Absorbing electromagnetic wavelength filaments and methods of making the same

Abstract

The application relates to an electromagnetic wave absorbing filament and a preparation method thereof, and belongs to the technical field of functional fibers. The preparation method of the application takes a magnetic stretching spinning system as an occurrence device, and comprises a double-screw extruder, a magnetic heating device and a multi-stage magnetic stretching device. The preparation method comprises the following steps: S1, marine plastic, nano inorganic magnetic material, nano modifier, filler, additive and silane coupling agent are added into the double-screw extruder and uniformly mixed, and functional masterbatch is obtained through granulation; the marine plastic is selected from PP plastic and / or PET plastic; S2, the functional masterbatch is subjected to magnetic heating through the magnetic heating device, and molten masterbatch is obtained; S3, the molten masterbatch passes through a pinhole plate, and nascent fibers are obtained; and S4, the nascent fibers are stretched through the multi-stage magnetic stretching device, and the electromagnetic wave absorbing filament with uniform distribution and excellent electromagnetic shielding capacity and other performances is obtained.

Description

Technical Field

[0001] This invention belongs to the field of functional fiber technology, and particularly relates to an electromagnetic wavelength absorbing fiber and its preparation method. Background Technology

[0002] Currently, marine debris has become a major global environmental problem, with plastic being a primary component. There are three main methods for handling plastic waste. The first method is direct transport to incineration plants, but this produces large amounts of toxic and harmful gases, polluting the environment; plastic waste cannot be recycled, hindering emission reduction and carbon reduction efforts. The second method involves manually or using compression tools to flatten the plastic during marine plastic collection to reduce its volume; then, it is packaged and transported to a plastic processing plant; at the plant, the received plastic undergoes dismantling, sorting, and cleaning. Dismantling mainly involves separating bottle caps from the bottle bodies (caps are typically made of PP, and bottles are typically made of PET), followed by sorting based on material. The sorted plastic waste is then cleaned; finally, the cleaned plastic waste is recycled. Dismantling, sorting, and cleaning are all manual operations, occupying significant factory space for storing plastic waste; the overall process is complex, time-consuming, and inefficient. The third method involves using a plastic crusher to shred the collected, dismantled, sorted, and washed plastic waste. Existing plastic crushers only have crushing capabilities and lack automatic feeding, washing, and impurity removal functions. The waste is then sorted according to its material, washed again, and finally recycled. Dismantling, sorting, and washing are all manual operations, occupying significant factory space for storing plastic waste. The overall process is complex, time-consuming, and inefficient. If marine materials could be directly utilized, eliminating the need for washing, considerable time could be saved.

[0003] Chinese invention patent CN115012055A discloses a method for preparing flexible stretchable magnetic wire and the flexible stretchable magnetic wire. The method involves mixing magnetic particles with an organic polymer using a hollow spiral mold to form a gel-like mixture. This gel-like mixture is then stirred until viscous and poured into the mold. After standing and curing, the flexible magnetic wire is obtained through post-processing. The basic principle is to use liquid spinning technology to extrude the mixture of organic polymer and magnetic particles and then pour it into a corresponding mold. However, agglomeration easily occurs during the curing process. Without stretching treatment, the tensile strength and elastic modulus of the resulting fiber decrease.

[0004] Chinese invention patent CN109859901A discloses a stretching device for producing ultra-fine electromagnetic wire, including a base, a first rotating shaft, a second rotating shaft, and a third rotating shaft. The three rotating shafts drive the wire rollers to rotate at different speeds. During rotation, the electromagnetic wire is stretched twice, improving the drawing efficiency of the ultra-fine electromagnetic wire. A polishing device is included to polish the surface of the electromagnetic wire, ensuring its uniformity and quality. For different wire diameters, polishing can be adjusted by changing the length of the electric push rod and the pressure of the spring. However, stretching using a localized point-force method can easily create weak points during stretching, affecting yarn quality.

[0005] Chinese invention patent CN114427136A discloses a fiber hot stretching and setting device and its stretching method, including: a heater; an oil tank placed on the heater, with an oil filling port on the top, and a heating groove formed by a downward indentation at the center of the top surface of the oil tank. This method utilizes oil bath heating for stretching, ensuring uniform contact between the fiber and the heating groove until the fiber softens. However, the heating process wastes resources, and the oil needs to be removed after hot stretching, making the process cumbersome and costly. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention provides an electromagnetic wavelength absorbing fiber and its preparation method. Using a magnetic stretching spinning system as the generating device, it effectively utilizes substances in seawater, reduces energy consumption during stretching, and enables precise stretching. This not only helps purify the marine environment but also allows for recycling, emission reduction, and carbon reduction.

[0007] The first objective of this invention is to provide a method for preparing electromagnetic wavelength-absorbing fibers, using a magnetic stretching spinning system as the generating device. The system includes a twin-screw extruder, a magnetic heating device, and a multi-stage magnetic stretching device. A pinhole plate is disposed between the magnetic heating device and the multi-stage magnetic stretching device. The magnetic heating device includes NS permanent magnets and a spiral spinning tube disposed between the NS permanent magnets. The spiral spinning tube contains a plurality of magnetic line-cutting elements. The inlet and outlet ends of the spiral spinning tube are respectively connected to the outlet of the twin-screw extruder and the pinhole plate. The preparation method includes the following steps:

[0008] S1. Marine plastic, nano-inorganic magnetic material, nano-modifier, filler, additives and silane coupling agent are added to a twin-screw extruder and mixed evenly, and functional masterbatch is obtained by granulation; the marine plastic is selected from PP plastic and / or PET plastic;

[0009] S2. The functional masterbatch is magnetically heated by a magnetic heating device to obtain molten masterbatch;

[0010] S3. Molten masterbatch passes through a perforated plate to obtain nascent fibers;

[0011] S4. The nascent fibers are stretched using a multi-stage magnetic stretching device to obtain the electromagnetic wavelength absorbing filament.

[0012] In one embodiment of the present invention, the spiral radius of the spiral spinning tube gradually increases, ensuring that the tube diameter remains constant while generating a smooth transition curve based on the original spiral, thus avoiding tube blockage. This results in a smooth flow field and increases the contact area. The initial spiral radius is 10cm-20cm, with 10-20 turns. The tube diameter of the spiral spinning tube is 2cm-4cm. The angle between the plane containing the end face of the spiral spinning tube and the horizontal plane is 5°-20°. The angle formed by the projection of the central axis of the spiral spinning tube onto the plane containing the NS permanent magnet is 10°-30°.

[0013] In one embodiment of the present invention, the number of the cutting magnetic field line elements is 500-1500; the connection method of the cutting magnetic field line elements is selected from series and / or parallel connection. The cutting magnetic field line element performs cutting magnetic field line motion, and the cutting magnetic field line element is made of a metal conductor material to form a closed loop.

[0014] In one embodiment of the present invention, the pinhole plate is provided with 36-72 sets of pinholes, and the tensile diameter of the pinholes is 0.2cm-1cm.

[0015] In one embodiment of the present invention, in S1, the nano-inorganic magnetic material is selected from one or more of neodymium iron boron magnetic materials, neodymium nickel cobalt magnetic materials, triferrite magnetic materials, chromium dioxide magnetic materials, and cobalt-iron oxide magnetic materials;

[0016] And / or, the nano-modifier is selected from titanium dioxide and / or silicon dioxide;

[0017] And / or, the filler is selected from one or more of carbon nanofibers, carbon nanotubes and carbon fibers;

[0018] And / or, the adjuvant is selected from one or more of citric acid, sodium citrate, potassium citrate, oxalic acid, sodium oxalate, or potassium oxalate;

[0019] And / or, the silane coupling agent is selected from one or more of KH550, KH560 and KH570.

[0020] In one embodiment of the present invention, in S1, the mass ratio of the marine plastic, nano-inorganic magnetic material, nano-modifier, filler, additive, and silane coupling agent is (60-80):(20-40):(1-10):(1-10):(1.5-9):(0.5-1). The marine plastic is derived from marine debris, a renewable resource, and is an environmentally friendly material. The nano-inorganic magnetic material provides electromagnetic shielding. The nano-modifier enhances the electromagnetic shielding effect and further improves filamentation performance, increasing the toughness and strength of the filament during use. The marine plastic, inorganic magnetic material, nano-modifier, a large number of copolymers with active functional groups, and the subsequently added silane coupling agent all further enhance adhesion, improve bonding strength, and extend service life.

[0021] In one embodiment of the present invention, in S1, during the granulation process, the twin-screw extruder is divided into five heating zones: zone one has a heating temperature of 260°C, zone two has a heating temperature of 275°C, zone three has a heating temperature of 280°C, zone four has a heating temperature of 278°C, and zone five has a heating temperature of 265°C.

[0022] In one embodiment of the invention, during S2, the advancing speed of the functional masterbatch is 0.1 m / s-2 m / s, and the magnetic induction intensity is 600 mT-1000 mT. By controlling the nascent fiber to be subjected to a constant tensile force during stretching, the fiber is magnetically stretched, and the entire fiber is stressed, rather than the stress concentrated at a single point as in the traditional method. Different stretching sections are used to adapt to the fiber's use under different conditions. The coil tube determines the magnitude of the magnetic field, and different numbers of turns provide different forces.

[0023] In one embodiment of the present invention, in S4, the number of stages of the multi-stage magnetic stretching device is 2-6, the elongation ratio is 1:(30-50), and the number of turns of the single-stage solenoid is 1-100.

[0024] In one embodiment of the present invention, in S4, the stretching process parameters are: temperature of 90℃-130℃, output power of 500W-1000W, and output current of 2A-8A.

[0025] A second objective of this invention is to provide an electromagnetic wavelength absorbing wire prepared by the method described.

[0026] The technical solution of the present invention has the following advantages compared with the prior art:

[0027] (1) The multi-stage magnetic stretching device used in the preparation method of this invention forms a uniform magnetic field after being energized during hot stretching, thereby forming uniformly distributed downward magnetic field lines. This transforms the point force in traditional stretching into force on the entire filament, reducing weak points and improving the tensile mechanical strength. The monofilament is uniform, which can significantly reduce the unevenness. The use of a magnetic heating device for magnetoelectric heating from the inside out allows for more precise heating of the heating area, further reducing heat loss.

[0028] (2) The preparation method described in this invention uses marine plastics as the base material, which solves the problem of marine debris, protects the marine environment, and reduces the environmental pollution caused by the production of polymer materials; moreover, marine plastics do not require extensive cleaning before use, thus reducing costs. Seawater immersion results in marine plastics carrying many marine substances, which, while solving environmental problems, utilizes marine resources and eliminates the traditional cleaning steps, reducing labor costs. Utilizing existing materials saves resources and protects the environment.

[0029] (3) The preparation method described in this invention uses marine plastic as raw material. The marine plastic is soaked in seawater and is attached with conductive particles such as sodium chloride and magnesium chloride in the sea. It can conduct electricity in the molten state. A large number of copolymers with active functional groups and the silane coupling agent added later further enhance the adhesion. The compatibility of each raw material component is improved by using the silane coupling agent, thereby giving full play to the mutual cooperation and synergistic effect of each raw material component. The excellent performance of each raw material component is combined. The self-assembly of nano-inorganic magnetic materials during hot stretching and the loose and porous stacking morphology caused by the filler can synergistically improve its electromagnetic shielding ability and effect. Attached Figure Description

[0030] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein:

[0031] Figure 1 This is a schematic diagram of the magnetic stretching spinning system of the present invention;

[0032] Figure 2 This is a cross-sectional view of the spiral spinning tube of the magnetic heating device of the present invention;

[0033] Figure 3 This is a schematic diagram showing the angle between the plane containing the end face of the spiral spinning tube of the present invention and the horizontal plane;

[0034] Figure 4 This is a schematic diagram showing the angle formed by the projection of the central axis of the spiral spinning tube of the present invention onto the plane where the NS permanent magnet is located;

[0035] Figure 5 This is a multi-level top view of the pinhole plate of the present invention;

[0036] Figure 6 This is a schematic diagram of the multi-stage magnetic stretching device of the present invention;

[0037] Explanation of reference numerals in the attached drawings: 1-Twin-screw extruder, 2-Magnetic heating device, 21-Spiral spinning pipe, 211-Cut magnetic line element, 3-Pinhole plate, 31-Pinhole, 32-Stretching pipe diameter, 33-Airflow hole, 4-Multi-stage magnetic stretching device, 41-First-stage magnetic stretching device, 42-Second-stage magnetic stretching device. Detailed Implementation

[0038] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0040] The electromagnetic wavelength absorbing wire of the present invention is produced using a magnetic stretching spinning system, and its structure is as follows: Figure 1-6 As shown, the device includes a twin-screw extruder 1, a magnetic heating device 2, and a multi-stage magnetic stretching device 4. A pinhole plate 3 is provided between the magnetic heating device and the multi-stage magnetic stretching device. The magnetic heating device includes an NS permanent magnet and a spiral spinning pipe 21 disposed between the NS permanent magnet. The spiral spinning pipe 21 is provided with several magnetic line cutting elements 211. The inlet and outlet ends of the spiral spinning pipe 21 are respectively connected to the outlet of the twin-screw extruder 1 and the pinhole plate 3. The pinhole plate 3 is provided with air passages 33. Marine plastics, nano-inorganic magnetic materials, nano-modifiers, fillers, additives, and silane coupling agents are added... The mixture is fed into a twin-screw extruder 1 for mixing and granulation to obtain functional masterbatch. The functional masterbatch enters the spiral spinning pipe 21 in the magnetic heating device 2. The magnetic line cutting element 211 in the spiral spinning pipe 2 generates current to magnetically heat the functional masterbatch to obtain molten masterbatch. The molten masterbatch passes through the pinholes 31 in the pinhole plate 3 below the spiral spinning pipe 2 and is stretched by the tube diameter 32 to form nascent fibers. The nascent fibers are stretched by a multi-stage magnetic stretching device 4 (a first-stage magnetic stretching device 41 and a second-stage magnetic stretching device 42, etc.) to obtain electromagnetic wavelength absorbing fibers.

[0041] Example 1

[0042] The electromagnetic wavelength absorbing wire and its preparation method of the present invention specifically include the following steps:

[0043] S1. Marine plastics, nano-neodymium iron boron magnetic materials, nano-modifier titanium dioxide, filler carbon nanofibers, auxiliary agent citric acid, and silane coupling agent KH550 are added to twin-screw extruder 1 in a mass ratio of 65:25:5:5:5:0.5 for mixing and granulation to obtain functional masterbatch. During the granulation process, the twin-screw extruder is divided into five heating zones: zone 1 has a heating temperature of 260℃, zone 2 has a heating temperature of 275℃, zone 3 has a heating temperature of 280℃, zone 4 has a heating temperature of 278℃, and zone 5 has a heating temperature of 265℃.

[0044] S2. The functional masterbatch enters the spiral spinning tube 21 of the magnetic heating device 2 at a speed of 1 m / s. The current generated by the cutting magnetic field lines of the magnetic field lines by the cutting magnetic field line element 211 in the spiral spinning tube 2 is used to magnetically heat the functional masterbatch to obtain molten masterbatch. Among them, the spiral radius of the spiral spinning tube 21 gradually increases, the initial spiral radius is 20 cm, and the number of turns is 20; the diameter of the spiral spinning tube is 4 cm; the angle α between the plane where the end face of the spiral spinning tube is located and the horizontal plane is 20°; the angle β formed by the projection of the central axis of the spiral spinning tube onto the plane where the NS permanent magnet is located is 30°; the number of cutting magnetic field line elements 211 is 500, connected in series, and the magnetic induction intensity is 1000 mT.

[0045] S3. The molten masterbatch passes through 36 sets of pinholes 31 with a stretching diameter of 0.2 cm in the pinhole plate 3 below the spiral spinning pipe 2 to form nascent fibers.

[0046] S4. The nascent fiber is stretched by the multi-stage magnetic stretching device 4 to obtain an electromagnetic wavelength absorbing filament; wherein, the multi-stage magnetic stretching device has 4 stages, an elongation ratio of 1:30, and the number of turns of the single-stage solenoid is 2, 10, 20, and 60 respectively; the stretching process parameters are: temperature of 100℃, output power of 880W, and output current of 4A.

[0047] Example 2

[0048] The electromagnetic wavelength absorbing wire and its preparation method of the present invention specifically include the following steps:

[0049] S1. Marine plastics, nano-neodymium iron boron magnetic materials, nano-modifier titanium dioxide, filler carbon nanofibers, auxiliary agent citric acid, and silane coupling agent KH550 are added to twin-screw extruder 1 in a mass ratio of 60:23:2:8:6:1 and mixed to obtain functional masterbatch. During the granulation process, the twin-screw extruder is divided into five heating zones: zone 1 has a heating temperature of 260℃, zone 2 has a heating temperature of 275℃, zone 3 has a heating temperature of 280℃, zone 4 has a heating temperature of 278℃, and zone 5 has a heating temperature of 265℃.

[0050] S2. The functional masterbatch enters the spiral spinning tube 21 of the magnetic heating device 2 at a speed of 1.5 m / s. The current generated by the cutting magnetic field lines of the magnetic field lines by the cutting magnetic field line element 211 in the spiral spinning tube 2 is used to magnetically heat the functional masterbatch to obtain molten masterbatch. Among them, the spiral radius of the spiral spinning tube 21 gradually increases, with an initial spiral radius of 15 cm and 15 turns; the diameter of the spiral spinning tube is 3 cm; the angle α between the plane where the end face of the spiral spinning tube is located and the horizontal plane is 15°; the angle β formed by the projection of the central axis of the spiral spinning tube onto the plane where the NS permanent magnet is located is 25°; the number of cutting magnetic field line elements 211 is 1000, connected in series, and the magnetic induction intensity is 800 mT.

[0051] S3. The molten masterbatch passes through 36 sets of pinholes 31 with a stretching diameter of 0.2 cm in the pinhole plate 3 below the spiral spinning pipe 2 to form nascent fibers.

[0052] S4. The nascent fiber is stretched by the multi-stage magnetic stretching device 4 to obtain an electromagnetic wavelength absorbing filament; wherein, the multi-stage magnetic stretching device has 6 stages, an elongation ratio of 1:50, and the number of turns of the single-stage solenoid is 2, 5, 10, 20, 40, and 100 respectively; the stretching process parameters are: temperature of 130℃, output power of 660W, and output current of 3A.

[0053] Example 3

[0054] The electromagnetic wavelength absorbing wire and its preparation method of the present invention specifically include the following steps:

[0055] S1. Marine plastic, nano-ferric oxide magnetic material, nano-modifier silicon dioxide, filler carbon nanotubes, auxiliary agent sodium citrate and silane coupling agent KH550 are added to twin-screw extruder 1 in a mass ratio of 65:25:5:5:5:0.5 for mixing and granulation to obtain functional masterbatch; wherein, during the granulation process, the twin-screw extruder is divided into five heating zones, the heating temperature of zone 1 is 260℃, the heating temperature of zone 2 is 275℃, the heating temperature of zone 3 is 280℃, the heating temperature of zone 4 is 278℃, and the heating temperature of zone 5 is 265℃;

[0056] S2. The functional masterbatch enters the spiral spinning tube 21 of the magnetic heating device 2 at a speed of 2 m / s. The current generated by the cutting magnetic field lines of the magnetic field lines by the cutting magnetic field line elements 211 in the spiral spinning tube 2 is used to magnetically heat the functional masterbatch to obtain molten masterbatch. Among them, the spiral radius of the spiral spinning tube 21 gradually increases, the initial spiral radius is 10 cm, and the number of turns is 10; the diameter of the spiral spinning tube is 2 cm; the angle α between the plane where the end face of the spiral spinning tube is located and the horizontal plane is 20°; the angle β formed by the projection of the central axis of the spiral spinning tube onto the plane where the NS permanent magnet is located is 10°; the number of cutting magnetic field line elements 211 is 1500, connected in series, and the magnetic induction intensity is 600 mT.

[0057] S3. The molten masterbatch passes through 36 sets of pinholes 31 with a stretching diameter of 0.2 cm in the pinhole plate 3 below the spiral spinning pipe 2 to form nascent fibers.

[0058] S4. The nascent fiber is stretched by the multi-stage magnetic stretching device 4 to obtain an electromagnetic wavelength absorbing filament; wherein, the multi-stage magnetic stretching device has 4 stages, the elongation ratio is 1:45, and the number of turns of the single-stage solenoid is 2, 10, 30, and 90 respectively; the stretching process parameters are: temperature is 120℃, output power is 660W, and output current is 3A.

[0059] Comparative Example 1

[0060] The process is basically the same as in Example 1, except that the magnetic heating method is replaced with the traditional electric current heating method, which heats from the outside in. Since the masterbatch is a poor conductor of heat, more power is needed to melt the masterbatch. Different drawing rollers are used for stretching, and the speed difference is used for stretching. At the later stretching stress points, breakage and fuzz appear.

[0061] Comparative Example 2

[0062] The process is basically the same as in Example 1, except that the marine plastic is replaced with a plastic bottle that has not been soaked in seawater, and no substances found in seawater are added. Since it does not contain some conductive particles, the resistance increases and the current decreases during the melting process, resulting in less heat generation. Consequently, the filament does not melt completely, leading to uneven melting.

[0063] Comparative Example 3

[0064] The results are basically the same as in Example 1, except that: no nano-modifiers silica and silane coupling agents were added, the bonding performance of each component decreased, and the fiber strength decreased during stretching.

[0065] Comparative Example 4

[0066] The basic structure is the same as in Example 1, except that no nano-iron oxide magnetic material is added. When the fiber is stretched by the magnetic field at the end, the tensile force is significantly reduced, the fiber orientation is reduced, and the thickness of the nascent fiber changes little when it passes through the stretching tube.

[0067] Test case

[0068] The electromagnetic shielding performance of the filaments prepared in Examples 1-3 and Comparative Examples 1-4 was tested.

[0069] (1) Electromagnetic shielding performance: Electromagnetic shielding performance was tested using a microwave network vector analyzer at a frequency of 2-18 GHz.

[0070] (2) Breaking strength: The fiber breaking strength was measured using a strength tester;

[0071] (3) Fiber diameter unevenness: According to the formula CV% = S / X*100%; where S is the standard deviation and x is the mean;

[0072] (4) Orientation degree: The orientation degree was measured using a two-dimensional X-ray diffractometer—a Bruker D8 diffractometer—and calculated according to the following formula. ) Calculation; where θ represents the molecular chain parallel to the orientation direction, and f represents the degree of orientation;

[0073] Table 1 shows the final measured properties of unmodified polyester fiber and modified polyester fiber:

[0074] Table 1

[0075] Sample Electromagnetic shielding (dB) Fracture strength (N) Fiber diameter unevenness (%) Orientation Example 1 30.1 5.8 0.94 0.92 Example 2 36.2 4.7 0.96 0.90 Example 3 28.7 5.5 0.85 0.91 Comparative Example 1 12.6 3.2 1.58 0.88 Comparative Example 2 9.8 2.7 4.78 0.86 Comparative Example 3 10.2 2.3 3.52 0.72 Comparative Example 4 0.5 1.9 2.35 0.69

[0076] As shown in Table 1, the fibers of the embodiments exhibit better performance. Comparing Example 1 and Comparative Example 1, it can be seen that the magnetic heating and multi-stage magnetic stretching device used results in better fiber orientation and breaking strength. After reducing knots, the fiber breaking strength is significantly improved. The use of an inside-out heating method, employing non-traditional pipe wall heating, reduces heat loss during convection, improves heating efficiency, accelerates the fusion of materials between masterbatches, and ensures uniform dispersion of functional materials, thus improving the overall electromagnetic shielding performance of the fiber. The formation of numerous hydrogen bonds from within further enhances fiber orientation, reduces fiber unevenness, and ultimately results in fibers with better overall integrity. Comparing Example 1 and Comparative Examples 2-4, it can be seen that the added magnetic particles and marine plastic interact with each other, greatly improving electromagnetic shielding efficiency. The addition of modifiers extends fiber life, further increases bonding effect, makes the connection tighter, improves mechanical strength, and expands the application range. The added modifiers can thicken the fiber and introduce new functional groups.

[0077] The components in this embodiment effectively enhance the different functions of the fiber, with each component working synergistically. By utilizing the functional groups contained in each component, different chemical bonds are formed, strengthening the integration between the components.

[0078] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for preparing an electromagnetic wavelength-absorbing wire, characterized in that, Using a magnetic stretching spinning system as the generating device, the system includes a twin-screw extruder, a magnetic heating device, and a multi-stage magnetic stretching device. A pinhole plate is disposed between the magnetic heating device and the multi-stage magnetic stretching device. The magnetic heating device includes NS permanent magnets and a spiral spinning tube disposed between the NS permanent magnets. The spiral spinning tube contains several elements that cut magnetic lines of force. The inlet and outlet ends of the spiral spinning tube are respectively connected to the outlet of the twin-screw extruder and the pinhole plate. The preparation method includes the following steps. S1. Marine plastic, nano-inorganic magnetic material, nano-modifier, filler, additives and silane coupling agent are added to a twin-screw extruder and mixed evenly, and functional masterbatch is obtained by granulation; the marine plastic is selected from PP plastic and / or PET plastic; S2. The functional masterbatch is magnetically heated by a magnetic heating device to obtain molten masterbatch; S3. Molten masterbatch passes through a perforated plate to obtain nascent fibers; S4. The nascent fibers are stretched using a multi-stage magnetic stretching device to obtain the electromagnetic wavelength absorbing filament.

2. The method for preparing an electromagnetic wavelength absorbing wire according to claim 1, characterized in that, The spiral radius of the spiral spinning tube gradually increases, with an initial spiral radius of 10cm-20cm and 10-20 turns; the diameter of the spiral spinning tube is 2cm-4cm; the angle between the plane containing the end face of the spiral spinning tube and the horizontal plane is 5°-20°; and the angle formed by the projection of the central axis of the spiral spinning tube onto the plane containing the NS permanent magnet is 10°-30°.

3. The method for preparing an electromagnetic wavelength absorbing wire according to claim 1, characterized in that, The number of the cutting magnetic field line elements is 500-1500; the connection method of the cutting magnetic field line elements is selected from series and / or parallel connection.

4. The method for preparing an electromagnetic wavelength absorbing wire according to claim 1, characterized in that, The pinhole plate has 36-72 sets of pinholes, and the tensile diameter of the pinholes is 0.2cm-1cm.

5. The method for preparing an electromagnetic wavelength absorbing wire according to claim 1, characterized in that, In S1, the nano-inorganic magnetic material is selected from one or more of neodymium iron boron magnetic materials, neodymium nickel cobalt magnetic materials, triferrite magnetic materials, chromium dioxide magnetic materials, and cobalt-iron oxide magnetic materials; And / or, the nano-modifier is selected from titanium dioxide and / or silicon dioxide; And / or, the filler is selected from one or more of carbon nanofibers, carbon nanotubes and carbon fibers; And / or, the adjuvant is selected from one or more of citric acid, sodium citrate, potassium citrate, oxalic acid, sodium oxalate, or potassium oxalate; And / or, the silane coupling agent is selected from one or more of KH550, KH560 and KH570.

6. The method for preparing an electromagnetic wavelength absorbing wire according to claim 1, characterized in that, In S1, the mass ratio of the marine plastic, nano-inorganic magnetic material, nano-modifier, filler, additive and silane coupling agent is (60-80):(20-40):(1-10):(1-10):(1.5-9):(0.5-1).

7. The method for preparing an electromagnetic wavelength absorbing wire according to claim 1, characterized in that, In S2, during the magnetic heating process, the propulsion speed of the functional masterbatch is 0.1m / s-2m / s, and the magnetic induction intensity is 600mT-1000mT.

8. The method for preparing an electromagnetic wavelength absorbing wire according to claim 1, characterized in that, In S4, the number of stages of the multi-stage magnetic stretching device is 2-6, the elongation ratio is 1:(30-50), and the number of turns of the single-stage solenoid is 1-100.

9. The method for preparing an electromagnetic wavelength absorbing wire according to claim 1, characterized in that, In S4, the stretching process parameters are: temperature 90℃-130℃, output power 500W-1000W, and output current 2A-8A.

10. An electromagnetic wavelength absorbing filament prepared by the method of any one of claims 1-9.

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