Termite-proof and low-heat-release cable

Abstract

The utility model relates to the technical field of cable design and manufacture, and provides an anti-termite and low-heat-release cable, which comprises a conductor. The insulating layer coats the outer surface of the conductor; the conductors and the insulating layers are combined to form insulating wire cores, two insulating wire cores are twisted to form a paired wire group, four insulating wire cores are twisted to form a four-wire group, and the insulating wire cores, the paired wire group and the four-wire group are cabled to form a cable core; cable core fillers are filled among the insulated wire cores, the paired wire group and the four-wire group; the cable core wrapping tape layer wraps the cable core and the cable core filler; the comprehensive protection layer coats the cable core belting layer and is used for providing comprehensive protection for the cable; the comprehensive protection layer is coated with the outer sheath, and the material of the outer sheath contains an insect-proof additive; the design of the cable core belting layer improves the overall flame retardance and heat insulation performance of the cable, and the insect-proof additive is added in the outer sheath to prevent insects from biting the cable, so that the risks of short circuit, electric leakage and even fire caused by insect biting are avoided, and the safe operation of a railway system is ensured.

Description

Technical Field

[0001] This utility model belongs to the field of cable design and manufacturing, specifically relating to a termite-proof and low-heat-release cable. Background Technology

[0002] PTYA23, a special type of railway signal cable with polyethylene insulated composite sheath, double steel tape armor, and polyethylene outer sheath, is designed specifically for railway systems. It is primarily used for signal control in railway signaling systems, urban rail transit systems, and monitoring and emergency systems. Due to its shielding properties, it can be laid in electrified sections or environments with strong electromagnetic interference.

[0003] Existing railway signal cables (PTYA23) generally use non-flame-retardant materials, or are simply upgraded by using halogen-free, low-smoke, flame-retardant polyolefin materials on the outer sheath. Although the insulation layer uses polyethylene insulation material with high volume resistivity and low relative permittivity to ensure the stability of signal transmission, the flame-retardant performance of the overall cable is still limited due to the flammability of polyethylene itself. Therefore, there are still significant safety hazards when laying them in densely populated areas.

[0004] The laying environment for railway signal cables is quite complex, with some lines needing to cross areas densely populated with termites. However, conventional railway signal cables currently lack termite protection. This makes the cable sheath and insulation layers susceptible to termite damage, potentially leading to cable breakage, short circuits, or signal transmission interruptions. In particular, when a short circuit occurs due to termite damage, it can cause electrical leakage or even fire, seriously threatening the normal operation of the railway system. Utility Model Content

[0005] In view of the above-mentioned shortcomings of the existing technology, the technical problem to be solved by this utility model is to propose a termite-proof and low-heat-release cable by filling the cable core between the insulated core, the pair group and the four-wire group with cable core filler, and covering the cable core and the cable core filler with cable core wrapping layer after cabling, thereby enhancing the overall structural stability and mechanical strength of the cable, and further improving the flame retardancy and heat insulation of the cable. Insect-proof additives are also added to the outer sheath material to provide the cable with effective insect-proof performance.

[0006] The technical solution adopted by this utility model to solve its technical problem is to propose a termite-proof and low-heat-release cable, including...

[0007] conductor;

[0008] An insulating layer covers the outer surface of the conductor to ensure the stability of signal transmission;

[0009] The conductor and the insulating layer are combined to form an insulated wire core. Two insulated wire cores are twisted into a pair of wires, and four insulated wire cores are twisted into a four-wire group. The insulated wire core, the pair of wires, and the four-wire group are combined to form a cable core.

[0010] The insulating core, the pair of wires and the four-wire group are filled with cable core filler, which is used to maintain the roundness of the cable and improve the flame retardant performance of the cable.

[0011] The cable core wrapping layer, which covers the cable core and the cable core filler, is used to improve the flame retardancy and heat insulation of the cable.

[0012] A comprehensive protective layer, which covers the wrapping layer, is used to provide comprehensive protection for the cable;

[0013] An outer sheath, which covers the integrated protective layer, contains insect-repellent additives in the outer sheath material to provide insect protection for the cable.

[0014] In the aforementioned termite-proof and low-heat-release cable, the outer sheath is made of B1 grade polyolefin.

[0015] In the aforementioned termite-proof and low-heat-release cable, the insect-repellent additive is a termite-repellent masterbatch comprising 5% of the outer sheath weight.

[0016] In the aforementioned termite-proof and low-heat-release cable, the conductor material is oxygen-free copper.

[0017] In the aforementioned termite-proof and low-heat-release cable, the insulation layer is made of polyethylene insulation material.

[0018] In the aforementioned termite-proof and low-heat-release cable, the core filling material is a polypropylene mesh tape.

[0019] In the aforementioned termite-proof and low-heat-release cable, the cable core wrapping layer is made of three layers of elastic tape overlapping and wrapping.

[0020] In the aforementioned termite-proof and low-heat-release cable, the integrated protective layer includes:

[0021] Double-sided aluminum-plastic composite tape is wrapped around the outer surface of the cable core sheath layer;

[0022] A medium-density polyethylene sheath covers the double-sided aluminum-plastic composite tape;

[0023] An oxygen barrier layer is wrapped around the outer surface of the medium-density polyethylene sheath.

[0024] A steel strip armor layer, which covers the outer surface of the oxygen barrier layer;

[0025] An armored strap layer, which wraps around the outer surface of the steel strap armored layer.

[0026] In the aforementioned termite-proof and low-heat-release cable, the oxygen barrier layer is made of B1 grade polyolefin oxygen barrier material.

[0027] In the aforementioned termite-proof and low-heat-release cable, the armor sheath layer is made of two layers of elastic tape wrapped together.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] (1) The design of the core wrapping layer improves the overall flame retardancy and heat insulation performance of the cable; the addition of insect-proof additives to the outer sheath prevents pests from biting the cable, thereby avoiding the risk of short circuit, leakage and even fire caused by insect bites, ensuring the safe operation of the railway system. At the same time, the outer sheath also has low heat release characteristics, which helps to reduce the heat diffusion rate in fire risk, thereby improving safety.

[0030] (2) The insulation layer is made of environmentally friendly high-density polyethylene insulation material. The environmentally friendly high-density polyethylene insulation material does not contain heavy metals, organic brominated compounds and phthalate esters that are harmful to people and the environment, and has excellent insulation extrusion performance.

[0031] (3) The cable core is filled with halogen-free, low-smoke, flame-retardant polypropylene mesh tape. This product does not contain harmful substances such as glass fiber, asbestos, and halogens, and meets the RoHS testing standards. This product is non-hygroscopic, has good flame retardancy, is soft and smooth, and has low smoke density. The cable core is densely filled, which can further reduce the heat conduction rate and reduce the impact of high temperature on the insulated core. Attached Figure Description

[0032] Figure 1 This is a structural diagram of the scheme;

[0033] Figure 2 This is a schematic diagram of the insulated wire core structure in this scheme;

[0034] Figure 3 This is a schematic diagram of the line group structure in this scheme;

[0035] Figure 4 This is a schematic diagram of the four-wire group structure in this scheme.

[0036] In the diagram, 1 is the conductor; 2 is the insulation layer; 3 is the insulated core; 4 is the pair; 5 is the four-wire pair; 6 is the core filler; 7 is the core wrapping layer; 8 is the outer sheath; 9 is the double-sided aluminum-plastic composite tape; 10 is the medium-density polyethylene sheath; 11 is the oxygen barrier layer; 12 is the steel tape armor layer; and 13 is the armor wrapping layer. Detailed Implementation

[0037] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0038] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0039] like Figure 1 As shown, this solution includes a termite-proof and low-heat-release cable, primarily used for railway signal cables.

[0040] like Figures 1 to 4 As shown, this solution provides a termite-resistant and low-heat-release cable, comprising: a conductor 1; an insulation layer 2, which covers the outer surface of the conductor 1 to ensure the stability of signal transmission; the conductor 1 and the insulation layer 2 combine to form an insulated core 3, two insulated cores 3 are twisted into a pair group 4, four insulated cores 3 are twisted into a four-wire group 5, and the insulated cores 3, the pair group 4, and the four-wire group 5 are cabled to form a cable core; a cable core filler 6 is filled between the insulated cores 3, the pair group 4, and the four-wire group 5, which is used to maintain the roundness of the cable and improve its flame retardant performance; a cable core wrapping layer 7, which covers the cable core and the cable core filler 6, and is used to improve the flame retardant and heat insulation properties of the cable; a comprehensive protective layer, which covers the wrapping layer, and is used to provide comprehensive protection for the cable; and an outer sheath 8, which covers the comprehensive protective layer, and the outer sheath 8 material contains insect-repellent additives to provide insect resistance for the cable.

[0041] Conductor 1, as the core component for signal transmission, ensures efficient and stable signal transmission. Insulation layer 2 covers the outer surface of conductor 1, ensuring the stability of signal transmission and reducing crosstalk between circuits. Insulated core 3, composed of conductor 1 and insulation layer 2, is the basic building block of the cable. By twisting two insulated cores 3 into a pair group 4 and four insulated cores 3 into a four-wire group 5, the structure can be made more stable, reducing electromagnetic coupling between circuits and improving the anti-interference capability between circuits. Insulated cores 3, pair groups 4, and four-wire groups 5 are arranged in a specific way and cabled to form the cable core. During this process, cable core filler 6 is filled between these components to maintain the roundness of the cable and improve its flame retardant performance. Cable core wrapping tape... Layer 7 covers the cable core and core filler 6, improving the cable's flame retardancy and heat insulation, and helping to maintain the cable's shape stability. The comprehensive protective layer further wraps around the core wrapping layer 7, providing more comprehensive protection, such as radial waterproofing and compressive strength, to cope with complex installation and operating environments. The outer sheath 8 is the outermost protective layer of the cable, directly exposed to the external environment. The outer sheath 8 material contains insect-repellent additives, especially for termite protection, preventing termites from gnawing on the cable and thus avoiding the risks of short circuits, leakage, and even fires caused by insect bites, ensuring the safe operation of the railway system. Simultaneously, the outer sheath 8 also has low heat release characteristics, helping to reduce the rate of heat diffusion in fire risks, thereby improving safety.

[0042] To facilitate identification and management, the insulated cores 3 are usually given different colors. During the manufacturing process, color differentiation is achieved by mixing base plastics (such as PVC, PE, etc.) with colorants and extruding them into insulation layers 2 of different colors. Modern production lines can control this process very precisely, thereby ensuring that the color of each batch of products is consistent and stable. In this embodiment, the wire group 4 consists of two insulated cores 3 of different colors, while the four-wire group 5 consists of four insulated cores 3 of different colors, and the corresponding colored yarn is wound on the outer layer, thereby further improving the convenience of identification and the overall safety performance.

[0043] Furthermore, the outer sheath 8 is made of B1-grade polyolefin. B1 grade is a classification of cable flammability, belonging to one level in the Chinese mandatory standard GB 31247 "Classification of Flammability of Cables and Optical Fibers". B1 grade indicates flame-retardant Class I cable, which is a flame-retardant cable. These cables are difficult to ignite when exposed to high temperatures and open flames in air, and even if they do ignite, they quickly self-extinguish, preventing the fire from spreading. This grade of material is suitable for applications with high fire protection requirements. Polyolefin is a general term for thermoplastic resins polymerized from olefin monomers such as ethylene and propylene, including polyethylene (PE) and polypropylene (PP). Polyolefin materials typically have good electrical insulation, chemical corrosion resistance, and mechanical strength. Through special formulations and treatments, polyolefins can achieve the B1 fire resistance standard while maintaining their original excellent performance. The outer sheath 8 in this design uses B1-grade polyolefin, ensuring excellent physical and electrical properties of the cable while significantly improving its fire safety. This design effectively reduces fire risk and limits flame spread in the event of a fire.

[0044] Further preferably, the insect-repellent additive is a 5% (by weight of the outer sheath) anti-termite masterbatch. Adding 5% (by weight of the total weight of the anti-termite masterbatch) to the outer sheath 8 material can effectively improve the cable's resistance to insect pests, especially termites and other insects that pose a serious threat to the cable. The anti-termite masterbatch contains effective ingredients that repel or poison insects. When termites attempt to bite the cable containing this additive, they will come into contact with and be affected by these ingredients, causing them to stay away or die, thereby protecting the cable from damage. Mixing the anti-termite masterbatch into the cable's outer sheath 8 material at a 5% (by weight of the outer sheath) ratio allows these active ingredients to be evenly distributed throughout the sheath 8, providing a long-lasting protective effect that remains effective even after prolonged exposure to the external environment.

[0045] Further preferably, conductor 1 is made of oxygen-free copper. Oxygen-free copper typically has a purity of over 99.99%, containing almost no oxygen or other impurities. Due to its extremely high purity, oxygen-free copper not only has very low resistivity but also exhibits excellent conductivity. In addition, by reducing oxygen content, oxygen-free copper significantly improves its oxidation and corrosion resistance, helping to extend the cable's service life and maintain performance stability in harsh environments. Selecting oxygen-free copper as conductor 1 not only improves the cable's conductivity and electrical performance but also enhances system reliability by increasing durability and environmental adaptability, while reducing maintenance frequency.

[0046] The insulation layer 2 is made of polyethylene insulation material. In this scheme, the preferred insulation material is environmentally friendly high-density polyethylene. Environmentally friendly high-density polyethylene insulation material has excellent performance. Its high-quality formula does not contain heavy metals or other harmful chemicals, which not only ensures the safety during use, but also reduces the risk of environmental pollution to soil and water sources after disposal. Compared with other types of polyethylene, environmentally friendly high-density polyethylene has higher crystallinity and tighter molecular chain arrangement, exhibiting better mechanical strength and impact resistance. In addition, environmentally friendly high-density polyethylene has high resistivity and low dielectric loss, making it an ideal electrical insulation material that can effectively reduce signal attenuation and energy loss.

[0047] More preferably, the core filler 6 is made of polypropylene mesh tape. Polypropylene mesh tape has good flexibility and strength, effectively filling the internal space of the core, maintaining the overall roundness of the cable, and preventing deformation when the cable is bent or subjected to external pressure. Its mesh structure provides buffer protection for the conductor 1 and insulation layer 2 within the core, reducing the risk of damage to the internal components of the cable from external mechanical stress. Furthermore, it effectively prevents moisture and other harmful substances from penetrating the core, further protecting the internal components. Using polypropylene mesh tape as the core filler 6 not only improves the structural stability and protective performance of the cable but also balances cost control and ease of construction, making it an ideal choice for achieving efficient and durable power transmission.

[0048] More preferably, the cable core wrapping layer 7 uses a three-layer elastic tape overlapping wrapping with low-smoke, halogen-free flame-retardant properties. The three-layer elastic tape overlapping wrapping has a special elongation rate of over 16%, making the wrapping tight and less prone to cracking. In contrast, ordinary products lack elongation, have loose wrapping, and are prone to cracking when the cable is bent. This product uses a special stretchable material that will not break even after being folded more than 25 times, ensuring that each reel of material can be used 100% without waste. Ordinary products use fiberglass materials, which usually break after 2-3 folds, resulting in incomplete use and significant waste. The three-layer elastic tape overlapping wrapping is soft and will not curl up during wrapping. Its softness is particularly prominent when used in winter, making wrapping easier. In addition, the three-layer elastic tape overlapping wrapping also has excellent flame-retardant properties, further improving the safety of the cable.

[0049] Furthermore, the comprehensive protective layer includes: a double-sided aluminum-plastic composite tape 9, which covers the outer surface of the cable core wrapping layer 7, providing electromagnetic shielding to prevent external electromagnetic interference from affecting the internal signal transmission of the cable, while also enhancing the overall mechanical strength of the cable; a medium-density polyethylene sheath 10, which covers the double-sided aluminum-plastic composite tape 9, serving as an intermediate protective layer, providing good abrasion resistance and impact resistance, further protecting the internal components of the cable from external physical damage; an oxygen barrier layer 11, which covers the outer surface of the medium-density polyethylene sheath 10, preventing oxygen from penetrating into the cable interior, delaying or preventing the aging of the cable materials, and reducing the release of harmful gases in high-temperature or fire conditions; a steel tape armor layer 12, which covers the outer surface of the oxygen barrier layer 11, providing additional mechanical protection for the cable, especially in terms of compressive and tensile strength; and an armor wrapping layer 13, which wraps around the outer surface of the steel tape armor layer 12, providing additional cushioning protection and ensuring a smooth cable surface for easy installation and maintenance.

[0050] More preferably, the oxygen barrier layer 11 is made of B1 grade polyolefin oxygen barrier material, which has halogen-free, low-smoke, and flame-retardant properties. This material not only has excellent flame-retardant properties, but also effectively prevents oxygen from penetrating into the cable, delays cable aging, and reduces the release of harmful gases in high-temperature or fire conditions, thereby improving the safety and service life of the cable. The oxygen barrier layer 11 gradually releases water of crystallization at high temperatures, lowering the temperature. During combustion, it can carbonize to form a protective shell, playing a buffering and heat-insulating role, further improving the overall flame-retardant performance of the cable. In addition, this material has low expansion during combustion and a stable and reliable structure, avoiding the phenomenon of the outer sheath 8 dripping or falling off due to excessive expansion.

[0051] More preferably, the material of the armor wrapping layer 13 is two layers of elastic tape wrapped together. This structure provides additional cushioning protection and enhances the overall mechanical strength of the cable. The elastic tape material is soft and has a certain elongation. It can maintain good flexibility under different environmental conditions and will not curl up when wrapped. After the sheath 8 is wrapped, the cable has a round and smooth appearance without wavy shape, which is beautiful and elegant.

[0052] It should be noted that in this utility model, the use of terms such as "first," "second," and "a" is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of those features. In the description of this utility model, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly defined. The terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two elements or the interaction between two elements, unless otherwise explicitly defined. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0053] Furthermore, the technical solutions of the various embodiments of this utility model can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the protection scope claimed by this utility model.

[0054] The specific embodiments described herein are merely illustrative examples illustrating the spirit of this utility model. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of this utility model or exceeding the scope defined by the appended claims.

Claims

1. A termite resistant and low heat release cable, characterized by, It comprises: a conductor; an insulation layer, which is wrapped on the outer surface of the conductor to ensure the stability of signal transmission; the conductor and the insulation layer are combined into an insulated core, two insulated cores are twisted into a pair of wire groups, four insulated cores are twisted into a four-wire group, and the insulated core, the pair of wire groups and the four-wire group form a cable core; the insulated core, the pair of wire groups and the four-wire group are filled with a cable core filler, which is used to maintain the roundness of the cable and improve the flame retardant performance of the cable; a cable core wrapping layer, which is wrapped on the cable core and the cable core filler, is used to improve the flame retardant and thermal insulation properties of the cable; a comprehensive protection layer, which is wrapped on the wrapping layer, is used to provide comprehensive protection for the cable; an outer sheath, which is wrapped on the comprehensive protection layer, has a worm-proof additive in the material of the outer sheath, which is used to provide worm-proof property for the cable.

2. The termite resistant and low heat release cable according to claim 1, wherein The material of the outer sheath is B1 grade polyolefin.

3. The termite resistant and low heat release cable according to claim 1, wherein The worm-proof additive is an ant ant master batch with a weight of 5% of the outer sheath.

4. The termite resistant and low heat release cable as claimed in claim 1, wherein, The conductor material is oxygen-free copper.

5. The termite resistant and low heat release cable as claimed in claim 1, wherein, The material of the insulation layer is polyethylene insulation material.

6. The termite resistant and low heat release cable as claimed in claim 1, wherein, The cable core filler material is polypropylene mesh belt.

7. The termite resistant and low heat release cable as claimed in claim 1, wherein, The cable core wrapping layer adopts three layers of elastic belt overlapping wrapping.

8. The termite resistant and low heat release cable as claimed in claim 1, wherein, The comprehensive protection layer comprises: a double-sided aluminum plastic composite belt, which is wrapped on the outer surface of the cable core wrapping layer; a medium density polyethylene sheath, which is wrapped on the double-sided aluminum plastic composite belt; an oxygen barrier layer, which is wrapped on the outer surface of the medium density polyethylene sheath; a steel belt armor layer, which is wrapped on the outer surface of the oxygen barrier layer; an armored wrapping layer, which is wrapped on the outer surface of the steel belt armor layer.

9. The termite resistant and low heat release cable as claimed in claim 8, wherein, The material of the oxygen barrier layer is B1 grade polyolefin oxygen barrier material.

10. The termite resistant and low heat release cable as claimed in claim 8, wherein, The material of the armored wrapping layer is two layers of elastic belt overlapping wrapping.

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