Manufacturing method of a rodent-proof and waterproof photovoltaic cable

Abstract

The present invention relates to the technical field of cables, and particularly to a manufacturing method of a rodent-proof and waterproof photovoltaic cable, the steps of which are as follows: Conductor stranding: A plurality of tinned copper wires are stranded outside the copper wire core to form a conductor; Insulation layer extrusion: Irradiated crosslinked polyethylene and irradiated crosslinked polyolefin are extruded in a double layer on the surface of the conductor to form an insulation layer; Preparation of a reinforcement layer: A carbon fiber layer is bonded between two nylon layers to form a sandwich-structured reinforcement layer, which is then coated outside the insulation layer; Preparation of a metal protection layer: A chain-structured metal protection layer is formed by using four-claw copper sheets outside the reinforcement layer; Preparation of a sheath: Polyolefin is extruded into a sheath layer on the outer layer of the metal protection layer by using a crosslinked material processed by a high-electricity electron beam. The cable of the present invention has ultraviolet resistance, waterproofness, flexibility, and rodent-proofness, and can withstand a wider range of temperature changes, thus extending the service life of the cable.

Description

Technical Field

[0001] The present invention relates to the technical field of cables, and particularly relates to a manufacturing method of a rodent-proof and waterproof photovoltaic cable. Background Art

[0002] For photovoltaic power stations built in places such as deserts, gobi deserts, wastelands, oceans, and farms, 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 No. CN114242307A discloses a waterproof, fireproof, and rodent- and ant-proof composite cable, which includes a core located at the center of the cable, and an anti-disengagement plate is attached to the outside of the core; it also includes: a fireproof silk ribbon, which is wrapped around the outside of the anti-disengagement plate; a polyethylene inner sheath layer, which is wrapped around the outside of the flame-retardant and water-blocking tape, and a galvanized steel strip armor is wrapped around the outside of the polyethylene inner sheath layer. This waterproof, fireproof, and rodent- and ant-proof composite cable includes a power core and a control core. The conductor uses a tinned copper conductor, and a halogen-free, low-smoke, flame-retardant, ceramizable polyolefin insulating material is extruded outside the conductor. The cable is formed by winding and wrapping a fireproof glass silk ribbon and a flame-retardant water-blocking tape, extruding a polyethylene inner sheath, steel strip armoring, winding a ceramizable silicone rubber tape, extruding a halogen-free, low-smoke, flame-retardant polyolefin sheath, and then extruding a nylon protection and strengthening layer outside, so that the finished cable has the characteristics of environmental protection, waterproof, fireproof, and rodent- and ant-proof, and can be widely used in line systems in special environments such as humid and airtight environments.

[0004] The strengthening layer of this patent is only made of one layer of nylon extrusion, and its anti-biting ability is slightly weak. A whole galvanized steel strip is used as the metal protection layer, and its bending performance is not good. Summary of the Invention

[0005] The present invention solves the problems of poor anti-biting and bending performance in related technologies, and proposes a manufacturing method of a rodent-proof and waterproof photovoltaic cable. The strengthening layer is a structure of two layers of nylon layers stacked with one layer of carbon fiber layer, which improves the strength of the cable and is more resistant to rodent biting; the metal protection 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, improving the bending ability of the cable.

[0006] To solve the above technical problems, the present invention is realized through the following technical solutions: A manufacturing method of a rodent-proof and waterproof photovoltaic cable, the steps are as follows: S1. Conductor stranding: Stranding a number of tinned copper wires outside the copper wire core to form a conductor; S2. Insulation layer extrusion: Double-extruding irradiated cross-linked polyethylene and irradiated cross-linked polyolefin on the surface of the conductor to form an insulation layer; S3. Preparing a strengthening layer: Bonding a carbon fiber layer between two nylon layers to form a sandwich-structured strengthening layer, and covering it outside the insulation layer; S4. Preparing a metal protection layer: Using four-claw copper sheets outside the strengthening layer to form a chain-structured metal protection layer; S5. Preparing a sheath: Extruding a cross-linked material made of polyolefin by high-electricity electron beam processing into a sheath layer on the outer layer of the metal protection layer.

[0007] As a preferred solution, in step S1, one end of the copper wire core and the tinned copper wire is passed through a stranding disc, and the other end of the tinned copper wire is fixed by a fixing member, and the tinned copper wire is stranded in the same direction outside the copper wire core by a stranding device to form a conductor.

[0008] As a preferred solution, in step S2, the irradiated cross-linked polyethylene cross-linked material and the irradiated cross-linked polyolefin cross-linked material are double-extruded through a double-extrusion machine under the condition of 180-220 °C to obtain an insulation layer, wherein the irradiation dose is 100-200 kgy, the irradiation temperature is maintained between 20-40 °C, and the irradiation time is 3-5 min.

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

[0010] As a preferred solution, PA12 particles are melt-extruded under the condition of 240-300 °C to form two nylon layers in the shape of tubes with different diameters. Glue is coated on the outer surface of the nylon layer with a smaller diameter and the inner surface of the nylon layer with a larger diameter, and the carbon fiber layer is adhered between the two nylon layers.

[0011] As a preferred solution, the four-claw copper sheet includes a horizontal body, a vertical body connected to the middle of the horizontal body and located above the horizontal body, two first hook-shaped claws respectively connected to both sides of the horizontal body and located above the horizontal body, and two second hook-shaped claws connected to the horizontal body and located below the horizontal body. The two first hook-shaped claws are symmetric with respect to the longitudinal center line of the vertical body and the hook parts are all inward, the two second hook-shaped claws are symmetric with respect to the longitudinal center line of the vertical body and the hook parts are outward, and there is a gap between the two second hook-shaped claws with a distance not less than the width of the vertical body.

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

[0013] As a preferred solution, in step S5, the irradiation dose of the high-electricity electron beam 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 beneficial effects of the present invention are as follows:

[0015] (1) The conductor of the present invention is formed by stranding a plurality of tinned copper wires outside the copper wire core. It not only has good electrical conductivity, but also has better strength than the tinned copper wires stranded alone;

[0016] (2) The reinforcing layer is a structure of two nylon layers stacked with one carbon fiber layer, which improves the strength of the cable and is more resistant to rodent bites; in addition, the carbon fiber layer is wavy or continuously V-shaped, which can resist the local depression of the cable caused by rodent bites;

[0017] (3) The metal protection layer of the present invention is a chain structure formed by a plurality of four-claw copper sheets, so that the 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 hooked claws, improving the bending ability of the cable;

[0018] (4) The insulating layer and the sheath are both extruded from irradiated cross-linked polyolefin, and have good ultraviolet resistance and corrosion resistance;

[0019] (5) The cable of the present invention has ultraviolet resistance, waterproofness and rodent bite resistance, and can withstand a larger range of temperature changes. At the same time, it also has the characteristics of withstanding pressure, bending, tension, cross-stretching load and strong impact, extending the service life of the cable. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is the overall structural schematic diagram of Embodiment 1 of the present invention;

[0021] Figure 2 is the overall structural schematic diagram of Embodiment 2 implemented by the present invention;

[0022] Figure 3 is the structural schematic diagram of a single four-claw copper sheet of the present invention;

[0023] Figure 4 is the structural schematic diagram of a metal protection layer formed by a plurality of four-claw copper sheets of the present invention.

[0024] In the figure:

[0025] 1. Conductor, 2. Insulating layer, 3. Reinforcing layer, 31. Nylon layer, 32. Carbon fiber layer, 4. Metal protective layer, 41. Horizontal body, 42. First hooked claw, 43. Second hooked claw, 44. Gap, 45. Vertical body, 5. Sheath layer. Detailed implementation

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually illustrative only and in no way limits the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0027] It should be noted that the terms used herein are only for describing specific implementation manners 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 forms are also intended to include the plural forms. In addition, it should be understood that when the terms "include" and / or "comprise" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or their combinations.

[0028] Unless otherwise specifically stated, the relative arrangements, numerical expressions, and numerical values of the components and steps set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be understood that, for the sake of convenience of description, the sizes of the various parts shown in the drawings are not drawn in actual proportional relationships. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and devices should be regarded as part of the authorized specification. In all the examples shown and discussed here, any specific value should be interpreted as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that: similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0029] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by orientation words such as "front, back, top, bottom, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom", etc. is usually based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description. Without contrary description, these orientation words do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation on the protection scope of the present invention; the orientation words "inside, outside" refer to the inside and outside relative to the contour of each component itself.

[0030] For the sake of convenience in description, spatial relative terms such as "above...", "over...", "on the upper surface of...", "upper" etc. can be used here to describe the spatial positional relationship between a device or feature shown in the drawings and other devices or features. It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation described in the drawings for the device. For example, if the device in the drawing is inverted, the device described as "above other devices or structures" or "over other devices or structures" will then be positioned as "below other devices or structures" or "under other devices or structures". Thus, the exemplary term "above..." can include both the orientations of "above..." and "below...". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and corresponding interpretations should be made for the spatial relative descriptions used here.

[0031] In addition, it should be noted that using words such as "first", "second" etc. to define components is only for the convenience of distinguishing the corresponding components. Without additional declaration, the above words have no special meaning. Therefore, it should not be construed as a limitation on the protection scope of the present invention.

[0032] Embodiment 1

[0033] As Figure 1 and 4 shown, a manufacturing method of a rodent-proof and waterproof photovoltaic cable is as follows:

[0034] S1. Stranding of Conductor 1: One end of the copper wire core 11 and the tinned copper wire 12 is passed through the stranding disc, and the other end of the tinned copper wire 12 is fixed by a fixing member. For example, the fixing member can be a hoop. The tinned copper wire 12 is stranded in the same direction on the outside of the copper wire core 11 by a stranding device to form Conductor 1.

[0035] S2. Extrusion of Insulation Layer 2: The irradiated cross-linked polyethylene cross-linked material is double-extruded through a double-layer extruder at 190 °C to obtain the insulation layer 2. Among them, the irradiation dose is 150 kGy, the irradiation temperature is maintained between 30 °C, the irradiation time is 4 min, and electron beam irradiation cross-linking or ultraviolet irradiation cross-linking is used.

[0036] S3. Preparation of Reinforcement Layer 3: PA12 particles are melt-extruded at 280 °C to form two nylon layers 31 with different diameters in a tubular shape. Glue or adhesive film 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 the carbon fiber layer 32 is adhered between the two nylon layers 31 to form a sandwich-structured reinforcement layer 3, and it is coated outside the insulation layer 2. In this embodiment, the radial cross-section of the carbon fiber layer 32 is a wavy structure; among them, the nylon layer 31 has excellent oil resistance, corrosion resistance, low thermal shrinkage, toughness and other properties, which can not only ensure that the insulation layer 2 is not mechanically damaged by the metal protection layer 4, but also prevent moisture from entering the insulation layer 2.

[0037] S4. Preparation of Metal Protection Layer 4: A chain-structured metal protection layer 4 is formed by using four-claw copper sheets outside the reinforcement layer 3. Among them, the four-claw copper sheet includes a horizontal body 41, a vertical body 45 connected to the middle of the horizontal body 41 and located above the horizontal body 41, two first hook-shaped claws 42 respectively connected to both sides of the horizontal body 41 and located above the horizontal body 41, and two second hook-shaped claws 43 connected to the horizontal body 41 and located below the horizontal body 41. The two first hook-shaped claws 42 are symmetric with respect to the longitudinal center line of the vertical body 45 and the hook parts are all inward, the two second hook-shaped claws 43 are symmetric with respect to the longitudinal center line of the vertical body 45 and the hook parts are outward, and there is a gap 44 between the two second hook-shaped claws 43 with a width not less than that of the vertical body 45. When in use, the hook part of the first hook-shaped claw 42 of one four-claw copper sheet is hooked with the hook part of the second hook-shaped claw 43 of another four-claw copper sheet, and the vertical body 45 of the other four-claw copper sheet is inserted into the gap 44 of one four-claw copper sheet to form a chain structure. Then, 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 bending ability of the cable is better.

[0038] S5. Preparation of Sheath Layer 5: The cross-linked material processed by high-electricity electron beam of polyethylene is extruded into a sheath layer 5 on the outer layer of the metal protection layer. Among them, the irradiation dose of the high-electricity electron beam is 120 kGy, the irradiation temperature is maintained between 25 °C, the irradiation time is 3.5 min, and the extrusion temperature is 200 °C. The sheath layer 5 has properties such as flame retardancy, ultraviolet resistance, corrosion resistance, waterproofness, etc., and can withstand a wider range of temperature changes (from -40 °C to 125 °C).

[0039] Example 2

[0040] As Figure 2 And3 As shown, different from Embodiment 1, in this embodiment, the radial cross-section of the carbon fiber layer 32 is a continuous V shape.

[0041] Comparative Example 1

[0042] Different from Embodiment 1, in this comparative example, the polyethylene and polyolefin in the insulating layer 2 and the sheath layer 5 are not irradiated.

[0043] Comparative Example 2

[0044] Different from Embodiment 1, in this comparative example, the reinforcing layer 3 uses a single layer of nylon layer 31.

[0045] Comparative Example 3

[0046] Different from Embodiment 1, in this comparative example, the metal protection layer 4 uses a whole copper sheet.

[0047] Comparative Example 4

[0048] Different from Embodiment 1, the conductor 1 in this embodiment is formed by stranding the same number of tinned copper wires 12 as in Embodiment 1.

[0049] The following table shows the anti-ultraviolet performance (the higher the grade, the better the anti-ultraviolet performance), compressive performance, bending performance test (the ratio of the bending radius to the outer diameter of the cable, the smaller the value, the better the bending performance), tensile strength, and conductivity of Embodiments 1-2 and Comparative Examples 1-3.

[0050] Table 1 Performance Tests of Each Embodiment and Each Comparative Example

[0051]

[0052] It can be seen from Embodiment 1 and Comparative Example 1 in the above table that after the polyethylene in the insulating layer 2 and the sheath layer 5 is irradiated and crosslinked, the anti-ultraviolet performance is improved; it can be seen from Embodiment 1 and Comparative Example 2 that using the sandwich-structured reinforcing layer 3 can significantly improve the compressive performance of the optical cable, making it more resistant to rodent bites; it can be seen from Embodiment 1 and Comparative Example 3 that using a chain structure in which multiple four-claw copper sheets are hooked together for the metal protection layer 4 can improve the bending performance of the optical cable, facilitating laying in some narrow spaces; it can be seen from the comparison between Embodiment 1 and Comparative Example 4 that compared with the tinned copper wires stranded alone, the conductor 1 formed by stranding several tinned copper wires outside the copper wire core has improved conductivity and strength.

[0053] The above is a preferred embodiment of the present invention. Those skilled in the art to which the present invention pertains are also able to make changes and modifications to the above embodiment. Therefore, the present invention is not limited to the above specific embodiments, and any obvious improvements, substitutions or variations made by those skilled in the art based on the present invention fall within the protection scope of the present invention.

Claims

1. A manufacturing method of a rodent-proof and waterproof photovoltaic cable, characterized in that, The steps are as follows: S1. Stranding of the conductor (1): A number of tinned copper wires (12) are stranded outside the copper wire core (11) to form the conductor (1); S2. Extrusion of the insulating layer (2): Irradiated cross-linked polyethylene and irradiated cross-linked polyolefin are extruded in a double layer on the surface of the conductor to form the insulating layer (2); S3. Preparation of the strengthening layer (3): A carbon fiber layer (32) is bonded between two nylon layers (31) to form a sandwich-structured strengthening layer (3), which is coated outside the insulating layer (2); S4. Preparation of the metal protection layer (4): A chain-structured metal protection layer (4) is formed by using four-claw copper sheets outside the strengthening layer (3); S5. Preparation of the sheath: The polyolefin is extruded into a sheath layer (5) on the outer layer of the metal protection layer by using a cross-linked material processed by a high-electricity electron beam.

2. The manufacturing method of the rodent-proof and waterproof photovoltaic cable according to claim 1, wherein: In step S1, one end of the copper wire core (11) and the tinned copper wire (12) passes through the stranding disc, the other end of the tinned copper wire (12) is fixed by a fixing member, and the tinned copper wire (12) is stranded in the same direction on the outside of the copper wire core (11) by a stranding device to form the conductor (1).

3. The manufacturing method of the rodent-proof and waterproof photovoltaic cable according to claim 1, characterized in that: In step S2, the irradiated cross-linked polyethylene cross-linked material and the irradiated cross-linked polyolefin cross-linked material are double-extruded by a double-extrusion machine at 180-220°C to obtain the insulating layer (2). Among them, the irradiation dose is 100-200 kgy, the irradiation temperature is maintained between 20-40°C, and the irradiation time is 3-5 min.

4. The manufacturing method of the rodent-proof and waterproof photovoltaic cable according to claim 1, characterized in that: The radial cross-section of the carbon fiber layer (32) is wavy or continuously V-shaped.

5. The manufacturing method of the rodent-proof and waterproof photovoltaic cable according to claim 4, characterized in that: PA12 particles are melt-extruded at 240-300°C to form two nylon layers (31) in the shape of tubes with 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 the carbon fiber layer (32) is bonded between the two nylon layers (31).

6. The manufacturing method of the rodent-proof and waterproof photovoltaic cable according to claim 1, characterized in that: The four-claw copper sheet includes a horizontal body (41), a vertical body (45) connected to the middle of the horizontal body (41) and located above the horizontal body (41), two first hook-shaped claws (42) respectively connected to both sides of the horizontal body (41) and located above the horizontal body (41), and two second hook-shaped claws (43) connected to the horizontal body (41) and located below the horizontal body (41). The two first hook-shaped claws (42) are symmetric with respect to the longitudinal center line of the vertical body (45) and the hook parts are all inward, the two second hook-shaped claws (43) are symmetric with respect to the longitudinal center line of the vertical body (45) and the hook parts are outward, and there is a gap (44) between the two second hook-shaped claws (43) with a distance not less than the width of the vertical body (45).

7. The manufacturing method of the rodent-proof and waterproof photovoltaic cable according to claim 6, characterized in that: The hook part of the first hook-shaped claw (42) of one four-claw copper sheet is hooked with the hook part of the second hook-shaped claw (43) of another four-claw copper sheet, and the vertical 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 manufacturing method of the rodent-proof and waterproof photovoltaic cable according to claim 1, characterized in that: In step S5, the irradiation dose of the high-electricity electron beam 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.

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