CN210925570U - Low-smoke halogen-free fire-resistant cable - Google Patents

Abstract

The utility model provides a low-smoke halogen-free fireproof cable, which comprises a low-smoke halogen-free flame-retardant polyolefin layer, a non-woven fabric belt, a glass fiber belt, an insulating filling layer and a plurality of cable core units from outside to inside in sequence; the low-smoke halogen-free flame-retardant polyolefin layer has good fire resistance, corrosion resistance and mechanical property, and reduces the release of toxic and harmful gases; the speed of temperature spreading to the core cable core unit during flame combustion is further ensured, and the fire-resistant efficiency is improved; the insulating filling layer can ensure that the cable does not support combustion when a fire disaster and flame combustion happen, and the structural requirements of the fire-resistant cable are met. The ceramic polyolefin insulating layer adopted by each cable core unit can be crusted when receiving flame high temperature, and can not burn like crosslinked polyethylene, and the insulating effect can still be achieved after crusting.

Description

Low-smoke halogen-free fire-resistant cable

Technical Field

The utility model belongs to the technical field of the cable, concretely relates to low smoke and zero halogen fire resisting cable.

Background

With the development of modern science and technology, energy and information are indispensable resources, and the transmission of electric energy and information can not be separated from cables, but unsafe cables are also one of important ways for spreading fire. According to incomplete statistics, accidents caused by cables in fire occupy about 35%, and about one third of dead people are suffocated and die due to toxic gas released when the cables are inhaled and burned. Thus, the prevention of cable burning, the prevention of the release of toxic and harmful corrosive gases and fumes has been a problem that must be faced by the cable industry.

The conventional fire-resistant cable protective layer material is mainly selected from fire-resistant polyvinyl chloride, chlorosulfonated polyethylene and other halogen-containing materials to prevent the spread of fire. However, these fire-resistant cables are flammable materials, and the materials release a large amount of toxic and harmful smoke and corrosive gases during combustion, so that the poor light transmission of the gases causes difficulties in fire scene escape and rescue, and the toxic gases easily suffocate people, thus seriously endangering the safety of lives and properties of people.

In order to achieve the purpose of fire prevention and fire resistance, high amount of sodium hydroxide or magnesium hydroxide or traditional high-efficiency fire retardants are added into polyethylene. The addition of high-content alkali can generate negative effects on the mechanical, physical and rheological properties and the processing capacity of polyolefin, a flame retardant coating adopted in the manufacturing process is mineral mud formed by mixing magnesium hydroxide and glue, belongs to a semi-conductive structure, an insulating single phase can be punctured to the mineral mud in a place with slightly damaged or thinner insulation, and the problem cannot be solved by only increasing the insulation thickness at present; in the preparation process, the mineral mud is soft in the extrusion process, and sometimes the mineral mud is not very stable in the extrusion process, so that the outer diameter of a cable core is not uniform, the outer diameter of a finished product is not uniform, the selection of a matched die is influenced, the use amount of materials for driving is influenced, and the appearance quality of the cable is also influenced; mineral mud is used as a fire-resistant layer, water can be separated out after a long time, and the quality and the service life of the cable are affected to a certain degree.

The traditional high-efficiency fire retardant generally contains halogen, particularly bromine, has high fire resistance efficiency, and has good fire resistance effect on high polymer materials after the fire retardant is compounded with antimony trioxide. However, such fire-resistant agents are gradually forbidden due to the fact that a large amount of hydrogen halide and smoke are released during combustion or processing, which causes secondary pollution to the environment.

Chinese patent 201610171783.9 discloses a magnesium hydroxide fire-resistant agent and a fire-resistant polymer for cables, a highly fire-resistant EVA resin cable material, the raw materials of which comprise EVA resin, ABS resin, PVC, chlorinated polyethylene, dicumyl peroxide, maleic anhydride, acrylic acid, methacrylic acid, modified magnesium hydroxide, sodium stearate, polyphosphate, low-density polyethylene, liquid paraffin, styrene, wood flour, red phosphorus, organic silicon, a fire-resistant agent, a phase solvent and an antioxidant. The utility model discloses a cable material mixes the modification through adding modified magnesium hydrate to the EVA resin, and then has improved the fire resistance of cable.

SUMMERY OF THE UTILITY MODEL

The utility model is directed to the above-mentioned defect, provide a effectively reduce cable poisonous and harmful gas, the fire resistance good, the corrosion resisting property good and the good low smoke and zero halogen fire resisting cable of mechanical properties of conflagration in-process release.

The utility model provides a following technical scheme:

a low-smoke halogen-free fire-resistant cable comprises a low-smoke halogen-free flame-retardant polyolefin layer, a non-woven fabric belt, a glass fiber belt, an insulating filling layer and a plurality of cable core units from outside to inside in sequence; the cable core unit comprises a ceramic polyolefin insulating layer, a mica tape insulating layer, a semi-conductive layer and a conductor from outside to inside in sequence.

As a further improvement of the above technical solution:

the mica tape insulating layer is formed by 2 layers of mica tapes with the thickness of 0.10 mm-0.20 mm in an overlapping and wrapping mode.

The cover overlapping rate of the mica tape is 15-25%.

The cover lapping rate of the glass fiber belt on the insulating filling layer is 10% -15%.

The conductor is formed by twisting a plurality of metal wires.

The lead is a silver-plated copper lead, and the thickness of the silver plating layer is not less than 2 mu m.

The cable core units are formed by winding and twisting in the same direction, and the pitch-diameter ratio is 30-40.

The semi-conductive layer is a modified graphene oxide layer.

The insulating filling layer is an inorganic rope or a glass fiber rope.

The utility model has the advantages that:

1) the distance between the insulating filling layer and the low-smoke halogen-free flame-retardant polyolefin layer is increased structurally through the non-woven fabric belt and the glass fiber belt, so that the speed of temperature spreading to a core cable core unit during flame combustion is further ensured, and the fire-resistant efficiency is improved; the insulating filling layer can ensure that the cable does not support combustion when a fire disaster and flame combustion happen, and the structural requirements of the fire-resistant cable are met. The ceramic polyolefin insulating layer that every cable core unit adopted can crust when receiving flame high temperature, can not burn like crosslinked polyethylene, still can play insulating effect after the crust, through adding the mica tape insulating layer, modified oxidation graphite alkene layer has further improved the fire resistance and the corrosion resisting property of every cable core unit between conductor and ceramic polyolefin insulating layer, guaranteed the normal transmission of cable internal current, can not inside because corrode the back, conductor contact between the cable core unit, lead to conflagration or circuit fault that the short circuit caused.

2) The pi orbitals of the graphene oxide employed form a dense delocalized electron cloud and subsequently block the gaps in its aromatic ring, thereby creating repulsive fields to the reacting atoms or molecules, thereby forming an intrinsic impermeability to most molecules. The geometrical pores of the graphene lattice are 0.064nm, theoretically preventing the formation of small molecules such as helium (0.208nm) and hydrogen (0.314nm), which makes graphene oxide possess passivation properties to protect the internal metals from oxidation and corrosion, even in harsh electrochemical environments. In addition, the graphene modified by phenylenediamine can effectively ensure the affinity to metals and inorganic substances, so that the technical problem of poor adhesion force which often causes delamination in application is solved, and the stacked phenylenediamine modified graphene layer can be used as a diffusion barrier between an internal conductor and a reactive chemical substance.

3) The utility model adopts the insulating material as the filling material of the insulating filling layer, even if the insulating layer has slight damage or is thin, the problem of single-phase breakdown can not occur directly, and the insulating layer of other phases is isolated from the insulating layer; because the cable is filled with inorganic ropes or glass fiber ropes, the outer diameter of the formed cable is more round compared with mineral mud, the outer diameter of a finished product is also more round, and the outer diameter is also more stable; compared with the mineral mud material in the prior art, the ceramic polyolefin insulating layer adopted by the cable core unit is safer and more stable, is directly ceramic during combustion, and has more advantages in fire resistance and insulating property; the extrusion of the extrusion contrast mineral mud of ceramic polyolefin is more convenient in the preparation cable, directly can go on the PVC extruder, and productivity and cost of labor contrast mineral mud can all be little a lot.

Drawings

The present invention will be described in more detail hereinafter based on embodiments and with reference to the accompanying drawings. Wherein:

fig. 1 is a schematic cross-sectional view of a low-smoke halogen-free fire-resistant cable provided in embodiment 1 of the present invention;

fig. 2 is a schematic cross-sectional view of a low-smoke halogen-free fire-resistant cable provided in embodiment 2 of the present invention;

fig. 3 is a schematic cross-sectional view of a low-smoke halogen-free fire-resistant cable provided in embodiment 3 of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

Example 1

As shown in fig. 1, the low-smoke halogen-free fire-resistant cable provided in this embodiment sequentially includes, from outside to inside, a low-smoke halogen-free flame-retardant polyolefin layer 1, a non-woven fabric tape 2, a glass fiber tape 3, an insulating filling layer 4, and 5 cable core units 5; the 5 cable core units 5 are twisted in the same direction, and the pitch-diameter ratio is 30. Each cable core unit 5 sequentially comprises a ceramic polyolefin insulating layer 5-1, a mica tape insulating layer 5-2, a modified graphene oxide layer 5-3 and a conductor 5-4 from outside to inside. The mica tape insulating layer 5-2 is composed of 2 layers of 0.10mm mica tapes 5-2, the cover ratio of the mica tapes is 15%, the cover ratio of the glass fiber tapes 3 to the insulating filling layer 4 is 10%, and the insulating filling layer 4 is an inorganic rope. The conductors 5-4 are formed by twisting a plurality of silver-plated copper wires, and the thickness of the silver plating layer is 2 mu m. The thickness of the low smoke halogen-free flame retardant polyolefin layer 1 is 0.035+1mm of outer diameter before extrusion.

Example 2

As shown in fig. 2, the low-smoke halogen-free fire-resistant cable provided in this embodiment sequentially includes, from outside to inside, a low-smoke halogen-free flame-retardant polyolefin layer 1, a non-woven fabric tape 2, a glass fiber tape 3, an insulating filling layer 4, and 4 cable core units 5; the 4 cable core units 5 are twisted in the same direction, and the pitch-diameter ratio is 40. Each cable core unit 5 sequentially comprises a ceramic polyolefin insulating layer 5-1, a mica tape insulating layer 5-2, a modified graphene oxide layer 5-3 and a conductor 5-4 from outside to inside. Wherein, the mica tape insulating layer 5-2 consists of two layers of mica tapes, namely 5-21 mica tapes and 5-22 mica tapes, the thicknesses of the two layers of mica tapes are 0.12mm and 0.15mm respectively, and the overlapping rate of the mica tapes is 25 percent. The cover lapping rate of the glass fiber belt on the insulating filling layer is 12%, and the insulating filling layer is a glass fiber rope. The conductor 5-4 is formed by twisting a plurality of silver-plated copper wires, and the thickness of the silver plating layer is 2.5 mu m. The thickness of the low smoke halogen-free flame retardant polyolefin layer 1 is 0.035+1mm of outer diameter before extrusion.

Example 3

As shown in fig. 3, the low-smoke halogen-free fire-resistant cable provided in this embodiment sequentially includes, from outside to inside, a low-smoke halogen-free flame-retardant polyolefin layer 1, a non-woven fabric tape 2, a glass fiber tape 3, an insulating filling layer 4, and 5 cable core units 5; the 5 cable core units 5 are twisted in the same direction, and the pitch-diameter ratio is 35. Each cable core unit 5 sequentially comprises a ceramic polyolefin insulating layer 5-1, a mica tape insulating layer 5-2, a phenylenediamine modified graphene oxide layer 5-3 and a conductor 5-4 from outside to inside. Wherein, the mica tape insulating layer 5-2 consists of two layers of mica tapes, namely 5-21 mica tapes and 5-22 mica tapes, the thickness of the two layers of mica tapes is 0.20mm respectively, and the overlapping rate of the mica tapes is 20%. The overlapping rate of the glass fiber belt 3 on the insulating filling layer 4 is 15%, and the insulating filling layer 4 is an inorganic rope. The conductors 5-4 are formed by twisting a plurality of silver-plated copper wires, and the thickness of the silver plating layer is 2.2 mu m. The thickness of the low smoke halogen-free flame retardant polyolefin layer 1 is 0.035+1mm of outer diameter before extrusion.

While the invention has been described with reference to a preferred embodiment, various modifications may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In particular, the technical features mentioned in the embodiments can be combined in any way as long as there is no structural conflict. The present invention is not limited to the particular embodiments disclosed herein, but encompasses all technical solutions falling within the scope of the claims.

Claims (7)

1. A low-smoke halogen-free fireproof cable is characterized by comprising a low-smoke halogen-free flame-retardant polyolefin layer (1), a non-woven fabric belt (2), a glass fiber belt (3), an insulating filling layer (4) and a plurality of cable core units (5) from outside to inside in sequence; the cable core unit (5) comprises a ceramic polyolefin insulating layer (5-1), a mica tape insulating layer (5-2), a semi-conductive layer (5-3) and a conductor (5-4) from outside to inside in sequence.

2. The low-smoke zero-halogen fire-resistant cable according to claim 1, wherein the mica tape insulating layer (5-2) is formed by 2 layers of 0.10 mm-0.20 mm thick mica tape by overlapping and lapping.

3. The low smoke zero halogen fire resistant cable of claim 2, wherein the mica tape overlapping rate is 15% -25%.

4. The low-smoke zero-halogen fire-resistant cable according to claim 1, wherein the overlapping rate of the glass fiber tape (3) to the insulating filling layer (4) is 10-15%.

5. The low smoke zero halogen fire resistant cable of claim 1, wherein said conductor (5-4) is formed by twisting a plurality of metal wires.

6. The low smoke zero halogen fire resistant cable of claim 5, wherein the wires are silver-plated copper wires, and the thickness of the silver plating layer is not less than 2 μm.

7. The low smoke zero halogen fire resistant cable of any one of claims 1 to 6, wherein the plurality of cable core units (5) are twisted in the same direction, and the pitch ratio is 30 to 40.

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