Polyvinyl chloride flame-retardant cable

Abstract

The utility model discloses a polyvinyl chloride flame-retardant cable, which comprises a cable core, an inner sheath, a first water-blocking tape layer, a water-blocking yarn filling layer, a second water-blocking tape layer, a plurality of first wrapping tape layers, a second wrapping tape layer and a metal sheath which are sequentially arranged from inside to outside. Wherein the cable core comprises a plurality of composite wire cores, and each composite wire core comprises a conductor, an insulating layer and a third wrapping tape layer which are sequentially arranged from inside to outside. The combination of the first water-blocking tape layer, the water-blocking yarn filling layer and the second water-blocking tape layer is adopted in the sheath structure, the combination structure design can effectively prevent water from invading the cable conductor, the conductor and the insulating layer in the cable are effectively protected from being affected by the humid environment, and therefore the reliability and the safety of the cable are ensured. Through the multi-layer water-blocking structure, the cable can maintain stable performance in a severe environment, and safety accidents caused by electrical faults are reduced.

Description

Technical Field

[0001] This utility model relates to the field of wire and cable technology, specifically to a polyvinyl chloride flame-retardant cable. Background Technology

[0002] GB31247-2014 "Classification of Combustion Performance of Cables and Optical Fibers" classifies the combustion performance of wires and cables into four levels: A, B1, B2 and B3. Among them, Class A (non-combustible cable) requires that the total calorific value (PCS) of the cable tested according to GB / T14402 "Determination of Combustion Performance and Calorific Value of Building Materials and Products" be ≤2.0MJ / kg to be judged as Class A.

[0003] Chinese utility model patent CN218730058U discloses a novel flame-retardant Class A power cable, comprising a cable core, multiple layers of first wrapping tape, second wrapping tape, and a metal sheath arranged sequentially from the inside out. The cable core includes multiple composite cores, each comprising a conductor, an insulation layer, and a third wrapping tape layer arranged sequentially from the inside out. The first wrapping tape layer is calcined mica tape wrapped around the cable core; the second wrapping tape layer is glass fiber tape wrapped around the first wrapping tape layer; and the third wrapping tape layer is calcined mica tape wrapped around the insulation layer. Through the above-mentioned reasonable structural design and material selection, the cable of this technology has passed combustion and fire resistance performance tests, and its combustion performance meets the Class A requirements of standard GB31247-2014 "Classification of Combustion Performance of Cables and Optical Fibers".

[0004] However, the applicant's research revealed that the existing products lack sufficient waterproofing. During transportation, laying, and pulling operations, if the metal sheath is damaged, moisture cannot be prevented from penetrating the cable, potentially causing safety accidents. Utility Model Content

[0005] To overcome the above-mentioned technical defects, this utility model provides a polyvinyl chloride flame-retardant cable.

[0006] To solve the above problems, this utility model is implemented according to the following technical solution:

[0007] The present invention discloses a polyvinyl chloride flame-retardant cable, comprising, from the inside out, a cable core, an inner sheath, a first water-blocking tape layer, a water-blocking yarn filling layer, a second water-blocking tape layer, multiple first wrapping tape layers, second wrapping tape layers, and a metal sheath.

[0008] The cable core includes multiple composite cores, each composite core comprising a conductor, an insulation layer, and a third wrapping tape layer arranged sequentially from the inside out.

[0009] Preferably, the first wrapping layer is calcined mica tape wrapped around the cable core;

[0010] The second wrapping tape layer is a glass fiber tape wrapped around the first wrapping tape layer;

[0011] The third wrapping layer is calcined mica tape wrapped around the insulating layer.

[0012] Preferably, the PVC flame-retardant cable has 3 to 6 layers of first wrapping tape.

[0013] Preferably, the inner sheath is made of polyvinyl chloride sheath material extruded and covered on the second water-blocking strip layer.

[0014] Preferably, the gaps in the cable core are filled with filler rope and water-blocking adhesive, wherein the filler rope is water-blocking yarn.

[0015] Preferably, the insulating layer is a polyetheretherketone material extruded and covered on the conductor.

[0016] Preferably, the metal sheath is an argon-arc welded corrugated copper tube.

[0017] Compared with the prior art, the beneficial effects of this utility model are:

[0018] This utility model provides a polyvinyl chloride flame-retardant cable, comprising, from the inside out, a cable core, an inner sheath, a first water-blocking tape layer, a water-blocking yarn filling layer, a second water-blocking tape layer, multiple first wrapping tape layers, second wrapping tape layers, and a metal sheath. The cable core comprises multiple composite cores, each composite core comprising, from the inside out, a conductor, an insulation layer, and a third wrapping tape layer.

[0019] The sheath structure employs a combination of a first water-blocking tape layer, a water-blocking yarn filling layer, and a second water-blocking tape layer. This combined structural design effectively prevents moisture from penetrating the cable conductor, protecting the internal conductor and insulation layers from the effects of a humid environment, thereby ensuring the cable's reliability and safety. Through this multi-layered water-blocking structure, the cable can maintain stable performance in harsh environments and reduce safety accidents caused by electrical faults. Attached Figure Description

[0020] The specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings, wherein:

[0021] Figure 1 This is a schematic diagram of the cross-sectional structure of the polyvinyl chloride flame-retardant cable of this utility model;

[0022] In the picture:

[0023] 10-Cable core, 11-Conductor, 12-Insulation layer, 13-Third wrapping tape layer;

[0024] 20-Inner sheath;

[0025] 30 - First water-blocking layer;

[0026] 40 - Water-resistant yarn filling layer;

[0027] 50 - Second water-blocking layer;

[0028] 60 - First wrapping tape layer;

[0029] 70 - Second wrapping tape layer;

[0030] 80 - Metal sheath. Detailed Implementation

[0031] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0032] like Figure 1 As shown, this utility model discloses a preferred structure for a polyvinyl chloride flame-retardant cable.

[0033] like Figure 1 As shown, the PVC flame-retardant cable includes, from the inside out, a cable core 10, an inner sheath 20, a first water-blocking tape layer 30, a water-blocking yarn filling layer 40, a second water-blocking tape layer 50, multiple first wrapping tape layers 60, second wrapping tape layers 70, and a metal sheath 80. The cable core includes multiple composite cores, and each composite core includes, from the inside out, a conductor 11, an insulation layer 12, and a third wrapping tape layer 13.

[0034] In one specific implementation, the inner sheath is made of polyvinyl chloride (PVC) extruded and covered onto the cable core. The inner sheath is located outside the cable core and serves to protect the cable core and insulation layer, preventing damage to the internal structure of the cable from the external environment.

[0035] In practical implementation, this technology imparts water-blocking properties to the cable through a combined structure of a first water-blocking tape layer, a water-blocking yarn filling layer, and a second water-blocking tape layer. Specifically, both the first and second water-blocking tape layers are formed by wrapping semi-conductive water-blocking tape. The layer structure is formed by a dense wrapping process using overlapping wrapping. The wrapping overlap rate is preferably between 25% and 35%. This overlap rate helps to form a denser waterproof layer, effectively preventing moisture intrusion.

[0036] In this field, water-blocking yarn is made by coating fibers with a water-absorbing material, wherein the surface of the yarn fibers is coated with the water-absorbing material. In a specific embodiment, water-blocking yarn is made by coating polyester fibers with a water-absorbing material.

[0037] The sheath structure of this technology employs a combination of a first water-blocking tape layer, a water-blocking yarn filling layer, and a second water-blocking tape layer. This combined structure effectively prevents moisture from penetrating the cable conductor, effectively protecting the internal conductor and insulation layer from the effects of a humid environment, thereby ensuring the reliability and safety of the cable. Through this multi-layered water-blocking structure, the cable can maintain stable performance in harsh environments and reduce safety accidents caused by electrical faults.

[0038] The first wrapping layer is calcined mica tape wrapped around the cable core; the second wrapping layer is glass fiber tape wrapped around the first wrapping layer; and the third wrapping layer is calcined mica tape wrapped around the insulation layer.

[0039] This invention addresses the numerous drawbacks of magnesium oxide mineral-insulated cables. Therefore, this PVC flame-retardant cable utilizes calcined mica tape as the insulation material, wrapping it around the conductor and applying multiple layers of calcined mica tape during cabling. Calcined mica tape is a composite material with extremely low calorific value.

[0040] On the other hand, a protective layer needs to be designed during cable cabling to prevent insulation damage during armoring, which would affect the cable's electrical performance. Therefore, this technology employs a multi-layer calcined mica tape + fiberglass tape. The fiberglass tape meets the Class A flammability requirements for materials. The multi-layer calcined mica tape also prevents broken fibers from the fiberglass tape from penetrating the cable core insulation layer, thus avoiding a decrease in cable insulation resistance.

[0041] In one specific implementation, the polyvinyl chloride flame-retardant cable is provided with 3 to 6 layers of first wrapping tape.

[0042] In one specific implementation, filler ropes are inserted into the gaps between the cable cores to ensure the cable's roundness. Multi-core cables need to be bundled, and filling is required during bundling to ensure the cable's roundness; the filler material also affects the performance of the finished product.

[0043] In this field, the filling materials for multi-core cables mainly include halogen-free flame-retardant filling rope, fiberglass rope, and ceramicized silicone filling strips. To optimize the water-blocking performance of the cable, in this invention, the filling rope is water-blocking yarn, and the gaps between the cable cores are filled with water-blocking yarn and water-blocking adhesive.

[0044] Specifically, the water-blocking adhesive is a semi-conductive resistive water-blocking adhesive.

[0045] In a preferred embodiment, the insulation layer is a polyetheretherketone (PEEK) material extruded onto the conductor. PEEK has a high melting point (334°C) and glass transition temperature (143°C), with a continuous operating temperature of 260°C; its use in the inner sheath meets the requirements for cable operation in high-temperature environments. PEEK is self-extinguishing and, even without any flame retardants, achieves the UL standard 94V-0 rating, the optimal level of flame retardancy.

[0046] In a preferred embodiment, the metal sheath is an argon-arc welded corrugated copper tube. After cabling, an armor layer needs to be designed outside the cable core to ensure that the fire resistance meets the standard requirements. Copper has a melting point of approximately 1083°C, at which point aluminum will melt, making it impossible to prevent moisture from entering the cable core. Therefore, an argon-arc welded corrugated copper tube was chosen for the metal sheath layer.

[0047] Through the above-mentioned reasonable structural design and material selection, the cable of this technology underwent combustion and fire resistance performance testing. The cable's combustion performance meets the Class A requirements of standard GB31247-2014 "Classification of Combustion Performance of Cables and Optical Fibers". Simultaneously, its fire resistance meets the requirements of BS8491:2008, meaning that the cable can continuously supply power to fire-fighting equipment for no less than 180 minutes under a 950℃ flame.

[0048] This utility model, through a rationally designed structure, meets the requirements of Class A flammability and circuit integrity, ensuring normal power supply under flame conditions while preventing the released heat from igniting flammable materials around the cable, thus guaranteeing the safety of personnel and property.

[0049] Other structures of the polyvinyl chloride flame-retardant cable described in this embodiment are referred to in the prior art.

[0050] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Therefore, any modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present utility model without departing from the technical solution of the present utility model shall still fall within the scope of the technical solution of the present utility model.

Claims

1. A flame-retardant polyvinyl chloride cable, characterized in that, It includes, from the inside out, a cable core, an inner sheath, a first water-blocking tape layer, a water-blocking yarn filling layer, a second water-blocking tape layer, multiple first wrapping tape layers, second wrapping tape layers, and a metal sheath; The cable core includes multiple composite cores, each composite core comprising a conductor, an insulation layer, and a third wrapping tape layer arranged sequentially from the inside out.

2. The polyvinyl chloride flame-retardant cable according to claim 1, characterized in that: The first wrapping layer is calcined mica tape wrapped around the cable core; The second wrapping tape layer is a glass fiber tape wrapped around the first wrapping tape layer; The third wrapping layer is calcined mica tape wrapped around the insulating layer.

3. The polyvinyl chloride flame-retardant cable according to claim 2, characterized in that: The PVC flame-retardant cable is provided with 3 to 6 layers of first wrapping tape.

4. The polyvinyl chloride flame-retardant cable according to claim 1, characterized in that: The inner sheath is made of polyvinyl chloride sheath material extruded and covered on the cable core.

5. A polyvinyl chloride flame-retardant cable according to claim 1, characterized in that: The gaps in the cable cores are filled with filler rope and water-blocking adhesive, and the filler rope is water-blocking yarn.

6. A polyvinyl chloride flame-retardant cable according to claim 1, characterized in that: The insulating layer is a polyetheretherketone material extruded and covered on the conductor.

7. A polyvinyl chloride flame-retardant cable according to claim 1, characterized in that: The metal sheath is an argon-arc welded corrugated copper tube.

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