Flame-retardant silica gel reinforced magnetic attraction wire and processing method thereof

Abstract

The application belongs to the technical field of wire and cable manufacturing, and particularly relates to a flame-retardant silica gel reinforced magnetic attraction wire and a processing method thereof. The magnetic attraction wire comprises a metal conductor, an insulation layer, an integrally formed magnetic attraction head and an outer sheath. Efficient chemical bonding and structural interlocking of the flame-retardant silica gel layer and the magnetic attraction functional structure at the interface are realized by optimizing the processing method. The preparation method comprises the following steps: metal conductor pretreatment and insulation layer forming, magnetic attraction connector prefabrication and online precise integration, composite forming and common vulcanization, gradient post-vulcanization and precise cutting, etc. The obtained magnetic attraction wire has high interface bonding strength, excellent overall flame retardancy and outstanding reliability, and can be integrated with a reed switch safety interlocking unit, thereby preparing a magnetic attraction wire with high interface bonding strength, excellent overall flame retardancy and intrinsic safety characteristics.

Description

Technical Field

[0001] This invention belongs to the field of wire and cable manufacturing technology, specifically relating to a flame-retardant silicone-reinforced magnetic wire and its processing method. Background Technology

[0002] Magnetic cables, as a type of cable that allows for quick connection and disconnection via magnetic interfaces, are increasingly widely used in fields such as new energy vehicle charging, portable energy storage devices, consumer electronics, and industrial mobile equipment due to their convenience. Their performance, particularly flame retardancy, connection reliability, and long-term durability, directly affects the safety and stability of the entire electrical system.

[0003] Currently, the manufacturing of magnetic wicking cables mainly adopts a post-assembly model, where a complete insulated cable is produced first, and then a magnetic connector is assembled at its end. However, the post-assembled connector is physically bonded to the cable body, relying on adhesives or mechanical clips. While the cable body typically possesses good flame-retardant properties, the plastic connector shell material often has insufficient flame-retardant ratings or is completely non-flame-retardant. Consequently, the post-assembled connector and connection points are weak points in flame retardancy, presenting problems such as difficulty in waterproof sealing, stress concentration at the connection points leading to breakage, and easy oxidation of electrical connection points. This is incompatible with the flame-retardant system of electromagnetic wicking cables, causing flames to spread along the interface. Furthermore, the post-assembly process is complex and difficult to scale up for continuous production.

[0004] Therefore, a flame-retardant silicone-reinforced magnetic wire and its processing method are provided to achieve chemical bonding and structural interlocking between the flame-retardant silicone layer and the magnetic functional structure at the interface, thereby preparing an electromagnetic wire with extremely high interfacial bonding strength, high overall flame retardancy and reliable connection performance. Summary of the Invention

[0005] To address the aforementioned shortcomings in the existing technology, this invention provides a flame-retardant silicone-reinforced magnetic wire and its processing method, thereby solving the problems mentioned in the background technology.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A method for processing flame-retardant silicone reinforced magnetic wire includes the following steps: S1: After surface treatment and gradient preheating of the metal conductor, the first flame-retardant silicone is extruded onto the surface of the metal conductor and vulcanized in sections with controlled temperature to form a cable body with an insulating layer. S2: A prefabricated magnetic connector is selectively assembled onto an intermediate carrier with micro-nano grooves, and precisely fixed to the end of the cable body through a visual positioning and robotic arm collaborative system. Electrical connection is achieved by high-frequency induction welding or precision crimping. S3: The end of the cable body is introduced into a modular composite mold, liquid silicone rubber is injected to cover the magnetic connector and pressure is maintained, a second flame-retardant silicone is extruded simultaneously, the temperature is raised to achieve co-curing, and after cooling, the cable semi-finished product with the magnetic connector integrated is obtained. S4: The semi-finished cable is subjected to three-stage gradient vulcanization, air-cooled and water-cooled composite cooling, and then laser-cut and the end face is processed to obtain the finished magnetic cable.

[0007] Furthermore, the first flame-retardant silicone and the second flame-retardant silicone are in the same vulcanization system, and both contain silane coupling agents and two-dimensional nanosheet materials; the liquid silicone rubber contains compatibilizers.

[0008] Further, in step S1, The surface treatment involves ultrasonic cleaning followed by plasma activation for 30-60 seconds on the metal conductor. The gradient preheating involves first preheating at 60-80℃ for 10-15 minutes, and then maintaining the temperature at 100-120℃ for 5-8 minutes. The first flame-retardant silicone rubber contains 0.5-1% silane coupling agent, forming an insulating layer with a thickness of 0.5-0.8 mm; The segmented temperature-controlled vulcanization process is as follows: the first stage is 180~200℃, the middle stage is 200~220℃, and the last stage is 190~210℃, with a total vulcanization time of 3~5 minutes.

[0009] Further, in step S2, the prefabrication of the magnetic connector includes: The magnetic elements are arranged and assembled in a Halbach array, and the magnetic elements are internally welded to the electrical connection terminals and the connection status monitoring unit.

[0010] Further, in step S3, the composite molding includes: The end of the cable body with the magnetic connector is inserted into the modular composite mold. After the modular composite mold is preheated to 80~100℃, liquid silicone rubber with 1~2% compatibilizer is injected at a speed of 0.5~1.0cm³ / s under the conditions of pressure 5~8MPa and temperature 120~140℃, and the pressure is held for 30~60 seconds. After the pressure is held, the second flame-retardant silicone is extruded simultaneously at a speed of 3~6 meters / minute, which is synchronized with the cable travel speed, to form a continuous outer sheath with a thickness of 0.8~1.2mm.

[0011] Further, in step S3, the co-vulcanization is carried out in the modular composite mold, the modular composite mold is heated to 160~180℃ and held for 40~60 seconds, so that the liquid silicone rubber and the second flame-retardant silicone rubber cross-link at the interface to form a chemically bonded integral encapsulation body and outer sheath; the demolding temperature is controlled at 60~80℃.

[0012] Furthermore, in step S4, the three-stage gradient post-vulcanization is as follows: The first stage involves treatment at 80-100℃ for 10-15 minutes, the second stage at 120-150℃ for 15-20 minutes, and the third stage at 180-200℃ for 20-30 minutes.

[0013] The present invention also includes a flame-retardant silicone reinforced magnetic wire, which is prepared by the processing method of the flame-retardant silicone reinforced magnetic wire, comprising a metal conductor, an insulating layer, a magnetic head and an outer sheath. The magnetic head includes an encapsulation body and a magnetic connector completely encapsulated by the encapsulation body. The encapsulation body and the outer sheath are chemically bonded as a whole formed by co-curing.

[0014] Furthermore, the insulating layer and the outer sheath are flame-retardant reinforced silicone layers containing reinforcing fillers, flame retardants, silane coupling agents and two-dimensional nanosheet materials, wherein the flame retardant is selected from at least one of metal hydroxides and phosphorus-nitrogen intumescent flame retardants.

[0015] Furthermore, the magnetic connector includes magnetic elements, electrical connection terminals, and a connection status detection unit. The magnetic elements are arranged in a Halbach array, and the magnetic connector is electrically connected to the metal conductor through the electrical connection terminals. The connection status monitoring unit is a reed switch, and its contacts are connected in series in the main conductive circuit. A first permanent magnet is provided inside the magnetic connector.

[0016] Compared with the prior art, the present invention has the following advantages: 1. A novel process flow is adopted, which includes online integrated magnetic connectors, partial injection molding, continuous extrusion, and in-situ co-curing. This process enables the standardized magnetic connectors and cable bodies to be integrally bonded at the molecular level using silicone material, fundamentally solving the challenges of interface bonding and flame retardancy continuity in post-assembly processes.

[0017] 2. The magnetic head (encapsulation body + magnetic connector) and the outer sheath are chemically bonded as a whole through co-curing, without any physical seams. It is waterproof, has excellent tensile and bending fatigue resistance, and has complete and uniform flame retardant properties.

[0018] 3. By integrating the connection status monitoring unit (such as a reed switch) into a standardized magnetic connector, hardware-level safety interlocking without the need for external circuitry is achieved.

[0019] 4. The online integrated packaging of standardized magnetic connectors is suitable for continuous or quasi-continuous production, with a high degree of automation, good product consistency, and production efficiency and cost far superior to post-assembly processes. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the preparation process of the flame-retardant silicone reinforced magnetic wire processing method of the present invention.

[0022] Figure 2 This is a schematic diagram of the cross-sectional structure of the cable body of the flame-retardant silicone-reinforced magnetic cable of the present invention.

[0023] Figure 3 This is a schematic diagram of the longitudinal cross-sectional structure of the flame-retardant silicone-reinforced magnetic suction wire in the magnetic suction head area of ​​the present invention.

[0024] In the figure, 1-metal conductor, 2-insulating layer, 3-magnetic head, 31-magnetic connector, 32-package, 311-magnetic element, 312-electrical connection terminal, 313-connection status detection unit, 3131-reed switch, 3132-first permanent magnet, 4-outer sheath. Detailed Implementation

[0025] like Figures 1-3 As shown, the present invention provides a method for processing flame-retardant silicone reinforced magnetic wire, comprising the following steps: S1: After surface treatment and gradient preheating pretreatment of the metal conductor 1, a first flame-retardant silicone is extruded onto the surface of the metal conductor 1 and vulcanized in sections with controlled temperature to form a cable body with an insulation layer 2; metal conductor 1 pretreatment and insulation layer 2 forming are performed: S11: The metal conductor 1 is surface treated by first using ultrasonic cleaning to remove surface oil and oxide layer, and then performing plasma activation treatment. The activation time is controlled to be 30-60 seconds to enhance the bonding activity between the conductor surface and the silicone material. S12: The surface-treated metal conductor 1 is preheated in a gradient. First, it is preheated at 60~80℃ for 10~15 minutes, and then the temperature is raised to 100~120℃ and held for 5~8 minutes to avoid the problem of interface bubbles caused by excessive temperature difference between the conductor and the adhesive. S13: The preheated metal conductor 1 is continuously fed into the die head of a precision extruder. The screw temperature of the extruder is controlled in segments: 100~120℃ in the feeding section, 130~150℃ in the plasticizing section, and 150~160℃ in the die head section. The first flame-retardant silicone rubber (containing raw rubber, reinforcing filler, flame retardant, vulcanizing agent, and 0.5~1% silane coupling agent) is heated and plasticized, and then continuously and uniformly extruded onto the surface of the metal conductor 1 at an extrusion speed of 1.5~2.5mm / s. The thickness of the insulation layer 2 is controlled to be 0.5~0.8mm, which can be precisely adjusted according to requirements. S14: The metal conductor 1 covered with uncured rubber compound immediately enters the segmented temperature-controlled curing pipeline. The curing temperature is set in segments: 180~200℃ in the front section, 200~220℃ in the middle section, and 190~210℃ in the rear section. The total curing time is controlled to be 3~5 minutes to ensure that the silicone is fully cross-linked and forms a dense insulation layer 2 with excellent electrical insulation performance and stable flame retardant effect, thus obtaining the cable body.

[0026] S2: A prefabricated magnetic connector 31 is selectively assembled onto an intermediate carrier with micro-nano grooves, and precisely fixed to the end of the cable body via a visual positioning and robotic arm collaborative system. Electrical connection is achieved using high-frequency induction welding or precision crimping; this realizes the prefabrication and precise online integration of the magnetic connector 31. S21: When the magnetic connector 31 is prefabricated offline, it is assembled using a precision mold. The magnetic components 311 are precisely arranged in a Halbach array to ensure optimized magnetic circuitry. The welding of the electrical connection terminal 312 to the magnetic components 311 and the connection status monitoring unit uses laser spot welding technology. The diameter of the solder joint is controlled at 0.8~1.2mm, and the welding temperature is controlled at 280~320℃ to avoid high-temperature damage to the components and to ensure the stability of the internal electrical connection. S22: The magnetic connector 31 can be selectively assembled on the intermediate carrier. The surface of the intermediate carrier has a pre-set micro-nano-level groove structure with a groove depth of 0.1~0.3mm. It can then form a mechanical interlock with the silicone material and further enhance the bonding strength with chemical bonding.

[0027] S23: Using a vision positioning and robotic arm collaborative system, the prefabricated magnetic connector 31 is grasped and precisely placed at a predetermined position at the end of the continuously moving cable body, with a positioning accuracy error ≤ ±0.1mm. A pneumatic clamping device is used for temporary fixation, with the clamping pressure controlled at 0.3~0.5MPa to avoid damage to the cable body and the magnetic connector 31.

[0028] S24: The electrical connection between the electrical connection terminal 312 and the metal conductor 1 is achieved by high-frequency induction welding or precision crimping: During induction welding, the induction frequency is 300~500kHz and the welding time is 1~3 seconds to ensure that the connection resistance is ≤5mΩ; During crimping, the crimping pressure is 8~12MPa and the crimping depth error is ≤±0.05mm to ensure the reliability of the connection.

[0029] S3: The end of the cable body is inserted into a modular composite mold, liquid silicone rubber is injected to cover the magnetic connector 31 and pressure is maintained, a second flame-retardant silicone rubber is extruded simultaneously, and co-curing is achieved by heating. After cooling, the cable is demolded to obtain a semi-finished cable with the magnetic connector 31 integrated into one piece; achieving composite molding and co-curing: S31: The end of the cable body, to which the magnetic connector 31 is fixed, is introduced into a precision composite mold. The mold adopts a modular design, and the surface of the cavity is nitrided with a roughness Ra≤0.05㎛ to reduce the resistance to the flow of the adhesive. After the mold is closed, the cavity is preheated to 80~100℃ by a temperature control system to lay the foundation for the flow and vulcanization of the adhesive. S32: Using a servo-driven injection molding system, the liquid silicone rubber (using the same vulcanization system as the second flame-retardant silicone rubber, with 1-2% compatibilizer added) is injected into the mold cavity at an injection speed of 0.5-1.0 cm³ / s under conditions of 5-8 MPa pressure and 120-140℃ temperature, ensuring that the liquid silicone rubber completely covers all outer surfaces and internal gaps of the magnetic connector 31, without air bubbles or insufficient adhesive. After injection, the pressure is maintained for 30-60 seconds at 3-5 MPa to ensure that the adhesive fully fills and adheres. S33: After the pressure holding is completed, the second flame-retardant silicone is continuously extruded through a second precision extruder. The screw temperature of the extruder is controlled at 130~160℃, and the extrusion speed is synchronized with the cable travel speed (3~6 meters / minute) to ensure that the silicone material forms a continuous and uniform coating layer around the insulation layer 2 and around the liquid silicone rubber covering the magnetic connector 31, with a thickness controlled at 0.8~1.2mm. S34: The composite mold is heated to 160~180℃ and held for 40~60 seconds, causing the liquid silicone rubber and the second flame-retardant silicone rubber to undergo a simultaneous cross-linking reaction at the interface, achieving molecular-level diffusion and chemical bonding, and integrally forming an encapsulation body 32 covering the magnetic connector 31 and a continuous cable outer sheath 4. The composite mold is cooled and demolded using circulating cooling water, with the demolding temperature controlled at 60~80℃ to avoid product deformation caused by high-temperature demolding, resulting in a semi-finished cable product integrally covered with the magnetic connector 31.

[0030] S4: The semi-finished cable undergoes a three-stage gradient post-curing process, followed by air-cooling and water-cooling composite cooling, and then laser precision cutting and end-face processing to obtain the finished magnetic cable; achieving gradient post-curing and precision cutting. S41: The semi-finished cable is subjected to gradient post-vulcanization treatment using a three-stage temperature-controlled process. First stage: 80~100℃ circulating hot air drying tunnel treatment for 1~1.5 hours to slowly release interface stress and avoid crack formation; Second stage: Treat at 120~150℃ for 1.5~2 hours to promote deep cross-linking of the rubber compound; Third stage: Oven treatment at 180~200℃ for 2~3 hours to stabilize the flame retardant system and mechanical properties, ensuring long-term stable product performance; S42: The cable after post-vulcanization enters the precision cooling channel and adopts a combined air-cooling and water-cooling method: first, it is cooled down to 100~120℃ by air cooling at 25~30℃, and then cooled down to room temperature by water cooling at 15~20℃. The cooling rate is controlled at 5~8℃ / minute to avoid residual internal stress caused by rapid cooling.

[0031] S43: According to the design length, a laser cutting machine is used for precise cutting with a cutting accuracy error of ≤±0.2mm. The cut end face is treated with hot air (temperature 200~250℃, time 5~10 seconds) to avoid cracking of the silicone layer and exposure of the conductor, thus obtaining the finished magnetic wire.

[0032] Furthermore, the connection status monitoring unit is preferably a reed switch 3131, whose contacts are connected in series in the main conductive circuit; the magnetic connector 31 is provided with a first permanent magnet 3132 for biasing the reed switch 3131 in the open state, and the polarity of the first permanent magnet 3132 is precisely positioned to ensure that the action sensitivity of the reed switch 3131 is ≤0.5mT.

[0033] Furthermore, 0.3-0.8% of two-dimensional nanosheet materials (such as graphene or montmorillonite) are added to the first and second flame-retardant silicone materials. A composite process of ultrasonic dispersion (power 300-500W, time 30-60 minutes) and mechanical stirring (speed 800-1200r / min, time 60-90 minutes) is used to ensure uniform dispersion of nanomaterials and improve flame retardant performance and mechanical strength.

[0034] Furthermore, an online quality monitoring system is adopted during the production process: the vulcanization temperature is monitored in real time by an infrared thermometer (error ≤ ±2℃), the thickness of the insulation layer 2 and the outer sheath 4 is monitored by a laser diameter gauge (error ≤ ±0.02mm), and the cable tension is monitored in real time by a tension sensor (controlled to 5~10N) to ensure that the production process is stable and controllable.

[0035] This invention also includes a flame-retardant silicone reinforced magnetic wick, prepared by the aforementioned processing method, comprising a metal conductor 1, an insulating layer 2 covering the metal conductor 1, an integrated magnetic head 3, and an outer sheath 4. The magnetic head 3 includes a magnetic connector 31 completely encapsulated by the encapsulation body 32. The encapsulation body 32 and the outer sheath 4 are chemically bonded as a whole formed by co-curing, without physical seams. The insulating layer 2 and the outer sheath 4 are both flame-retardant reinforced silicone layers containing reinforcing fillers, flame retardants, silane coupling agents, and two-dimensional nanosheet materials. The flame retardant is selected from at least one of metal hydroxides and phosphorus-nitrogen intumescent flame retardants. The magnetic connector 31 includes a magnetic element 311, an electrical connection terminal 312, and a connection status detection unit 313, and is reliably electrically connected to the metal conductor 1 through the electrical connection terminal 312. Example 1

[0036] S1: Nineteen 0.15mm tin-plated copper conductors are selected, ultrasonically cleaned, and then subjected to 60-second plasma activation treatment, followed by gradient preheating at 70℃ for 13 minutes and holding at 110℃ for 7 minutes. A first flame-retardant silicone rubber (containing 0.8% silane coupling agent and 0.5% graphene nanosheets, ultrasonically dispersed at 400W for 40 minutes and mechanically stirred at 1000r / min for 80 minutes) is extruded through a 45mm precision extruder at an extrusion speed of 2.0mm / s, resulting in an insulation layer thickness of 0.6mm. The material then enters a segmented temperature-controlled vulcanization pipeline (front section 190℃, middle section 210℃, rear section 200℃) for 4 minutes to form the cable body.

[0037] S2: During the prefabrication of the magnetic connector, the magnetic components are arranged in a Halbach array, and the internal connection is completed by laser spot welding (solder point diameter 1.0mm, temperature 300℃); the surface of the intermediate carrier has a pre-set 0.2mm deep micro-nano groove. The connector is precisely placed on the end of the cable body through a vision positioning and robotic arm system (positioning error ≤ ±0.1mm), pneumatically clamped with 0.4MPa, and connected to the conductor by 400kHz high-frequency induction welding (welding time 2 seconds), with a conduction resistance ≤3mΩ.

[0038] S3: The cable body end is inserted into a modular composite mold (cavity Ra=0.03㎛, preheated to 90℃), and liquid silicone rubber (with 1.5% compatibilizer added) is injected at an injection pressure of 6MPa, a temperature of 130℃, and a speed of 0.8cm³ / s, holding the pressure for 40 seconds. Subsequently, a second flame-retardant silicone rubber (using the same vulcanization system as the liquid silicone rubber) is extruded simultaneously at a speed of 4m / min, with an outer sheath thickness of 1.0mm. The mold is heated to 170℃ and held for 50 seconds, then cooled to 70℃ for demolding, yielding a semi-finished cable with an integrated magnetic connector.

[0039] S4: The semi-finished cable undergoes a three-stage gradient vulcanization process: 1.2 hours at 80℃, 1.8 hours at 130℃, and 2.5 hours at 190℃. It is then cooled to room temperature using a combination of air and water cooling, and cut to the designed length using a laser cutting machine (error ≤ ±0.2mm). The end face is then treated with 220℃ hot air for 8 seconds to obtain the finished magnetic cable.

[0040] The performance of the obtained magnetic cable is as follows: the peel strength between the magnetic head and the cable body reaches 5.3 N / mm; the entire cable passes the UL94 V-0 vertical burning test (sample thickness 1.6mm) with a limiting oxygen index (LOI) of 52%; it has not failed after more than 35,000 cycles of 500g suspension and 90° bending tests; the connection resistance is stable at 2.8 mΩ; after 72 hours of 5% NaCl salt spray test, the change rate of the resistance is ≤3%; the fluctuation of key performance between product batches is ≤±2%. Example 2

[0041] S1: Sixteen 0.18mm silver-plated copper conductors are selected, ultrasonically cleaned, and then subjected to 45-second plasma activation treatment, followed by gradient preheating at 65℃ for 12 minutes and holding at 115℃ for 6 minutes. A first flame-retardant silicone (containing 0.6% silane coupling agent and 0.3% montmorillonite nanosheets, ultrasonically dispersed at 350W for 50 minutes and mechanically stirred at 900r / min for 70 minutes) is extruded through a 40mm precision extruder at an extrusion speed of 1.8mm / s, resulting in an insulation layer thickness of 0.7mm. The material then enters a segmented temperature-controlled vulcanization pipeline (front section 185℃, middle section 215℃, rear section 195℃) for 3.5 minutes to form the cable body.

[0042] S2: The prefabrication and integration process of the magnetic connector is the same as in Example 1, but a precision crimping process (pressure 10MPa, crimping depth error ±0.04mm) is used to connect the electrical connection terminal and the conductor.

[0043] S3: Preheat the composite mold to 85℃, inject liquid silicone rubber at a pressure of 7MPa, a temperature of 135℃, and a speed of 0.6cm³ / s, holding the pressure for 50 seconds. Extrude the second flame-retardant silicone at a speed of 5 meters / minute, with an outer sheath thickness of 1.1mm. Cure at a common temperature of 175℃ for 45 seconds, then cool and demold to obtain a semi-finished cable with an integrated magnetic connector.

[0044] S4: The semi-finished cable is subjected to a gradient vulcanization process: 90℃ for 1 hour, 140℃ for 1.5 hours, and 195℃ for 2 hours. The cooling and cutting process is the same as in Example 1.

[0045] The performance of the obtained magnetic wire is as follows: its interface peel strength is 5.1 N / mm; the flame retardancy rating of the whole wire reaches UL94 V-0 level, the limiting oxygen index (LOI) is 50%; it has not failed after more than 32,000 bending tests; the conduction resistance is 3.2 mΩ; the resistance change rate after salt spray test is ≤3.5%; the performance fluctuation between batches is ≤±2.5%.

[0046] Proportional Design Comparative Example 1 (Post-assembly process) For comparison, a comparative sample was prepared according to the currently common post-assembly method: the cable body was made using the same metal conductor and first flame-retardant silicone as in Example 1. The magnetic connector used an injection-molded general-purpose plastic shell (flame retardant rating UL94 HB). The magnetic connector (without micro-nano groove intermediate carrier) was placed into the shell, and the cable conductor and connector terminal were manually soldered together. Epoxy resin was applied to the mating surfaces of the upper and lower shells for bonding and cured at room temperature for 24 hours. Silicone sealant was applied to the cable outlet.

[0047] Performance test results: The interface peel strength was only 0.8-1.2 N / mm (adhesive layer failure); in the flame retardant test of the entire production line, the plastic shell of the connector burned rapidly, and the flame retardant rating only reached V-2 level, with a limiting oxygen index of 38%; the flexural strength test failed to reach 5000 cycles before breaking at the root of the connector; the conductivity change rate after the salt spray test exceeded 25%; and it failed the IPX8 waterproof test. The product performance consistency was poor, with large fluctuations between batches.

[0048] Comparative Example 2 (Comparison of processes without co-vulcanization and nano-reinforcement) To further verify the effectiveness of the key technologies of this invention, a Comparative Example 2 sample was prepared: the cable body was the same as in Example 1. The magnetic connector was injection molded using the same mold and liquid silicone rubber (without compatibilizer), and an independent magnetic head was separately vulcanized. This magnetic head was then bonded to the cable end with silicone adhesive and reinforced with heat-shrink tubing. Finally, ordinary flame-retardant silicone (without two-dimensional nanosheet material) was extruded around the cable as an outer sheath.

[0049] Performance test results: The interfacial peel strength was 1.5-2.0 N / mm (adhesive interface failure); the flame retardancy rating of the entire line was V-1, and the limiting oxygen index was 45%; the adhesive joint cracked after approximately 15,000 flexural cycles; the resistivity change rate after salt spray testing was ≥10%; it also failed the IPX8 waterproof test. Although its performance was better than Comparative Example 1, it was significantly lower than Examples 1 and 2.

[0050] By comparing the performance data of Examples 1 and 2 with those of Comparative Examples 1 and 2, the following conclusions can be drawn: Compared with the traditional post-assembly process (Comparative Example 1), the embodiments of the present invention have achieved improvements in product interface bonding strength, overall flame retardant safety, mechanical durability, environmental sealing reliability and product consistency, and have comprehensively solved the problems pointed out in the background art; Compared to the comparative process (Comparative Example 2) which uses similar materials but lacks core technology, the embodiments of the present invention still have significant advantages in key indicators such as interfacial bonding strength, flame retardancy rating, and flexural life. This proves that "co-vulcanization to form chemical bonds" and "nanomaterial reinforcement" are not simple substitutions, but rather core technical features that produce synergistic effects. The performance data of Example 1 and Example 2 are similar and both are at an excellent level, indicating that the optimized processing method of the present invention has good process tolerance and repeatability within a certain parameter range, and can stably prepare high-performance products.

[0051] The above description discloses only one preferred embodiment of the present invention, and should not be construed as limiting the scope of the present invention. Those skilled in the art will understand that all or part of the processes of the above embodiments can be implemented, and equivalent changes made in accordance with the claims of the present invention are still within the scope of the invention.

Claims

1. A method for processing flame-retardant silicone reinforced magnetic wire, characterized in that, Includes the following steps: S1: After surface treatment and gradient preheating of the metal conductor, the first flame-retardant silicone is extruded onto the surface of the metal conductor and vulcanized in sections with controlled temperature to form a cable body with an insulating layer. S2: A prefabricated magnetic connector is selectively assembled onto an intermediate carrier with micro-nano grooves, and precisely fixed to the end of the cable body through a visual positioning and robotic arm collaborative system. Electrical connection is achieved by high-frequency induction welding or precision crimping. S3: The end of the cable body is introduced into a modular composite mold, liquid silicone rubber is injected to cover the magnetic connector and pressure is maintained, a second flame-retardant silicone is extruded simultaneously, the temperature is raised to achieve co-curing, and after cooling, the cable semi-finished product with the magnetic connector integrated is obtained. Step S3 further includes: introducing the end of the cable body with the fixed magnetic connector into the modular composite mold; after preheating the modular composite mold to 80~100℃, injecting liquid silicone rubber with 1~2% compatibilizer at a speed of 0.5~1.0cm³ / s under pressure of 5~8MPa and temperature of 120~140℃, and holding the pressure for 30~60 seconds; after holding the pressure, simultaneously extruding the second flame-retardant silicone rubber at a speed of 3~6 meters / minute synchronized with the cable travel speed to form a continuous outer sheath with a thickness of 0.8~1.2mm; in step S3, the co-vulcanization is carried out in the modular composite mold, which is heated to 160~180℃ and held for 40~60 seconds to allow the liquid silicone rubber and the second flame-retardant silicone rubber to cross-link synchronously at the interface, forming a chemically bonded integral encapsulation and outer sheath; the demolding temperature is controlled at 60~80℃; S4: The semi-finished cable is subjected to three-stage gradient vulcanization, air-cooled and water-cooled composite cooling, and then laser-cut and the end face is processed to obtain the finished magnetic cable.

2. The processing method of a flame-retardant silicone reinforced magnetic wire as described in claim 1, characterized in that, The first flame-retardant silicone and the second flame-retardant silicone are in the same vulcanization system, both containing silane coupling agents and two-dimensional nanosheet materials; the liquid silicone rubber contains compatibilizers.

3. The processing method of a flame-retardant silicone reinforced magnetic wire as described in claim 1, characterized in that, In step S1, The surface treatment involves ultrasonic cleaning followed by plasma activation for 30-60 seconds on the metal conductor. The gradient preheating involves first preheating at 60-80℃ for 10-15 minutes, and then maintaining the temperature at 100-120℃ for 5-8 minutes. The first flame-retardant silicone rubber contains 0.5-1% silane coupling agent, forming an insulating layer with a thickness of 0.5-0.8 mm; The segmented temperature-controlled vulcanization process is as follows: the first stage is 180~200℃, the middle stage is 200~220℃, and the last stage is 190~210℃, with a total vulcanization time of 3~5 minutes.

4. The processing method of a flame-retardant silicone reinforced magnetic wire as described in claim 1, characterized in that, In step S2, the prefabrication of the magnetic connector includes: The magnetic components are arranged and assembled in a Halbach array, and the magnetic components are internally welded to the electrical connection terminals and the connection status monitoring unit.

5. The processing method of a flame-retardant silicone reinforced magnetic wire as described in claim 1, characterized in that, In step S4, the three-stage gradient post-vulcanization is as follows: The first stage involves treatment at 80-100℃ for 10-15 minutes, the second stage at 120-150℃ for 15-20 minutes, and the third stage at 180-200℃ for 20-30 minutes.

6. A flame-retardant silicone-reinforced magnetic wire, prepared by the processing method of any one of claims 1 to 5, characterized in that, It includes a metal conductor, an insulating layer, a magnetic head, and an outer sheath. The magnetic head includes an encapsulation body and a magnetic connector completely enclosed by the encapsulation body. The encapsulation body and the outer sheath are chemically bonded as a whole formed by co-curing.

7. The flame-retardant silicone-reinforced magnetic cable as described in claim 6, characterized in that, The insulating layer and the outer sheath are flame-retardant reinforced silicone layers containing reinforcing fillers, flame retardants, silane coupling agents and two-dimensional nanosheet materials. The flame retardant is selected from at least one of metal hydroxides and phosphorus-nitrogen intumescent flame retardants.

8. The flame-retardant silicone-reinforced magnetic cable as described in claim 7, characterized in that, The magnetic connector includes magnetic elements, electrical connection terminals, and a connection status monitoring unit. The magnetic elements are arranged in a Halbach array. The magnetic connector is electrically connected to the metal conductor through the electrical connection terminals. The connection status monitoring unit is a reed switch, and its contacts are connected in series in the main conductive circuit. A first permanent magnet is provided inside the magnetic connector.

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