A high flame-retardant high-elongation polyethylene sheath armored control cable

Abstract

The utility model discloses a kind of high flame-retardant high elongation polyethylene sheath armoured control cable, belong to control cable technical field.Cable includes cable core, tape layer, shielding layer, inner liner, armoring layer, armoring outer flame-retardant tape layer and outer sheath;The cable core with the shielding layer between the setting tape layer;The shielding layer with the armoring layer between the setting inner liner;The armoring layer with outer sheath between the setting armoring outer flame-retardant tape layer;The cable core inside is provided with several crosslinked polyethylene insulated single wire;The crosslinked polyethylene insulated single wire includes crosslinked polyethylene insulation and soft copper conductor.The cable simple structure can effectively meet the comprehensive demand of high flame-retardant and high elongation, and ensure excellent flame-retardant performance.

Description

Technical Field

[0001] This utility model relates to the field of control cable technology, specifically to a high flame-retardant, high elongation polyethylene sheathed armored control cable. Background Technology

[0002] In numerous fields such as industrial production, construction engineering, transportation, and power transmission, control cables serve as critical infrastructure for signal transmission and equipment control. Their operational stability and environmental adaptability directly affect the safe and reliable operation of the entire system. With the continuous improvement of cable performance requirements in modern industry, especially the increasing demand for durability under extreme climatic conditions, the shortcomings of traditional control cables in terms of sheath performance and structural design have gradually become apparent, making them unable to meet the requirements of complex operating conditions.

[0003] Currently, the widely used ordinary low-smoke halogen-free flame-retardant armored control cables on the market mostly use low-smoke halogen-free polyolefin flame-retardant sheath material for their outer sheath. Although this type of cable has certain advantages in terms of flame retardancy and environmental protection, its sheath has significant shortcomings in mechanical properties. Tests show that its tensile strength is only 9.0 MPa, and its elongation at break is as low as 125%. In the high-temperature environment of summer, low-smoke halogen-free polyolefin sheath material is prone to thermal aging, increasing material brittleness. Coupled with the low elongation at break, this makes the sheath extremely prone to cracking. This not only damages the insulation protection performance of the cable but may also cause internal conductor moisture absorption, short circuits, and other faults, seriously affecting the cable's service life and system operational safety. Meanwhile, another commonly used type of ordinary PVC sheathed flame-retardant armored control cable, although its sheath mechanical properties are slightly improved, with a tensile strength of up to 12.5 MPa and an elongation at break of 150%, still has a low elongation at break index, and PVC material itself has poor low-temperature resistance. In cold winter conditions, the PVC sheath loses its elasticity due to low-temperature shrinkage, resulting in a significant decrease in material toughness. The low elongation at break makes the sheath prone to cracking when subjected to slight external forces or temperature changes. This cracking problem is more frequent, especially in the frigid northern regions, posing a great threat to the outdoor laying and long-term operation of cables, and increasing maintenance costs and safety risks.

[0004] To address the performance deficiencies of traditional cables, a series of technological improvements have been attempted in related fields, and some patented technologies have been disclosed. For example, patent number CN202322017458.5 proposes a high flame-retardant polyethylene sheathed cable. This cable attempts to improve cable durability through a multi-layered filling and protection design, using a structure consisting of a cable core, insulation sheath, a first filling layer, a first non-woven fabric layer, a second filling layer, tensile fibers, a second non-woven fabric layer, and a protective mesh sleeve. The first filling layer uses plastic filler to prevent mutual wear between cable cores, the second filling layer uses cotton rope filler to prevent bending and breakage of the cable core, and the protective mesh sleeve design aims to achieve heat dissipation from the sheath. However, this technical solution has significant shortcomings. Its cable structure includes two filling layers, two wrapping layers, and a protective mesh sleeve, making the overall structure overly complex. This leads to a significant increase in production steps and a cumbersome process, reducing production efficiency and significantly increasing material and processing costs, hindering large-scale application. Furthermore, patent number CN202011484994.0 discloses an environmentally friendly flame-retardant polyethylene cable. This cable features a multi-layered structure including a wear-resistant layer, a heat-insulating layer, a bending-resistant layer, a buffer layer, an insulation layer, a high-temperature resistant layer, a rubber layer, and a reinforcing layer. The aim is to improve the cable's bending resistance and toughness through multi-dimensional protection, preventing breakage in winter. However, this technical solution also has significant drawbacks: firstly, the patent document does not explicitly specify the cable's flame-retardant rating, making it impossible to confirm whether it meets the requirements for high flame-retardant performance (such as flame-retardant Class B or higher) in industrial settings, thus limiting its applicability; secondly, the excessive number of functional layers complicates the cable structure, significantly increasing the cable's outer diameter. This not only increases material usage and production costs but also places higher demands on the cable's installation space, particularly increasing the difficulty of installation in confined environments.

[0005] In summary, current control cables either suffer from low elongation at break of the sheath, making them prone to cracking under extreme temperatures, or they exhibit drawbacks such as complex structures, high costs, and unclear flame retardant ratings. These limitations make it difficult to simultaneously meet the comprehensive requirements of high flame retardancy, excellent adaptability to high and low temperature environments, simple and reasonable structural design, and cost control. Therefore, developing a control cable sheath technology that combines high flame retardancy rating, high elongation at break, simple structure, and controllable cost has become a key direction for addressing current industry pain points and promoting the performance upgrade of control cables. Utility Model Content

[0006] To address the problems of existing control cables or sheaths having low elongation at break, susceptibility to cracking at extreme temperatures, or complex structures and unclear flame retardant ratings, making it difficult to meet comprehensive requirements, this utility model provides a high flame retardant, high elongation polyethylene sheathed armored control cable. It has a simple structure, effectively meets the combined requirements of high flame retardancy and high elongation, and ensures excellent flame retardant performance.

[0007] To achieve the above objectives, the present invention provides the following technical solution.

[0008] This utility model provides a high flame-retardant, high-elongation polyethylene sheathed armored control cable, comprising a cable core, a wrapping layer, a shielding layer, an inner liner, an armoring layer, an outer flame-retardant wrapping layer, and an outer sheath; the wrapping layer is disposed between the cable core and the shielding layer; the inner liner is disposed between the shielding layer and the armoring layer; the outer flame-retardant wrapping layer is disposed between the armoring layer and the outer sheath; a plurality of cross-linked polyethylene insulated single wires are disposed inside the cable core; each cross-linked polyethylene insulated single wire comprises cross-linked polyethylene insulation and a soft copper conductor.

[0009] Optionally, the wrapping layer is made of non-hygroscopic tape.

[0010] Optionally, the shielding layer is a single layer of copper strip.

[0011] Optionally, the inner lining layer is made of halogen-free, low-smoke, flame-retardant polyolefin oxygen-barrier filling material.

[0012] Optionally, the nominal thickness of the inner lining is 1.4 mm.

[0013] Optionally, the armor layer consists of two layers of galvanized steel strips wrapped around the outside of the inner lining layer with gaps.

[0014] Optionally, when the two layers of galvanized steel strips are wrapped around the outside of the inner lining layer, the wrapping gap ratio shall not exceed 50% of the width of the galvanized steel strips.

[0015] Optionally, the outer flame-retardant wrapping layer of the armor is made by overlapping and wrapping several layers of alkali-free glass fiber tape on the outer layer of the armor; the overlap rate of the wrapping is not less than 15% of the bandwidth.

[0016] Optionally, the thickness of the alkali-free glass fiber tape is 0.2 mm.

[0017] Optionally, the outer sheath is made of flame-retardant polyethylene material with high flame retardancy and high elongation.

[0018] Compared with the prior art, the present invention has the following beneficial effects: This utility model has a simple and clear structure, sequentially arranged as a cable core, wrapping layer, shielding layer, inner lining layer, armor layer, outer flame-retardant wrapping layer, and outer sheath. Each layer has a clear division of labor and works synergistically. The armor layer enhances the cable's mechanical strength, effectively resisting external mechanical damage such as compression and impact. The outer flame-retardant wrapping layer and outer sheath together constitute a powerful flame-retardant system. The flame-retardant wrapping layer uses special flame-retardant materials that can quickly form a heat insulation layer in the event of a fire, preventing the spread of flames and buying valuable time for personnel evacuation and equipment protection. The outer sheath further improves the cable's flame-retardant rating, ensuring that the cable remains relatively stable even after prolonged exposure to flames, and does not easily burn or contribute to combustion. This clear flame-retardant design and excellent flame-retardant performance meet the stringent safety requirements of modern engineering projects, providing reliable protection for electrical safety in various locations. The cable core uses cross-linked polyethylene insulated single wires, which consist of cross-linked polyethylene insulation and a soft copper conductor. Cross-linked polyethylene (XLPE) undergoes a special process, resulting in a more stable and compact molecular structure, which endows the cable with excellent flexibility and elasticity. Compared to traditional materials, XLPE can better withstand stress without breaking under tensile forces, significantly improving the cable's elongation at break. This means that in practical applications, even if the cable needs to be frequently bent, twisted, or subjected to a certain degree of tension, it can maintain good structural integrity, greatly reducing the risk of cable damage due to low elongation at break, extending the cable's service life, and reducing the frequency and cost of cable replacement.

[0019] Furthermore, the polyethylene sheath material, carefully selected and formulated, exhibits excellent temperature resistance. In low-temperature environments, the flexibility of the polyethylene molecular chains is maintained, preventing them from becoming brittle and hardening due to temperature drops, thus effectively preventing cable cracking under cold conditions. In high-temperature environments, the polyethylene material remains stable, without easily decomposing or deforming, ensuring that the cable's physical and electrical properties are unaffected. This stability under extreme temperatures allows this cable to be widely used in various harsh environments, such as outdoor projects in cold regions and high-temperature industrial sites, greatly expanding its application range. Attached Figure Description

[0020] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of this invention in any way. In the drawings: Figure 1 This is a schematic diagram of the structure of a high flame-retardant, high elongation polyethylene sheathed armored control cable according to the present invention.

[0021] In the diagram, 1 is the cable core; 11 is the cross-linked polyethylene insulated single wire; 111 is the cross-linked polyethylene insulation layer; 112 is the soft copper conductor; 2 is the wrapping layer; 3 is the shielding layer; 4 is the inner lining layer; 5 is the armor layer; 6 is the armored outer flame-retardant wrapping layer; and 7 is the outer sheath. Detailed Implementation

[0022] To enable those skilled in the art to better understand the technical solutions of this utility model, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings. The described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this utility model.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0024] To address the problems of existing control cables or sheaths having low elongation at break, susceptibility to cracking at extreme temperatures, or complex structures, high costs, and unclear flame retardant ratings, making it difficult to meet comprehensive requirements, this utility model provides a high flame retardant, high elongation polyethylene sheathed armored control cable, such as... Figure 1 As shown, it includes cable core 1, wrapping layer 2, shielding layer 3, inner lining layer 4, armor layer 5, armored outer flame-retardant wrapping layer 6, and outer sheath 7.

[0025] The cable core 1 is provided with a wrapping layer 2 on the outside; the wrapping layer 2 is provided with a shielding layer 3 on the outside; the shielding layer 3 is provided with an inner lining layer 4 on the outside; the inner lining layer 4 is provided with an armor layer 5 on the outside; the armor layer 5 is provided with an armored outer flame-retardant wrapping layer 6 on the outside; the armored outer flame-retardant wrapping layer 6 is provided with an outer sheath 7 on the outside.

[0026] The cable core 1 is made of several cross-linked polyethylene insulated single wires 11 twisted together; the cross-linked polyethylene insulated single wire 11 is formed by extruding a cross-linked polyethylene insulation layer 111 over a soft copper conductor 112.

[0027] The outer sheath 2 is wrapped around the cable core using a non-hygroscopic tape overlapping method; the shielding layer 3 is formed by a single layer of copper tape wrapping; the inner liner 4 is made of extruded halogen-free, low-smoke, flame-retardant polyolefin oxygen-barrier filling material, and the nominal thickness of the inner liner 4 is 1.4mm; the armor layer 5 is formed by intermittently wrapping two layers of galvanized steel tape, with the wrapping gap ratio not exceeding 50% of the width of the galvanized steel tape; the outer flame-retardant armor sheath 6 is wrapped around the armor layer using a multi-layer alkali-free glass fiber tape overlapping method, with the alkali-free glass fiber tape thickness being 0.2mm and the wrapping overlap rate not less than 15% of the bandwidth; the outer sheath 7 is made of high flame-retardant, high-elongation flame-retardant polyethylene sheath material, with a breaking elongation of over 400%.

[0028] This invention is applicable to applications such as subways where high flame retardancy ratings are required. Flame-retardant polyethylene sheathing material is based on polyethylene and modified by adding flame retardants and synergists. However, the addition of flame retardant powder can cause molecular agglomeration, affecting the elongation at break, resulting in an elongation at break of only 125%. This invention addresses this by selecting a surface-modified polyethylene resin with an elongation at break of 600% and using modified nano-level flame retardants to improve the compatibility between the flame retardant and the polyethylene base material, ensuring uniform dispersion of the sheathing material system. Furthermore, improvements are made to the modular shearing and conveying module combination of the twin-screw extruder to enhance the plasticization effect of the polyethylene sheathing material, achieving a significant increase in the elongation at break of the flame-retardant polyethylene sheath to over 400%. Therefore, this invention not only meets users' requirements for high elongation performance in control cables, but also provides excellent flame retardant performance through adjustments to the cable structure and sheathing material. The manufacturing process is simple, satisfying the requirements for high flame retardancy and high elongation performance in control cables.

[0029] In summary, this utility model effectively improves insulation performance and ensures the safety of cable use. It employs a low-smoke, halogen-free oxygen barrier layer, effectively preventing oxygen from entering the insulation layer. All materials are halogen-free and low-smoke, offering excellent environmental performance, non-toxicity, and low smoke. Furthermore, it exhibits high flame retardancy, increasing the elongation at break from 150% to 400%, and the production process is simple. The cable uses polyolefin materials, which are easy to extrude. A halogen-free, low-smoke, flame-retardant polyolefin oxygen barrier filler is used as the oxygen barrier layer, achieving shell formation upon exposure to fire and ensuring the oxygen barrier layer does not detach after fire. A single or multiple layers of alkali-free fiberglass tape are wrapped around the armor layer to isolate the cable core from fire, ensuring the product's flame-retardant performance requirements. A high-flame-retardant, high-elongation polyethylene sheath layer is used, meeting the requirements for both high flame retardancy and high elongation. The structure is simple, production efficiency is high, and flame-retardant performance is excellent, satisfying the requirements for both high flame retardancy and high elongation.

[0030] Many embodiments and applications beyond the examples provided will be apparent to those skilled in the art upon reading the foregoing description. Therefore, the scope of this teaching should not be determined by reference to the foregoing description, but rather by reference to the foregoing claims and the full scope of their equivalents. For purposes of completeness, all articles and references, including patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein in the foregoing claims is not intended as a waiver of that subject matter, nor should it be construed as an indication that the applicant has not considered that subject matter as part of the disclosed utility model subject matter.

[0031] The above content provides a further detailed description of this utility model. It should not be considered that the specific embodiments of this utility model are limited to this. For those skilled in the art, several simple deductions or substitutions can be made without departing from the concept of this utility model, and all such deductions or substitutions should be considered to fall within the scope of protection of this utility model as defined by the submitted claims.

Claims

1. A high flame-retardant, high elongation polyethylene sheathed armored control cable, characterized in that, It includes a cable core (1), a wrapping layer (2), a shielding layer (3), an inner lining layer (4), an armor layer (5), an outer flame-retardant wrapping layer (6), and an outer sheath (7). The wrapping layer (2) is provided between the cable core (1) and the shielding layer (3). The inner lining layer (4) is provided between the shielding layer (3) and the armor layer (5). The armor outer flame-retardant wrapping layer (6) is provided between the armor layer (5) and the outer sheath (7); The cable core (1) is provided with several cross-linked polyethylene insulated single wires (11). The cross-linked polyethylene insulated single wire (11) includes cross-linked polyethylene insulation (111) and soft copper conductor (112).

2. The high flame-retardant, high elongation polyethylene sheathed armored control cable according to claim 1, characterized in that, The wrapping layer (2) is made of non-hygroscopic tape.

3. The high flame-retardant, high elongation polyethylene sheathed armored control cable according to claim 1, characterized in that, The shielding layer (3) is made of a single layer of copper strip.

4. The high flame-retardant, high elongation polyethylene sheathed armored control cable according to claim 1, characterized in that, The inner lining (4) is made of halogen-free, low-smoke, flame-retardant polyolefin oxygen-barrier filling material.

5. The high flame-retardant, high elongation polyethylene sheathed armored control cable according to claim 1, characterized in that, The nominal thickness of the inner lining (4) is 1.4 mm.

6. The high flame-retardant, high elongation polyethylene sheathed armored control cable according to claim 1, characterized in that, The armor layer (5) is made by wrapping two layers of galvanized steel strips with gaps around the outside of the inner lining layer (4).

7. A high flame-retardant, high elongation polyethylene sheathed armored control cable according to claim 6, characterized in that, When the two layers of galvanized steel strip are wrapped around the outer side of the inner lining (4), the wrapping gap ratio shall not be greater than 50% of the width of the galvanized steel strip.

8. The high flame-retardant, high elongation polyethylene sheathed armored control cable according to claim 1, characterized in that, The outer flame-retardant wrapping layer (6) of the armor adopts a wrapping method of several layers of alkali-free glass fiber tape overlapping and wrapping on the outer layer of the armor layer (5); the wrapping overlap rate is not less than 15% of the bandwidth.

9. A high flame-retardant, high elongation polyethylene sheathed armored control cable according to claim 8, characterized in that, The thickness of the alkali-free glass fiber tape is 0.2 mm.

10. A high flame-retardant, high elongation polyethylene sheathed armored control cable according to claim 1, characterized in that, The outer sheath (7) is made of flame-retardant polyethylene material with high flame retardancy and high elongation.

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