Layered compression conductor and anti-sinking environment-friendly polypropylene cable

Abstract

The invention belongs to the technical field of cables, and particularly relates to a layered compression conductor and an anti-sinking environment-friendly polypropylene cable. The layered compressed conductor comprises a central layer and at least three peripheral layers, the central layer and the peripheral layers are copper monofilaments of a circular structure, the compression coefficient of the first layer, close to the central layer, of the peripheral layers is 0.83-0.85, the compression coefficient of the second layer is 0.85-0.88, and the compression coefficients of the outermost layer and the secondary outer layer are 0.90-0.92 and 0.85-0.88 respectively; the anti-sinking environment-friendly polypropylene cable sequentially comprises a layered compression conductor, an anti-sinking conductor shielding layer, an insulating layer, an insulating shielding layer, a metal shielding layer, a binding tape and a sheath layer from inside to outside. The layered compressed conductor is obtained by adjusting the compression coefficient of each layer of the layered compressed conductor, and the anti-depression environment-friendly polypropylene cable is obtained by combining effective cable materials, so that the effect of relieving or avoiding conductor shielding depression is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of cables, and particularly relates to a hierarchically compacted conductor and a depression-proof environmental protection polypropylene cable. Background Art

[0002] With the rapid development of modernization and technology, wire and cable have evolved from simple telephone and telegraph cables in the past to cables with thousands of pairs, coaxial cables, optical cables, data cables, and even combined communication cables, etc., which have put forward higher requirements for the safety of wire and cable. Some cross-linked cables put into operation are facing problems such as the disposal at the end of the product life cycle. How to better solve the environmental protection treatment after the end of the product life cycle, while reducing the energy consumption during the product production process and other issues, and achieving green environmental protection has a very important impact on the development of the wire and cable industry.

[0003] Existing cables commonly use cross-linked polyethylene materials. Due to the non-recyclability of cross-linked polyethylene, the waste generated during the production and use of cables cannot be effectively reused, which will not only cause waste of resources but also cause secondary pollution to the environment. At the same time, when the conductor in the cable is stranded, if the tension control between the layers of the conductor is insufficient, the stranding rate, stranding pitch diameter ratio, etc. are not properly controlled, and the inner diameter of the stranding die is not appropriate, etc., the surface of the stranded conductor will be loose, there will be gaps between the outermost conductors and they are not tight enough, which will cause the conductor shielding material to squeeze into the conductor area, resulting in conductor shielding depression, and the combination of the conductor shielding layer and the insulating layer is not perfect, resulting in uneven internal electric field distribution, seriously affecting the electrical performance and service life of the cable. Therefore, achieving anti-depression of the conductor shielding layer is of great significance for improving the performance and service life of polypropylene insulated power cables. Summary of the Invention

[0004] The purpose of the present invention is to provide a hierarchically compacted conductor and a depression-proof environmental protection polypropylene cable for the above technical problems, and by adjusting the compaction coefficient of the conductor layer and combining effective cable materials, the effect of alleviating or avoiding conductor shielding depression is achieved.

[0005] The hierarchically compacted conductor in the technical solution of the present invention includes a central layer and an outer layer. Both the central layer and the outer layer are copper single wires with a circular structure. There are at least three layers in the outer layer. The compaction coefficient of the first layer of the outer layer close to the central layer is 0.83 - 0.85, the compaction coefficient of the second layer is 0.85 - 0.88, and the compaction coefficients of the outermost layer and the second outermost layer are 0.90 - 0.92 and 0.85 - 0.88 respectively.

[0006] By adjusting the compaction coefficient of the inner layer of the conductor and the compaction coefficient of the outer layer of the conductor, the degree of rebound after conductor compaction is controlled, so that the conductor structure is tight and it is not easy to appear depression phenomenon.

[0007] Preferably, the cross-sectional area of the above-mentioned laminated compacted conductor is 300 to 500 mm2, preferably 400 mm2.

[0008] Furthermore, the structure of the laminated compacted conductor is laminated as 1 + 6 + 12 + 18 + 24.

[0009] Furthermore, when the structure of the laminated compacted conductor is laminated as 1 + 6 + 12 + 18 + 24, 6 copper single wires, 12 copper single wires, 18 copper single wires, and 24 copper single wires are successively stranded on the middle 1 copper single wire.

[0010] Furthermore, the diameter of the copper single wires in the laminated compacted conductor is 2.5 to 3.0 mm.

[0011] Furthermore, the pitch diameter ratio of the first layer of the outer layer of the laminated compacted conductor is 23 to 27, the pitch diameter ratio of the second layer is 19 to 22, the pitch diameter ratio of the third layer is 14 to 16, and the pitch diameter ratio of the fourth layer is 12 to 14.

[0012] The present invention also provides an anti-dent environmental protection polypropylene cable, which successively includes a laminated compacted conductor, an anti-dent conductor shielding layer, an insulating layer, an insulating shielding layer, a metal shielding layer, a binding tape, and a sheath layer from inside to outside; the insulating shielding layer, the insulating layer, and the anti-dent conductor shielding layer are extruded on the laminated compacted conductor, the metal shielding layer is wound around the insulating shielding layer, and the sheath layer is extruded after binding.

[0013] Furthermore, the anti-dent conductor shielding layer uses a thermoplastic polypropylene anti-dent shielding material.

[0014] Furthermore, the thermoplastic polypropylene anti-dent shielding material includes the following components in parts by weight: 40 to 60 parts of polypropylene, 30 to 50 parts of POE elastomer, 10 to 20 parts of carbon nanotubes, 0.5 to 1.0 part of lubricant, 0.1 to 0.5 part of antioxidant, and 0.2 to 0.5 part of copper inhibitor.

[0015] Introducing an appropriate amount of carbon nanotubes into the thermoplastic polypropylene anti-dent shielding material can improve the melt strength, reduce the fluidity of the shielding material, make it not easy to enter the gaps between the conductors, and play an anti-dent role.

[0016] Furthermore, the insulating layer uses a thermoplastic polypropylene insulating material.

[0017] Furthermore, the thermoplastic polypropylene insulating material includes the following components in parts by weight: 40 to 60 parts of polypropylene, 30 to 50 parts of POE elastomer, 1.0 to 5.0 parts of inorganic filler, and 0.1 to 1.0 part of antioxidant.

[0018] Furthermore, the insulating shielding layer uses a thermoplastic polypropylene shielding material.

[0019] Further, the thermoplastic polypropylene shielding material comprises the following components in parts by weight: 40-60 parts of polypropylene, 30-50 parts of POE elastomer, 1.0-2.0 parts of carbon black, 1.0-2.0 parts of lubricant, and 0.1-0.5 parts of antioxidant.

[0020] Further, the metal shielding layer is made of copper tape.

[0021] Preferably, the binding tape is a non-woven fabric tape.

[0022] Further, the sheath layer is made of a flexible polypropylene sheath material.

[0023] Further, the flexible polypropylene sheath material comprises the following components in parts by weight: 100-120 parts of polypropylene resin, 60-120 parts of flexible modifier, 0.5-2.0 parts of lubricant, 0.5-1.0 parts of antioxidant, 0.2-0.5 parts of copper-resistant agent, and 0.2-0.4 parts of plasticizer.

[0024] The flexible polypropylene cable sheath material has very good low-temperature resistance and flexibility, and can effectively improve the original stress whitening resistance and improvement of the polypropylene cable material.

[0025] Preferably, the flexible modifier is a toughening agent and a flexible filler mixed in a mass ratio of 0.5-1.5:0.5-1.5; wherein the flexible filler is preferably SR-2 type flexible filler, and the toughening agent is preferably POE toughening agent. Further, the plasticizer is an aliphatic dibasic acid ester plasticizer, one or more of bis(2-ethylhexyl) adipate, di-tert-butyl adipate, bis(2-ethylhexyl) sebacate, and divinyl sebacate.

[0026] Preferably, the lubricant includes but is not limited to one or more of stearamide, oleic acid amide, fatty acid, methyl silicone oil, liquid paraffin, and polyethylene oxide.

[0027] Preferably, the antioxidant includes but is not limited to one or more of antioxidant 1010, antioxidant 168, antioxidant 2264, antioxidant 264, antioxidant DLTP, and antioxidant ODP.

[0028] Compared with the prior art, the technical solution of the present invention has the following beneficial effects: (1) By adjusting the compaction coefficient of each layer of the stratified compacted conductor, a stratified compacted conductor is obtained, and combined with effective cable materials, an anti-dent environmental protection type polypropylene cable is obtained, achieving the effect of alleviating or avoiding conductor shielding dents; (2) By adjusting the compaction coefficient of the outer layer of the stratified compacted conductor, the rebound degree after conductor compaction is controlled, so that the conductor structure is tight and it is not easy to have dent phenomenon; (3) Introducing an appropriate amount of carbon nanotubes into the thermoplastic polypropylene anti-dent shielding material can improve the melt strength, reduce the fluidity of the shielding material, making it difficult to enter the gaps between conductors, thus playing an anti-dent role. (4) The flexible polypropylene cable sheath material has very good low-temperature resistance and flexibility, which can effectively improve the original stress whitening phenomenon and improvement of the polypropylene cable material. Brief Description of the Drawings

[0029] Figure 1 It is a schematic diagram of the hierarchical compacted conductor of the present invention; Figure 2 It is a schematic diagram of the anti-dent environmentally friendly polypropylene cable of the present invention; In the figure: 1 - hierarchical compacted conductor, 2 - anti-dent conductor shielding layer, 3 - insulating layer, 4 - insulating shielding layer, 5 - metal shielding layer, 6 - binding tape, 7 - sheath layer. Specific Embodiments

[0030] The technical solutions of the present invention will be further described and illustrated below through specific embodiments and drawings. It should be understood that the specific embodiments described herein are only used to help understand the present invention and are not used for specific limitations of the present invention. And the drawings used herein are only for better explaining the content disclosed by the present invention and do not have a limiting effect on the protection scope. If there is no special description, the raw materials used in the embodiments of the present invention are all common raw materials in the art, and the methods used in the embodiments are all conventional methods in the art.

[0031] In the following examples and comparative examples, the thermoplastic polypropylene insulating material used for the insulating layer and the thermoplastic polypropylene shielding material used for the insulating shielding layer were purchased from Zhejiang Wanma High Polymer Materials Group Co., Ltd., and the copper inhibitor was purchased from Guangyuanda (Tianjin) Technology Co., Ltd.

[0032] The hierarchical compacted conductor of the present invention is as Figure 1 shown, including a central layer and a peripheral layer, and the peripheral layer includes a first layer, a second layer, a third layer, and a fourth layer; the anti-dent environmentally friendly polypropylene cable is as Figure 2 shown, and successively includes a hierarchical compacted conductor 1, an anti-dent conductor shielding layer 2, an insulating layer 3, an insulating shielding layer 4, a metal shielding layer 5, a binding tape 6, and a sheath layer 7 from the inside to the outside, wherein the cross-sectional area of the hierarchical compacted conductor is 400 mm2.

[0033] Example 1

[0034] In this embodiment, the stranded and compacted conductor includes a central layer and a peripheral layer. Both the central layer and the peripheral layer are copper single wires with a circular structure and a diameter of 2.88 mm. The structure of the stranded and compacted conductor is divided into 1+6+12+18+24. Six copper single wires, twelve copper single wires, eighteen copper single wires, and twenty-four copper single wires are successively stranded on the middle single copper wire. The compaction factor of the first layer of the peripheral layer is 0.85, and the compaction factors of the second, third, and fourth layers are 0.88, 0.88, and 0.91 respectively. The pitch diameter ratio of the first layer is 24, the pitch diameter ratio of the second layer is 20, the pitch diameter ratio of the third layer is 15, and the pitch diameter ratio of the fourth layer is 14.

[0035] Embodiment 2

[0036] In this embodiment, the stranded and compacted conductor includes a central layer and a peripheral layer. Both the central layer and the peripheral layer are copper single wires with a circular structure and a diameter of 2.88 mm. The structure of the stranded and compacted conductor is divided into 1+6+12+18+24. Six copper single wires, twelve copper single wires, eighteen copper single wires, and twenty-four copper single wires are successively stranded on the middle single copper wire. The compaction factor of the first layer of the peripheral layer is 0.85, and the compaction factors of the second, third, and fourth layers are 0.85, 0.85, and 0.92 respectively. The pitch diameter ratio of the first layer is 24, the pitch diameter ratio of the second layer is 21, the pitch diameter ratio of the third layer is 16, and the pitch diameter ratio of the fourth layer is 13.

[0037] Application Example 1 In this application example, for the anti-dent environmental protection polypropylene cable, first, an anti-dent conductor shielding layer, an insulating layer, and an insulating shielding layer are successively extruded on the stranded and compacted conductor of Embodiment 1; then a copper tape is wound, followed by winding with a non-woven fabric tape, and finally a sheath layer is extruded; the anti-dent conductor shielding layer uses a thermoplastic polypropylene anti-dent shielding material, which includes the following components in parts by weight: 50 parts of polypropylene, 40 parts of POE elastomer, 12 parts of carbon nanotubes, 0.6 part of stearamide, 0.1 part of antioxidant 1010, and 0.3 part of copper anti-agent; the sheath layer uses a flexible polypropylene sheath material, which includes the following components in parts by weight: 100 parts of polypropylene resin, 80 parts of flexible modifier, 0.8 part of stearamide, 0.8 part of antioxidant 1010, 0.3 part of copper anti-agent, and 0.3 part of bis(2-ethylhexyl) adipate. The flexible modifier is a mixture of a POE toughening agent and an SR-2 type flexible filler in a mass ratio of 1.0:1.0.

[0038] Application Example 2 In the anti-dent environmental protection polypropylene cable of the embodiment of the present application, first, an anti-dent conductor shielding layer, an insulating layer, and an insulating shielding layer are successively extruded on the stratified compacted conductor of Embodiment 2; then, a copper tape is wound, and a non-woven fabric tape is wound, and finally, a sheath layer is extruded; the anti-dent conductor shielding layer uses a thermoplastic polypropylene anti-dent shielding material, which includes the following components in parts by weight: 50 parts of polypropylene, 40 parts of POE elastomer, 12 parts of carbon nanotubes, 0.6 part of stearamide, 0.1 part of antioxidant 1010, and 0.3 part of copper anti-agent; the sheath layer uses a flexible polypropylene sheath material, which includes the following components in parts by weight: 100 parts of polypropylene resin, 80 parts of flexible modifier, 0.8 part of stearamide, 0.8 part of antioxidant 1010, 0.3 part of copper anti-agent, and 0.3 part of bis(2-ethylhexyl) adipate. The flexible modifier is a mixture of a POE toughening agent and an SR-2 type flexible filler in a mass ratio of 1.0:1.0.

[0039] Application Example 3 The difference between the embodiment of the present application and Application Example 1 is only that: the thermoplastic polypropylene anti-dent shielding material includes the following components in parts by weight: 50 parts of polypropylene, 35 parts of POE elastomer, 15 parts of carbon nanotubes, 0.6 part of stearamide, 0.1 part of antioxidant 1010, and 0.3 part of copper anti-agent; the flexible polypropylene sheath material includes the following components in parts by weight: 100 parts of polypropylene resin, 90 parts of flexible modifier, 1.0 part of stearamide, 0.8 part of antioxidant 1010, 0.3 part of copper anti-agent, and 0.3 part of bis(2-ethylhexyl) adipate. The flexible modifier is a mixture of a POE toughening agent and an SR-2 type flexible filler in a mass ratio of 1.0:1.0.

[0040] Application Example 4 The difference between the embodiment of the present application and Application Example 1 is only that: the thermoplastic polypropylene anti-dent shielding material includes the following components in parts by weight: 55 parts of polypropylene, 40 parts of POE elastomer, 18 parts of carbon nanotubes, 0.8 part of stearamide, 0.2 part of antioxidant 1010, and 0.3 part of copper anti-agent; the flexible polypropylene sheath material includes the following components in parts by weight: 100 parts of polypropylene resin, 95 parts of flexible modifier, 1.0 part of stearamide, 0.8 part of antioxidant 1010, 0.3 part of copper anti-agent, and 0.3 part of bis(2-ethylhexyl) adipate. The flexible modifier is a mixture of a POE toughening agent and an SR-2 type flexible filler in a mass ratio of 1.0:1.0.

[0041] Application Example 5 The difference between the embodiment of the present application and Application Example 1 is only that: the thermoplastic polypropylene anti-dent shielding material includes the following components in parts by weight: 50 parts of polypropylene, 40 parts of POE elastomer, 5 parts of carbon nanotubes, 0.6 part of stearamide, 0.1 part of antioxidant 1010, and 0.3 part of copper anti-agent.

[0042] Application Example 6 The difference between this application example and Application Example 1 is only that: the thermoplastic polypropylene anti-dent shielding material comprises the following components in parts by weight: 50 parts of polypropylene, 40 parts of POE elastomer, 25 parts of carbon nanotubes, 0.6 part of stearamide, 0.1 part of antioxidant 1010 and 0.3 part of copper anti-agent.

[0043] Application Comparative Example 1 The difference between this application comparative example and Application Example 1 is only that: the stranded compacted conductor comprises a central layer and a peripheral layer. Both the central layer and the peripheral layer are copper single wires with a circular structure, having a diameter of 2.88 mm. The structure of the stranded compacted conductor is stranded in a pattern of 1+6+12+18+24. On the middle 1 copper single wire, 6 copper single wires, 12 copper single wires, 18 copper single wires and 24 copper single wires are successively stranded. The compaction coefficient of the first layer of the peripheral layer is 0.85, and the compaction coefficients of the second, third and fourth layers are 0.88, 0.86 and 0.94 respectively. The pitch diameter ratio of the first layer is 24, the pitch diameter ratio of the second layer is 20, the pitch diameter ratio of the third layer is 15, and the pitch diameter ratio of the fourth layer is 14.

[0044] Application Comparative Example 2 The difference between this application comparative example and Application Example 1 is only that: the thermoplastic polypropylene anti-dent shielding material comprises the following components in parts by weight: 50 parts of polypropylene, 40 parts of POE elastomer, 0.6 part of stearamide, 0.1 part of antioxidant 1010 and 0.3 part of copper anti-agent.

[0045] For the performance tests of the polypropylene cables obtained from the above application examples and application comparative examples, in the water absorption test, the dried sample is placed in water at 85 °C for 336 h, the weight difference before and after being placed in water is measured, and the water absorption is calculated; in the high-temperature pressure test, a test tool is pressed on the specimen according to the specified force, and the specimen is placed in an air oven at 130 °C for 6 h. After the time is up, the specimen is cooled, and the percentage of the indentation depth to the cable diameter is measured; in the low-temperature tensile test, a specimen piece with a specified shape is placed on a tensile machine in a low-temperature box at -25 °C, cooled for at least 4 h, and the elongation rate is measured according to the specified tensile speed; in the flame retardancy test, the combustion height is the difference between the distance between the lower edge of the upper bracket and the starting point of the lower carbonization and the distance between the lower edge of the upper bracket and the starting point of the upper carbonization. The test results are shown in Table 1.

[0046]

[0047] The anti-sag environmental protection polypropylene cables obtained from Application Examples 1-4 meet the regulations of standards such as T / CEEIA 591-2022 and TICW 8-2012, showing excellent mechanical properties, water resistance, high temperature resistance, low temperature resistance and flame retardancy. The long-term working temperature is 105°C, which is much higher than the working temperature of 90°C for cross-linked polyethylene insulation. In the thermoplastic polypropylene anti-sag shielding material used in Application Example 5, a small amount of carbon nanotubes is added, and the fluidity of the shielding material is a bit larger, but the mechanical properties of the obtained polypropylene cable become worse and the sag phenomenon is obvious. In the thermoplastic polypropylene anti-sag shielding material used in Application Example 6, an excessive amount of carbon nanotubes is added, the fluidity of the shielding material becomes worse, the strength increases while the elasticity weakens, and the elongation at break is greatly reduced, and the service performance also becomes worse. In Comparative Example 1, the compacting coefficients of the outermost layer and the second outermost layer in the stranded compacted conductor are increased, and the sag phenomenon is relatively serious. In Comparative Example 2, in the thermoplastic polypropylene anti-sag shielding material used, no carbon nanotubes are added, the fluidity of the shielding material is even greater, the mechanical properties of the obtained polypropylene cable are even worse, and the sag phenomenon is even more obvious.

[0048] Finally, it should be noted that the specific embodiments described herein are only examples of the spirit of the present invention and not limitations on the embodiments of the present invention. Those skilled in the technical field to which the present invention pertains can make various modifications or supplements to the described embodiments or use similar methods for substitution. There is no need and no way to list all the embodiments here. And these obvious changes or variations derived from the essence of the present invention still fall within the protection scope of the present invention. Interpreting them as any additional restrictions is contrary to the spirit of the present invention.

Claims

1. A layered compacted conductor, characterized in that: The invention comprises a central layer and an outer layer, both of which are copper monofilaments of circular structure. The outer layer has at least three layers, the compression coefficient of the first layer close to the central layer is 0.83-0.85, the compression coefficient of the second layer is 0.85-0.88, the compression coefficients of the outermost layer and the second outer layer are 0.90-0.92 and 0.85-0.88 respectively.

2. The layered compressed conductor according to claim 1, characterized in that: The structure of the layered compressed conductor is layered as 1+6+12+18+24.

3. The layered compressed conductor according to claim 2, characterized in that: When the structure of the layered compressed conductor is 1+6+12+18+24, 6 copper monofilaments, 12 copper monofilaments, 18 copper monofilaments and 24 copper monofilaments are twisted in sequence on the middle copper monofilament.

4. The layered compressed conductor according to claim 2, characterized in that: The pitch-diameter ratio of the first layer of the outer layer in the layered compressed conductor is 23-27, the pitch-diameter ratio of the second layer is 19-22, the pitch-diameter ratio of the third layer is 14-16, and the pitch-diameter ratio of the fourth layer is 12-14.

5. An anti-sag environmentally friendly polypropylene cable, characterized in that: The invention comprises, from the inside to the outside, the layered compressed conductor (1), the anti-sag conductor shielding layer (2), the insulating layer (3), the insulating shielding layer (4), the metal shielding layer (5), the binding tape (6) and the sheath layer (7) as claimed in claim 1; the insulating shielding layer (4), the insulating layer (3) and the anti-sag conductor shielding layer (2) are extruded on the layered compressed conductor (1), the metal shielding layer (5) is wrapped on the insulating shielding layer (4), and the sheath layer (7) is extruded after binding.

6. The anti-sag environment-friendly polypropylene cable according to claim 5, characterized in that: The anti-sag conductor shielding layer (2) is made of thermoplastic polypropylene anti-sag shielding material.

7. The anti-sag environment-friendly polypropylene cable according to claim 6, characterized in that: The thermoplastic polypropylene anti-sag shielding material comprises the following components in parts by weight: 40-60 parts of polypropylene, 30-50 parts of POE elastomer, 10-20 parts of carbon nanotubes, 0.5-1.0 parts of lubricant, 0.1-0.5 parts of antioxidant and 0.2-0.5 parts of anti-copper agent.

8. The anti-sag environment-friendly polypropylene cable according to claim 5, characterized in that: The insulating layer (3) is made of thermoplastic polypropylene insulating material; and / or the insulating shielding layer (4) is made of thermoplastic polypropylene shielding material; and / or the metal shielding layer (5) is made of copper tape.

9. The anti-sag environment-friendly polypropylene cable according to claim 5, characterized in that: The sheath layer (7) is made of flexible polypropylene sheath material.

10. The anti-sag environment-friendly polypropylene cable according to claim 9, characterized in that: The flexible polypropylene sheath material comprises the following components in parts by weight: 100-120 parts of polypropylene resin, 60-120 parts of flexibility modifier, 0.5-2.0 parts of lubricant, 0.5-1.0 parts of antioxidant, 0.2-0.5 parts of anti-copper agent and 0.2-0.4 parts of plasticizer.

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