Manufacturing method of waterproof photovoltaic cable capable of preventing rodent from biting

Abstract

The invention relates to the technical field of cables, in particular to a manufacturing method of a waterproof photovoltaic cable capable of preventing rodents from biting, which comprises the following steps of: conductor twisting: twisting a plurality of tinned copper wires on the outer side of a copper wire core body to form a conductor; extrusion of an insulating layer: performing double-layer extrusion on irradiation cross-linked polyethylene and irradiation cross-linked polyolefin on the surface of the conductor to form the insulating layer; preparing a reinforcing layer: bonding a carbon fiber layer between the two nylon layers to form the reinforcing layer with a sandwich structure, and coating the insulating layer with the reinforcing layer; preparing a metal protection layer: forming the metal protection layer with a chain type structure outside the insulating layer by adopting a four-claw copper sheet; and preparing a sheath: extruding a cross-linking material formed by processing polyolefin by adopting a high-electrical electron beam on the outer layer of the metal protection layer to form a sheath layer. The cable provided by the invention has ultraviolet resistance, waterproofness, bendability and rodent biting resistance, and can bear temperature change in a larger range, and the service life of the cable can be prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of cables, and in particular to a method for manufacturing a waterproof photovoltaic cable that is resistant to rodent gnawing. Background Art

[0002] For photovoltaic power stations built in deserts, Gobi deserts, wastelands, oceans, farms and other places, their photovoltaic cables need to operate under harsh environmental conditions such as high temperature, low temperature, high humidity, ultraviolet radiation and rodents.

[0003] Chinese patent publication number CN114242307A discloses a waterproof, fireproof, rat-proof and ant-proof composite cable, including a core body located at the center of the cable, the outer side of the core body is attached with an anti-slip plate; it also includes: a fireproof ribbon, which is attached and wrapped on the outer side of the anti-slip plate; a polyethylene inner sheath layer, which is wrapped on the outer side of the flame-retardant and water-blocking tape, and the outer side of the polyethylene inner sheath layer is wrapped with a galvanized steel belt armor. The waterproof, fireproof, rat-proof and ant-proof composite cable includes a power core and a control core, a tinned copper conductor, a halogen-free, low-smoke, flame-retardant ceramic polyolefin insulation material is extruded on the conductor, the cable is wrapped with a fireproof glass ribbon, a flame-retardant water-blocking tape, an extruded polyethylene inner sheath, a steel belt armor, a ceramic silicone rubber tape, an extruded halogen-free, low-smoke, flame-retardant polyolefin sheath, and an extruded nylon protective reinforcement layer, so that the finished cable has the characteristics of environmental protection, waterproof, fireproof, and rat-proof, and can be widely used in line systems in special environments such as humid and closed environments.

[0004] The reinforcement layer of this patent is only made of a layer of nylon extrusion, which has slightly weak anti-bite ability. A whole piece of galvanized steel belt is used as the metal protective layer, which has poor bending performance. Summary of the invention

[0005] The present invention solves the problems of poor anti-gnawing and bending performance in the related art, and proposes a manufacturing method for a rodent-resistant and waterproof photovoltaic cable. The reinforcement layer is a structure of two nylon layers superimposed on a carbon fiber layer, which improves the strength of the cable and makes it more resistant to rodent gnawing; the metal protective layer is a chain structure formed by multiple four-claw copper sheets, so that the two four-claw copper sheets hooked together can move relative to each other within a certain range, but will not separate from each other under the action of the hooked claws, thereby improving the bending ability of the cable.

[0006] In order to solve the above technical problems, the present invention is achieved through the following technical solutions: a method for manufacturing a rodent-proof and waterproof photovoltaic cable, the steps are as follows: S1, conductor twisting: twisting a number of tinned copper wires on the outside of the copper wire core to form a conductor; S2, insulation layer extrusion: double-layer extrusion of irradiated cross-linked polyethylene and irradiated cross-linked polyolefin on the surface of the conductor to form an insulation layer; S3, preparation of a reinforcement layer: bonding a carbon fiber layer between two nylon layers to form a sandwich-structured reinforcement layer, and covering the outside of the insulation layer; S4, preparation of a metal protective layer: a four-claw copper sheet is used to form a chain-structured metal protective layer outside the insulation layer; S5, preparation of a sheath: a cross-linked material made of polyolefin processed by a high-electricity electron beam is extruded on the outer layer of the metal protective layer to form a sheath layer.

[0007] As a preferred embodiment, in step S1, the copper wire core and one end of the tinned copper wire are passed through a twisting disk, the other end of the tinned copper wire is fixed by a fixing member, and the tinned copper wire is twisted in the same direction on the outside of the copper wire core by a twisting device to form a conductor.

[0008] As a preferred embodiment, in step S2, the polyethylene cross-linked material and the polyolefin cross-linked material are cross-linked by radiation through a double-layer extruder at 180-220°C to obtain an insulating layer, wherein the radiation dose is 100-200 kgy, the radiation temperature is maintained between 20-40°C, and the radiation time is 3-5 min.

[0009] As a preferred solution, the radial cross section of the carbon fiber layer is wavy or continuous V-shaped.

[0010] As a preferred solution, PA12 particles are melt-extruded at 240-300°C to form two tubular nylon layers of different diameters, glue is coated on the outer surface of the nylon layer with a small diameter and the inner surface of the nylon layer with a large diameter, and the carbon fiber layer is glued between the two nylon layers.

[0011] As a preferred embodiment, the four-claw copper sheet includes a transverse body, a longitudinal body connected to the middle of the transverse body and located above the transverse body, two first hook-shaped claws respectively connected to the two sides of the transverse body and located above the transverse body, and two second hook-shaped claws connected to the transverse body and located below the transverse body, the two first hook-shaped claws are symmetrical along the longitudinal center line of the longitudinal body and the hooks are both facing inward, the two second hook-shaped claws are symmetrical along the longitudinal center line of the longitudinal body and the hooks are facing outward, and there is a gap between the two second hook-shaped claws that is not less than the width of the longitudinal body.

[0012] As a preferred solution, the hook portion of the first hook-shaped claw of a four-claw copper sheet is hooked with the hook portion of the second hook-shaped claw of another four-claw copper sheet, and the longitudinal body of the other four-claw copper sheet is inserted into the gap of a four-claw copper sheet to form the chain structure.

[0013] As a preferred solution, in step S5, the high-conductivity electron beam irradiation dose is 100-200 kgy, the irradiation temperature is maintained between 20-40°C, the irradiation time is 3-5 min, and the extrusion temperature is 180-220°C.

[0014] Compared with the prior art, the present invention has the following beneficial effects: The conductor of the present invention is formed by twisting a plurality of tinned copper wires outside a copper wire core body, and not only has good conductivity, but also has better strength than that of a single twisted tinned copper wire; The reinforcement layer is a structure of two nylon layers superimposed on a carbon fiber layer, which improves the strength of the cable and is more resistant to rodents. In addition, the carbon fiber layer is wavy or continuous V-shaped, which can resist local depression of the cable caused by rodents. The metal protective layer of the present invention is a chain structure formed by multiple four-claw copper sheets, so that two four-claw copper sheets hooked together can move relatively within a certain range, but will not separate from each other under the action of the hook-shaped claws, thereby improving the bending ability of the cable; The insulation layer and sheath are extruded from radiation-crosslinked polyolefin, which has good UV resistance and corrosion resistance. The cable of the present invention is UV-resistant, waterproof and rodent-resistant, and can withstand a wider range of temperature changes. It also has the characteristics of withstanding pressure, bending, tension, cross-tensile loads and strong impacts, thereby extending the service life of the cable. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic diagram of the overall structure of Embodiment 1 of the present invention; Figure 2 It is a schematic diagram of the overall structure of Embodiment 2 of the present invention; Figure 3 It is a schematic diagram of the structure of a single four-claw copper sheet of the present invention; Figure 4 It is a schematic diagram of the structure of a metal protective layer formed by a plurality of four-claw copper sheets of the present invention.

[0016] In the figure: Conductor, 2, insulation layer, 3, reinforcement layer, 31, nylon layer, 32, carbon fiber layer, 4, metal protective layer, 41, transverse body, 42, first hook-shaped claw, 43, second hook-shaped claw, 44, gap, 45, longitudinal body, 5, sheath layer. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0019] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, numerical expressions and numerical values ​​do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be regarded as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0020] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the devices or elements referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention. The directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0021] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0022] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0023] Example 1

[0024] like Figure 1 and 4 As shown, a method for manufacturing a waterproof photovoltaic cable that is resistant to rodent gnawing is provided, and the steps are as follows: S1. Twisting of conductor 1: Pass the copper wire core 11 and one end of the tinned copper wire 12 through a twisting disk, and fix the other end of the tinned copper wire 12 by a fixing device, such as a clamp, and twist the tinned copper wire 12 in the same direction on the outside of the copper wire core 11 by a twisting device to form a conductor 1.

[0025] S2. Extrusion of insulating layer 2: Extruding the polyethylene cross-linked material through radiation cross-linking through a double-layer extruder at 190° C. to obtain insulating layer 2, wherein the radiation dose is 150 kgy, the radiation temperature is maintained at 30° C., the radiation time is 4 min, and electron beam radiation cross-linking or ultraviolet radiation cross-linking is adopted.

[0026] S3. Preparation of reinforcing layer 3: PA12 particles are melt-extruded at 280°C to form two tubular nylon layers 31 of different diameters, glue or adhesive film is applied to the outer surface of the nylon layer 31 with a small diameter and the inner surface of the nylon layer 31 with a large diameter, and a carbon fiber layer 32 is adhered between the two nylon layers 31 to form a reinforcing layer 3 of a sandwich structure, and the reinforcing layer 3 is wrapped around the outside of the insulating layer 2. In this embodiment, the radial cross-section of the carbon fiber layer 32 is a wavy structure; wherein the nylon layer 31 has excellent properties such as oil resistance, corrosion resistance, low heat shrinkage, and toughness, which can not only ensure that the insulating layer 2 is not mechanically damaged by the metal protective layer 4, but also prevent moisture from entering the insulating layer 2.

[0027] S4, prepare metal protective layer 4: use four-claw copper sheet to form metal protective layer 4 of chain structure outside insulating layer 3, wherein the four-claw copper sheet includes a horizontal body 41, a vertical body 45 connected to the middle of horizontal body 41 and located on horizontal body 41, two first hook-shaped claws 42 connected to both sides of horizontal body 41 and located on horizontal body 41, and two second hook-shaped claws 43 connected to horizontal body 41 and located under horizontal body 41, the two first hook-shaped claws 42 are symmetrical along the longitudinal midline of longitudinal body 45 and the hooks are both inward, and the two second hook-shaped claws 43 are symmetrical along the longitudinal midline of longitudinal body 45. The lines are symmetrical and the hooks are outward, and there is a gap 44 between the two second hook-shaped claws 43, the distance of which is not less than the width of the longitudinal body 45. When in use, the hook of the first hook-shaped claw 42 of a four-claw copper sheet is hooked with the hook of the second hook-shaped claw 43 of another four-claw copper sheet, and the longitudinal body 45 of the other four-claw copper sheet is inserted into the gap 44 of a four-claw copper sheet to form a chain structure. The two four-claw copper sheets can move relative to each other within a certain range, but will not separate from each other under the action of the hook-shaped claws. Compared with a whole copper sheet, the cable has better bending ability.

[0028] S5. Preparation of sheath layer 5: Extruding a cross-linked material made of polyethylene processed by high-conductivity electron beam on the outer layer of the metal protective layer to form sheath layer 5, wherein the high-conductivity electron beam irradiation dose is 120 kgy, the irradiation temperature is maintained at 25°C, the irradiation time is 3.5 min, and the extrusion temperature is 200°C. The sheath layer 5 has flame retardant, UV resistance, corrosion resistance, waterproof and other properties, and can withstand a wider range of temperature changes (from -40°C to 125°C).

[0029] Example 2

[0030] like Figure 2 and 3 As shown, different from the embodiment 1, in this embodiment, the radial cross section of the carbon fiber layer 3 is a continuous V-shape.

[0031] Comparative Example 1 Different from Example 1, in this comparative example, the polyethylene and polyolefin in the insulating layer 2 and the sheath layer 5 are not irradiated.

[0032] Comparative Example 2 Different from Example 1, the reinforcement layer 3 in this comparative example adopts a nylon layer 31 .

[0033] Comparative Example 3 Different from Example 1, the metal protective layer 4 in this comparative example adopts a whole copper sheet.

[0034] Comparative Example 4 Different from the first embodiment, the conductor 1 in the present embodiment is formed by twisting the same number of tinned copper wires 12 in the first embodiment.

[0035] The following table shows the UV resistance (the higher the level, the better the UV resistance), compression resistance, bending performance test (the ratio of bending radius to cable outer diameter, the smaller the value, the better the bending performance), tensile strength, and conductivity of Examples 1-2 and Comparative Examples 1-3.

[0036] Table 1 Performance tests of various embodiments and comparative examples

[0037] It can be seen from Example 1 and Comparative Example 1 in the above table that the polyethylene in the insulating layer 2 and the sheath layer 5 has improved anti-ultraviolet performance after radiation cross-linking; it can be seen from Example 1 and Comparative Example 2 that the reinforcing layer 3 with a sandwich structure can significantly improve the compressive performance of the optical cable, thereby being more resistant to rodent gnawing; it can be seen from Example 1 and Comparative Example 3 that the metal protective layer 4 adopts a chain structure of multiple four-claw copper sheets hooked together, which can improve the bending performance of the optical cable, thereby facilitating the laying of some narrow spaces; it can be seen from the comparison between Example 1 and Comparative Example 4 that, compared with individually twisted tinned copper wires, the conductor 1 formed by twisting a plurality of tinned copper wires on the outside of the copper wire core has improved conductivity and strength.

[0038] The above are preferred implementation modes of the present invention. Those skilled in the art to which the present invention belongs can also change and modify the above implementation modes. Therefore, the present invention is not limited to the above specific implementation modes. Any obvious improvements, substitutions or modifications made by those skilled in the art on the basis of the present invention belong to the protection scope of the present invention.

Claims

1. A method for manufacturing a waterproof photovoltaic cable that is resistant to rodent gnawing, characterized in that: Here are the steps: S1. Conductor (1) twisting: a plurality of tinned copper wires (12) are twisted outside a copper wire core (11) to form a conductor (1); S2, extrusion of insulating layer (2): extruding radiation cross-linked polyethylene and radiation cross-linked polyolefin in double layers on the surface of the conductor to form an insulating layer (2); S3, preparing a reinforcing layer (3): bonding a carbon fiber layer (32) between two nylon layers (31) to form a reinforcing layer (3) with a sandwich structure, and covering the insulating layer (2); S4, preparing a metal protective layer (4): using a four-claw copper sheet to form a metal protective layer (4) with a chain structure outside the insulating layer (3); S5, preparing the sheath: extruding a cross-linked material made of polyolefin processed by high-electricity electron beam onto the outer layer of the metal protective layer to form a sheath layer (5).

2. The method for manufacturing a rodent-resistant waterproof photovoltaic cable according to claim 1, characterized in that: In step S1, a copper wire core (11) and one end of a tinned copper wire (12) are passed through a twisting disk, the other end of the tinned copper wire (12) is fixed by a fixing member, and the tinned copper wire (12) is twisted in the same direction on the outside of the copper wire core (11) by a twisting device to form a conductor (1).

3. The method for manufacturing a rodent-resistant waterproof photovoltaic cable according to claim 1, characterized in that: In step S2, the polyethylene cross-linked material and the polyolefin cross-linked material are cross-linked by radiation through a double-layer extruder at 180-220° C. to obtain an insulating layer (2), wherein the radiation dose is 100-200 kgy, the radiation temperature is maintained between 20-40° C., and the radiation time is 3-5 min.

4. The method for manufacturing a rodent-resistant waterproof photovoltaic cable according to claim 1, characterized in that: The radial cross section of the carbon fiber layer (3) is wavy or continuous V-shaped.

5. The method for manufacturing a rodent-resistant waterproof photovoltaic cable according to claim 4, characterized in that: PA12 particles are melt-extruded at 240-300° C. to form two tubular nylon layers (31) of different diameters, glue is coated on the outer surface of the nylon layer (31) with a smaller diameter and the inner surface of the nylon layer (31) with a larger diameter, and a carbon fiber layer (32) is bonded between the two nylon layers (31).

6. The method for manufacturing a rodent-resistant waterproof photovoltaic cable according to claim 1, characterized in that: The four-claw copper sheet comprises a transverse body (41), a longitudinal body (45) connected to the middle of the transverse body (41) and located on the transverse body (41), two first hook-shaped claws (42) connected to both sides of the transverse body (41) and located on the transverse body (41), and two second hook-shaped claws (43) connected to the transverse body (41) and located below the transverse body (41), the two first hook-shaped claws (42) are symmetrical along the longitudinal midline of the longitudinal body (45) and the hook portions are both inwardly facing, the two second hook-shaped claws (43) are symmetrical along the longitudinal midline of the longitudinal body (45) and the hook portions are outwardly facing, and there is a gap (44) between the two second hook-shaped claws (43) with a distance not less than the width of the longitudinal body (45).

7. The method for manufacturing a rodent-resistant waterproof photovoltaic cable according to claim 6, characterized in that: The hook portion of the first hook-shaped claw (42) of one four-claw copper sheet is hooked with the hook portion of the second hook-shaped claw (43) of another four-claw copper sheet, and the longitudinal body (45) of the other four-claw copper sheet is inserted into the gap (44) of one four-claw copper sheet to form the chain structure.

8. The method for manufacturing a rodent-resistant waterproof photovoltaic cable according to claim 1, characterized in that: In step S5, the high-conductivity electron beam irradiation dose is 100-200 kgy, the irradiation temperature is maintained between 20-40° C., the irradiation time is 3-5 min, and the extrusion temperature is 180-220° C.

Images