Shielding cable and preparation method thereof

Abstract

The invention discloses a shielding cable and a preparation method thereof, the shielding cable comprises a conductor core, an insulating layer and a composite shielding tape which are sequentially sleeved from inside to outside, the composite shielding tape wraps the periphery of the insulating layer, and the composite shielding tape comprises a metal alloy layer, a PE tape and a nanometer shielding coating, the metal alloy layer and the nanometer shielding coating are arranged on the surfaces of the two sides of the PE belt respectively, and the metal alloy layer is attached to the insulating layer. The metal alloy is good in corrosion resistance, and the service life of the shielding composite belt can be prolonged. The nano shielding coating adopts a water-soluble formula, so that the nano shielding coating is more environment-friendly, and volatile organic compounds can be effectively reduced.

Description

Technical Field

[0001] The present invention relates to the field of shielded cable manufacturing, and more specifically, to a shielded cable and a preparation method thereof. Background Art

[0002] Shielded cables are mainly used for information transmission. In order to ensure the transmission performance in an electromagnetic interference environment, on the basis of reducing the electromagnetic energy radiated outward by the system itself, it is also necessary to have the ability to resist external electromagnetic interference. In general, the structure of electromagnetic shielding cables from the inside to the outside is a conductive core, an insulating layer, a shielding layer and an outer sheath. Among them, the conductive core is used to transmit electrical signals, and the material is mainly copper or copper-zinc alloy. The shielding layer is usually formed by metal wire weaving, metal tape or electrochemical plating coated on the outside of the insulating layer to shield electromagnetic interference or useless external signals. However, in actual use, on the one hand, the existing shielding layer cannot simultaneously shield low-frequency electromagnetic signal interference and high-frequency electromagnetic signal interference; on the other hand, the existing shielding layer is a combination of tinned copper wire weaving and aluminum-plastic composite tape, and the quality is heavy. Summary of the invention

[0003] An object of the present invention is to provide a new technical solution for a shielded cable and a method for preparing the same.

[0004] According to a first aspect of the present invention, a shielded cable is provided, characterized in that it comprises a conductor core, an insulating layer and a composite shielding tape which are sequentially sleeved from the inside to the outside, the composite shielding tape is wrapped around the outer periphery of the insulating layer, the composite shielding tape comprises a metal alloy layer, a PE tape and a nano-shielding coating, the metal alloy layer and the nano-shielding coating are respectively arranged on both side surfaces of the PE tape, and the metal alloy layer is attached to the insulating layer;

[0005] The nano shielding coating comprises the following raw materials in the following weight proportions:

[0006] 5-20 parts of kaolin; 1-5 parts of titanium dioxide; 1-10 parts of carbon black; 0.05-2 parts of nano Cu powder; 0.01-1 parts of talc; 0.01-0.5 parts of hydroxyethyl cellulose; 0.01-0.5 parts of sodium hexametaphosphate; 0.05-1 parts of sodium polyacrylate;

[0007] 20-50 parts of water-based acrylic emulsion;

[0008] Stabilizer 0.1-2 parts;

[0009] Anti-settling agent 0.1-4 parts; Ethylene glycol 0.5-4 parts; Tributyl phosphate 0.1-5 parts;

[0010] Defoaming agent 0.1-4 parts.

[0011] Optionally, the shielded cable further comprises a wrapping layer arranged on the outer periphery of the composite shielding tape and a sheath layer sleeved over the wrapping layer, and the wrapping direction of the wrapping layer is opposite to the wrapping direction of the composite shielding tape.

[0012] Optionally, the wrapping overlap rate of the composite shielding tape is 15%-30%; the wrapping overlap rate of the wrapping tape is 4%-10%.

[0013] According to a second aspect of the present invention, a method for preparing a shielded cable is provided, characterized in that it comprises the following steps:

[0014] S1, the metal alloy layer is structured into a strip-shaped member, and the strip-shaped member is preheated;

[0015] S2, attaching the preheated strip-shaped component to one side surface of the PE tape;

[0016] S3, coating the other side surface of the PE tape with a nano-shielding coating to form the nano-shielding coating, thereby obtaining the composite shielding tape;

[0017] S4, wrapping the composite shielding tape around the outer periphery of the insulation layer of the shielded cable;

[0018] S5, wrapping the wrapping layer around the outside of the composite shielding tape;

[0019] S6, extruding a sheath layer on the outer periphery of the wrapping layer.

[0020] Optionally, in said S3, it includes:

[0021] S30, preparing a nano shielding coating;

[0022] S31, applying the nano-shielding coating prepared in S30 to the other side surface of the PE tape to obtain a PE tape preform;

[0023] S32, curing the PE tape preform obtained in S31 at a constant temperature, with a curing temperature of 25° C. to 40° C. and a curing time of 12 min to 60 min;

[0024] S31 and S32 are repeated at least twice.

[0025] Optionally, the thickness of the nano shielding coating is 20-100 μm.

[0026] Optionally, in S30, the following steps are included:

[0027] S301, mixing and grinding solid raw materials of kaolin, titanium dioxide, carbon black, nano Cu powder, talcum powder, hydroxyethyl cellulose, sodium hexametaphosphate, and sodium polyacrylate to obtain a mixed powder;

[0028] S302, adding the mixed powder into an aqueous solution of an aqueous acrylic emulsion, and performing a first electromagnetic stirring to obtain a first prefabricated liquid;

[0029] S303, adding a liquid raw material anti-settling agent, ethylene glycol, a stabilizer, and tributyl phosphate to the first prefabricated liquid to obtain a second prefabricated liquid;

[0030] S304, subjecting the second preformed liquid to a second electromagnetic stirring to obtain a third preformed liquid;

[0031] S305, adding a defoaming agent to the third prefabricated liquid, and performing a third electromagnetic stirring to obtain the nano-shielding coating.

[0032] Optionally, the stirring speed of the first electromagnetic stirring is 1100-1500 r / min, and the stirring time is 15-40 min;

[0033] The stirring speed of the second electromagnetic stirring is 800-1200 r / min, and the stirring time is 10-20 min;

[0034] The third electromagnetic stirring includes low-speed stirring and high-speed stirring in sequence, wherein the stirring speed of the low-speed stirring is 500-1000 r / min and the stirring time is 5-10 min; the stirring speed of the high-speed stirring is 1100-1500 r / min and the stirring time is 10-20 min.

[0035] Optionally, the anti-settling agent is at least one of BYK-420 and PAMID-D772; the stabilizer is AMP-95; and the defoamer is Hyperlev F40.

[0036] Optionally, the metal alloy layer is made of magnesium foil alloy, aluminum foil alloy or copper foil alloy.

[0037] Optionally, S2 includes:

[0038] S21, laminating the strip-shaped component preheated to a temperature of 130-180° C. with the PE tape to form a first composite tape;

[0039] S22, passing the first composite tape through a heating box at a temperature of 130-180° C., and pressing the first composite tape through a roller press located in the heating box to form a second composite tape, wherein the roller press applies a pressure of 2-10 kgf to the first composite tape during the pressing process, and heats the strip-shaped member to 150-200° C.;

[0040] S23, the second composite tape enters a cooling box with a temperature lower than 30°C arranged at the downstream side of the heating box and stays there for 60 seconds to 300 seconds, and the temperature of the second composite tape is cooled to a range of 30-50°C, so as to adhere the strip-shaped component to one side surface of the PE tape.

[0041] A shielded cable and a preparation method thereof according to the present disclosure have the following beneficial effects:

[0042] Metal alloys have a good shielding effect on high-frequency electromagnetic waves, and nano-shielding coatings have a good shielding effect on low-frequency electromagnetic waves. Therefore, the same composite shielding tape has a metal alloy layer and a nano-shielding layer on both sides, which can shield both low-frequency electromagnetic waves and high-frequency electromagnetic waves at the same time, thereby improving the shielding effect of the composite shielding tape and realizing multi-band electromagnetic shielding during the use of the car.

[0043] Metal alloys have good corrosion resistance, which can extend the service life of shielding composite tapes. Nano shielding coatings use a water-soluble formula, which is more environmentally friendly and can effectively reduce volatile organic compounds.

[0044] Through the shielded cable with the composite shielding tape disclosed in the present invention, the composite shielding tape can simultaneously shield low-frequency electromagnetic waves and high-frequency electromagnetic waves, thereby improving the shielding effect of the composite shielding tape and realizing multi-band electromagnetic shielding during the use of the automobile.

[0045] Further features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the present invention with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0047] Figure 1 A structure of a shielded cable provided in a preferred embodiment of the present invention;

[0048] Figure 2 is a cross-sectional view of a composite shielding tape;

[0049] Figure 3 A flowchart of a method for preparing a shielded cable provided in a preferred embodiment of the present invention;

[0050] Figure 4 A flow chart of providing a nano-shielding coating on a composite shielding tape according to the present invention;

[0051] Figure 5 This is a flow chart of preparing the nano shielding coating in the present invention;

[0052] Figure 6is a flow chart of the method for laminating the PE tape and the strip-shaped component in the present invention;

[0053] Figure 7 The figure is a production flow chart of laminating the PE tape and the belt-shaped component in the present invention.

[0054] The following are marked in the figure:

[0055] 10-conductor core; 11-insulating layer; 12-composite shielding tape; 13-wrapping tape; 14-sheath layer; 15-PE tape; 16-metal alloy layer; 17-nano shielding coating; 18-preheating roller; 19-roller laminating machine; 20-heating box; 21-roller pressing machine; 22-pressing roller; 23-heating roller; 24-cooling box; 25-straightening roller; 26-winding equipment. DETAILED DESCRIPTION

[0056] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention unless otherwise specifically stated.

[0057] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0058] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.

[0059] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0060] According to a shielded cable disclosed in the present invention, Figures 1 to 7 As shown, it includes a conductor core 10, an insulating layer 11 and a composite shielding tape 12 which are sequentially sleeved from the inside to the outside, the composite shielding tape 12 is wrapped around the outer periphery of the insulating layer 11, the composite shielding tape 12 includes a metal alloy layer 16, a PE tape 15 and a nano-shielding coating 17, the metal alloy layer 16 and the nano-shielding coating 17 are respectively arranged on both side surfaces of the PE tape 15, and the metal alloy layer 16 is attached to the insulating layer 11;

[0061] The nano shielding coating 17 comprises the following raw materials in the following weight proportions:

[0062] 5-20 parts of kaolin; 1-5 parts of titanium dioxide; 1-10 parts of carbon black; 0.05-2 parts of nano Cu powder; 0.01-1 parts of talc; 0.01-0.5 parts of hydroxyethyl cellulose; 0.01-0.5 parts of sodium hexametaphosphate; 0.05-1 parts of sodium polyacrylate;

[0063] 20-50 parts of water-based acrylic emulsion;

[0064] Stabilizer 0.1-2 parts;

[0065] Anti-settling agent 0.1-4 parts; Ethylene glycol 0.5-4 parts; Tributyl phosphate 0.1-5 parts;

[0066] Defoaming agent 0.1-4 parts.

[0067] The metal alloy has a good shielding effect on high-frequency electromagnetic waves, and the nano-shielding coating 17 has a good shielding effect on low-frequency electromagnetic waves. Therefore, the metal alloy layer 16 and the nano-shielding layer are respectively provided on both sides of the same composite shielding tape 12, which can simultaneously shield low-frequency electromagnetic waves and high-frequency electromagnetic waves, thereby improving the shielding effect of the composite shielding tape 12 and realizing multi-band electromagnetic shielding during the use of the automobile.

[0068] The metal alloy has good corrosion resistance and can extend the service life of the shielding composite tape. The nano shielding coating 17 uses a water-soluble formula, which is more environmentally friendly and can effectively reduce volatile organic compounds.

[0069] In specific implementation, the frequency of the low-frequency electromagnetic wave is usually 9kHz-30MHz, and the frequency of the high-frequency electromagnetic wave is usually 30MHz-1000MHz; the PE tape 15 can be a PE plastic film.

[0070] According to an embodiment of a shielded cable disclosed herein, the shielded cable further includes a wrapping layer arranged on the periphery of the composite shielding tape 12 and a sheath layer 14 sleeved over the wrapping layer, and the wrapping direction of the wrapping layer is opposite to that of the composite shielding tape 12 .

[0071] The wrapping direction of the wrapping layer is opposite to the wrapping direction of the composite shielding tape 12 , which can make the structure of the shielded cable more stable, prevent wrinkles from appearing at the bends of the cable, and enhance the flexibility of the cable.

[0072] The wrapping layer can be a mica tape or a non-woven fabric layer, both of which can play a flame retardant role; at the same time, since the nano-shielding coating 17 of the shielding composite tape is located on the outside, it also plays a role in protecting the nano-shielding coating 17 during the process of the sheath layer 14, preventing the nano-shielding coating 17 from being scratched and broken, affecting the shielding effect of the composite shielding tape 12.

[0073] Specifically, the wrapping overlap rate of the composite shielding tape 12 is 15%-30%; the wrapping overlap rate of the wrapping tape 13 is 4%-10%.

[0074] The wrapping overlap rate of the composite shielding tape 12 of 15%-30% can ensure that when the cable is bent, the outer periphery of the cable is covered by the composite shielding tape 12. While meeting the flexibility requirements of the cable, it has a protective effect on the metal alloy layer 16 and the nano-shielding layer of the composite shielding tape 12 to prevent the metal alloy layer 16 and the nano-shielding layer from breaking when bent.

[0075] The wrapping overlap rate of the wrapping tape 13 of 4%-10% can also ensure that the wrapping tape 13 covers the entire surface of the nano-shielding layer when the cable is bent, preventing the nano-shielding layer from contacting the sheath layer 14 during use of the cable and damaging the nano-shielding layer of the composite shielding tape 12.

[0076] The method for preparing a shielded cable according to the present disclosure comprises the following steps:

[0077] S1, the metal alloy layer 16 is constructed into a strip-shaped member, and the strip-shaped member is preheated;

[0078] S2, attaching the preheated strip-shaped component to one side surface of the PE tape 15;

[0079] S3, coating the other side surface of the PE tape 15 with a nano-shielding coating to form the nano-shielding coating 17, thereby obtaining the composite shielding tape 12;

[0080] S4, wrapping the composite shielding tape 12 around the outer periphery of the insulating layer 11 of the shielded cable;

[0081] S5, wrapping the wrapping layer around the outside of the composite shielding tape 12;

[0082] S6, extruding a sheath layer 14 around the cladding layer.

[0083] In a specific implementation, the metal alloy layer 16 is constructed as a strip-shaped component, the thickness of the strip-shaped component can be 0.1mm-0.3mm, and the width can be 20mm-40mm; the thickness of the PE tape 15 can be 0.01mm-0.10mm, and the width of the PE tape 15 matches the width of the strip-shaped component.

[0084] Through the above S1 to S6, a shielded cable with a composite shielding tape 12 can be obtained. The composite shielding tape 12 can shield both low-frequency electromagnetic waves and high-frequency electromagnetic waves, thereby improving the shielding effect of the composite shielding tape 12 and realizing multi-band electromagnetic shielding during the use of the car.

[0085] Specifically, S3 includes:

[0086] S30, preparing a nano shielding coating;

[0087] S31, applying the nano-shielding coating prepared in S30 to the other side surface of the PE tape 15 to obtain a PE tape 15 preform;

[0088] S32, curing the PE tape 15 preform obtained in S31 at a constant temperature, with a curing temperature of 25° C. to 40° C. and a curing time of 12 min to 60 min;

[0089] S31 and S32 are repeated at least twice.

[0090] The nano-shielding coating prepared in S30 is applied to the other side surface of the PE tape 15 in S31 by a brushing method, and then a curing treatment is performed in S32. S31 and S32 are repeated as needed to form a nano-shielding coating 17 of a required texture on the other side of the PE tape 15.

[0091] More specifically, the thickness of the nano-shielding coating 17 is 20-100 μm. Within this range, the nano-shielding coating 17 has a good effect on low-frequency electromagnetic waves and plays an increased role in shielding 9kHz-30MHz low-frequency electromagnetic signals. In all 9kHz-30MHz frequency bands, the nano-shielding coating 17 at this thickness can make the shielding effect more stable. When the thickness of the nano-shielding coating 17 is greater than 100 μm, the adhesion of the nano-shielding coating 17 becomes poor and it is easy to fall off.

[0092] More specifically, in S30, the following steps are included:

[0093] S301, mixing and grinding solid raw materials of kaolin, titanium dioxide, carbon black, nano Cu powder, talcum powder, hydroxyethyl cellulose, sodium hexametaphosphate, and sodium polyacrylate to obtain a mixed powder;

[0094] S302, adding the mixed powder into an aqueous solution of an aqueous acrylic emulsion, and performing a first electromagnetic stirring to obtain a first prefabricated liquid;

[0095] S303, adding a liquid raw material anti-settling agent, ethylene glycol, a stabilizer, and tributyl phosphate to the first prefabricated liquid to obtain a second prefabricated liquid;

[0096] S304, subjecting the second preformed liquid to a second electromagnetic stirring to obtain a third preformed liquid;

[0097] S305, adding a defoaming agent to the third prefabricated liquid, and performing a third electromagnetic stirring to obtain the nano-shielding coating.

[0098] The mixed powder in S301 can be obtained by grinding with a grinder;

[0099] Among them, kaolin can increase the viscosity and rheology of the nano-shielding coating, improve the adhesion and wear resistance of the nano-shielding coating 17, and increase the hardness and durability of the nano-shielding coating 17. Talc has good lubricity, reduces the viscosity of the nano-shielding coating, and enhances the toughness of the nano-shielding coating 17. Titanium dioxide enhances the strength and adhesion of the nano-shielding coating 17 and extends the service life of the nano-shielding coating 17. It also increases the viscosity and rheological properties of the nano-shielding coating, facilitates coating, and helps maintain the stability of the nano-shielding coating 17. Carbon ink and nano Cu powder are the main components of the conductive agent as the nano-shielding coating 17 to play an electromagnetic shielding role. Hydroxyethyl cellulose and sodium polyacrylate play a thickening role, improving the coating's hanging and stability. Sodium hexametaphosphate can reduce the interaction of particles in the suspension and improve the fluidity of the coating. The main film-forming adhesive of the water-based acrylic emulsion can improve the fluidity and wettability of the coating, so that the coating and the substrate molecules are in close contact to achieve high adhesion.

[0100] In S302, 20-50 parts of aqueous acrylic emulsion are dissolved in 30-70 parts of water to form an aqueous solution of aqueous acrylic emulsion, the mixed powder of S301 is added to the aqueous solution of aqueous acrylic emulsion and electromagnetic stirring is performed for the first time to form a first prefabricated liquid; the liquid raw material in S303 is added to obtain a second prefabricated liquid, and the second prefabricated liquid is electromagnetically stirred for a second time in S304 to obtain a third prefabricated liquid; finally, the defoaming agent in S305 is added, the stirring speed is lowered and electromagnetic stirring is performed for a third time to obtain the nano-shielding coating.

[0101] In S303, ethylene glycol is used as a film-forming aid. As the amount of ethylene glycol added increases, the curing time of the coating also decreases. Tributyl phosphate is not easy to generate bubbles when the coating is applied, and it is not easy to generate pinholes after drying, ensuring the continuity of the coating. The anti-settling agent and stabilizer can make the nano-shielding coating form a suspended slurry, and the defoaming agent prevents the generation of bubbles in the process of preparing the suspended slurry.

[0102] More specifically, the stirring speed of the first electromagnetic stirring is 1100-1500 r / min, and the stirring time is 15-40 min;

[0103] The stirring speed of the second electromagnetic stirring is 800-1200 r / min, and the stirring time is 10-20 min;

[0104] The third electromagnetic stirring includes low-speed stirring and high-speed stirring in sequence, wherein the stirring speed of the low-speed stirring is 500-1000 r / min and the stirring time is 5-10 min; the stirring speed of the high-speed stirring is 1100-1500 r / min and the stirring time is 10-20 min.

[0105] The mixed powder can be evenly dispersed through three electromagnetic stirrings to form a nano-shielding coating, so that the nano-shielding layer forms a uniform and stable suspension.

[0106] More specifically, the anti-settling agent is at least one of BYK-420 and PAMID-D772; the stabilizer is AMP-95; and the defoamer is Hyperlev F40.

[0107] BYK-420 is produced by BYK Chemical Co., Ltd., PAMID-D772 is produced by Guangdong Core Materials Co., Ltd.; AMP-95 is produced by Angers Chemical Company; Hyperlev F40 is produced by Guangdong Core Materials Co., Ltd.; In actual applications, the two anti-settling agents are selected at the same time, BYK-420 makes the fine particles in the mixed powder suspended in the aqueous solution of the water-based acrylic emulsion, and PAMID-D772 prevents the nano-shielding coating from hanging on the container wall.

[0108] Specifically, the material of the metal alloy layer 16 is magnesium foil alloy, aluminum foil alloy or copper foil alloy. The advantages of magnesium foil alloy are light weight and stable electromagnetic signal shielding performance; aluminum foil alloy has good electrical conductivity, ductility, and light weight; copper foil alloy has good electrical conductivity, thermal conductivity, ductility and corrosion resistance. Through the characteristics of the material of the above-mentioned metal alloy layer 16, a shielding composite tape with good flexibility can be produced, and the shielding composite tape is guaranteed to have a good electromagnetic signal shielding effect.

[0109] Specifically, S2 includes:

[0110] S21, laminating the strip-shaped component preheated to a temperature of 130-180° C. with the PE tape 15 to form a first composite tape;

[0111] S22, passing the first composite tape through a heating box 20 at a temperature of 130-180° C., and pressing the first composite tape through a roller pressing machine 21 located in the heating box 20 to form a second composite tape, wherein the roller pressing machine 21 applies a pressure of 2-10 kgf to the first composite tape during the pressing process, and heats the strip-shaped component to 150-200° C.;

[0112] S23, the second composite tape enters the cooling box 24 with a temperature lower than 30°C arranged at the downstream side of the heating box 20 and stays there for 60 seconds to 300 seconds, and the temperature of the second composite tape is cooled to the range of 30-50°C, so as to adhere the strip-shaped component to one side surface of the PE tape 15.

[0113] In S21, the strip component is preheated by at least one preheating roller 18. The temperature of the preheating roller 18 can make the metal alloy layer 16 reach 130°C-180°C. The preheated strip component and the unheated PE tape 15 are pressed together by a roller laminating machine 19 to achieve lamination of the strip component and the PE tape 15. The roller laminating machine 19 includes a pair of laminating rollers located on both sides of the first composite tape. In S21, the preheating can better laminate the strip component on the PE tape 15 to form a first composite tape. In the process of laminating the PE tape 15 on the strip component, the focus is on ensuring the alignment between the strip component and the PE tape 15. In S22, the first composite tape is passed through the roller pressing machine 21 in the heating box 20, so that the PE tape 15 is firmly attached to the strip-shaped component. In this process, attention should be paid to controlling the temperature. If the temperature is too low, the adhesion between the metal alloy layer 16 and the PE tape 15 will be affected. If the temperature is too high, the PE tape 15 will easily soften and melt. The upper roller in the roller pressing machine 21 is the pressing roller 22, which is attached to the PE tape 15 and applies a pressure of 2-10kgf toward the side of the strip-shaped component to the PE tape 15, so that the PE tape 15 and the strip-shaped component of the metal alloy layer 16 are more firmly combined. The lower roller is the heating roller 23, which is attached to the strip-shaped component to heat the metal alloy layer 16 and play a supporting role, so as to ensure that the metal alloy layer 16 reaches the hot pressing temperature (150-200°C) while not overheating the PE tape 15. The temperature of the heating box 20 in S22 is the same as the preheating temperature and lower than the heating roller 23. When the heating roller 23 heats the metal alloy layer 16, it can ensure that the metal alloy layer 16 reaches the hot pressing temperature while the PE tape 15 will not form wrinkles or deformation due to the large difference between the ambient temperature of the PE tape and the hot pressing temperature provided by the heating roller 23 to the strip component; in S23, the temperature of the second composite tape is controlled at about 40°C by the cooling box 24 to avoid the PE tape 15 from sticking after being rewound by the winding device 26; at the same time, at least one pair of straightening rollers 25 opposed to each other are arranged in the cooling box 24 to straighten the second composite tape.

[0114] Although some specific embodiments of the present invention have been described in detail by way of example, it will be appreciated by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It will be appreciated by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A shielded cable, characterized in that: It comprises a conductor core, an insulating layer and a composite shielding tape which are sequentially sleeved from the inside to the outside, the composite shielding tape is wrapped around the outer periphery of the insulating layer, the composite shielding tape comprises a metal alloy layer, a PE tape and a nano-shielding coating, the metal alloy layer and the nano-shielding coating are respectively arranged on both side surfaces of the PE tape, and the metal alloy layer is attached to the insulating layer; The nano shielding coating comprises the following raw materials in the following weight proportions: 5-20 parts of kaolin; 1-5 parts of titanium dioxide; 1-10 parts of carbon black; 0.05-2 parts of nano Cu powder; 0.01-1 parts of talc; 0.01-0.5 parts of hydroxyethyl cellulose; 0.01-0.5 parts of sodium hexametaphosphate; 0.05-1 parts of sodium polyacrylate; 20-50 parts of water-based acrylic emulsion; Stabilizer 0.1-2 parts; Anti-settling agent 0.1-4 parts; Ethylene glycol 0.5-4 parts; Tributyl phosphate 0.1-5 parts; Defoaming agent 0.1-4 parts.

2. The shielded cable according to claim 1, characterized in that: The shielded cable further comprises a wrapping layer arranged on the outer periphery of the composite shielding tape and a sheath layer sleeved on the wrapping layer, and the wrapping direction of the wrapping layer is opposite to the wrapping direction of the composite shielding tape.

3. The shielded cable according to claim 2, characterized in that: The wrapping overlap rate of the composite shielding tape is 15%-30%; the wrapping overlap rate of the wrapping tape is 4%-10%.

4. The method for preparing a shielded cable according to any one of claims 1 to 3, characterized in that: The following steps are involved: S1, the metal alloy layer is structured into a strip-shaped member, and the strip-shaped member is preheated; S2, attaching the preheated strip-shaped component to one side surface of the PE tape; S3, coating the other side surface of the PE tape with a nano-shielding coating to form the nano-shielding coating, thereby obtaining the composite shielding tape; S4, wrapping the composite shielding tape around the outer periphery of the insulation layer of the shielded cable; S5, wrapping the wrapping layer around the outside of the composite shielding tape; S6, extruding a sheath layer on the outer periphery of the wrapping layer.

5. The method for preparing a shielded cable according to claim 4, characterized in that: In said S3, it includes: S30, preparing a nano shielding coating; S31, applying the nano-shielding coating prepared in S30 to the other side surface of the PE tape to obtain a PE tape preform; S32, curing the PE tape preform obtained in S31 at a constant temperature, with a curing temperature of 25° C. to 40° C. and a curing time of 12 min to 60 min; S31 and S32 are repeated at least twice.

6. The method for preparing a shielded cable according to claim 5, characterized in that: The thickness of the nano shielding coating is 20-100 μm.

7. The method for preparing a shielded cable according to claim 5, characterized in that: In S30, it includes: S301, mixing and grinding solid raw materials of kaolin, titanium dioxide, carbon black, nano Cu powder, talcum powder, hydroxyethyl cellulose, sodium hexametaphosphate, and sodium polyacrylate to obtain a mixed powder; S302, adding the mixed powder into an aqueous solution of an aqueous acrylic emulsion, and performing a first electromagnetic stirring to obtain a first prefabricated liquid; S303, adding a liquid raw material anti-settling agent, ethylene glycol, a stabilizer, and tributyl phosphate to the first prefabricated liquid to obtain a second prefabricated liquid; S304, subjecting the second preformed liquid to a second electromagnetic stirring to obtain a third preformed liquid; S305, adding a defoaming agent to the third prefabricated liquid, and performing a third electromagnetic stirring to obtain the nano-shielding coating.

8. The method for preparing a shielded cable according to claim 7, characterized in that: The stirring speed of the first electromagnetic stirring is 1100-1500 r / min, and the stirring time is 15-40 min; The stirring speed of the second electromagnetic stirring is 800-1200 r / min, and the stirring time is 10-20 min; The third electromagnetic stirring includes low-speed stirring and high-speed stirring in sequence, wherein the stirring speed of the low-speed stirring is 500-1000 r / min and the stirring time is 5-10 min; the stirring speed of the high-speed stirring is 1100-1500 r / min and the stirring time is 10-20 min.

9. The method for preparing a shielded cable according to claim 8, characterized in that: The anti-settling agent is selected from at least one of BYK-420 and PAMID-D772; the stabilizer is selected from AMP-95; and the defoamer is selected from Hyperlev F40.

10. The method for preparing a shielded cable according to claim 4, characterized in that: The material of the metal alloy layer is magnesium foil alloy, aluminum foil alloy or copper foil alloy.

11. The method for preparing a shielded cable according to claim 4, characterized in that: Included in S2: S21, laminating the strip-shaped component preheated to a temperature of 130-180° C. with the PE tape to form a first composite tape; S22, passing the first composite tape through a heating box at a temperature of 130-180° C., and pressing the first composite tape through a roller press located in the heating box to form a second composite tape, wherein the roller press applies a pressure of 2-10 kgf to the first composite tape during the pressing process, and heats the strip-shaped member to 150-200° C.; S23, the second composite tape enters a cooling box with a temperature lower than 30°C arranged at the downstream side of the heating box and stays there for 60 seconds to 300 seconds, and the temperature of the second composite tape is cooled to a range of 30-50°C, so as to adhere the strip-shaped component to one side surface of the PE tape.

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