High-flexibility control cable and method for manufacturing the same

Abstract

The application discloses a kind of high flexibility control cable and preparation method thereof, belong to cable technical field.Firstly, base resin, antioxidant, auxiliary agent and color masterbatch are mixed, graphene composite functional masterbatch is added to continue mixing, then dehumidification drying is obtained mixed material, then mixed material is transferred to extruder and is melted extruded sheath, then it is cooled and shaped using supercritical CO2, and high flexibility control cable is obtained.The application discloses a simple idea of lubricant physical blending, by aminoization to PTFE, carboxylated graphene and epoxy functionalized SiO2 microspheres are selected, so that each functional component is connected by covalent bond or strong hydrogen bond with TPU matrix, graphene composite functional masterbatch is constructed, so that the cable has excellent properties such as low friction and high wear resistance, and the durability and stability in long-term use or harsh medium environment.

Description

Technical Field

[0001] This invention relates to the field of cable technology, specifically to a highly flexible control cable and its manufacturing method. Background Technology

[0002] Highly flexible control cables serve as the "nerves" of modern automated equipment, particularly in intelligent production systems within the chemical industry. Widely used in cable chains, robot joints, and high-speed reciprocating mobile devices, they are responsible for the stable transmission of power and control signals under continuous bending and torsional mechanical stress. In chemical environments, these cables must withstand millions of bending cycles and cope with complex extreme conditions, including splashes of corrosive chemicals (acids, alkalis, solvents), alternating high and low temperatures, and continuous friction with other components or the cable itself in confined spaces. Therefore, the performance of their outer sheath material directly determines the cable's reliability, signal stability, and service life.

[0003] Currently, most mainstream high-flexibility cables on the market use polyurethane, polyvinyl chloride, or special rubber for their sheaths. In practical chemical applications, especially in high-speed cable carrier systems, these materials reveal two interconnected core defects: First, there is the problem of dynamic friction and wear. Long-term, high-speed reciprocating friction between the sheath material and the cable carrier rail or adjacent cables leads to continuous surface wear. This not only causes the sheath to thin and crack, losing its protective function for the internal core wires, but the dust generated by the wear can also cause contamination or short-circuit risks in precision equipment. Second, there is the systemic risk caused by a high coefficient of friction. An excessively high coefficient of friction on the sheath surface significantly increases the resistance to cable movement in the cable carrier, leading to poor dragging, abnormal noise, and accelerated localized temperature rise. To address the aforementioned wear and friction problems, existing technologies primarily employ two improvement methods. The first is physical blending of lubricants, which involves directly incorporating solid lubricants such as polytetrafluoroethylene (PTFE) powder, silicone oil, or molybdenum disulfide into the sheath material. While this method can reduce the initial coefficient of friction to some extent, the lubricant is only physically dispersed within the polymer matrix, resulting in weak interfacial bonding. Under continuous friction and chemical corrosion, the lubricant rapidly migrates, precipitates, and is depleted, leading to a sharp decline in lubrication effectiveness and making it unsustainable. Furthermore, adding large amounts of soft lubricants typically weakens the sheath's mechanical strength, tear resistance, and adhesion to the cable shielding layer. The second method is surface coating treatment, such as applying a low-friction coating to the outside of the sheath. However, under continuous bending dynamic stress, the interface between this coating and the substrate easily becomes a weak point, leading to coating peeling. Moreover, once localized damage occurs, corrosive media can penetrate the interface, accelerating failure.

[0004] Therefore, given the shortcomings of existing technologies, it is essential to propose a new highly flexible control cable and its manufacturing method. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a highly flexible control cable and its preparation method.

[0006] The first aspect of this invention is to provide a highly flexible control cable, comprising, by weight, the following components: 100 parts of matrix resin, 13-17 parts of graphene composite functional masterbatch, 0.3-0.7 parts of antioxidant, 0.2-0.5 parts of additives, and 0.8-1.2 parts of color masterbatch; The graphene composite functional masterbatch is prepared by the following steps: (1) Disperse PTFE micro powder in a solvent, add silane coupling agent and reflux reaction, filter, wash and dry after the reaction to obtain modified PTFE powder; (2) A mixture is obtained by mixing carboxylated graphene, modified PTFE powder, epoxy-functionalized SiO2 microspheres and dispersant; (3) The mixture and TPU carrier resin are melt-blended and granulated to obtain graphene composite functional masterbatch.

[0007] It should be noted that this invention creatively prepares graphene composite functional masterbatch through the synergistic effect of chemical bonding and physical shearing. The active functional groups (-COOH) on the surface of carboxyl-containing graphene react chemically with corresponding groups (such as -NH2) on the matrix polymer or compatibilizer, or form strong hydrogen bonds, thereby chemically anchoring the graphene sheets in the matrix, improving interfacial adhesion, and preventing interfacial slippage and performance degradation during use. In the physical processing stage of melt blending and granulation, the high shear force generated by the screw further exfoliates and disperses the graphene aggregates, uniformly distributing them within the polymer melt. This solves the problem of nanofiller agglomeration in the polymer matrix and constructs a stable reinforcing network.

[0008] In some embodiments, the solvent is a 75-85% aqueous ethanol solution; the silane coupling agent is selected from at least one of KH-550 and KH-560, and the mass amount of the silane coupling agent is 3-7% of the mass of the PTFE micro powder.

[0009] In some embodiments, the mass ratio of carboxylated graphene, modified PTFE powder, epoxy-functionalized SiO2 microspheres, and dispersant is 8-12:23-26:10-15:4-6; the dispersant is selected from at least one of maleic anhydride-grafted polyethylene wax and maleic anhydride-grafted ethylene-vinyl acetate copolymer.

[0010] In some embodiments, the mass ratio of the mixture to the TPU carrier resin is 1.8-2.3:2.

[0011] In some embodiments, in step (1), the reflux reaction is carried out by stirring at 75-85°C for 3.5-4.5 hours; in step (3), the melt blending granulation parameters are 145-155°C in zone 1, 160-170°C in zone 2, 168-172°C in zone 3, 170-180°C at the die head, and 180-220 rpm for the screw speed.

[0012] A second aspect of this invention is to provide a method for preparing a highly flexible control cable, comprising the following steps: S1: Mix the matrix resin, antioxidant, additives and color masterbatch, add graphene composite functional masterbatch and continue mixing, then dehumidify and dry to obtain the mixture; S2: The mixture is transferred to an extruder to melt and extrude the sheath, and then cooled and shaped using supercritical CO2 to obtain a highly flexible control cable.

[0013] In some embodiments, the antioxidant is obtained by compounding antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1; the adjuvant is selected from at least one of pentaerythritol stearate and ethylene bis-stearamide.

[0014] In some embodiments, in S1, the mixing time is 5-15 min, and the dehumidification and drying are carried out at 75-85°C for 3.5-4.5 h.

[0015] In some embodiments, in S2, the process parameters for melt extrusion are 165-175°C in zone 1, 178-182°C in zone 2, 180-185°C in zone 3, 182-187°C at the die head, and a screw speed of 270-290 rpm.

[0016] In some embodiments, in S2, supercritical CO2 cooling is defined as spraying supercritical CO2 fluid at a temperature of 30-32°C and a pressure of 7.5 MPa or higher into the sheath surface in a mist form.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention abandons the simplistic approach of physical blending of lubricants. By amination of PTFE and the selection of carboxylated graphene and epoxy-functionalized SiO2 microspheres, covalent or strong hydrogen bonds are formed between the functional components and with the TPU matrix, constructing a stable, internally strongly correlated composite lubrication enhancement system—graphene composite functional masterbatch. This masterbatch can be directly and uniformly dispersed during subsequent cable sheath extrusion, achieving efficient performance transfer and long-term stability, avoiding matrix softening problems caused by migration and precipitation. The reinforcement and lubrication functions of graphene synergistically improve material strength and tribological properties, ensuring the durability and stability of excellent properties such as low friction and high wear resistance in long-term use or harsh environments.

[0018] 2. The preparation method proposed in this invention adopts a supercritical CO2 cooling and shaping process. It utilizes the extremely high diffusion coefficient and penetration ability of supercritical fluid (CO2 with temperature and pressure above the critical point) to uniformly penetrate into the interior of the stretched and oriented polymer melt in a short time. Subsequently, the CO2 undergoes a phase change expansion and rapid heat absorption by rapidly depressurizing, thereby achieving rapid cooling of the polymer from the core layer to the surface layer. This cools and fixes the ordered arrangement structure of molecular chains and nanofillers formed in the melt in the strong tensile flow field, effectively suppressing thermal relaxation and structural springback caused by insufficient conventional cooling rates, significantly reducing internal stress and crystallization defects, avoiding warping and uneven shrinkage caused by uneven cooling, improving the dimensional stability and surface smoothness of the product, and forming a denser microstructure, thereby improving the final mechanical strength, wear resistance and media resistance of the material. Detailed Implementation

[0019] The present invention will now be described in further detail with reference to specific embodiments.

[0020] Example 1

[0021] A highly flexible control cable, comprising the following components by weight: 100 parts of matrix resin (polyether type TPU (Shore A 85-90A)), 15 parts of graphene composite functional masterbatch, 0.5 parts of antioxidant, 0.3 parts of additives, and 1 part of color masterbatch; The graphene composite functional masterbatch is prepared by the following steps: (1) Disperse PTFE micro powder in 80% ethanol aqueous solution, add silane coupling agent KH-550 and stir at 80℃ for 4h. After the reaction is completed, filter, wash and dry to obtain modified PTFE powder; wherein, the mass amount of silane coupling agent is 5% of the mass of PTFE micro powder; (2) A mixture was prepared by mixing carboxylated graphene (produced by Nanjing Xianfeng Nano), modified PTFE powder, epoxy-functionalized SiO2 microspheres and maleic anhydride-grafted polyethylene wax in a mass ratio of 10:24:13:5. (3) The graphene composite functional masterbatch is obtained by melt blending and granulating the mixture with TPU carrier resin at a mass ratio of 2.1:2; wherein the melt blending and granulation parameters are 150℃ in zone 1, 165℃ in zone 2, 170℃ in zone 3, and 175℃ at the die head; and the screw speed is 200 rpm.

[0022] The aforementioned highly flexible control cable is prepared by the following steps: S1: Mix the matrix resin, antioxidant, pentaerythritol stearate and color masterbatch for 10 min, add graphene composite functional masterbatch and continue mixing, and then dry at 80℃ for 4 h to obtain the mixture; wherein, the antioxidant is antioxidant 1010 and antioxidant 168 compounded in a mass ratio of 1:1. S2: The mixture is transferred to an extruder for melt extrusion of the sheath. Then, supercritical CO2 fluid at a temperature of 31°C and a pressure of 7.5MPa or higher is sprayed onto the sheath surface in a mist form. After cooling and shaping, a highly flexible control cable is obtained. The melt extrusion process parameters are: Zone 1 170°C, Zone 2 180°C, Zone 3 183°C, Die head 185°C, and screw speed 280 rpm.

[0023] Example 2

[0024] A highly flexible control cable, comprising the following components by weight: 100 parts of matrix resin (polyether-type TPU (Shore A 85-90A)), 17 parts of graphene composite functional masterbatch, 0.7 parts of antioxidant, 0.5 parts of additives, and 1.2 parts of color masterbatch; The graphene composite functional masterbatch is prepared by the following steps: (1) Disperse PTFE micro powder in 85% ethanol aqueous solution, add silane coupling agent KH-560 and stir at 85℃ for 4.5h. After the reaction is completed, filter, wash and dry to obtain modified PTFE powder; wherein, the mass amount of silane coupling agent is 7% of the mass of PTFE micro powder; (2) A mixture was prepared by mixing carboxylated graphene (produced by Nanjing Xianfeng Nano), modified PTFE powder, epoxy-functionalized SiO2 microspheres and maleic anhydride-grafted ethylene-vinyl acetate copolymer in a mass ratio of 12:26:15:6. (3) A graphene composite functional masterbatch is obtained by melt blending and granulating a mixture with a mass ratio of 2.3:2 and TPU carrier resin; wherein the melt blending and granulation parameters are 155℃ in zone 1, 170℃ in zone 2, 172℃ in zone 3, and 180℃ at the die head; and the screw speed is 220 rpm.

[0025] The aforementioned highly flexible control cable is prepared by the following steps: S1: Mix the matrix resin, antioxidant, ethylene bis-stearamide and color masterbatch for 15 min, add graphene composite functional masterbatch and continue mixing, then dry at 85℃ for 3.5 h to obtain the mixture; wherein, the antioxidant is antioxidant 1010 and antioxidant 168 compounded in a mass ratio of 1:1. S2: The mixture is transferred to an extruder for melt extrusion of the sheath. Then, supercritical CO2 fluid at a temperature of 32°C and a pressure of 7.5MPa or higher is sprayed onto the sheath surface in a mist form. After cooling and shaping, a highly flexible control cable is obtained. The melt extrusion process parameters are: Zone 1 175°C, Zone 2 182°C, Zone 3 185°C, Die Head 187°C, and Screw Speed ​​290 rpm.

[0026] Example 3

[0027] A highly flexible control cable, comprising the following components by weight: 100 parts of matrix resin (polyether-type TPU (Shore A 85-90A)), 13 parts of graphene composite functional masterbatch, 0.3 parts of antioxidant, 0.2 parts of additives, and 0.8 parts of color masterbatch; The graphene composite functional masterbatch is prepared by the following steps: (1) Disperse PTFE micro powder in a 75% ethanol aqueous solution, add silane coupling agent KH-550 and stir at 75℃ for 4.5h. After the reaction is completed, filter, wash and dry to obtain modified PTFE powder; wherein, the mass amount of silane coupling agent is 3% of the mass of PTFE micro powder; (2) A mixture was prepared by mixing carboxylated graphene (produced by Xi'an Qiyue Biotechnology), modified PTFE powder, epoxy-functionalized SiO2 microspheres and maleic anhydride-grafted polyethylene wax in a mass ratio of 8:23:10:4. (3) A graphene composite functional masterbatch is obtained by melt blending and granulating a mixture with a mass ratio of 1.8:2 and TPU carrier resin; wherein the melt blending and granulation parameters are 145℃ in zone 1, 160℃ in zone 2, 168℃ in zone 3, and 170℃ at the die head; and the screw speed is 180 rpm.

[0028] The aforementioned highly flexible control cable is prepared by the following steps: S1: Mix the matrix resin, antioxidant, pentaerythritol stearate and color masterbatch for 5 min, add graphene composite functional masterbatch and continue mixing, then dry at 75℃ for 3.5 h to obtain the mixture; wherein, the antioxidant is obtained by compounding antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1. S2: The mixture is transferred to an extruder for melt extrusion of the sheath. Then, supercritical CO2 fluid at a temperature of 30°C and a pressure of 7.5MPa or higher is sprayed onto the sheath surface in a mist form. After cooling and shaping, a highly flexible control cable is obtained. The melt extrusion process parameters are: Zone 1 165°C, Zone 2 178°C, Zone 3 180°C, Die Head 182°C, and Screw Speed ​​270 rpm.

[0029] Example 4

[0030] A highly flexible control cable, comprising the following components by weight: 100 parts of matrix resin (polyether-type TPU (Shore A 85-90A)), 14 parts of graphene composite functional masterbatch, 0.4 parts of antioxidant, 0.3 parts of additives, and 0.9 parts of color masterbatch; The graphene composite functional masterbatch is prepared by the following steps: (1) PTFE micro powder was dispersed in an 80% ethanol aqueous solution, and silane coupling agent KH-550 was added. The mixture was stirred at 75°C for 4 hours. After the reaction was completed, the mixture was filtered, washed, and dried to obtain modified PTFE powder. The mass of the silane coupling agent was 4% of the mass of the PTFE micro powder. (2) A mixture was prepared by mixing carboxylated graphene (produced by Xi'an Qiyue Biotechnology), modified PTFE powder, epoxy-functionalized SiO2 microspheres and maleic anhydride-grafted ethylene-vinyl acetate copolymer in a mass ratio of 9:24:11:5. (3) A graphene composite functional masterbatch is obtained by melt blending and granulating a mixture with a mass ratio of 1.9:2 and TPU carrier resin; wherein the melt blending and granulation parameters are 145℃ in zone 1, 165℃ in zone 2, 168℃ in zone 3, and 175℃ at the die head; and the screw speed is 190 rpm.

[0031] The aforementioned highly flexible control cable is prepared by the following steps: S1: Mix the matrix resin, antioxidant, pentaerythritol stearate and color masterbatch for 10 min, add graphene composite functional masterbatch and continue mixing, and then dry at 80℃ for 4.5 h to obtain the mixture; wherein, the antioxidant is obtained by compounding antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1. S2: The mixture is transferred to an extruder for melt extrusion of the sheath. Then, supercritical CO2 fluid at a temperature of 30°C and a pressure of 7.5MPa or higher is sprayed onto the sheath surface in a mist form. After cooling and shaping, a highly flexible control cable is obtained. The melt extrusion process parameters are: Zone 1 170°C, Zone 2 182°C, Zone 3 185°C, Die Head 187°C, and Screw Speed ​​275rpm.

[0032] Example 5

[0033] A highly flexible control cable, comprising the following components by weight: 100 parts of matrix resin (polyether-type TPU (Shore A 85-90A)), 16 parts of graphene composite functional masterbatch, 0.6 parts of antioxidant, 0.4 parts of additives, and 1.1 parts of color masterbatch; The graphene composite functional masterbatch is prepared by the following steps: (1) Disperse PTFE micro powder in 85% ethanol aqueous solution, add silane coupling agent KH-560 and stir at 85℃ for 4.5h. After the reaction is completed, filter, wash and dry to obtain modified PTFE powder; wherein, the mass amount of silane coupling agent is 6% of the mass of PTFE micro powder; (2) A mixture was prepared by mixing carboxylated graphene (produced by Xi'an Qiyue Biotechnology), modified PTFE powder, epoxy-functionalized SiO2 microspheres and maleic anhydride-grafted polyethylene wax in a mass ratio of 11:25:14:6. (3) The graphene composite functional masterbatch is obtained by melt blending and granulating the mixture with TPU carrier resin at a mass ratio of 2.2:2; wherein the melt blending and granulation parameters are 150℃ in zone 1, 165℃ in zone 2, 168℃ in zone 3, and 175℃ at the die head; and the screw speed is 215 rpm.

[0034] The aforementioned highly flexible control cable is prepared by the following steps: S1: Mix the matrix resin, antioxidant, pentaerythritol stearate and color masterbatch for 15 min, add graphene composite functional masterbatch and continue mixing, and then dry at 85℃ for 4.5 h to obtain the mixture; wherein, the antioxidant is obtained by compounding antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1. S2: The mixture is transferred to an extruder for melt extrusion of the sheath. Then, supercritical CO2 fluid at a temperature of 30°C and a pressure of 7.5MPa or higher is sprayed onto the sheath surface in a mist form. After cooling and shaping, a highly flexible control cable is obtained. The melt extrusion process parameters are: Zone 1 175°C, Zone 2 180°C, Zone 3 185°C, Die Head 187°C, and Screw Speed ​​285 rpm.

[0035] Comparative Example 1

[0036] It is basically the same as Example 1, except that no graphene composite functional masterbatch is added.

[0037] Comparative Example 2

[0038] It is basically the same as Example 1, except that the carboxylated graphene is replaced with the same amount of graphene.

[0039] Comparative Example 3

[0040] The process is basically the same as in Example 1, except that the supercritical CO2 cooling and shaping process is replaced by air cooling, that is, the sheath is melt-extruded in step S2 and then cooled by natural air.

[0041] The cables prepared in Examples 1-5 and Comparative Examples 1-3 were subjected to performance tests, and the test results are shown in Table 1.

[0042] Tensile properties were tested according to standard GB / T 2951.11. Five dumbbell-shaped specimens were prepared from the cable sheath and continuously stretched on a tensile testing machine at a speed of (500±50) mm / min until fracture. The maximum tensile force and elongation were recorded, and the tensile strength and elongation at break were calculated.

[0043] The abrasion resistance test was conducted according to standard GB / T 5013.2. Samples were cut from the sheath and fixed onto a rotating cylindrical roller. Under a vertical pressure of 1 N, abrasive cloth of a specific specification was used as the abrasive, causing 6000 reciprocating friction strokes between the sample surface and the abrasive. After the test, the mass loss (mg) of the sample was measured. The less the loss, the better the abrasion resistance.

[0044] The bending performance test is conducted according to standard TICW 21-2019. A finished cable of a specified length is installed on a cable chain bending tester, with one end fixed and the other end reciprocating in a bending motion at a speed of approximately 1 m / s within a 1 m travel distance. The test continues until a break in the internal conductors of the cable or a visible crack appears in the sheath. The number of bending cycles completed at this point is recorded.

[0045] The friction coefficient test is performed according to standard GB / T 10006. A flat sample is cut from the sheath and fixed on the slider. The slider is pulled at a speed of (150±10) mm / min on a clean stainless steel plate. The dynamic friction force during the sliding process is recorded by the sensor, and the dynamic friction coefficient is calculated.

[0046] The tear strength test is performed in accordance with standard GB / T 529-1999. A right-angled specimen without cuts is cut off from the sheath. The specimen is stretched at a speed of (500±50) mm / min on a tensile testing machine. The maximum force during the tearing process is recorded, and the tear strength (kN / m) is calculated.

[0047] Table 1

[0048] As can be seen from Table 1, the performance data of the high-flexibility control cables prepared in Examples 1-5 of the present invention are all better than those of the comparative examples. They have excellent wear resistance, low friction characteristics, mechanical strength, toughness and bending life, and can effectively reduce failures caused by frictional heat and wear debris, thus significantly extending the service life of the cables.

[0049] As can be seen from Comparative Examples 1-3, Comparative Example 1, lacking the addition of graphene composite functional masterbatch, lacks the "reinforcement-lubrication" structure constructed by chemical bonding of carboxylated graphene, modified PTFE, and SiO2 microspheres. The material lacks both a nano-reinforcing phase to improve strength and an effective solid lubricating phase to reduce friction, resulting in a significant decrease in mechanical properties, wear resistance, and lubricity. Comparative Example 2 uses ordinary graphene, which only undergoes physical adsorption with the TPU matrix and lubricant, resulting in weak interfacial bonding. Under stress (tension, bending, friction), the graphene easily separates from the matrix or agglomerates, failing to effectively transfer stress or form a stable lubricating film. Comparative Example 3 employs an air-cooling process, which is slow, causing significant thermal relaxation of the molecular chains and graphene sheets. This results in the material's internal structure being unable to efficiently transfer and disperse stress during dynamic bending, and the surface failing to maintain the most stable low-friction state, thus reducing bending life and wear resistance, and increasing the coefficient of friction.

[0050] The above descriptions are merely some embodiments of the present invention. Those skilled in the art can make various modifications and improvements without departing from the inventive concept of the present invention, and these all fall within the scope of protection of the present invention.

Claims

1. A highly flexible control cable, characterized in that, By mass, it includes the following components: 100 parts of matrix resin, 13-17 parts of graphene composite functional masterbatch, 0.3-0.7 parts of antioxidant, 0.2-0.5 parts of additives, and 0.8-1.2 parts of color masterbatch; The graphene composite functional masterbatch is prepared by the following steps: (1) Disperse PTFE micro powder in a solvent, add silane coupling agent and reflux reaction, filter, wash and dry after the reaction to obtain modified PTFE powder; (2) A mixture is obtained by mixing carboxylated graphene, the modified PTFE powder, epoxy-functionalized SiO2 microspheres and a dispersant; (3) The mixture and TPU carrier resin are melt-blended and granulated to obtain the graphene composite functional masterbatch.

2. The highly flexible control cable according to claim 1, characterized in that, The solvent is a 75-85% aqueous ethanol solution; the silane coupling agent is selected from at least one of KH-550 and KH-560, and the mass amount of the silane coupling agent is 3-7% of the mass of the PTFE micro powder.

3. The highly flexible control cable according to claim 1, characterized in that, The mass ratio of the carboxylated graphene, modified PTFE powder, epoxy-functionalized SiO2 microspheres, and dispersant is 8-12:23-26:10-15:4-6; the dispersant is selected from at least one of maleic anhydride-grafted polyethylene wax and maleic anhydride-grafted ethylene-vinyl acetate copolymer.

4. The highly flexible control cable according to claim 1, characterized in that, The mass ratio of the mixture to the TPU carrier resin is 1.8-2.3:

2.

5. The highly flexible control cable according to claim 1, characterized in that, In step (1), the reflux reaction is carried out by stirring at 75-85℃ for 3.5-4.5h; in step (3), the melt blending granulation parameters are 145-155℃ in zone 1, 160-170℃ in zone 2, 168-172℃ in zone 3, 170-180℃ at the die head, and 180-220 rpm for the screw speed.

6. A method for preparing a highly flexible control cable according to any one of claims 1-5, characterized in that, Includes the following steps: S1: Mix the matrix resin, antioxidant, additives and color masterbatch, add graphene composite functional masterbatch and continue mixing, then dehumidify and dry to obtain the mixture; S2: The mixture is transferred to an extruder for melt extrusion of the sheath, and then cooled and shaped using supercritical CO2 to obtain the high-flexibility control cable.

7. The highly flexible control cable according to claim 6, characterized in that, The antioxidant is obtained by compounding antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1; the adjuvant is selected from at least one of pentaerythritol stearate and ethylene bis-stearamide.

8. The highly flexible control cable according to claim 6, characterized in that, In S1, the mixing time is 5-15 min, and the dehumidification and drying are carried out at 75-85℃ for 3.5-4.5 h.

9. The highly flexible control cable according to claim 6, characterized in that, In S2, the process parameters for melt extrusion are: zone 1 165-175℃, zone 2 178-182℃, zone 3 180-185℃, die head 182-187℃, and screw speed 270-290rpm.

10. The highly flexible control cable according to claim 6, characterized in that, In S2, the supercritical CO2 cooling is defined as spraying supercritical CO2 fluid with a temperature of 30-32℃ and a pressure of 7.5MPa or higher into the sheath surface in a mist form.

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