitudinally wrap the cable core with a layer of aluminum tape by argon arc welding and perform corrugation treatment to obtain an aluminum sheath; Step 5: Wrap two layers of ceramic silicone rubber tape around the outer surface of the aluminum sheath in an overlapping wrapping manner to obtain a silicone rubber tape layer; Step 6: Uniformly extrude the outer sheath material onto the outer periphery of the silicone rubber tape layer as an outer sheath to obtain a finished cable.

2. A process for preparing a B1-level high flame-retardant NS-type fireproof cable according to claim 1, characterized in that: Step 1: 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 mm 2 , the cross-sectional area of ​​the copper conductor B is 25mm 2 ; The copper conductor A is obtained by 10 copper strands with a diameter of 2.62±0.02mm; the copper conductor B is obtained by 7 copper strands with a diameter of 2.10±0.02mm.

3. A process for preparing a B1-level high flame-retardant NS-type fireproof cable according to claim 1, characterized in that: The overlapping rate of the three-layer three-in-one phlogopite tapes in step 2 is 15-30%.

4. A process for preparing a B1-level highly flame-retardant NS-type fireproof cable according to claim 1, characterized in that: In step 3, the overlapping rate of the two layers of halogen-free flame retardant tapes is 15-25%.

5. The process for preparing a B1-level high flame-retardant NS-type fireproof cable according to claim 1, characterized in that: In step 5, the overlapping rate of the two layers of ceramic silicone rubber tapes is 8-15%.

6. A process for preparing a B1-level highly flame-retardant NS-type fireproof cable according to claim 1, characterized in that: The preparation method of the ceramic silicone rubber belt in step 5 is: After mixing silicone rubber and white carbon black according to the mass ratio, kneading at 80-90°C and 50-70rmp for 15-25min, then adding ceramic filler and flame retardant, kneading at 90-110°C and 80-100rmp for 0.6-1h, passing through an open mill for 20-30 times after cooling, then adding vulcanizing agent, kneading at 60-90°C and 30-50rmp for 10-20min, and coating the obtained mixture on release paper through a coater with a coating thickness of 0.3-0.5mm, and curing at 120-140°C for 1-3h to obtain a ceramic silicone rubber belt.

7. A process for preparing a B1-level highly flame-retardant NS-type fireproof cable according to claim 6, characterized in that: The mass ratio of the silicone rubber, white carbon black, ceramic filler, flame retardant and vulcanizer is 8-12:2.5-3.5:3-5:1-1.5:0.2-0.3; The preparation method of the ceramic filler is: Sodium silicate and deionized water are used to prepare a sodium silicate solution with a concentration of 20wt%, and aluminum oxide, aluminum phosphate, zirconium oxide and 20wt% sodium silicate solution are mixed according to a mass ratio of 1:0.1-0.3:0.3-0.7:2.7-3.3, and then 2.5-3.5wt% of sodium dodecylbenzene sulfonate and 5-10wt% of silica sol are added to the mass of aluminum oxide. The ultrasonic frequency is set to 40-60kHz, the ultrasonic power is 400-600W, and the ultrasonic is 1 .5-2.5h, while ultrasonicating, add 0.05-0.15mol / L dilute hydrochloric acid solution and 0.05-0.15mol / L sodium hydroxide solution to adjust the pH to 9-10, let it stand for 0.5h after the ultrasonication, filter to obtain the coated product, rinse with deionized water, dry at 90℃ for 3-5h to obtain the dry product, put the dry product into a muffle furnace, heat to 1300-1400℃ at a rate of 5℃ / min, and keep it warm for 6-10h to obtain a ceramic filler.

8. The process for preparing a B1-level highly flame-retardant NS-type fireproof 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 process for preparing a B1-level high flame-retardant NS-type fireproof cable according to claim 1, characterized in that: The parameters of the extrusion equipment of the outer sheath material in step 6 are: the temperature of barrel zone 1 is 137-141°C, the temperature of barrel zone 2 is 143-145°C, the temperature of barrel zone 3 is 147-151°C, the temperature of barrel zone 4 is 156-158°C, the temperature of barrel zone 5 is 162-164°C, the temperature of barrel zone 6 is 160-164°C, the temperature of flange area is 160-164°C, the temperature of die zone 1 is 165-167°C, the temperature of die zone 2 is 186-190°C, and the temperature of die zone 3 is 200-202°C.

10. A process for preparing a B1-level highly flame-retardant NS-type fireproof cable according to claim 9, characterized in that: The extrusion screw of the extrusion equipment adopts a 1.1:1 low compression ratio halogen-free and low-smoke screw, and adopts a tube extrusion die.

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