Tensile multi-strand flexible wire compensation cable

Abstract

The invention discloses a tensile multi-strand flexible wire compensation cable, and belongs to the technical field of cables. The invention provides a tensile multi-strand flexible wire compensation cable. The tensile multi-strand flexible wire compensation cable comprises a conductor, a bonding layer, a tensile layer, an insulating layer, a shielding layer and a sheath layer, the conductor is formed by twisting 24 strands of silver-plated copper wires; eVA-g-MAH is adopted as the bonding layer; the tensile layer is formed by weaving chemically modified PET industrial yarns, and a carboxyl group, a phosphonic acid group and a needle-like n-HA micro-nano structure are constructed on the surface of the tensile layer; and the insulating layer and the sheath layer respectively contain EVA-g-MAH and tetraphenyl ethylene acrylate, so that multiple chemical bonding and mechanical interlocking are realized. The tensile strength, the bending resistance and the interlayer binding force of the cable can be remarkably improved, core breakage and interface stripping are effectively prevented, and the service life is prolonged.

Description

Technical Field

[0001] This invention belongs to the field of cable technology, specifically relating to a tensile-resistant multi-strand flexible compensating cable. Background Technology

[0002] Multi-strand flexible compensating cables are widely used in thermocouple temperature measurement and industrial equipment signal transmission. However, under dynamic conditions of frequent bending or stretching (such as in mobile device wiring and vibration environments), they are prone to conductor core breakage and delamination between the tensile layer and insulation layer, leading to signal transmission interruptions and shortened service life. Existing technologies often use aramid fiber as the tensile material, but this material is expensive and has poor interfacial compatibility with the insulation layer due to its surface chemical inertness. On the other hand, while ordinary polyester or nylon tensile materials are cheaper, their tensile modulus is low and their fatigue resistance is limited, resulting in a significant deficiency in balancing the flexibility and tensile reliability of the flexible cable.

[0003] Application CN116864202A discloses a thermocouple compensation cable, which features a reinforced steel core at the center of the conductor to improve its compressive and tear resistance, and an external recessed channel design to facilitate localized shearing and repair. While this solution introduces a metal reinforcement structure to enhance mechanical strength, its core focus is on compressive strength and localized repairability. It does not specifically address conductor fatigue fracture during repeated bending and stretching of multi-strand flexible wires, nor the stability of the interface between the tensile layer and the insulation layer. Furthermore, the rigidity of the steel core may adversely affect the overall flexibility of the cable, making it unsuitable for applications requiring frequent movement or bending. Application CN104332228A discloses a pressure-resistant and heat-insulating thermocouple compensation cable, which uses an elastic steel frame composed of elastic metal plates to fix the compensation cable in a specific position to improve its pressure resistance. While this structure enhances the cable's mechanical support capabilities, its focus is on pressure resistance and thermal insulation, with tensile strength not being its primary design objective. Furthermore, the metal frame structure also limits the cable's bending performance and does not address the collaborative deformation mechanism between the multi-strand soft conductor and tensile elements, making it difficult to effectively mitigate the damage to the conductor caused by dynamic tensile stress.

[0004] In summary, existing technologies still have room for improvement in balancing the high flexibility and high tensile reliability of multi-strand flexible compensation cables. In particular, the systematic optimization of tensile element material selection, structural layout, and interface compatibility with the insulation layer has not been fully resolved. Summary of the Invention

[0005] This invention provides a tensile-stranded flexible compensating cable, which aims to prepare modified PET industrial yarn with high tensile strength, excellent fatigue resistance and interfacial compatibility as tensile layer material through a four-step continuous chemical modification process, and solve the problems of easy conductor core breakage and interface delamination between tensile layer and insulation layer in the prior art by combining multi-level structural collaborative design.

[0006] The objective of this invention can be achieved through the following technical solutions: A tensile-resistant multi-strand flexible compensating cable comprises, from the inside out, a conductor, an adhesive layer, a tensile-resistant layer, an insulation layer, a shielding layer, and a sheath layer; The conductor is made of 100 parts by weight of 24 strands of silver-plated copper wire with a diameter of 0.12 mm, with a stranding pitch of 10~12 mm; The adhesive layer comprises 100 parts by weight of EVA-g-MAH with a thickness of 0.1±0.02 mm; The tensile layer is woven from 60 parts by weight of modified PET industrial yarn, the modified PET industrial yarn having a diameter of 0.18 mm, a weaving density of 90~92%, and a weaving angle of 45~50°; The insulating layer is formed by extrusion of 60 parts by weight of high-density polyethylene and 40 parts by weight of EVA-g-MAH, with a thickness of 1.0±0.1 mm; The shielding layer is composed of 90 parts by weight of tin-plated copper wire with a diameter of 0.08 mm and 10 parts by weight of carbon fiber, with a weaving density of 95%. The sheath layer is formed by extrusion of 50 parts by weight of polyvinyl chloride and 50 parts by weight of tetrastyrene acrylate, with a thickness of 1.2±0.1 mm.

[0007] By setting an ultrathin adhesive layer between the conductor and the tensile layer, and performing a four-step continuous chemical modification on PET industrial yarn, a micro / nanostructure of carboxyl groups, phosphonic acid groups, and needle-like nano-hydroxyapatite is constructed on its surface, enabling multiple chemical bonds and mechanical interlocking between the tensile layer and adjacent functional layers. This structural design solves the problems of high cost, interfacial inertness, and insufficient tensile modulus of ordinary polyester fibers, common in traditional aramid fibers. The conductor uses multiple strands of fine-diameter silver-plated copper wire to reduce stress concentration in individual filaments; the maleic anhydride groups in the adhesive layer EVA-g-MAH form coordination bonds with the silver plating layer and simultaneously undergo esterification with the carboxyl groups on the surface of the tensile layer; the EVA-g-MAH in the insulation layer chemically crosslinks with the phosphonic acid groups and carboxyl groups in the tensile layer; and the acrylate groups in the sheath layer form hydrogen bonds with the hydroxyl groups on the surface of the needle-like nano-hydroxyapatite, achieving interfacial mechanical anchoring through the needle-like protrusions of the nano-hydroxyapatite.

[0008] Furthermore, antioxidant 1010 is added to the adhesive layer, and the weight ratio of EVA-g-MAH to antioxidant 1010 is 100:0.3~0.5; antioxidant 168 and ultraviolet absorber UV-531 are added to the insulating layer, and the weight ratio of high-density polyethylene, EVA-g-MAH, antioxidant 168 and ultraviolet absorber UV-531 is 60:40:(0.2~0.3):(0.1~0.2); calcium-zinc stabilizer and plasticizer DOP are added to the sheath layer, and the weight ratio of polyvinyl chloride, tetrastyrene acrylate, calcium-zinc stabilizer and plasticizer DOP is 50:50:0.5:0.3.

[0009] Antioxidant 168 (phosphite) and antioxidant 1010 (adhesive layer migration) form a synergistic antioxidant effect, decomposing hydrogen peroxide; UV-531 absorbs 290~400nm ultraviolet light, preventing material aging; the formulation design balances anti-aging effect and dielectric properties, with no significant exudation. DOP (dioctyl phthalate) improves the processing fluidity and sheath flexibility of PVC, preventing excessive hardness from affecting cable bending; the formulation ensures processing stability and interfacial bonding strength, with no risk of exudation.

[0010] Furthermore, the four-step modification process for the modified PET industrial yarn is as follows: A1. PET industrial fibers are activated by plasma treatment in an argon / ozone mixed gas atmosphere and then immersed in a 3wt% glycerol aqueous solution. A2. Activated PET industrial filaments, maleic anhydride, itaconic acid and azobisisobutyronitrile are mixed and stirred to obtain copolymerized PET industrial filaments; A3. Crosslinked PET industrial fibers are obtained by mixing and stirring copolymerized PET industrial fibers, aminotrimethylenephosphonic acid and ferric chloride hexahydrate. A4. Modified PET industrial filaments were prepared by mixing cross-linked PET industrial filaments, needle-like nano-hydroxyapatite, and aluminate coupling agent DL-411-A and then ultrasonically treating the mixture.

[0011] The surface of raw PET is inert, and a single modification cannot simultaneously obtain sufficient functional groups and mechanically interlocked structures. A1 generates dual active sites, A2 introduces carboxyl groups and double bonds, A3 constructs a stable cross-linked network, and A4 forms needle-like protrusions, gradually realizing the micro-nano structures required for chemical bonding and mechanical interlocking, thus solving the problems of interfacial inertness and insufficient tensile modulus of ordinary PET.

[0012] Furthermore, the volume ratio of argon to ozone in A1 is 80:20; the weight ratio of PET industrial filament to 3wt% glycerol aqueous solution is 100:(50~80); the synergistic effect of plasma high-energy particles and ozone causes the ester bonds on the PET surface to break, generating dual active sites of hydroxyl and carboxyl groups, and glycerol stabilizes the active groups through hydrogen bonds.

[0013] Furthermore, the plasma treatment conditions in A1 include a power of 150-180W, a pressure of 0.05-0.08MPa, and a time of 6-8min; the immersion treatment conditions include a temperature of 24-26℃ and a time of 10-15min. These parameters are designed to ensure efficient generation of uniformly distributed dual active sites without damaging the mechanical properties of PET.

[0014] Furthermore, the weight ratio of activated PET industrial filament, maleic anhydride, itaconic acid, and azobisisobutyronitrile in A2 is 100:(6~8):(4~6):(0.2~0.4); maleic anhydride and itaconic acid are copolymerized under free radical initiation and grafted onto the PET surface through esterification reaction to introduce more carboxyl groups and carbon-carbon double bonds.

[0015] Furthermore, the mixing and stirring reaction conditions in A2 include a temperature of 70-78℃, a time of 4-6 hours, and a rotation speed of 200-300 r / min. These parameters are designed to achieve uniform and efficient grafting, ensuring consistent distribution of functional groups.

[0016] Furthermore, the weight ratio of the A3 copolyester PET industrial filament, aminotrimethylenephosphonic acid, and ferric chloride hexahydrate is 100:(5~7):(0.05~0.1); the phosphonic acid group of aminotrimethylenephosphonic acid is in Fe... 3+ Under catalysis, it forms covalent bonds with carboxyl groups and double bonds, and constructs a chelate cross-linked network with metal ions.

[0017] Furthermore, the mixing and stirring reaction conditions in A3 include a temperature of 60-65°C, a time of 6-8 hours, and a rotation speed of 150-200 r / min. Excessive temperature accelerates ATMP decomposition, while insufficient time leads to inadequate cross-linking; the rotation speed ensures uniform reaction and avoids localized differences in cross-linking density.

[0018] Furthermore, the weight ratio of cross-linked PET industrial filament, needle-shaped nano-hydroxyapatite, and aluminate coupling agent DL-411-A in A4 is 100:(2.5~3.5):(1.0~1.5); one end of the aluminate coupling agent dehydrates and condenses with the needle-shaped nano-hydroxyapatite, and the other end coordinates with the aminotrimethylene phosphonate phosphonate group, so that the needle-shaped nano-hydroxyapatite is grafted to form micron-sized needle-shaped protrusions.

[0019] Furthermore, the ultrasonic treatment conditions include first dispersing at 24-26℃ with a power of 300-350W for 45-60 minutes, then purging with nitrogen at 10-15 mL / min for 20 minutes, followed by heating to 80-85℃ and maintaining ultrasonic power at 150-200W for 4-6 hours. Low-temperature, high-power ultrasound breaks up n-HA aggregation, and nitrogen purging removes oxygen to prevent PET oxidation; high-temperature, low-power ultrasound promotes the coupling agent reaction and ensures strong grafting; the time parameters ensure uniform dispersion and sufficient reaction, prevent n-HA detachment, and ensure the stability of the mechanically interlocked structure.

[0020] Secondly, a method for preparing a tensile-resistant multi-strand flexible compensating cable includes the following steps: S1. Twist 24 strands of silver-plated copper wire with a diameter of 0.12mm through a high-speed wire bundling machine at a tension of 3~5N, a speed of 80~100m / min, and a pitch of 10~12mm. The coil diameter is... 300~ 400mm, after twisting, proceed directly to the next process; S2. Adhesive layer coating: EVA-g-MAH is mixed with antioxidant 1010 and melted in three temperature ranges of 145℃ / 150℃ / 155℃ using a micro extrusion coating machine. The mixture is then coated onto the conductor surface at a speed of 4~6m / min, with a coating thickness of 0.1±0.02mm. After cooling in a water bath at 25~30℃ and drying with hot air at 40~50℃, the mixture is wound up under a tension of 4~6N. S3. Tensile layer weaving: Modified PET industrial yarn is loaded into a 32~48 spindle high-speed weaving machine and woven onto the outer surface of the adhesive layer with a tension of 5~8N, a speed of 6~8m / min, a weaving angle of 45~50°, and a density of 90~92%. S4. Insulation layer extrusion: High-density polyethylene, EVA-g-MAH, antioxidant 168 and UV-531 are mixed and melted in a single screw extruder at four temperature ranges of 150℃ / 160℃ / 165℃ / 170℃. The mixture is then extruded over the tensile layer at a speed of 3.5~4.5m / min to a thickness of 1.0±0.1mm. After cooling in a water bath at 30~35℃, the mixture is wound up. S5. Shielding layer braiding: Tinned copper wire is mixed with carbon fiber and braided onto the outside of the insulation layer by a double wire bundle braiding machine at a tension of 4~6N, a speed of 5~7m / min, and a density of 95%. S6. Polyvinyl chloride, tetrastyrene acrylate, calcium zinc stabilizer and DOP are mixed and melted in a single screw extruder at four temperature ranges of 140℃ / 150℃ / 155℃ / 160℃. The mixture is then extruded onto the outside of the shielding layer at a speed of 3~4m / min, with a thickness of 1.2±0.1mm. Subsequently, it is vulcanized in an 85℃ hot air vulcanizing furnace for 3 hours. After natural cooling, it is cut and stored to obtain a tensile-resistant multi-strand flexible compensating cable.

[0021] First, in step S1, multiple strands of fine-diameter silver-plated copper wire are twisted together to reduce bending stiffness; in step S2, the ultra-thin adhesive layer eliminates interfacial slippage by coordinating maleic anhydride groups with the silver plating layer and esterifying with the carboxyl groups of the tensile layer; in step S3, the modified PET filament braided layer provides high tensile modulus and fatigue resistance; in step S4, the insulating layer EVA-g-MAH reacts with the phosphonic acid / carboxyl groups of the tensile layer to improve interfacial peel strength; in step S5, carbon fiber fills the gaps between the tin-plated copper wires to enhance the tensile strength of the shielding layer; in step S6, vulcanization promotes the formation of hydrogen bonds between the acrylate groups of the sheath layer and the hydroxyl groups of the needle-like nano-hydroxyapatite, achieving mechanical interlocking by combining the needle-like structure.

[0022] The beneficial effects of this invention are: (1) The tensile-resistant multi-strand flexible compensating cable of the present invention achieves excellent comprehensive performance through reasonable layered structure design and synergistic effect of material ratio. The cable is arranged from the inside out as conductor, adhesive layer, tensile layer, insulation layer, shielding layer and sheath layer, realizing precise matching of material and structural parameters of each layer: the conductor is made of 100 parts by weight of 24 strands of silver-plated copper wire with a diameter of 0.12 mm, twisted at a pitch of 10~12 mm, and coated with an ultra-thin adhesive layer with a thickness of 0.1±0.02 mm composed of 100 parts by weight of EVA-g-MAH, which not only gives the conductor good flexibility, but also allows the maleic anhydride group of EVA-g-MAH to form a coordination effect with the silver plating layer. At the same time, the group can undergo esterification condensation reaction with the carboxyl group on the surface of the tensile layer; the tensile layer is woven from 60 parts by weight of modified PET industrial yarn with a diameter of 0.18 mm, with a weaving density of 90~92% and a weaving angle of 45~50°, and its surface The contained carboxyl groups, phosphonic acid groups, and needle-like nano-hydroxyapatite hydroxyl groups can form stable bonds with the adhesive layer, insulation layer, and sheath layer, respectively. The insulation layer is a co-extrusion structure of 60 parts by weight of high-density polyethylene and 40 parts by weight of EVA-g-MAH, with a thickness of 1.0±0.1mm. The interfacial bonding strength is enhanced by the covalent connection between EVA-g-MAH and the functional groups on the surface of the tensile layer. The shielding layer is made of 90 parts by weight of tin-plated copper wire with a diameter of 0.08mm and 10 parts by weight of carbon fiber composite braiding, with a braiding density of 95%. The sheath layer is a co-extrusion structure of 50 parts by weight of polyvinyl chloride and 50 parts by weight of tetraphenylethylene acrylate, with a thickness of 1.2±0.1mm. The above structures further ensure the stability of the overall cable structure and achieve a dual reinforcement effect of chemical bonding and mechanical interlocking.

[0023] (2) The tensile-resistant multi-strand flexible compensating cable provided by this invention effectively solves the core technical problems of traditional compensating cables under dynamic working conditions through the above-mentioned structural design. It can effectively overcome the defects of conductor core breakage and interface peeling between tensile layer and insulation layer in frequent bending, stretching and vibration environments. Through the synergistic effect of each layer structure, the cable has both balanced flexibility and tensile performance, which can not only meet the flexible layout requirements in the wiring process, but also stably resist the external force under dynamic working conditions. At the same time, the composite braided design of the shielding layer ensures good electromagnetic anti-interference ability and ensures the stability of signal transmission. With the help of the precise ratio of each structural layer and the interface reinforcement design, the structural stability and durability of the cable are significantly improved, which can greatly reduce the maintenance costs and production downtime losses caused by product failure. It is suitable for various scenarios such as thermocouple temperature measurement and industrial equipment signal transmission. It is especially suitable for complex working environments such as mobile industrial equipment and vibrating machinery, and has extremely high practical value and wide applicability. Detailed Implementation

[0024] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below.

[0025] The specific embodiments of the present invention will be described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.

[0026] Example 1

[0027] This embodiment provides a tensile-resistant multi-strand flexible compensating cable, which is prepared through the following steps: A1. 100 parts by weight of PET industrial filament are passed through a sealed plasma reaction chamber, and a mixed gas (V0) is introduced under a power of 150W and a chamber pressure of 0.08MPa. 氩气 :V 臭氧 =80:20), continuously treated for 8 min, immediately immersed in 80 parts of 3wt% glycerol aqueous solution, soaked at 26℃ for 15 min, rinsed 3 times with deionized water, dried under vacuum at 70℃ and -0.08MPa for 6 h, and wound up with 6N tension to obtain activated PET industrial yarn; A2. Place 100 parts by weight of activated PET industrial yarn in a three-necked flask containing 200 parts by weight of acetone, 6 parts by weight of maleic anhydride, and 6 parts by weight of itaconic acid. Purge with nitrogen at 15 mL / min for 30 min, then add 0.2-0.4 parts by weight of azobisisobutyronitrile (AIBN). Reflux at 78°C for 6 h with stirring at 300 rpm. After the reaction, wash with acetone four times and dry at 85°C to constant weight to obtain copolymerized PET industrial yarn. A3. Place 100 parts by weight of copolymerized PET industrial filament in a reactor containing 120 parts by weight of 0.1 mol / L acetate-sodium acetate buffer, 5 parts by weight of aminotrimethylenephosphonic acid, and 0.1 parts by weight of ferric chloride hexahydrate. Adjust the pH to 5.5, purge with nitrogen at 12 mL / min, react at 65°C for 8 h with stirring at 200 rpm. After the reaction, wash three times with deionized water, cure with hot air at 120°C for 2 h, and cool naturally to 26°C to obtain cross-linked PET industrial filament. A4. 100 parts by weight of cross-linked PET industrial yarn were placed in an ultrasonic reactor containing 150 parts by weight of anhydrous ethanol, 2.5 parts by weight of needle-shaped nano-hydroxyapatite (particle size 30nm), and 1.5 parts by weight of aluminate coupling agent DL-411-A. The mixture was first dispersed by ultrasonication at 26℃ and 350W for 60min, then purged with nitrogen at 15mL / min for 20min, and then heated to 85℃ and maintained at 200W ultrasonic power for 6h. After the reaction, the mixture was vacuum filtered, washed twice with anhydrous ethanol, dried at 110℃ to constant weight, and wound up under 7N tension to obtain modified PET industrial yarn. S1. Conductor stranding: 100 parts by weight of 24 strands of 0.12mm diameter silver-plated copper wire are stranded through a high-speed wire bundling machine at a tension of 5N, a speed of 100m / min, and a pitch of 12mm. The coil diameter is... 400mm, after twisting, proceed directly to the next process; S2. Adhesive layer coating: 100 parts by weight of EVA-g-MAH and 0.5 parts by weight of antioxidant 1010 are mixed and melted in three temperature ranges of 145℃ / 150℃ / 155℃ using a micro extrusion coating machine. The mixture is then coated onto the conductor surface at a speed of 6m / min, with a coating thickness of 0.1mm. After cooling in a 30℃ water bath and drying with hot air at 50℃, the mixture is wound up under 6N tension. S3. Tensile layer weaving: 80 parts by weight of modified PET industrial yarn are loaded into a 48-spindle high-speed weaving machine and woven onto the outer surface of the adhesive layer with a tension of 8N, a speed of 8m / min, a weaving angle of 50°, and a density of 90%. S4. Insulation layer extrusion: 60 parts by weight of high-density polyethylene, 40 parts by weight of EVA-g-MAH, 0.3 parts by weight of antioxidant 168 and 0.2 parts by weight of ultraviolet absorber UV-531 are mixed and melted in a single screw extruder at four temperature ranges of 150℃ / 160℃ / 165℃ / 170℃, and extruded over the tensile layer at a speed of 4.5m / min to a thickness of 1.0mm. After cooling in a 35℃ water bath, the mixture is wound up. S5. Shielding layer braiding: 90 parts by weight of tin-plated copper wire with a diameter of 0.08mm is mixed with 10 parts by weight of carbon fiber and braided on the outside of the insulation layer by a double wire bundle braiding machine with a tension of 6N, a speed of 7m / min and a density of 95%. S6. Sheath extrusion and vulcanization: 50 parts by weight of polyvinyl chloride, 50 parts by weight of tetrastyrene acrylate, 0.5 parts by weight of calcium-zinc stabilizer HCZ1083S and 0.3 parts by weight of plasticizer DOP are mixed and melted in a single screw extruder at four temperature ranges of 140℃ / 150℃ / 155℃ / 160℃. The mixture is then extruded onto the outside of the shielding layer at a speed of 4m / min to a thickness of 1.2mm. Subsequently, it is vulcanized in an 85℃ hot air vulcanizing furnace for 3 hours. After natural cooling, it is cut and stored to obtain a tensile-resistant multi-strand flexible compensating cable.

[0028] Example 2

[0029] The difference between this embodiment and Example 6 is that the plasma power is 160W, the amount of maleic anhydride is 6.5 parts by weight, the amount of aminotrimethylenephosphonic acid is 5.5 parts by weight, the amount of needle-like nano-hydroxyapatite is 2.7 parts by weight, and the tensile layer weaving density is 90.5%. The remaining raw materials and preparation process are the same as in Example 6.

[0030] Example 3

[0031] The difference between this embodiment and Example 6 is that the plasma power is 165W, the amount of maleic anhydride is 7 parts by weight, the amount of aminotrimethylenephosphonic acid is 6 parts by weight, the amount of needle-like nano-hydroxyapatite is 3.0 parts by weight, and the tensile layer weaving density is 91%. The remaining raw materials and preparation process are the same as in Example 6.

[0032] Example 4

[0033] The difference between this embodiment and Example 6 is that the plasma power is 170W, the amount of maleic anhydride is 7 parts by weight, the amount of aminotrimethylenephosphonic acid is 6 parts by weight, the amount of needle-like nano-hydroxyapatite is 3.0 parts by weight, and the tensile layer weaving density is 91%. The remaining raw materials and preparation process are the same as in Example 6.

[0034] Example 5

[0035] The difference between this embodiment and Example 6 is that the plasma power is 175W, the amount of maleic anhydride is 7.5 parts by weight, the amount of aminotrimethylenephosphonic acid is 6.5 parts by weight, the amount of needle-like nano-hydroxyapatite is 3.3 parts by weight, and the tensile layer weaving density is 91.5%. The remaining raw materials and preparation process are the same as in Example 6.

[0036] Example 6

[0037] The difference between this embodiment and Example 6 is that the plasma power is 180W, the amount of maleic anhydride is 8 parts by weight, the amount of aminotrimethylenephosphonic acid is 7 parts by weight, the amount of needle-like nano-hydroxyapatite is 3.5 parts by weight, and the tensile layer weaving density is 92%. The remaining raw materials and preparation process are the same as in Example 6.

[0038] Comparative Example 1

[0039] Compared with Example 6, this comparative example differs in that step A1 is removed, and the PET industrial yarn is directly subjected to step A2. The remaining raw materials and preparation process are the same as in Example 6.

[0040] Comparative Example 2

[0041] The difference between this comparative example and Example 6 is that itaconic acid in step A2 is removed, while the remaining raw materials and preparation process remain the same as in Example 6.

[0042] Comparative Example 3

[0043] The difference between this comparative example and Example 6 is that 7 parts by weight of aminotrimethylenephosphonic acid in step A3 are replaced with 7 parts by weight of E-51 epoxy crosslinking agent, while the other raw materials and preparation process remain the same as in Example 6.

[0044] Comparative Example 4

[0045] The difference between this comparative example and Example 6 is that 3.5 parts by weight of needle-shaped nano-hydroxyapatite in step A4 is replaced with 3.5 parts by weight of spherical nano-silica (particle size 30nm), while the other raw materials and preparation process remain the same as in Example 6.

[0046] Comparative Example 5

[0047] The difference between this comparative example and Example 6 is that step S2 is removed, while the remaining raw materials and preparation process remain the same as in Example 6.

[0048] Comparative Example 6

[0049] The difference between this comparative example and Example 6 is that EVA-g-MAH in step S4 is removed, while the remaining raw materials and preparation process remain the same as in Example 6.

[0050] Comparative Example 7

[0051] Compared with Example 6, the difference in this comparative example is that the modified PET industrial yarn in step S3 is replaced with polyimide fiber, while the other raw materials and preparation process remain the same as in Example 6.

[0052] Comparative Example 8

[0053] The difference between this comparative example and Example 6 is that the carbon fiber in step S5 is removed, while the other raw materials and preparation process remain the same as in Example 6.

[0054] Performance testing

[0055] All tensile-strand flexible compensating cables prepared in the embodiments and comparative examples were subjected to the following performance tests: 1. Tensile strength test: Cut a 500mm long cable, remove the sheath and shielding layers to expose the tensile layer, fix both ends to the tensile testing machine fixture, and test at a tensile speed of 50mm / min at room temperature (25℃). Record the maximum tensile force at break.

[0056] 2. Interface peel strength test: Cut a 100mm long cable, cut the insulation layer and tensile layer along the axial direction, peel the length of 50mm, fix both ends to a tensile testing machine, and test at room temperature (25℃) with a peeling speed of 10mm / min. Record the average peel force and calculate the peel strength (peel force / peel width).

[0057] 3. Fatigue resistance test: Cut a 1000mm long cable, fix both ends to the fatigue testing machine, apply a constant tensile force of 50N in the middle, bend at a 180° angle, bend at a frequency of 10 times / min, and cycle 10,000 times. After the test, test the conductor breakage rate (number of broken conductors / total number of conductors × 100%) and the interface peel strength attenuation rate.

[0058] 4. Flexibility test: Cut a 300mm long cable and bend it around cylinders of different diameters. Record the minimum bending radius of the cable without cracks or structural damage at room temperature (25℃).

[0059] 5. Electromagnetic shielding effectiveness test: Cut a 200mm long cable, remove the sheath layer to expose the shielding layer, test the frequency 100kHz-1GHz, and record the average shielding effectiveness.

[0060] The results are shown in Table 1: Table 1

[0061] The test results in Table 1 show a systematic improvement trend in the test data of Examples 1 to 6, with Example 6 achieving the best performance: tensile strength of 1200N, interfacial peel strength of 3.2N / mm, core breakage rate after fatigue cycles of 0.5%, peel strength attenuation rate of 8%, minimum bending radius of 5.0 times the cable outer diameter, and electromagnetic shielding effectiveness of 85dB. This performance improvement stems from the synergistic effect of a four-step continuous chemical modification process and a multi-level structure: plasma-ozone activation constructs hydroxyl / carboxyl dual active sites on the surface of PET industrial yarn; maleic anhydride-itaconic acid co-grafting introduces a dual carboxyl system; and aminotrimethylene phosphonic acid is added to Fe... 3+Under catalysis, a phosphonic acid-based chelate crosslinking network is formed. Needle-shaped nano-hydroxyapatite, through an aluminate coupling agent, constructs a micron-scale protrusion structure, giving the tensile layer surface both chemically active sites and a mechanically anchored morphology. This design enables the maleic anhydride groups of the adhesive layer EVA-g-MAH to form coordination bonds with the silver-plated conductor and undergo esterification with the carboxyl groups of the tensile layer; the maleic anhydride of the insulating layer EVA-g-MAH forms covalent crosslinks with the phosphonic acid / carboxyl groups of the tensile layer; and the ester groups of the tetraphenyl acrylate in the sheath layer form a hydrogen bond network with the hydroxyl groups of the needle-shaped nano-hydroxyapatite, achieving mechanical interlocking with the needle-shaped protrusions.

[0062] Comparative data verified the irreplaceability of each technical element: Comparative Example 1, due to the lack of plasma activation, resulted in insufficient surface active sites, causing the interfacial peel strength to drop to 1.2 N / mm and the core breakage rate to reach 8.5%; Comparative Example 2, due to the lack of itaconic acid disrupting the co-grafting synergistic effect, saw the peel strength attenuation rate rise to 52%; Comparative Example 3, using an epoxy crosslinking agent to replace the phosphonic acid-based chelating system, saw the tensile strength plummet to 680 N; Comparative Example 4, using spherical silica to replace needle-like hydroxyapatite, experienced mechanical interlock failure, resulting in a peel strength attenuation rate as high as 45%; Comparative Example 5, the removal of the adhesive layer caused slippage at the conductor-tensile layer interface, leading to a surge in the core breakage rate to 10.2%; Comparative Example 6, removing the insulating layer EVA-g-MAH interrupted chemical bonding, resulting in a tensile strength of only 650 N; Comparative Example 7, using unmodified polyimide fibers, suffered from deteriorated flexibility due to surface inertness (minimum bending radius 8.5 times); Comparative Example 8, the lack of carbon fiber reduced the tensile strength of the shielding layer, causing the electromagnetic shielding effectiveness to drop to 75 dB. Data shows that the carboxyl-phosphonic acid-needle-micro / nano structure three-in-one interface regulation system constructed by the four-step modification process, together with the EVA-g-MAH mediated interlayer chemical bonding network, effectively solves the problems of uneven stress transmission and interface delamination under dynamic working conditions, so that tensile strength, interfacial bonding force and flexibility are dynamically balanced, and it is especially suitable for complex working environments such as vibrating machinery.

[0063] The above-disclosed embodiments are merely a few specific examples of the present invention. However, the embodiments of the present invention are not limited thereto, and any variations that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A tensile-resistant multi-strand flexible compensating cable, characterized in that, From the inside out, it includes the conductor, adhesive layer, tensile layer, insulating layer, shielding layer, and sheath layer. The conductor is made of 100 parts by weight of 24 strands of silver-plated copper wire with a diameter of 0.12 mm, with a stranding pitch of 10~12 mm; The adhesive layer comprises 100 parts by weight of EVA-g-MAH with a maleic anhydride grafting rate of 8~10wt% and a thickness of 0.1±0.02mm. The tensile layer is woven from 60 parts by weight of modified PET industrial yarn, the modified PET industrial yarn having a diameter of 0.18 mm, a weaving density of 90~92%, and a weaving angle of 45~50°; The insulating layer is formed by extrusion of 60 parts by weight of high-density polyethylene and 40 parts by weight of EVA-g-MAH, with a thickness of 1.0±0.1 mm; The shielding layer is composed of 90 parts by weight of tin-plated copper wire with a diameter of 0.08 mm and 10 parts by weight of carbon fiber, with a weaving density of 95%. The sheath layer is formed by extrusion of 50 parts by weight of polyvinyl chloride and 50 parts by weight of tetrastyrene acrylate, with a thickness of 1.2±0.1 mm.

2. The tensile-resistant multi-strand flexible compensating cable according to claim 1, characterized in that, Antioxidant 1010 is also added to the adhesive layer, and the weight ratio of EVA-g-MAH to antioxidant 1010 is 100:0.3~0.5; The insulating layer also contains antioxidant 168 and ultraviolet absorber UV-531, with the weight ratio of high-density polyethylene, EVA-g-MAH, antioxidant 168 and ultraviolet absorber UV-531 being 60:40:(0.2~0.3):(0.1~0.2). The sheath layer also contains calcium-zinc stabilizer and plasticizer DOP, with the weight ratio of polyvinyl chloride, tetrastyrene acrylate, calcium-zinc stabilizer and plasticizer DOP being 50:50:0.5:0.

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3. The tensile-resistant multi-strand flexible compensating cable according to claim 1, characterized in that, The four-step modification process for the modified PET industrial yarn is as follows: A1. PET industrial fibers are activated by plasma treatment in an argon / ozone mixed gas atmosphere and then immersed in a 3wt% glycerol aqueous solution. A2. Activated PET industrial filaments, maleic anhydride, itaconic acid and azobisisobutyronitrile are mixed and stirred to obtain copolymerized PET industrial filaments; A3. Crosslinked PET industrial fibers are obtained by mixing and stirring copolymerized PET industrial fibers, aminotrimethylenephosphonic acid and ferric chloride hexahydrate. A4. Modified PET industrial filaments were prepared by mixing cross-linked PET industrial filaments, needle-like nano-hydroxyapatite, and aluminate coupling agent DL-411-A and then ultrasonically treating the mixture.

4. A tensile-resistant multi-strand flexible compensating cable according to claim 3, characterized in that, The volume ratio of argon to ozone in A1 is 80:20; the weight ratio of PET industrial yarn to 3wt% glycerol aqueous solution is 100:(50~80).

5. A tensile-resistant multi-strand flexible compensating cable according to claim 3, characterized in that, The conditions for plasma treatment in A1 include a power of 150-180W, a pressure of 0.05-0.08MPa, and a time of 6-8min; the conditions for immersion treatment include a temperature of 24-26℃ and a time of 10-15min.

6. A tensile-resistant multi-strand flexible compensating cable according to claim 3, characterized in that, The weight ratio of activated PET industrial filament, maleic anhydride, itaconic acid, and azobisisobutyronitrile in A2 is 100:(6~8):(4~6):(0.2~0.4); The mixing and stirring conditions in A2 include a temperature of 70-78°C, a time of 4-6 hours, and a rotation speed of 200-300 r / min.

7. A tensile-resistant multi-strand flexible compensating cable according to claim 3, characterized in that, The weight ratio of the copolymerized PET industrial filament, aminotrimethylenephosphonic acid, and ferric chloride hexahydrate in A3 is 100:(5~7):(0.05~0.1); the mixing and stirring reaction conditions in A3 include a temperature of 60~65℃, a time of 6~8h, and a rotation speed of 150~200r / min.

8. A tensile-resistant multi-strand flexible compensating cable according to claim 3, characterized in that, The weight ratio of cross-linked PET industrial filaments, needle-like nano-hydroxyapatite, and aluminate coupling agent DL-411-A in A4 is 100:(2.5~3.5):(1.0~1.5).

9. A tensile-resistant multi-strand flexible compensating cable according to claim 3, characterized in that, The conditions for ultrasonic treatment include first dispersing at 24-26℃ with a power of 300-350W for 45-60 minutes, then purging with nitrogen at 10-15mL / min for 20 minutes, followed by raising the temperature to 80-85℃ and maintaining an ultrasonic power of 150-200W for 4-6 hours.

10. A tensile-resistant multi-strand flexible compensating cable according to claim 1, characterized in that, Its preparation method includes the following steps: S1. Twist 24 strands of silver-plated copper wire with a diameter of 0.12mm through a high-speed wire bundling machine at a tension of 3~5N, a speed of 80~100m / min, and a pitch of 10~12mm. The coil diameter is... 300~ 400mm, after twisting, proceed directly to the next process; S2. Adhesive layer coating: EVA-g-MAH is mixed with antioxidant 1010 and melted in three temperature ranges of 145℃ / 150℃ / 155℃ using a micro extrusion coating machine. The mixture is then coated onto the conductor surface at a speed of 4~6m / min, with a coating thickness of 0.1±0.02mm. After cooling in a water bath at 25~30℃ and drying with hot air at 40~50℃, the mixture is wound up under a tension of 4~6N. S3. Tensile layer weaving: Modified PET industrial yarn is loaded into a 32~48 spindle high-speed weaving machine and woven onto the outer surface of the adhesive layer with a tension of 5~8N, a speed of 6~8m / min, a weaving angle of 45~50°, and a density of 90~92%. S4. Insulation layer extrusion: High-density polyethylene, EVA-g-MAH, antioxidant 168 and UV-531 are mixed and melted in a single screw extruder at four temperature ranges of 150℃ / 160℃ / 165℃ / 170℃. The mixture is then extruded over the tensile layer at a speed of 3.5~4.5m / min to a thickness of 1.0±0.1mm. After cooling in a water bath at 30~35℃, the mixture is wound up. S5. Shielding layer braiding: Tinned copper wire is mixed with carbon fiber and braided onto the outside of the insulation layer by a double wire bundle braiding machine at a tension of 4~6N, a speed of 5~7m / min, and a density of 95%. S6. Polyvinyl chloride, tetrastyrene acrylate, calcium zinc stabilizer and DOP are mixed and melted in a single screw extruder at four temperature ranges of 140℃ / 150℃ / 155℃ / 160℃. The mixture is then extruded onto the outside of the shielding layer at a speed of 3~4m / min, with a thickness of 1.2±0.1mm. Subsequently, it is vulcanized in an 85℃ hot air vulcanizing furnace for 3 hours. After natural cooling, it is cut and stored to obtain a tensile-resistant multi-strand flexible compensating cable.

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