Composite cable with double-layer insulation flame-retardant structure and preparation method thereof

Abstract

The invention discloses a composite cable with a double-layer insulation flame-retardant structure and a preparation method thereof, and relates to the technical field of power cable production, the composite cable comprises at least two mutually twisted cable cores, each cable core comprises a conductor and an insulation layer wrapping the surface of the cable core, the insulation layer comprises a first insulation layer and a second insulation layer from inside to outside, and the first insulation layer and the second insulation layer are arranged on the conductor. A heat absorption layer is arranged between the first insulating layer and the second insulating layer, a plurality of inert gas isolation units are arranged in the second insulating layer, the heat absorption layer comprises a perfluoroethanone solution, the heat absorption layer is arranged between the first insulating layer and the second insulating layer, and when the heat absorption layer is burnt, the perfluoroethanone solution can rapidly absorb heat and take away nearby heat, so that the heat absorption efficiency is improved. Meanwhile, an isolating layer is formed on the surface of the second insulating layer to reduce dilution oxygen and carry out flame retardance; and meanwhile, gel is mixed into the perfluoroethanone solution, so that the perfluoroethanone solution cannot flow randomly in an environment of 100-110 DEG C, has adsorbability and is reliably adsorbed on the surface of the first insulating layer, and the effectiveness of preparation is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of power cable production, and in particular to a composite cable with a double-layer insulation and flame-retardant structure and a preparation method thereof. Background Art

[0002] Composite cable refers to a cable composed of two or more different functional materials or structures, which realizes multifunctional, high-performance or special-purpose power or signal transmission by integrating multiple conductors, insulation layers, shielding layers or sheaths.

[0003] For composite cables, the flame retardant effect is of paramount importance. They can work in harsh working environments and achieve flame retardancy to a certain extent. Therefore, improving the flame retardant effect of composite cables is an important direction of current composite cable research. Summary of the Invention

[0004] In order to overcome the above-mentioned deficiencies, the present invention provides a composite cable with a double-layer insulation flame-retardant structure and a preparation method thereof.

[0005] The present invention achieves the above-mentioned purpose through the following technical solutions: A composite cable with a double-layer insulation and flame-retardant structure includes at least two twisted cable cores, the cable core including a conductor and an insulation layer wrapped around the surface of the cable core, the insulation layer including a first insulation layer and a second insulation layer from the inside to the outside, a heat-absorbing layer is provided between the first insulation layer and the second insulation layer, a plurality of inert gas isolation units are provided in the second insulation layer, and the heat-absorbing layer includes a perfluoroacetone solution.

[0006] Preferably, the heat absorption layer is evenly distributed in an S-shaped circumferential direction between the first insulating layer and the second insulating layer, so that the heat absorption layer can be evenly distributed between the first insulating layer and the second insulating layer, so that when the heat absorption layer reacts, the cable core can be fully protected.

[0007] Preferably, gel is mixed into the perfluoroacetone solution for temporary shaping when the perfluoroacetone solution is coated on the surface of the first insulating layer.

[0008] Preferably, the first insulating layer is made of cross-linked polyethylene, and the second insulating layer is made of low-smoke halogen-free flame-retardant polyolefin.

[0009] Preferably, the outer periphery of the twisted cable cores is provided with an inner lining layer, a metal layer and a protective outer layer in sequence from the inside to the outside.

[0010] Preferably, a filling layer is provided between the cable core and the inner lining layer, and the filling layer is provided with a flame retardant filler.

[0011] A method for preparing the composite cable with a double-layer insulation flame-retardant structure as described above, the method comprising the following specific steps: Step S1: In the first chamber of the extruder, a first insulating layer is formed on the outer surface of the conductor, and then the conductor enters the second chamber of the extruder; Step S2: In the second chamber of the extruder, a heat-absorbing layer is uniformly coated on the surface of the first insulating layer in a circumferential direction. The coating nozzle rotates uniformly in a circumferential direction. The width of the heat-absorbing layer is 1 to 2 cm, and the height of the heat-absorbing layer is 3 mm. The heat-absorbing layer then enters the third chamber of the extruder. Step S3: forming a second insulating layer on the outer surface of the first insulating layer in the third chamber of the extruder, and injecting an inert gas into the second insulating layer through a needle; Step S4, twisting at least two cable cores together to form a composite cable; Step S5, extruding an inner lining layer on the outer surface of the composite cable; Step S6: coating the outer surface of the inner lining layer with a metal strip to form a metal layer; Step S7: Extruding a protective outer layer on the outer surface of the metal layer.

[0012] Preferably, the temperature of the first chamber is 90-125°C, the temperature of the second chamber is 100-110°C, and the temperature of the third chamber is 160-190°C.

[0013] Preferably, in step S3, the temperature of the second chamber is raised to the temperature of the third chamber within 1 to 2 seconds, so as to perform shaping before the perfluoroacetone solution of the heat absorption layer melts.

[0014] Preferably, the thickness of the second insulating layer is 3 mm, and the inert gas is evenly distributed in several rows in the second insulating layer, wherein the depth of one row is 1.5 mm and the depth of an adjacent row is 2.5 mm.

[0015] The beneficial effects of the present invention are as follows: in the composite cable with a double-layer insulation flame-retardant structure and the preparation method thereof: 1. A heat-absorbing layer is provided between the first insulating layer and the second insulating layer. When the heat-absorbing layer burns, the perfluoroacetone solution will quickly absorb heat and draw away nearby heat, while forming an isolation layer on the surface of the second insulating layer to reduce oxygen dilution and provide flame retardancy. At the same time, gel is mixed into the perfluoroacetone solution, which can prevent the perfluoroacetone solution from flowing freely in an environment of 100-110°C. At the same time, it also has adsorption properties and can be reliably adsorbed on the surface of the first insulating layer, thus achieving the effectiveness of the preparation. 2. The heat-absorbing layer is evenly distributed in an S-shaped circumferential direction between the first insulating layer and the second insulating layer, so that the heat-absorbing layer can be evenly distributed between the first insulating layer and the second insulating layer, so that when the heat-absorbing layer reacts, the cable core can be fully protected. At the same time, with the inert gas isolation units evenly distributed at equal intervals, it can ensure that the composite cable can achieve the effect of flame retardancy in the entire range. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 It is a structural schematic diagram of the present invention; Figure 2 It is a diagram of the method steps of the present invention. DETAILED DESCRIPTION

[0017] The present invention will now be described in further detail with reference to the accompanying drawings, which are simplified schematic diagrams that illustrate the basic structure of the present invention in a schematic manner.

[0018] like Figure 1 and Figure 2 As shown, a composite cable with a double-layer insulation and flame-retardant structure includes at least two twisted cable cores. The cable core includes a conductor 1 and an insulation layer wrapped around the surface of the cable core. The insulation layer includes a first insulation layer 2 and a second insulation layer 4 from the inside out. A heat-absorbing layer 3 is provided between the first insulation layer 2 and the second insulation layer 4. The second insulation layer 4 is provided with a plurality of inert gas isolation units. The heat-absorbing layer 3 includes a perfluoroacetone solution. When a fire occurs, the inert gas in the second insulation layer 4 is emitted as it burns, forming an isolation layer on the surface of the second insulation layer 4 to reduce oxygen dilution. When the fire reaches the first insulation layer 2, the heat-absorbing layer 3 simultaneously burns. At this time, the perfluoroacetone solution will quickly absorb heat and form an isolation layer on the surface of the second insulation layer 4 to further reduce oxygen dilution and provide flame retardancy.

[0019] Specifically, the heat absorption layer 3 is evenly distributed in an S-shaped circumferential direction between the first insulating layer 2 and the second insulating layer 4, so that the heat absorption layer 3 can be evenly distributed between the first insulating layer 2 and the second insulating layer 4, so that when the heat absorption layer 3 reacts, the cable core can be fully protected.

[0020] Specifically, gel is mixed into the perfluoroacetone solution for temporary shaping when the perfluoroacetone solution is coated on the surface of the first insulating layer 2. The ratio of gel to perfluoroacetone is 1:10, which can prevent the perfluoroacetone solution from flowing freely in an environment of 100-110°C. At the same time, it also has adsorption properties and can be reliably adsorbed on the surface of the first insulating layer 2.

[0021] Specifically, the first insulating layer 2 is made of cross-linked polyethylene, and the second insulating layer 4 is made of low-smoke halogen-free flame-retardant polyolefin.

[0022] Specifically, the outer periphery of the twisted cable core is provided with an inner lining layer 5, a metal layer 6, and a protective outer layer 7, from the inside out. The inner lining layer 5 is made of a ceramic polyolefin material. Because ceramic polyolefin material can form a ceramic-like hard shell under flame combustion or high temperature, the protective outer layer 7 is made of a low-smoke, halogen-free, flame-retardant polyolefin material.

[0023] Specifically, a filling layer is provided between the cable core and the inner lining layer 5 , and the filling layer is provided with a flame retardant filler.

[0024] A method for preparing a composite cable with a double-layer insulation flame-retardant structure, the method comprising the following specific steps: Step S1: In the first chamber of the extruder, a first insulating layer 2 is formed on the outer surface of the conductor 1, and then the conductor enters the second chamber of the extruder; Step S2: In the second chamber of the extruder, a heat-absorbing layer 3 is uniformly coated on the surface of the first insulating layer 2 in a circumferential direction. The coating nozzle rotates uniformly in a circumferential direction. The width of the heat-absorbing layer 3 is 1 to 2 cm, and the height of the heat-absorbing layer 3 is 3 mm. The heat-absorbing layer 3 then enters the third chamber of the extruder. Step S3: forming a second insulating layer 4 on the outer surface of the first insulating layer 2 in the third chamber of the extruder, and injecting an inert gas into the second insulating layer 4 through a needle; Step S4, twisting at least two cable cores together to form a composite cable; Step S5, extruding an inner lining layer 5 on the outer surface of the composite cable; Step S6: coating the outer surface of the lining layer 5 with a metal strip to form a metal layer 6; Step S7: Extruding a protective outer layer 7 on the outer surface of the metal layer 6 .

[0025] Specifically, the temperature of the first chamber is 90-125°C, the temperature of the second chamber is 100-110°C, and the temperature of the third chamber is 160-190°C.

[0026] Specifically, in step S3, the temperature of the second chamber is raised to the temperature of the third chamber within 1 to 2 seconds, so as to set the heat absorption layer 3 before the perfluoroacetone solution melts.

[0027] Specifically, the thickness of the second insulating layer 4 is 3 mm, and the inert gas is evenly distributed in several rows in the second insulating layer 4, where the depth of one row is 1.5 mm and the depth of the adjacent row is 2.5 mm. When the second insulating layer 4 is burning, the inert gas can be evenly distributed in sequence.

[0028] The above description is for inspiration. Based on the above description, relevant personnel can make various changes and modifications without departing from the technical concept of this invention. The technical scope of this invention is not limited to the content of the specification, but must be determined according to the scope of the claims.

Claims

1. A composite cable with a double-layer insulation and flame-retardant structure, characterized in that: The invention comprises at least two cable cores twisted together, wherein the cable core comprises a conductor and an insulating layer wrapped around the surface of the cable core, wherein the insulating layer comprises a first insulating layer and a second insulating layer from the inside out, a heat absorbing layer is provided between the first insulating layer and the second insulating layer, and a plurality of inert gas isolation units are provided in the second insulating layer, and the heat absorbing layer comprises a perfluoroacetone solution.

2. The composite cable with double-layer insulation and flame-retardant structure according to claim 1, characterized in that: The heat absorption layer is S-shaped and evenly distributed circumferentially between the first insulating layer and the second insulating layer.

3. The composite cable with double-layer insulation and flame-retardant structure according to claim 1, characterized in that: The perfluoroacetone solution is mixed with gel.

4. The composite cable with a double-layer insulation and flame-retardant structure according to claim 1, characterized in that: The first insulating layer is made of cross-linked polyethylene, and the second insulating layer is made of low-smoke halogen-free flame-retardant polyolefin.

5. The composite cable with double-layer insulation and flame-retardant structure according to claim 1, characterized in that: The outer periphery of the mutually twisted cable core is provided with an inner lining layer, a metal layer and a protective outer layer in sequence from the inside to the outside.

6. The composite cable with double-layer insulation and flame-retardant structure according to claim 1, characterized in that: A filling layer is provided between the cable core and the inner lining layer, and the filling layer is provided with a flame retardant filler.

7. A method for preparing a composite cable with a double-layer insulation and flame-retardant structure according to any one of claims 1 to 6, characterized in that: The preparation method comprises the following specific steps: Step S1: In the first chamber of the extruder, a first insulating layer is formed on the outer surface of the conductor, and then the conductor enters the second chamber of the extruder; Step S2: In the second chamber of the extruder, a heat-absorbing layer is uniformly coated on the surface of the first insulating layer in a circumferential direction. The coating nozzle rotates uniformly in a circumferential direction. The width of the heat-absorbing layer is 1 to 2 cm, and the height of the heat-absorbing layer is 3 mm. The heat-absorbing layer then enters the third chamber of the extruder. Step S3: forming a second insulating layer on the outer surface of the first insulating layer in the third chamber of the extruder, and injecting an inert gas into the second insulating layer through a needle; Step S4, twisting at least two cable cores together to form a composite cable; Step S5, extruding an inner lining layer on the outer surface of the composite cable; Step S6: coating the outer surface of the inner lining layer with a metal strip to form a metal layer; Step S7: Extruding a protective outer layer on the outer surface of the metal layer.

8. The method for preparing a composite cable with a double-layer insulation and flame-retardant structure according to claim 7, characterized in that: The temperature of the first chamber is 90-125°C, the temperature of the second chamber is 100-110°C, and the temperature of the third chamber is 160-190°C.

9. The method for preparing a composite cable with a double-layer insulation and flame-retardant structure according to claim 8, characterized in that: In step S3, the temperature of the second chamber is raised to the temperature of the third chamber within 1 to 2 seconds.

10. The method for preparing a composite cable with a double-layer insulation and flame-retardant structure according to claim 7, characterized in that: The thickness of the second insulating layer is 3 mm. The inert gas is evenly distributed in several rows in the second insulating layer, wherein the depth of one row is 1.5 mm and the depth of an adjacent row is 2.5 mm.

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