Copper core cross-linked polyethylene insulated B1-level halogen-free low-smoke flame-retardant special cable

Abstract

The utility model provides a copper core cross-linked polyethylene insulation B1-level halogen-free low-smoke flame-retardant special cable, which comprises a cable core, a flame-retardant filling rope, a wrapping layer, a flame-retardant adhesive tape layer, a total shielding layer, a ceramic fireproof layer and an outer sheath, wherein the cable core is formed by wrapping control wire cores and power wire cores. The cross-linked polyethylene sheath forms an outer protection layer, the ceramic fireproof layer forms a middle crusting flame-retardant layer, and the flame-retardant adhesive tape layer is combined with the expansive graphite to form an inner isolation layer, so that multiple flame-retardant isolation of the cable core is realized, drippings are combusted, toxic smoke is released to inhibit corrosion, and B1-level flame-retardant requirements are met and exceeded. And due to the use of the low-smoke halogen-free material, the release of toxic gas can be reduced during combustion. And meanwhile, the flame-retardant filling rope with double-layer hardness is twisted in the wire core, so that the whole cable is round, the cable core is fully filled with the flame-retardant material, a better flame-retardant effect is achieved, certain buffering, compression-resistant, torsion-resistant and fatigue-resistant effects are achieved, and the mechanical property of the cable is improved.

Description

Technical Field

[0001] This utility model relates to the field of wire and cable technology, and more specifically to a copper core cross-linked polyethylene insulated B1-grade halogen-free, low-smoke, flame-retardant special cable. Background Technology

[0002] B1-grade flame-retardant cables are primarily used in locations with high fire resistance, smoke control, and fire safety requirements, such as high-rise buildings, rail transit stations, airports, bus stations, train stations, hospitals, financial institutions, and other densely populated public places. With the large-scale application of high-rise buildings, electrical equipment, automated production lines, and industrial control systems, B1-grade flame-retardant wires and cables are increasingly appearing in engineering applications. These cables impose specific additional requirements on combustion (dripping materials), smoke release (smoke toxicity), and corrosiveness. They effectively suppress the spread of flames during a fire and do not release toxic gases (such as hydrogen halides) during combustion, resulting in low smoke production, which facilitates personnel evacuation and fire rescue.

[0003] The design of B1-grade halogen-free low-smoke flame-retardant cables aims to improve the stability and flame-retardant ability of materials at high temperatures by using halogen-free or low-halogen materials such as polyolefins as the insulation and sheathing materials, and by adding flame retardants such as aluminum hydroxide. This also reduces and eliminates the release of halogen gases (which are highly toxic). Simultaneously, the compact design reduces the oxygen contact area, thereby lowering the combustion rate. However, with the increasing complexity of electrical equipment in high-rise buildings, rail transit stations, airports, bus stations, train stations, hospitals, financial institutions, and other locations, as well as the use of high-power electrical equipment such as large-scale testing equipment (CT scanners, MRI scanners, radiotherapy systems, etc.), data centers, high-voltage power stations, and underground control centers, increasingly higher requirements are being placed on the mechanical properties, electromagnetic shielding performance, resistance to mechanical fatigue, low-smoke flame retardancy, and fire and temperature resistance protection levels of cables, in addition to meeting the basic B1-grade flame retardant requirement. The existing design method of using polyolefins combined with flame retardants in the sheath and insulation layers to improve flame-retardant and smoke-suppressing performance is gradually becoming insufficient. Utility Model Content

[0004] In view of the defects and deficiencies of the prior art, according to the first aspect of this utility model, a copper core cross-linked polyethylene insulated B1-grade halogen-free low-smoke flame-retardant special cable is proposed, comprising:

[0005] The cable core includes a control wire core and a power wire core twisted together with copper wires. The gap between the control wire core, the power wire core and the wrapping layer is filled with flame-retardant filler rope. The control wire core, the power wire core and the flame-retardant filler rope are wrapped by the wrapping layer to form a circular cross-section to form the cable core.

[0006] A flame-retardant tape layer is wrapped around the outer circumferential surface of the wrapping layer. Expanded graphite is covered on the surface where the flame-retardant tape layer and the wrapping layer are adhered and then bonded to the wrapping layer to form a wrapped shape.

[0007] The overall shielding layer is woven and wrapped around the outer circumferential surface of the flame-retardant tape layer;

[0008] The ceramicized fireproof layer is formed by wrapping a ceramicized fireproof silicone rubber composite tape around the outer circumferential surface of the total shielding layer; and

[0009] The outer sheath is extruded and covered on the outer circumferential surface of the ceramicized fireproof layer;

[0010] The flame-retardant filling rope includes a flame-retardant support core strip and a foamed flame-retardant layer extruded on the outside of the flame-retardant support core strip, wherein the hardness of the foamed flame-retardant layer is less than the hardness of the flame-retardant support core strip.

[0011] The ceramicized fireproof layer is a composite tape made of flame-retardant inorganic filler type silicone rubber and glass fiber cloth calendered together. The thickness of the composite tape is 0.1mm to 1mm, and it has a strength of less than 1.50g / cm³. 3 The density value.

[0012] As an optional implementation, the control core includes a control conductor, a first insulation layer extruded on the outside of the control conductor, and a first shielding layer braided on the outside of the first insulation layer, wherein the first insulation layer is a flame-retardant foam insulation layer.

[0013] As an optional implementation, the power conductor includes a power conductor core and a second insulation layer extruded onto the outside of the power conductor core, wherein the second insulation layer is a polyolefin insulation layer.

[0014] As an optional implementation, the total shielding layer includes multiple cross-woven composite shielding fibers, each composite shielding fiber comprising intertwined metal wires and semi-conductive fibers, wherein the hardness of the semi-conductive fibers is less than that of the metal wires, so that when the composite shielding fibers are bent, the metal wires can compress the semi-conductive fibers.

[0015] As an optional implementation, the weaving density of the composite shielding fiber is set to 80% to 95%.

[0016] As an optional implementation, the flame-retardant support core strip is a glass fiber bundle, and the foamed flame-retardant layer is flame-retardant EVA foam, which wraps the glass fiber bundle.

[0017] As an optional implementation, the thickness ratio of the flame-retardant support core strip to the foamed flame-retardant layer is set to 1:1 to 3.

[0018] As an optional implementation, the flame-retardant tape layer is made of polyurethane flame-retardant tape or glass fiber fabric flame-retardant tape.

[0019] As an optional embodiment, the expanded graphite is selected with a median particle size of 10μm to 200μm, and the total coverage density on the surface of the flame-retardant tape layer is 0.05g / cm³. 2 ~0.5g / cm 2 .

[0020] As an optional implementation, the outer sheath includes a cross-linked polyethylene sheath.

[0021] Compared with existing technologies, the B1-grade halogen-free, low-smoke, flame-retardant special cable proposed in this utility model achieves multiple flame-retardant barriers for the cable core through an outer layer of cross-linked polyethylene sheath, a middle layer of ceramicized fire-retardant shell, and an inner layer of flame-retardant tape combined with expandable graphite as a buffer barrier. This provides excellent suppression of combustion drips, toxic fumes, and surrounding corrosive media, meeting and exceeding the requirements of the B1-grade flame-retardant rating. The use of low-smoke, halogen-free materials reduces the release of toxic gases during combustion. Simultaneously, the double-layered, hard flame-retardant filler rope stranded within the core not only makes the cable more rounded but also allows the flame-retardant material to fully fill the core, providing better flame retardancy and offering buffering, compression resistance, torsional resistance, and fatigue resistance, thus improving the cable's mechanical properties.

[0022] The composite shielding uses a total shielding layer woven from metal wires and semi-conductive fibers, which not only has a good shielding effect, but also makes the total shielding layer more flexible and has a longer service life under bending and torsion conditions. Attached Figure Description

[0023] The accompanying drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component shown in the various figures may be denoted by the same reference numeral. For clarity, not every component is labeled in each figure. Embodiments of various aspects of the present invention will now be described by way of example and with reference to the accompanying drawings.

[0024] Figure 1 This is a schematic diagram of the cross-sectional structure of a B1-grade halogen-free, low-smoke, flame-retardant special cable as shown in an embodiment of this utility model.

[0025] Figure 2 This is a partially enlarged schematic diagram of the shielding layer in the B1-grade halogen-free, low-smoke, flame-retardant special cable shown in this embodiment of the present invention.

[0026] Figure 3 This is a schematic diagram of the cross-sectional structure of the composite shielding fiber in the B1-grade halogen-free low-smoke flame-retardant special cable shown in this embodiment of the present invention. Detailed Implementation

[0027] To better understand the technical content of this utility model, specific embodiments are provided below in conjunction with the accompanying drawings.

[0028] Example 1

[0029] Combination Figure 1 As shown, the B1-grade halogen-free low-smoke flame-retardant special cable according to an embodiment of the present utility model includes: a cable core formed by winding control wire core 10 and power wire core 20, a flame-retardant filler rope 30, a wrapping layer 40, a flame-retardant tape layer 50, a total shielding layer 60, a ceramicized fireproof layer 70, and an outer sheath 80.

[0030] Combination Figure 1 As shown, the cable core includes a control wire core 10 and a power wire core 20 twisted together with copper wires. The gap between the control wire core 10, the power wire core 20 and the wrapping layer 40 is filled with flame-retardant filler rope 30. The control wire core 10, the power wire core 20 and the flame-retardant filler rope 30 are wrapped by the wrapping layer 40 to form a circular cross-section to form the cable core.

[0031] Flame-retardant tape layer 50 is wrapped around the outer circumferential surface of wrapping layer 40. Expanded graphite is covered on the surface where flame-retardant tape layer 50 and wrapping layer 40 are attached, and then bonded to wrapping layer 40 to form a shape.

[0032] The total shielding layer 60 is woven and wrapped around the outer circumferential surface of the flame-retardant tape layer 50.

[0033] The ceramicized fireproof layer 70 is formed by wrapping a ceramicized fireproof silicone rubber composite tape around the outer circumferential surface of the total shielding layer 60.

[0034] The outer sheath 80 is extruded and wrapped around the outer circumferential surface of the ceramic fireproof layer 70.

[0035] As an optional embodiment, the flame-retardant filler rope 30 includes a flame-retardant support core strip 31 and a foamed flame-retardant layer 32 extruded on the outside of the flame-retardant support core strip 31, wherein the hardness of the foamed flame-retardant layer 32 is less than the hardness of the flame-retardant support core strip 31.

[0036] As an optional embodiment, the ceramicized fireproof layer 70 is a composite tape made of flame-retardant inorganic filler type silicone rubber and glass fiber cloth calendering, the thickness of the composite tape is 0.1mm to 1mm, and has a strength of less than 1.50g / cm³. 3 The density value.

[0037] As an optional embodiment, the control core 10 includes a control conductor 11, a first insulation layer 12 extruded on the outside of the control conductor 11, and a first shielding layer 13 braided on the outside of the first insulation layer 12, wherein the first insulation layer 12 is a flame-retardant foam insulation layer.

[0038] As an optional embodiment, the power conductor 20 includes a power conductor 21 and a second insulation layer 22 extruded on the outside of the power conductor 21, wherein the second insulation layer 22 is a polyolefin insulation layer.

[0039] As an optional embodiment, the total shielding layer 60 includes multiple cross-woven composite shielding fibers 61. The composite shielding fibers 61 include intertwined metal wires 611 and semi-conductive fibers 612, and the hardness of the semi-conductive fibers 612 is less than that of the metal wires 611, so that when the composite shielding fibers 61 are bent, the metal wires 611 can press the semi-conductive fibers 612 tightly.

[0040] As an optional embodiment, the weaving density of the composite shielding fiber 61 is set to 80% to 95%.

[0041] As an optional embodiment, the flame-retardant support core strip 31 is a glass fiber bundle, and the foamed flame-retardant layer 32 is a flame-retardant EVA foam that wraps the glass fiber bundle.

[0042] As an optional embodiment, the thickness ratio of the flame-retardant support core strip 31 to the foamed flame-retardant layer 32 is set to 1:1 to 3.

[0043] As an optional embodiment, the flame-retardant tape layer 50 is made of polyurethane flame-retardant tape or wrapped with fiberglass fabric flame-retardant tape.

[0044] As an optional embodiment, the expanded graphite is selected with a median particle size of 10 μm to 200 μm, and the total coverage density on the surface of the flame-retardant tape layer 50 is 0.05 g / cm³. 2 ~0.5g / cm 2 .

[0045] As an optional embodiment, the outer sheath 80 includes a cross-linked polyethylene sheath.

[0046] Example 2

[0047] like Figures 1 to 3 As shown, in conjunction with the copper core cross-linked polyethylene insulated B1-grade halogen-free low-smoke flame-retardant special cable of Embodiment 1 above, the specific design of the cable is further elaborated and explained in this embodiment.

[0048] The cable core uses a 1+6 twisted control core 10 and power core 20 to make the cable core structure more compact.

[0049] Combination Figure 1 As shown, the control conductor 10 includes a control conductor 11, a first insulation layer 12 extruded on the outside of the control conductor 11, and a first shielding layer 13 braided on the outside of the first insulation layer 12.

[0050] In a further design, the control conductor 11 is made of multiple twisted pairs of wires and is used for the transmission of control signals.

[0051] The first insulation layer 12 includes a flame-retardant foam insulation layer, such as flame-retardant EVA foam, which not only has good flame-retardant effect, but also good insulation and elasticity. It can work with the outer first shielding layer 13 to make the control wire core 10 more flexible. When the control wire core 10 is bent or twisted, the first shielding layer 13 can compress the space of the first insulation layer 12 inward, thereby releasing the stress when the first shielding layer 13 is bent, making the control wire core 10 resistant to bending and twisting, and improving mechanical properties.

[0052] Combination Figure 1 The power conductor 20 shown includes a power conductor 21 and a second insulation layer 22 extruded on the outside of the power conductor 21.

[0053] The power conductor 21 is made of multiple annealed oxygen-free fine metal wires twisted together, and the second insulation layer 22 is extruded with cross-linked polyethylene to form a flexible insulation layer.

[0054] Preferably, both the control conductor 11 and the power conductor 21 are made of annealed oxygen-free copper wire.

[0055] In a further design, when the power conductor 20 is twisted with the control conductor 10, the flame-retardant foam insulation layer filled in the control conductor 10 can also provide stress relief space for the cable core to bend.

[0056] Furthermore, the flame-retardant filler rope 30 inside the cable core is wrapped by the wrapping layer 40, making the cross-section of the cable core circular. The wrapping layer 40 is made of polyester tape with an overlap rate of 25% to 40%, and the cable core is wrapped by a wrapping machine.

[0057] As an optional embodiment, the flame-retardant filler rope 30 includes a flame-retardant support core strip 31 and a foamed flame-retardant layer 32 extruded onto the outside of the flame-retardant support core strip 31. The flame-retardant support core strip 31 is made of glass fiber bundles, and the foamed flame-retardant layer 32 is made of flame-retardant EVA foam, which wraps around the glass fiber bundles. The density of the flame-retardant support core strip 31 is greater than the density of the foamed flame-retardant layer 32, making the hardness of the foamed flame-retardant layer 32 less than the hardness of the flame-retardant support core strip 31.

[0058] In a preferred embodiment, the thickness ratio of the flame-retardant support core strip 31 to the foamed flame-retardant layer 32 is set to 1:1 to 3. In this way, the flame-retardant support core strip 31 located in the inner layer plays a supporting and shaping role, while the foamed flame-retardant layer 32 in the outer layer can fill the gaps and fill the gap space. This not only makes the cable more round, but also allows the flame-retardant material to be fully filled into the cable core, thus playing a better flame-retardant role.

[0059] Combined with appendix Figure 1As shown, a flame-retardant tape layer 50 is wrapped around the outer circumferential surface of a wrapping layer 40. Expanded graphite is covered on the surface where the flame-retardant tape layer 50 and the wrapping layer 40 are bonded together and then bonded to the wrapping layer 40 to form a wrapped shape.

[0060] As an example, the flame-retardant tape layer 50 is made of polyurethane flame-retardant tape or fiberglass fabric flame-retardant tape. The expanded graphite is selected with a median particle size of 10μm to 200μm, preferably 10μm to 100μm, and the total coverage density on the surface of the flame-retardant tape layer 50 is 0.05 g / cm³. 2 ~0.5g / cm 2 Therefore, when the cable catches fire, the expandable graphite can expand rapidly upon heating, increasing its surface area and using its worm-like structure to form interlocking layers, which then bond to the surface of the flame-retardant tape layer 50 to form an insulating layer, preventing further combustion and thus playing a flame-retardant role.

[0061] To be understood, in the embodiments of the present invention, the adhesive layer coated on the surface of the polyurethane flame-retardant tape or the fiberglass fabric flame-retardant tape serves to adhere the expanded graphite powder. The adhesive layer is thin and can be made of silicone rubber adhesive or acrylic adhesive with a high temperature resistance range of approximately 200-250°C, achieving the temperature resistance level of the cross-linked polyethylene sheath. When the cable experiences a short circuit or combustion, the resulting high temperatures will gradually cause the expanded graphite to overcome the interlayer bonding force and rapidly expand (up to 100-300 times) to form an insulating bonding layer.

[0062] Combined with appendix Figure 1 As shown, the total shielding layer 60 is woven and wrapped around the outside of the flame-retardant tape layer 50. (In conjunction with the attached...) Figure 2 , 3 As shown, the total shielding layer 60 includes multiple cross-woven composite shielding fibers 61. The composite shielding fibers 61 include intertwined metal wires 611 and semi-conductive fibers 612. The hardness of the semi-conductive fibers 612 is less than that of the metal wires 611, so that when the composite shielding fibers 61 are bent, the metal wires 611 can compress the semi-conductive fibers 612.

[0063] In some embodiments, the semi-conductive fiber 612 may be made of conductive polymer material, such as polyaniline. The conductive polyaniline fiber prepared by chemical synthesis and spinning technology has good stability and conductivity. The total shielding layer 60 formed by twisting the metal wire 611 and the semi-conductive fiber 612 together not only improves the shielding effect of the existing design using metal wire weaving alone, but also makes the total shielding layer 60 more flexible as a whole.

[0064] Specifically, the metal wire 611 and the semi-conductive fiber 612 are twisted together in a 1+N structure, with one of the semi-conductive fibers 612 located at the center.

[0065] As an example, the weaving density of the composite shielding fiber 61 is set to 80%–95%.

[0066] Therefore, the total shielding layer 60 has the effect of significantly improving the shielding effectiveness and enhancing the reliability of signal transmission for the inner control core 10 and power core 20.

[0067] The ceramicized fireproof layer 70 is formed by wrapping a ceramicized fireproof silicone rubber composite tape around the outer circumference of the main shielding layer 60. The ceramicized fireproof layer 70 is a composite tape made of flame-retardant inorganic filler silicone rubber and glass fiber cloth calendering. The ceramicized fireproof layer can quickly form a dense and hard ceramic body at high temperatures, which can effectively prevent the spread of flames. In addition, the ceramic body has good heat insulation properties, which can reduce the transfer of heat to the protected object or structure. Especially in the field of wire and cable, the ceramicized fireproof layer can ensure the uninterrupted operation of power and communication lines in a fire, and buy valuable time for personnel escape and property rescue.

[0068] As an example, combined Figure 1 The outer sheath 80 is made of cross-linked polyethylene and is extruded and wrapped around the outside of the ceramic fireproof layer 70.

[0069] As a high-strength, heat-resistant, cold-resistant, water-resistant, and non-aging cable sheath material, cross-linked polyethylene sheath is halogen-free, non-flammable, and produces less smoke when burning. It meets fire protection standards such as UL94V0 and environmental standards such as RoHS and REACH.

[0070] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Those skilled in the art to which this invention pertains can make various modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of this invention shall be determined by the claims.

Claims

1. A copper-core, cross-linked polyethylene-insulated, B1-grade halogen-free, low-smoke, flame-retardant special cable, characterized in that... include: The cable core includes a control wire core (10) and a power wire core (20) twisted together with copper wires. The gap between the control wire core (10), the power wire core (20) and the wrapping layer (40) is filled with flame-retardant filler rope (30). The control wire core (10), the power wire core (20) and the flame-retardant filler rope (30) are wrapped by the wrapping layer (40) so that their cross-section forms a circle to form the cable core. Flame-retardant tape layer (50) is wrapped around the outer circumferential surface of the wrapping layer (40). Expanded graphite is covered on the surface of the flame-retardant tape layer (50) and the wrapping layer (40) and then bonded and wrapped with the wrapping layer (40) to form a shape. The total shielding layer (60) is woven and wrapped around the outer circumferential surface of the flame-retardant tape layer (50); The ceramicized fireproof layer (70) is formed by wrapping a ceramicized fireproof silicone rubber composite tape around the outer circumferential surface of the total shielding layer (60); as well as The outer sheath (80) is extruded and covered on the outer circumferential surface of the ceramicized fireproof layer (70); The flame-retardant filling rope (30) includes a flame-retardant support core strip (31) and a foamed flame-retardant layer (32) extruded on the outside of the flame-retardant support core strip (31). The hardness of the foamed flame-retardant layer (32) is less than that of the flame-retardant support core strip (31). The ceramicized fireproof layer (70) is a composite tape made of flame-retardant inorganic filler type silicone rubber and glass fiber cloth calendering. The thickness of the composite tape is 0.1mm to 1mm, and it has a strength of less than 1.50g / cm³. 3 The density value.

2. The copper core cross-linked polyethylene insulated B1-grade halogen-free low-smoke flame-retardant special cable according to claim 1, characterized in that, The control core (10) includes a control conductor (11), a first insulation layer (12) extruded on the outside of the control conductor (11), and a first shielding layer (13) braided on the outside of the first insulation layer (12), wherein the first insulation layer (12) is a flame-retardant foam insulation layer.

3. The copper core cross-linked polyethylene insulated B1-grade halogen-free low-smoke flame-retardant special cable according to claim 1, characterized in that, The power conductor (20) includes a power conductor (21) and a second insulation layer (22) extruded on the outside of the power conductor (21), wherein the second insulation layer (22) is a polyolefin insulation layer.

4. The copper core cross-linked polyethylene insulated B1-grade halogen-free low-smoke flame-retardant special cable according to claim 1, characterized in that, The total shielding layer (60) includes multiple cross-woven composite shielding fibers (61). The composite shielding fibers (61) include twisted metal wires (611) and semi-conductive fibers (612). The hardness of the semi-conductive fibers (612) is less than that of the metal wires (611), so that when the composite shielding fibers (61) are bent, the metal wires (611) can press the semi-conductive fibers (612) together.

5. The copper core cross-linked polyethylene insulated B1-grade halogen-free low-smoke flame-retardant special cable according to claim 4, characterized in that, The weaving density of the composite shielding fiber (61) is set to 80%–95%.

6. The copper core cross-linked polyethylene insulated B1-grade halogen-free low-smoke flame-retardant special cable according to claim 5, characterized in that, The flame-retardant support core strip (31) is a glass fiber bundle, and the foamed flame-retardant layer (32) is a flame-retardant EVA foam that wraps the glass fiber bundle.

7. The copper core cross-linked polyethylene insulated B1-grade halogen-free low-smoke flame-retardant special cable according to claim 1 or 6, characterized in that, The thickness ratio of the flame-retardant support core strip (31) to the foamed flame-retardant layer (32) is set to 1:1 to 3.

8. The copper core cross-linked polyethylene insulated B1-grade halogen-free low-smoke flame-retardant special cable according to claim 1, characterized in that, The flame-retardant tape layer (50) is made of polyurethane flame-retardant tape or glass fiber fabric flame-retardant tape.

9. The copper core cross-linked polyethylene insulated B1-grade halogen-free low-smoke flame-retardant special cable according to claim 8, characterized in that, The expanded graphite is selected with a median particle size of 10μm to 200μm, and the total coverage density on the surface of the flame-retardant tape layer (50) is 0.05g / cm³. 2 ~0.5g / cm 2 .

10. The copper core cross-linked polyethylene insulated B1-grade halogen-free low-smoke flame-retardant special cable according to claim 1, characterized in that, The outer sheath (80) includes a cross-linked polyethylene sheath.

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