Fireproof shielding instrument cable and production process thereof

Abstract

The invention discloses a fireproof shielding instrument cable and a production process thereof, and belongs to the technical field of cable manufacturing, and the cable comprises a conductor layer, a fireproof layer, an insulating layer, a sub-shielding layer, a cabling filling layer, a total shielding layer and an outer sheath layer from inside to outside; the conductor layer is a carbon nanotube copper alloy conductor, the fireproof layer is a double-sided plastic-coated water glass calcined mica tape, the sub-shielding layer and the total shielding layer are of a composite structure of weaving, a fireproof coating and a copper tape, and the outer sheath layer is of a ceramic silicone rubber and modified polyether-ether-ketone double-sheath structure. The production process comprises the steps of conductor preparation, sequential forming of each layer, cabling filling, shielding, sheath extrusion and the like. The cable can resist the temperature of 1000-1200 DEG C, has a multi-layer fireproof shielding effect, is high in structural reliability, is halogen-free from all materials, has the service life exceeding 30 years, is suitable for instrument signal transmission and power transmission in fireproof places, and solves the problem that the existing cable is easy to lose efficacy in an extreme environment.

Description

Technical Field

[0001] This invention relates to the field of wire and cable technology, and in particular to a fireproof shielded instrument cable and its manufacturing process. Background Technology

[0002] In fields such as industrial automation, petrochemicals, and power transmission, instrument cables, as core components for signal transmission and power delivery, are widely used in connecting various instrument devices. However, existing instrument cables suffer from numerous insurmountable defects under extreme environments such as high temperatures and fires. Insufficient temperature resistance of the conductor; traditional copper conductors are prone to softening or oxidation at high temperatures, which leads to a significant decrease in conductivity or even circuit breakage, making it impossible to guarantee the continuous transmission of power and signals. The insulation materials have poor fire resistance. Conventional polyvinyl chloride, cross-linked polyethylene and other insulation layers are prone to carbonization and failure at high temperatures, making it difficult to maintain the insulation integrity of the circuit. The shielding structure is simple. The sub-shielding and overall shielding of existing cables mostly use a single tinned copper wire braided layer, which is poor in fire resistance and easily melts at high temperatures, causing electromagnetic shielding failure and affecting the stability of signal transmission. Insufficient flame retardancy of filler and sheath means that ordinary filler materials and outer sheaths are easily combustible in a fire, releasing toxic and harmful gases and failing to effectively insulate against heat transfer, further exacerbating cable damage.

[0003] The aforementioned defects make existing instrument cables extremely prone to failure in extreme environments such as fires, which can cause equipment failure and system paralysis, and pose a serious threat to the lives of on-site personnel. Therefore, the development of a new type of instrument cable with high temperature resistance and multi-layer fireproof shielding has become an urgent need in the industry. Summary of the Invention

[0004] The technical problem to be solved by this invention is that the current fireproof shielded instrument cables have insufficient temperature resistance of conductors, poor fire resistance of insulation materials, simple shielding structure, and insufficient flame retardancy of filling and sheath.

[0005] The technical solution adopted by this invention to solve its technical problem is: a fireproof shielded instrument cable, which includes, from the inside out, a conductor layer, a fire-resistant layer, an insulation layer, a sub-shielding layer, a cabling filling layer, a total shielding layer, and an outer sheath layer; the conductor layer is a carbon nanotube copper alloy conductor, which is made by melting and annealing GRCop-84 copper alloy and carbon nanotubes, with a temperature resistance rating ≥1000℃ and a conductivity ≥90%IACS; the fire-resistant layer is a three-layer, 0.14mm double-sided plastic-coated water glass calcined mica tape overlapping wrapping layer.

[0006] The insulation layer is a high-strength silicone rubber insulation layer with an extruded structure and a thickness of 0.50-0.60 mm. The sub-shielding layer includes a first polyester tape, a second polyester tape, a third polyester tape, a tin-plated carbon nanotube copper alloy conductor braided sub-shielding layer, and a first nano-ceramic-based fireproof and heat-insulating coating. The braiding density of the tin-plated carbon nanotube copper alloy conductor braided sub-shielding layer (5) is ≥90%, and the coating thickness of the nano-ceramic-based fireproof and heat-insulating coating is 0.120-0.180 mm. The first polyester tape and the second polyester tape are respectively wrapped around the inner and outer sides of the tin-plated carbon nanotube copper alloy conductor braided sub-shielding layer.

[0007] The cable filling layer is a high flame-retardant epoxy resin filling layer, which fills the gaps between the cable cores. After the cable cores are cabled, a third polyester tape is wrapped around the outside. The overall shielding layer is a composite structure. The inner layer is a tin-plated carbon nanotube copper alloy conductor braided overall shielding layer with a braiding density of ≥90%. The surface of the tin-plated carbon nanotube copper alloy conductor braided overall shielding layer is coated with a second nano-ceramic-based fireproof and heat-insulating coating with a thickness of 0.120-0.180 mm. The outer layer is a copper tape shielding layer with a copper tape thickness of 0.060 mm and a wrapping overlap rate of ≥25%.

[0008] The outer sheath layer has a double sheath structure, including an inner high-temperature resistant ceramicized silicone rubber sheath layer and an outer modified polyetheretherketone sheath layer. The thickness of the high-temperature resistant ceramicized silicone rubber sheath layer is ≥1.15mm, and the thickness of the modified polyetheretherketone sheath layer is ≥1.15mm.

[0009] A manufacturing process for a fire-resistant shielded instrument cable includes the following steps: Step 1: Melt and anneal GRCop-84 copper alloy with carbon nanotubes, and then draw them into single solid carbon nanotube copper alloy conductors to form a conductor layer. Step 2: Three layers of 0.14mm double-sided plastic-coated water glass calcined mica tape are overlapped and wrapped around the outside of the carbon nanotube copper alloy conductor of the conductor layer to form a refractory layer; Step 3: Extrude a high-strength silicone rubber layer onto the outside of the double-sided plastic-coated water glass calcined mica tape of the refractory layer to form a high-strength silicone rubber insulation layer with a thickness of 0.50-0.60 mm; Step 4: Twist the insulated wire cores covered with high-strength silicone rubber insulation layer and wrap them around the first polyester tape. Then braid a tin-plated carbon nanotube copper alloy conductor braid to form a tin-plated carbon nanotube copper alloy conductor braided sub-shielding layer. Subsequently, dip and coat the surface of the braided layer with the first nano-ceramic-based fireproof and heat-insulating coating. After the dip and coating is completed, wrap the second polyester tape again to form a sub-shielding layer. Step 5: After shielding, the wire cores are cabled, and a high flame-retardant epoxy resin filling layer is used to fill the gaps between the cable cores. After cable formation, a third polyester tape is wrapped around the cable to form a cable filling layer. Step 6: Weave a tin-plated carbon nanotube copper alloy conductor braid layer on the outside of the cable filling layer to form a tin-plated carbon nanotube copper alloy conductor braided total shielding layer, and then coat the surface of the braid layer with a second nano-ceramic-based fireproof and heat-insulating coating, and then wrap copper strips to form a copper strip shielding layer, thus forming the total shielding layer. Step 7: Extrude a high-temperature resistant ceramicized silicone rubber sheath layer and a modified polyether ether ketone sheath layer sequentially on the outside of the main shielding layer to form an outer sheath layer, thus obtaining a fireproof shielded instrument cable.

[0010] In step 4, the braiding density of the tin-plated carbon nanotube copper alloy conductor braided shielding layer is ≥90%, and the coating thickness of the first nano-ceramic-based fireproof and heat-insulating coating is 0.120~0.180mm.

[0011] In step 6, the copper strip of the copper strip shielding layer has a thickness of 0.060 mm and a wrapping overlap rate of ≥25%; in step 7, the thickness of the high-temperature resistant ceramicized silicone rubber sheath layer and the modified polyether ether ketone sheath layer is ≥1.15 mm.

[0012] The outer surface of the carbon nanotube copper alloy conductor is coated with a nano-scale aluminum-titanium composite anti-oxidation coating. The thickness of the nano-scale aluminum-titanium composite anti-oxidation coating is 0.005-0.01 mm. The nano-scale aluminum-titanium composite anti-oxidation coating is formed by vacuum magnetron sputtering and has an adhesion force ≥50 MPa with the carbon nanotube copper alloy conductor.

[0013] A tin-plated copper grounding terminal is welded to the outside of the copper strip shielding layer. The tin-plated copper grounding terminal is a stamped sheet structure with a length of 15-20 mm and a width of 8-10 mm. The weld between the tin-plated copper grounding terminal and the copper strip shielding layer is covered with a fireproof, insulating, and waterproof rubber sleeve. The fireproof, insulating, and waterproof rubber sleeve is made of silicone rubber with a thickness of 0.8-1.0 mm.

[0014] The outer surface of the modified polyether ether ketone sheath layer is provided with annular anti-slip and wear-resistant textures. The annular anti-slip and wear-resistant textures are integrally extruded, with a texture height of 0.3 to 0.5 mm and a texture spacing of 1.0 to 1.5 mm. Furthermore, the modified polyether ether ketone sheath layer contains 3% to 5% by weight of nano-silicon carbide wear-resistant particles.

[0015] The beneficial effects of this invention are: (1) The present invention uses carbon nanotube copper alloy conductor with a temperature resistance rating of ≥1000℃. Combined with a double-sided plastic-coated water glass calcined mica tape fire-resistant layer, the cable can work continuously for more than 1 hour in a high temperature environment of 1000℃~1200℃, which far exceeds the temperature resistance limit of ≤300℃ of traditional cables. In addition, a nano-level aluminum-titanium composite anti-oxidation coating is added to the surface of the conductor. The vacuum magnetron sputtering molding has strong bonding force, effectively preventing conductor oxidation at high temperature and further improving the high temperature resistance stability of the conductor. (2) The sub-shielding layer and the main shielding layer adopt a composite structure of "carbon nanotube copper alloy braid + nano ceramic base fireproof coating + copper strip wrapping" to achieve the dual functions of electromagnetic shielding and flame isolation under high temperature environment, effectively avoiding electromagnetic shielding failure. At the same time, the main shielding layer adds a special tin-plated copper grounding terminal, which is matched with a fireproof insulating and waterproof rubber sleeve to improve the grounding reliability of the shielding layer and completely solve the signal interference problem caused by poor grounding contact. (3) The high flame-retardant epoxy resin filling layer and the outer sheath layer form a dense carbonized layer in the fire, which can effectively isolate oxygen and heat transfer, and ensure the integrity of the overall cable structure. The double sheath structure further improves the structural stability of the cable in the fire-resistant impact environment. (4) The entire material system used in the cable is halogen-free, and no toxic gases are released during combustion, reducing secondary hazards at the fire scene; (5) Nano-silicon carbide wear-resistant particles are added to the modified polyether ether ketone sheath layer, and the outer surface is formed with annular anti-slip wear-resistant texture. The integral extrusion molding structure is firm, which not only improves the wear resistance of the sheath layer, but also solves the slippage problem during cable laying. At the same time, the silicone rubber insulation layer, the ceramicized silicone rubber sheath and the carbon nanotube copper alloy conductor all have excellent aging resistance, which extends the service life of the cable to more than 30 years and reduces the equipment maintenance and replacement costs. (6) The production process has added processes such as anti-oxidation coating, grounding terminal welding, and sheath pattern molding. The process is smoothly connected, the molding accuracy is high, and the industrial production of the new technical features can be stably realized, ensuring the consistency of product quality. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0017] Figure 1 This is a schematic diagram of the cross-sectional structure of the fireproof shielded instrument cable of the present invention.

[0018] In the diagram, 1. Carbon nanotube copper alloy conductor, 2. Double-sided coated water glass calcined mica tape, 3. High-strength silicone rubber insulation layer, 41. First polyester tape, 42. Second polyester tape, 43. Third polyester tape, 5. Tin-plated carbon nanotube copper alloy conductor braided sub-shielding layer, 6. First nano-ceramic-based fireproof and heat-insulating coating, 7. High flame-retardant epoxy resin filler layer, 8. Tin-plated carbon nanotube copper alloy conductor braided overall shielding layer, 9. Second nano-ceramic-based fireproof and heat-insulating coating, 10. Copper tape shielding layer, 11. High-temperature resistant ceramicized silicone rubber sheath layer, 12. Modified polyetheretherketone sheath layer, 13. Nano-grade aluminum-titanium composite anti-oxidation coating, 14. Tin-plated copper grounding terminal, 15. Annular anti-slip and wear-resistant texture. Detailed Implementation

[0019] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the invention, and therefore only show the components relevant to the invention.

[0020] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0021] Figure 1 The fire-resistant shielded instrument cable shown comprises, from the inside out, a conductor layer, a fire-resistant layer, an insulation layer, a sub-shielding layer, a cabling filler layer, a main shielding layer, and an outer sheath layer. The specific structure and parameters of each layer are as follows: Conductor layer: A carbon nanotube copper alloy conductor 1 is used. This conductor is made by melting and annealing GRCop-84 copper alloy and carbon nanotubes. It has a temperature resistance of ≥1000℃ and a conductivity of ≥90% IACS. It is made into a single solid conductor by drawing. The outer surface of the carbon nanotube copper alloy conductor 1 is tightly coated with a nano-level aluminum-titanium composite anti-oxidation coating 13. This nano-level aluminum-titanium composite anti-oxidation coating 13 is a nano-level aluminum-titanium composite coating with a thickness controlled between 0.005 and 0.01 mm. It is formed by vacuum magnetron sputtering and has a bonding force with the carbon nanotube copper alloy conductor 1 of ≥50 MPa. It can effectively block the conductor from contacting oxygen in high-temperature environments, prevent the conductor from oxidizing and softening, and improve the high-temperature stability and service life of the conductor layer.

[0022] Fire-resistant layer: Three layers of 0.14mm double-sided plastic-coated water glass calcined mica tape 2 are overlapped and wrapped around the outside of the conductor layer. The water glass coating on the surface of the mica tape forms a ceramic porous heat insulation layer when heated during combustion, ensuring the integrity and continuity of the mica tape. Insulation layer: A high-strength silicone rubber layer is extruded on the outside of the fire-resistant layer to form a high-strength silicone rubber insulation layer 3 with a thickness of 0.50-0.60mm, which enhances the mechanical strength of the cable and the structural integrity of the fire-resistant insulation layer; Sub-shielding layer: After the insulated wire cores are twisted together, they are first wrapped with a first polyester tape 41, and then a tin-plated carbon nanotube copper alloy conductor braided layer is formed to form a tin-plated carbon nanotube copper alloy conductor braided sub-shielding layer 5 with a braiding density ≥90%. The surface of the braided layer is coated with a first nano-ceramic-based fireproof and heat-insulating coating 6 with a coating thickness of 0.120~0.180mm. After coating, a second polyester tape 42 is wrapped around it again. Cable filling layer: The shielded wire cores are cabled, and the gaps between the cable cores are filled with high flame retardant epoxy resin to form a high flame retardant epoxy resin filling layer 7, which ensures the roundness of the cable and blocks heat transfer. After the cable is cabled, a third polyester tape 43 is wrapped around it. Overall shielding layer: A composite shielding structure, the inner layer is a tin-plated carbon nanotube copper alloy conductor braided shielding layer forming a tin-plated carbon nanotube copper alloy conductor braided overall shielding layer 8, with a braiding density ≥90%, and the surface of the braided layer is coated with a 0.120–0.180 mm thick second nano-ceramic-based fireproof and heat-insulating coating 9; the outer layer is a copper strip wrapped shielding layer forming a copper strip shielding layer 10, with a copper strip thickness of 0.060 mm and a wrapping overlap rate ≥25%; a shielding layer grounding component is fixedly installed on the outer side of the copper strip shielding layer 10. The component includes a tin-plated copper grounding terminal 14 and a fireproof, insulating, and waterproof sleeve. The tin-plated copper grounding terminal 14 is a stamped sheet structure with a length of 15-20 mm and a width of 8-10 mm. It is connected to the copper strip shielding layer 10 by a soldering process. The solder joint is tightly covered with a fireproof, insulating, and waterproof sleeve made of silicone rubber with a thickness of 0.8-1.0 mm. This not only ensures the reliability of the grounding of the shielding layer but also prevents oxidation, water ingress, and burn-off in the fire at the solder joint, thereby improving the electromagnetic shielding stability of the shielding layer. Outer sheath layer: It has a double sheath structure. A high-temperature resistant ceramicized silicone rubber sheath layer 11 with a thickness ≥1.15mm is first extruded on the outside of the total shielding layer. Then, a modified polyetheretherketone (PEEK) sheath layer 12 with a thickness ≥1.15mm is extruded on the outside of the modified PEEK sheath layer 12. The modified PEEK sheath layer 12 contains nano-silicon carbide wear-resistant particles, which are uniformly dispersed in the modified PEEK substrate at a mass ratio of 3% to 5%. At the same time, the outer surface of the modified PEEK sheath layer 12 is integrally extruded with annular anti-slip wear-resistant texture 15, with a texture height of 0.3 to 0.5mm and a texture spacing of 1.0 to 1.5mm. In combination with the anti-slip wear-resistant texture, the wear resistance and anti-slip performance of the outer sheath layer are greatly improved, preventing the sheath from being damaged by friction during cable laying and use, and enhancing the mechanical protection capability of the outer sheath layer.

[0023] This invention also provides a manufacturing process for the aforementioned fire-resistant shielded instrument cable, comprising the following steps: Step 1: Prepare carbon nanotube copper alloy conductor 1. GRCop-84 copper alloy and carbon nanotubes are melted and annealed, and then drawn into a single solid conductor by wire drawing process. A 0.005-0.01 mm nano-scale aluminum-titanium composite coating is coated on the outer surface of the conductor by vacuum magnetron sputtering process to form a nano-scale aluminum-titanium composite anti-oxidation coating 13, which together constitute the conductor layer.

[0024] Step 2: Overlap three layers of 0.14mm double-sided plastic-coated water glass calcined mica tape 2 on the outside of the conductor layer to form a refractory layer; Step 3: Form a 0.50-0.60mm thick high-strength silicone rubber insulation layer 3 on the outside of the refractory layer using an extrusion process; Step 4: Twist the insulated wire cores together and wrap them around the first polyester tape 41. Braid the tin-plated carbon nanotube copper alloy conductor braid to form the tin-plated carbon nanotube copper alloy conductor braided sub-shielding layer 5. After impregnating and coating with the first nano ceramic-based fireproof and heat-insulating coating 6, wrap the first polyester tape 42 again to form the sub-shielding layer. Step 5: The shielded wire cores are cabled, and the gaps between the cable cores are filled with high flame retardant epoxy resin to form high flame retardant epoxy resin filler 7. After cable formation, the first polyester tape 43 is wrapped around to form the cable filling layer. Step 6: Braid a tin-plated carbon nanotube copper alloy conductor braid layer on the outside of the cable filling layer to form a tin-plated carbon nanotube copper alloy conductor braided total shielding layer 8, and then coat it with a second nano-ceramic-based fireproof and heat-insulating coating 9. Then wrap copper strip around it to form a copper strip shielding layer 10. Solder a tin-plated copper grounding terminal 14 on the outside of the copper strip shielding layer 10, and cover the solder joint with a silicone rubber fireproof insulating and waterproof sleeve to assemble the shielding layer grounding assembly, which constitutes the total shielding layer.

[0025] Step 7: On the outside of the main shielding layer, extrude a high-temperature resistant ceramicized silicone rubber sheath to form a high-temperature resistant ceramicized silicone rubber sheath layer 11 and a modified polyether ether ketone sheath to form a modified polyether ether ketone sheath layer 12, forming an outer sheath layer with a double sheath structure, to obtain a fireproof shielded instrument cable.

[0026] The outer surface of the carbon nanotube copper alloy conductor 1 is coated with a nano-scale aluminum-titanium composite anti-oxidation coating 13. The thickness of the nano-scale aluminum-titanium composite anti-oxidation coating 13 is 0.005-0.01 mm. The nano-scale aluminum-titanium composite anti-oxidation coating 13 is formed by vacuum magnetron sputtering and has a bonding force with the carbon nanotube copper alloy conductor 1 ≥50 MPa.

[0027] A tin-plated copper grounding terminal 14 is welded to the outside of the copper strip shielding layer 10. The tin-plated copper grounding terminal 14 is a stamped sheet structure with a length of 15-20 mm and a width of 8-10 mm. The weld between the tin-plated copper grounding terminal 14 and the copper strip shielding layer 10 is covered with a fireproof, insulating, and waterproof rubber sleeve. The fireproof, insulating, and waterproof rubber sleeve is made of silicone rubber with a thickness of 0.8-1.0 mm.

[0028] The outer surface of the modified polyether ether ketone sheath layer 12 is provided with annular anti-slip and wear-resistant texture 15. The annular anti-slip and wear-resistant texture 15 is integrally extruded, with a texture height of 0.3 to 0.5 mm and a texture spacing of 1.0 to 1.5 mm. Furthermore, the modified polyether ether ketone sheath layer 12 contains 3% to 5% by weight of nano-silicon carbide wear-resistant particles.

[0029] Example 1: This example provides a fireproof shielded instrument cable. Its conductor layer uses a carbon nanotube copper alloy conductor 1, with a 0.005mm thick nano-grade aluminum-titanium composite anti-oxidation coating 13 on the outer surface. The nano-aluminum-titanium composite coating has a bonding strength of 50MPa. It is drawn into a single solid conductor, with a temperature resistance of 1000℃ and a conductivity of 90% IACS. The fire-resistant layer consists of three layers of 0.14mm double-sided plastic-coated water glass calcined mica tape 2, overlapped and wrapped. The insulation layer is a 0.55mm thick high-strength silicone rubber insulation layer 3. The sub-shielding layer is a tin-plated carbon nanotube copper alloy conductor braided sub-shielding layer 5 (braiding density 90%) + a 0.15mm thick first nano-ceramic-based fireproof and heat-insulating coating 6, wrapped both inside and out with polyester tape 4. The cable filling layer is a high-resistance... The shielding layer consists of an epoxy resin filler layer 7; a total shielding layer consisting of a tin-plated carbon nanotube copper alloy conductor braided total shielding layer 8 (braiding density 90%) + a 0.15mm thick second nano-ceramic-based fireproof and heat-insulating coating 9 + a 0.060mm thick copper strip shielding layer 10 (overlap rate 25%); a shielding layer grounding component is set on the outside of the copper strip shielding layer 10, including a 15mm×8mm tin-plated copper grounding terminal + a 0.8mm thick silicone rubber sleeve; the outer sheath layer consists of a 1.15mm thick high-temperature resistant ceramicized silicone rubber sheath layer 11 + a 1.15mm thick modified polyetheretherketone sheath layer 12, in which 3% by mass of nano-silicon carbide particles are mixed, and the outer surface is formed with an annular anti-slip and wear-resistant texture with a texture height of 0.3mm and a texture spacing of 1.0mm.

[0030] The manufacturing process for this cable is as follows: The GRCop-84 copper alloy was melted and annealed with carbon nanotubes, and then drawn into a carbon nanotube copper alloy conductor 1. A 0.005mm nano-scale aluminum-titanium composite anti-oxidation coating 13 was coated by vacuum magnetron sputtering. Three layers of 0.14mm double-sided plastic-coated water glass calcined mica tape 2 are wrapped around the outside of the nano-level aluminum-titanium composite anti-oxidation coating 13; Extruded 0.55mm high-strength silicone rubber insulation layer 3; After the insulated wire cores are twisted together, they are wrapped with polyester tape 4, and a 90% density tin-plated carbon nanotube copper alloy braided layer is woven to form a tin-plated carbon nanotube copper alloy conductor braided shielding layer 5. 6. 0.15mm first nano ceramic-based fireproof and heat-insulating coating is applied, and then polyester tape 4 is wrapped around it again. The wire cores are cabled, and the gaps are filled with high flame-retardant epoxy resin. After the cable is formed, it is wrapped with polyester tape 4. A tin-plated carbon nanotube copper alloy braided layer with a density of 90% is woven to form a tin-plated carbon nanotube copper alloy conductor braided total shielding layer 8. A 0.15mm second nano-ceramic-based fireproof and heat-insulating coating 9 is impregnated and coated. A 0.060mm thick copper strip shielding layer 10 is then wrapped around it with an overlap rate of 25%. A 15mm×8mm tin-plated copper grounding terminal is welded and covered with a 0.8mm silicone rubber sleeve to form a shielding grounding assembly. 3% nano-silicon carbide particles are mixed with modified polyetheretherketone (PEEK) substrate, and then extruded sequentially to form a 1.15mm high-temperature resistant ceramicized silicone rubber sheath layer 11 and a 1.15mm modified PEEK sheath layer 12. During extrusion, annular anti-slip and wear-resistant texture 15 is formed to form a wear-resistant reinforcing layer for the sheath, thus obtaining the finished cable.

[0031] The cable prepared in this embodiment was subjected to simulated fire tests according to IEC60331-1 and IEC60331-2 standards. It was continuously heated at 1000℃ for 1 hour. The insulation resistance of the cable remained stable, the shielding effectiveness did not decrease, the line continuity performance was good, the nano-level aluminum-titanium composite anti-oxidation coating 13 effectively prevented conductor oxidation, the grounding component of the shielding layer had good grounding contact, the wear-resistant reinforcement layer of the sheath showed no wear or peeling, and the overall structural integrity of the cable was not damaged.

[0032] Example 2 differs from Example 1 in that: the outer surface of the carbon nanotube copper alloy conductor 1 is coated with a 0.01mm thick nano-level aluminum-titanium composite anti-oxidation coating 13; the high-strength silicone rubber insulation layer 3 has a thickness of 0.60mm; the first nano-ceramic-based fireproof and heat-insulating coating 6 and the second nano-ceramic-based fireproof and heat-insulating coating 9 on the surface of the tin-plated carbon nanotube copper alloy conductor braided shielding layer 5 and the tin-plated carbon nanotube copper alloy conductor braided total shielding layer 8 have a thickness of 0.180mm; the copper strip shielding layer 10 has a wrapping overlap rate of 30%; the shielding layer grounding component is a 20mm×10mm tin-plated copper grounding terminal + a 1.0mm thick silicone rubber sleeve; the outer sheath layer's high-temperature resistant ceramicized silicone rubber sheath layer 11 and modified polyetheretherketone sheath layer 12 both have a thickness of 1.20mm; the modified polyetheretherketone sheath layer 12 contains a sheath wear-resistant reinforcing layer with a mass ratio of 5%; and the outer surface has an annular anti-slip wear-resistant texture with a texture height of 0.5mm and a texture spacing of 1.5mm.

[0033] Verified by simulated fire tests according to IEC60331-1 and IEC60331-2 standards, the cable can maintain stable insulation performance, shielding effectiveness and switching performance even after working continuously for 1 hour in a high-temperature environment of 1200℃. The nano-level aluminum-titanium composite anti-oxidation coating 13 effectively blocks high-temperature oxidation. The shielding layer grounding component does not desolder under high temperature, the rubber sheath does not burn, the sheath wear-resistant reinforcement layer maintains good wear resistance and anti-slip performance, and the cable structure is undamaged.

[0034] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A fire-resistant shielded instrument cable, characterized in that, From the inside out, it includes a conductor layer, a fire-resistant layer, an insulation layer, a sub-shielding layer, a cabling filling layer, a total shielding layer, and an outer sheath layer; the conductor layer is a carbon nanotube copper alloy conductor (1), which is made of GRCop-84 copper alloy and carbon nanotubes through melting and annealing, with a temperature resistance rating of ≥1000℃ and a conductivity of ≥90%IACS; the fire-resistant layer is a three-layer 0.14mm double-sided plastic-coated water glass calcined mica tape (2) overlapping wrapping layer.

2. The fireproof shielded instrument cable according to claim 1, characterized in that, The insulating layer is a high-strength silicone rubber insulating layer (3), which is an extruded layer structure with a thickness of 0.50-0.60 mm; the sub-shielding layer includes a first polyester tape (41), a second polyester tape (42), a third polyester tape (43), a tin-plated carbon nanotube copper alloy conductor braided sub-shielding layer (5), and a first nano-ceramic-based fireproof and heat-insulating coating (6). The braiding density of the tin-plated carbon nanotube copper alloy conductor braided sub-shielding layer (5) is ≥90%, and the coating thickness of the first nano-ceramic-based fireproof and heat-insulating coating (6) is 0.120-0.180 mm. The first polyester tape (41) and the second polyester tape (42) are respectively wrapped around the inner and outer sides of the tin-plated carbon nanotube copper alloy conductor braided sub-shielding layer (5).

3. The fireproof shielded instrument cable according to claim 1, characterized in that, The cable filling layer is a high flame-retardant epoxy resin filling layer (7), which fills the gap between the cable cores. After the cable cores are cabled, a third polyester tape (43) is wrapped around the outside. The total shielding layer is a composite structure. The inner layer is a tin-plated carbon nanotube copper alloy conductor braided total shielding layer (8), with a braiding density ≥90%. The surface of the tin-plated carbon nanotube copper alloy conductor braided total shielding layer (8) is coated with a second nano-ceramic-based fireproof and heat-insulating coating (9) with a thickness of 0.120~0.180mm. The outer layer is a copper tape shielding layer (10), with a copper tape thickness of 0.060mm and a wrapping overlap rate ≥25%.

4. The fireproof shielded instrument cable according to claim 1, characterized in that, The outer sheath layer has a double sheath structure, including an inner high-temperature resistant ceramicized silicone rubber sheath layer (11) and an outer modified polyether ether ketone sheath layer (12). The thickness of the high-temperature resistant ceramicized silicone rubber sheath layer (11) is ≥1.15mm, and the thickness of the modified polyether ether ketone sheath layer (12) is ≥1.15mm.

5. A manufacturing process for a fire-resistant shielded instrument cable as described in any one of claims 1-4, characterized in that, Includes the following steps: Step 1: Melt and anneal GRCop-84 copper alloy with carbon nanotubes, and then draw them into a single solid carbon nanotube copper alloy conductor (1) to form a conductor layer. Step 2: Three layers of 0.14mm double-sided plastic-coated water glass calcined mica tape (2) are overlapped and wrapped around the outside of the carbon nanotube copper alloy conductor (1) of the conductor layer to form a refractory layer; Step 3: Extrude a high-strength silicone rubber layer onto the outside of the double-sided plastic-coated water glass calcined mica tape (2) of the refractory layer to form a high-strength silicone rubber insulation layer (3) with a thickness of 0.50-0.60 mm; Step 4: Twist the insulated wire core covered with high-strength silicone rubber insulation layer (3) and wrap it around the first polyester tape (41). Then braid the tin-plated carbon nanotube copper alloy conductor braid to form a tin-plated carbon nanotube copper alloy conductor braided sub-shielding layer (5). Subsequently, dip the surface of the braided layer with the first nano ceramic-based fireproof and heat-insulating coating (6). After the dip coating is completed, wrap the second polyester tape (42) again to form a sub-shielding layer. Step 5: After shielding, the wire cores are cabled, and high flame-retardant epoxy resin (7) is used to fill the gaps between the cable cores. After cable formation, the third polyester tape (43) is wrapped around the cable to form a cable filling layer. Step 6: Weave a tin-plated carbon nanotube copper alloy conductor braid layer on the outside of the cable filling layer to form a tin-plated carbon nanotube copper alloy conductor braided total shielding layer (8), and dip the surface of the braid layer into a second nano-ceramic-based fireproof and heat-insulating coating (9), and then wrap copper strips to form a copper strip shielding layer (10), thus forming the total shielding layer. Step 7: Extrude a high-temperature resistant ceramicized silicone rubber sheath layer (11) and a modified polyether ether ketone sheath layer (12) sequentially on the outside of the main shielding layer to form an outer sheath layer, thus obtaining a fireproof shielded instrument cable.

6. The production process according to claim 5, characterized in that, The braiding density of the tin-plated carbon nanotube copper alloy conductor braided shielding layer (5) in step 4 is ≥90%, and the coating thickness of the first nano-ceramic-based fireproof and heat-insulating coating (6) is 0.120~0.180mm.

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