WO2021022760A1 - Air-blowing micro-cable - Google Patents

Abstract

Provided is an air-blowing micro-cable (100), comprising a reinforcer (10), a cable core arranged around the reinforcer (10), and an outer sheath (50) wrapped outside the cable core. The cable core comprises a plurality of loose sleeves (20), and the loose sleeves (20) are filled with optical fibers (21) and a water-blocking substance. The air-blowing micro-cable (100) further comprises a fireproof layer (40), and the fireproof layer (40) is arranged between the cable core and the outer sheath (50). According to the air-blowing micro cable (100), the fireproof layer (40) is additionally arranged outside the cable core, such that the influence of flames on the cable core during combustion is reduced, and the safety is high.

Description

Air blowing microcable Technical field

The invention relates to the field of communication cables, in particular to an air blown micro cable.

Background technique

Compared with traditional optical cables, air-blown micro-cables have the same number of cores in terms of material consumption and processing costs are greatly reduced, the structure is small, light weight, and high fiber density. When laying, it can be directly installed in the existing communication pipeline, effectively saving pipeline resources and meeting the construction needs of network expansion. Air-blown micro-cable generally adopts a loose tube layer stranded structure, and the loose tube adopts polybutylene terephthalate (PBT) or modified polypropylene (PP) material, and is filled with fiber paste for water blocking and external protection Set of extruded polyethylene or nylon material. Due to the air blowing method, the overall structure of the micro cable is small in size and light in weight. Therefore, conventional air-blown micro-cables have no flame retardant properties. In the event of a fire, they are easy to support combustion and promote the rapid spread of fire. At the same time, due to the existence of fiber paste, it will further burn and release a large amount of heat and smoke, destroying communication lines, and a large amount of smoke. And heat can cause harm to the human body.

Summary of the invention

In view of this, it is necessary to provide an improved air-blown microcable, which has flame retardant properties.

The present invention provides an air-blown micro-cable, comprising a reinforcing member, a cable core arranged around the reinforcing member, and an outer sheath covering the cable core. The cable core includes a plurality of loose tubes. The loose tube is filled with an optical fiber and a water-blocking substance. The air-blown microcable also includes a fireproof layer, which is arranged between the cable core and the outer sheath.

Further, a water-blocking yarn is filled between the cable core and the reinforcing member, and the cable core is wound with a binding yarn.

Further, the water blocking material includes one of a water blocking yarn, a flame-retardant fiber paste with low calorific value and low smoke content, and a water blocking powder.

Further, the loose tube is made of low-smoke halogen-free flame-retardant polyolefin material, flame-retardant PBT or flame-retardant PP material.

Further, the cable core further includes a plurality of filler wires twisted with the loose tube, and the number of the filler wires and the loose tube varies according to the number of cores of the optical fiber.

Further, the filling line is extruded from a low-smoke halogen-free flame-retardant polyolefin material, the filling line oxygen index is greater than 32%, and the maximum specific optical density during flame combustion is less than 60.

Further, the fire protection layer is longitudinally wrapped or wrapped by polyimide film, mica tape or non-metallic braided tape, and the number of longitudinally wrapped or wrapped layers is single layer or multiple layers.

Further, the reinforcing member is a non-metal reinforced plastic rod made of a non-metallic material, the tensile strength of the non-metal reinforced plastic rod is greater than 1100 MPa, and the elastic modulus is greater than 55 GPa.

Further, the surface of the reinforcing member is provided with an overmolding layer, the thickness of the overmolding layer is 0.2mm-0.4mm, and the overmolding layer is made of low-smoke halogen-free flame-retardant polyolefin.

Further, the air-blown microcable further includes a tear cord, which is arranged between the fireproof layer and the outer sheath for facilitating peeling off the outer sheath.

In the above air-blown micro-cable, a fireproof layer is added outside the cable core to reduce the influence of flame on the cable core during combustion, and has high safety.

Description of the drawings

FIG. 1 is a schematic diagram of the structure of an air-blown microcable in an embodiment of the present invention.

Symbol description of main components

Air blowing microcable 100 Reinforcement 10 Loose tube 20 optical fiber twenty one Fill line 30

Water blocking yarn 31 Fireproof layer 40 Outer sheath 50 Tear rope 60

The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings.

detailed description

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with 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. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

It should be noted that when a component is referred to as being "installed on" another component, it can be directly on the other component or a central component may also exist. When a component is considered to be "installed on" another component, it can be directly installed on another component or a centered component may exist at the same time.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field of the present invention. The terms used in the description of the present invention herein are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. The term "or/and" as used herein includes any and all combinations of one or more related listed items.

Please refer to FIG. 1. The air-blown microcable 100 shown in FIG. 1 is used for laying in a communication pipeline for information transmission, and includes a reinforcement 10, a loose tube 20 and a filling line 30 arranged around the reinforcement 10 in order from the inside to the outside. , Fireproof layer 40, outer sheath 50.

The reinforcing member 10 is arranged at the center of the air-blown microcable 100 to provide a central support function to provide support for the loose tube 20 and the filling line 30 arranged outside the reinforcing member 10. The central reinforcement 10 can be made of a material with a certain strength. In one embodiment, the reinforcing member 10 is a non-metal reinforced plastic rod made of a non-metallic material. The non-metallic material may be a fiber reinforced composite material, such as CFRP, GFRP, AFRP, BFRP, and the like. FRP composite material is a high-performance material formed by mixing fiber material and matrix material (resin) according to a certain ratio. It is light and hard, non-conductive, high mechanical strength, and corrosion resistant. The tensile strength of the non-metal reinforced plastic rod made of the non-metallic material is greater than 1100 MPa, and the elastic modulus is greater than 55 GPa. In other embodiments, the reinforcing member 10 is formed by stranding steel wires or other equivalent reinforcing materials, such as multi-layer steel wire stranding, wherein the number of stranded layers can be 1, 2, or 3 layers or Multi-layer, can be set according to strength needs. In one embodiment, the reinforcing member 10 is further provided with an overmolding layer, and the overmolding layer is made of low-smoke, halogen-free, flame-retardant polyolefin, and has a thickness of 0.2 mm to 0.4 mm.

The loose tube 20 and the filling wire 30 are arranged in layers on the outer periphery of the reinforcing member 10 to form the core of the air-blown microcable 100, and the gap between the two and the reinforcing member 10 is filled with water blocking Yarn 31, the cable core is wound with a binding yarn to ensure the roundness of the cable core. In one embodiment, the cable core is formed by twisting 4 loose tubes 20 and 2 filling wires 30, and each loose tube 20 is provided with 12-core optical fibers. In one embodiment, the cable core is composed of 6 to 24 strands. To ensure the stranding effect, the number of the loose tube 20 and the filler wire 30 can be set according to the actual number of fiber cores. The filling line 30 adjusts the number of the loose tube 20. When the number of fiber cores is large, the loose tube 20 of the same specification can be used to replace the filling line 30. When the number of fiber cores is small, it can be used The filling line 30 of the same specification replaces the loose tube 20. In one embodiment, the cable core can also be double-layered to increase the number of optical fiber cores to 24-288 cores. In one embodiment, the binding yarn is made of low linear density aramid material.

The loose tube 20 is extruded from a flame-retardant material. In one embodiment, the loose tube 20 is made of low-smoke halogen-free flame-retardant polyolefin material, the oxygen index of the loose tube 20 is greater than 32%, and the maximum specific optical density during flaming combustion is less than 80. In other embodiments, the loose tube may also be made of high-performance flame-retardant PBT or flame-retardant PP material.

The loose tube 20 is filled with an optical fiber 21 and a water blocking substance (not labeled). In one embodiment, the loose tube 20 is filled with the 12-core optical fiber 21, and the diameter of the coating layer of the optical fiber 21 is 245 μm to 255 μm. In other embodiments, the optical fiber 21 may be a small-sized optical fiber with a coating diameter of 180 μm to 200 μm to reduce the size of the loose tube 20. The type of the optical fiber 21 may be G.652 or G.657 optical fiber, and the number of cores of the optical fiber 21 in each loose tube 20 may be 6 to 24 cores. The water blocking substance is filled in the loose tube 20 for dry water blocking. In one embodiment, the water blocking material is water blocking yarn. In other embodiments, the water blocking substance may be a flame-retardant fiber paste or water blocking powder with low calorific value and low smoke emission.

The filling line 30 is extruded from a low-smoke halogen-free flame-retardant polyolefin material with an oxygen index greater than 32% and a maximum specific optical density of less than 60 during flame combustion. The specifications of the filling line 30 are the same as those of the loose sleeve. Tube 20 is consistent.

The fireproof layer 40 is wrapped around the cable core composed of the loose tube 20 and the filler wire 30. In one embodiment, the fireproof layer 40 is longitudinally wrapped or wrapped by polyimide film, the number of longitudinally wrapped or wrapped layers is single layer or multiple layers, the thickness is 0.2mm-0.4mm, and the overlap width is 2mm～4mm. In other embodiments, the fireproof layer 40 is longitudinally wrapped or wrapped by mica tape or non-metallic braided tape, and the number of longitudinally wrapped or wrapped layers is single layer or multiple layers.

The outer sheath 50 is extruded on the fireproof layer 40. In one embodiment, the outer sheath 50 is made of high-performance, low-smoke, halogen-free, flame-retardant polyolefin material, with an oxygen index greater than 36%, and a maximum specific optical density less than 60 during flame combustion. In other embodiments, the outer sheath 50 is made of a low-friction, low-smoke, halogen-free flame-retardant polyolefin material, such as low-friction LSZH or low-friction flame-retardant PE, and the outer sheath 50 can also be a flame-retardant nylon material. When the material of the outer sheath 50 is on fire, the flame spread rate is low, the amount of combustion heat release is low, and the amount of smoke is small. In one embodiment, the 48-core air blown microcable 100 has a wall thickness of 0.4 mm to 0.8 mm in the outer sheath 50, and the outer diameter of the air blown micro cable 100 is 5.8 mm to 6.8 mm. Air blow laying is carried out in a sub-pipe with a specification of 10mm/8mm.

The air-blown microcable 100 further includes a tear cord 60 which is arranged between the outer sheath 50 and the fireproof layer 40 to facilitate the peeling of the outer sheath 50.

The above-mentioned air-blown micro-cable loose tube, outer sheath and necessary filling materials are all made of low-smoke, high flame-retardant materials, and a fireproof layer is added outside the cable core to reduce the influence of flame on the cable core during combustion, and is safe High performance; adopts a fully dry structure design to avoid the release of a large amount of heat and smoke when the filled fiber paste is on fire, and it is also beneficial to eliminate the need to clean the grease when the fiber is connected, reducing the cost of fiber optic cable installation.

A person of ordinary skill in the art should realize that the above embodiments are only used to illustrate the present invention, but not to limit the present invention, as long as appropriate changes are made to the above embodiments within the essential spirit of the present invention. And changes fall within the scope of protection of the present invention.

Claims (10)

An air-blown micro-cable, comprising a strength member, a cable core arranged around the strength member, and an outer sheath covering the cable core. The cable core includes a plurality of loose tubes, and the loose tube It is filled with optical fibers and water-blocking substances, and is characterized in that the air-blown micro-cable further includes a fireproof layer, and the fireproof layer is arranged between the cable core and the outer sheath. The air-blown micro-cable according to claim 1, wherein a water-blocking yarn is filled between the cable core and the reinforcing member, and the cable core is wound with a tying yarn. The air-blown microcable according to claim 1, wherein the water blocking material comprises one of a water blocking yarn, a low-calorific value and low-smoke flame retardant fiber paste, and a water blocking powder. The air-blown microcable of claim 1, wherein the loose tube is made of low-smoke halogen-free flame-retardant polyolefin material, flame-retardant PBT or flame-retardant PP material. The air-blown micro-cable according to claim 1, wherein the cable core further comprises a plurality of filler wires twisted with the loose tube, and the number of the filler wires and the loose tube is according to The number of cores of the optical fiber changes. The air-blown microcable according to claim 1, wherein the filling line is extruded from a low-smoke, halogen-free flame-retardant polyolefin material, and the filling line has an oxygen index greater than 32%, which is the largest during flame combustion. The specific optical density is less than 60. The air-blown micro-cable according to claim 1, wherein the fireproof layer is longitudinally wrapped or wrapped by polyimide film, mica tape or non-metallic braided tape, and the longitudinally wrapped or wrapped layer The number is single layer or multiple layers. The air-blown micro-cable according to claim 1, wherein the reinforcing member is a non-metal reinforced plastic rod made of non-metallic materials, and the tensile strength of the non-metal reinforced plastic rod is greater than 1100 MPa, and the elastic modulus Greater than 55GPa. The air-blown micro-cable according to claim 1, wherein the surface of the reinforcing member is provided with a sheathing layer, the thickness of the sheathing layer is 0.2mm ~ 0.4mm, and the sheathing layer is low-smoke, halogen-free Made of flame retardant polyolefin. The air-blown micro-cable according to claim 1, wherein the air-blown micro-cable further comprises a tear cord, and the tear cord is arranged between the fireproof layer and the outer sheath for facilitating stripping. Open the outer sheath.

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