Hollow core fiber optic cable

Abstract

The utility model relates to communication cable technology field especially relates to a kind of hollow optical fiber cable.The hollow optical fiber cable includes central reinforcing member, multiple optical fiber units and outer sheath layer;Multiple optical fiber units are arranged in the periphery of central reinforcing member to form cable core, and outer sheath layer is coated in the outside of cable core;Each optical fiber unit includes loose tube and hollow optical fiber filled in loose tube;Hollow optical fiber is coated with at least one buffer layer;Outer sheath layer is filled with microcapsule, and microcapsule is filled with composite biological repellent agent.Several buffer layers are coated on the outside of hollow optical fiber, which can absorb stress, block high temperature and mechanical damage by buffer layer.Filled with microcapsule particles containing composite biological repellent agent in outer sheath layer, the capsule wall can block the contact between repellent agent and external air, slow down the evaporation rate of repellent agent, effectively extend the maintenance duration of repellent agent.

Description

Technical Field

[0001] This utility model relates to the field of communication optical cable technology, and in particular to a hollow-core optical fiber cable. Background Technology

[0002] Existing rodent control methods for optical cables mainly fall into two categories: physical protection and chemical repellency. Physical protection relies on metal or high-hardness non-metallic armor layers to resist gnawing. However, metal armor increases weight and diameter, is susceptible to corrosion and electromagnetic interference, and a single non-metallic hard layer lacks sufficient long-term bite resistance. Chemical repellency involves adding irritants such as capsaicin to the sheath to repel rodents, but it suffers from drawbacks such as failing to meet environmental standards, short-term effectiveness, and the ease with which rodents develop tolerance. Furthermore, both methods often employ a single protective mechanism, resulting in a significant decline in long-term rodent control effectiveness.

[0003] Hollow-core optical fibers, with their low delay, low nonlinearity, and high precision, are well-suited for critical field applications such as energy security monitoring and ecological environment observation, possessing irreplaceable application potential. However, hollow-core optical fibers are inherently fragile and expensive, with repair costs and difficulties far exceeding those of ordinary optical fibers. Rodent control in field environments remains a significant challenge. Therefore, it is necessary to develop entirely new overall structural designs that balance hollow-core fiber protection with multiple rodent-proof mechanisms. Utility Model Content

[0004] The purpose of this invention is to provide a hollow-core optical fiber cable to solve the technical problems of existing technologies, such as the easy damage of hollow-core optical fibers, the easy volatilization of chemical repellents in the sheath, short effective time, easy tolerance of rodents, and significant long-term decay of rodent-proof effect.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A hollow-core optical fiber cable includes a central strengthening member, multiple optical fiber units, and an outer sheath layer; Multiple optical fiber units are arranged around the outer periphery of the central reinforcing member to form a cable core, and the outer sheath covers the outside of the cable core; Each of the optical fiber units includes a loose tube and a hollow optical fiber filled within the loose tube; The hollow optical fiber is covered with at least one buffer layer. The outer sheath is filled with microcapsules, and the microcapsules are filled with a composite biological repellent.

[0006] In some embodiments, the hollow optical fiber is covered with multiple buffer layers, and the hardness of each buffer layer increases sequentially from the inside to the outside.

[0007] In some embodiments, each hollow optical fiber is sequentially covered from the inside out with a first buffer layer, a second buffer layer, and a third buffer layer, wherein: The material of the first buffer layer includes polyurethane acrylate; The material of the second buffer layer includes silicone rubber; The material of the third buffer layer includes polyimide.

[0008] In some embodiments, each of the loose tubes is filled with one hollow optical fiber and multiple solid optical fibers; And / or, each of the loose tubes is externally covered with a first layer of shear-thickening fluid.

[0009] In some embodiments, the cable core further includes a plurality of filler ropes arranged around the periphery of the central reinforcement, each of the filler ropes being covered with an inner sheath layer. The inner sheath layer is filled with microcapsules.

[0010] In some embodiments, the wall material of the microcapsules includes maltodextrin; And / or, the composite biological repellent includes irritant components, repulsive components, and natural enemy components; And / or, the composite biological repellent includes at least one of carvacrol, thymol, cinnamaldehyde, and trimethylpyridine; And / or, the solvent for the microcapsules includes propylene glycol.

[0011] In some embodiments, the hollow fiber optic cable further includes a non-metallic armor layer, which covers the outside of the cable core and is located inside the outer sheath layer.

[0012] In some embodiments, the hollow fiber optic cable further includes a second shear-thickening fluid layer, which covers the outside of the cable core and is located inside the outer sheath layer.

[0013] In some embodiments, the cable core is sequentially covered from the inside out with the non-metallic armor layer, the second shear-thickening fluid layer, and the outer sheath layer.

[0014] In some embodiments, the material of the non-metallic armor layer includes non-metallic glass fiber reinforced plastic; The second shear-thickening fluid layer comprises a polyethylene glycol polymer medium and silica dispersed in the polyethylene glycol polymer medium.

[0015] The beneficial effects of this utility model are: The hollow fiber optic cable provided by this utility model includes a central strengthening member, multiple fiber units, and an outer sheath layer; multiple fiber units are arranged around the central strengthening member to form a cable core, and the outer sheath layer covers the outside of the cable core; each fiber unit includes a loose tube, and hollow fiber and solid fiber filled in the loose tube; the hollow fiber is covered with at least one buffer layer; the outer sheath layer is filled with microcapsules, and the microcapsules are filled with a composite biological repellent agent.

[0016] By coating the hollow optical fiber with several buffer layers, the buffer layers can absorb stress, block high temperatures and mechanical damage, effectively protecting the integrity of the fiber's interior and extending its service life. Regarding rodent repellency, compared to conventional methods that involve adding irritants such as capsaicin to the sheath, this application fills the outer sheath with microcapsule particles containing a composite biological repellent. The capsule wall prevents the repellent from contacting the outside air, slowing its evaporation rate and effectively extending its duration of action. Furthermore, this repellent uses a composite chemical composition, avoiding the problem of tolerance that can easily develop with single chemical components, significantly extending the protective effect. Attached Figure Description

[0017] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 A schematic cross-sectional view of the hollow-core optical fiber cable provided in the embodiments of this application; Figure 2 A schematic diagram of the cross-section of the hollow optical fiber and its buffer layer provided in the embodiments of this application.

[0019] icon: 1-Center reinforcement; 2-Fiber unit; 21-Loose tube; 22-Hollow fiber; 23-First buffer layer; 24-Second buffer layer; 25-Third buffer layer; 26-Fiber grease; 27-First shear thickening fluid layer; 3- Filler rope; 4-Inner sheath layer; 5-Microcapsules; 6-Non-metallic armor layer; 7-Second shear-thickening fluid layer; 8-Outer sheath layer. Detailed Implementation

[0020] The technical solution of this utility model will be clearly and completely described below with reference to the embodiments. Obviously, 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 are within the protection scope of this utility model.

[0021] It should be noted that in the description of this utility model, the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used solely for the convenience of describing this utility model and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0022] It should be noted that in the description of this utility model, the terms "connection" and "installation" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or a connection through an intermediate medium; they can refer to a mechanical connection or an electrical connection. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0023] Reference Figure 1 and Figure 2 The hollow fiber optic cable provided in this application includes a central strengthening member 1, multiple fiber units 2, and an outer sheath layer 8; multiple fiber units 2 are arranged around the central strengthening member 1 to form a cable core, and the outer sheath layer 8 covers the outside of the cable core; each fiber unit 2 includes a loose tube 21 and a hollow fiber 22 filled in the loose tube 21; the hollow fiber 22 is covered with at least one buffer layer; the outer sheath layer 8 is filled with microcapsules 5, and the microcapsules 5 are filled with a composite biological repellent.

[0024] By coating the hollow optical fiber 22 with several buffer layers, the buffer layers can absorb stress, block high temperatures and mechanical damage, effectively protect the integrity of the optical fiber's interior, and extend its service life. Regarding rodent repellency, compared to conventional methods that involve adding irritants such as capsaicin to the sheath, this application fills the outer sheath layer 8 with microcapsule particles containing a composite biological repellent. The capsule wall prevents the repellent from contacting the outside air, slowing down its evaporation rate and effectively extending its duration of action. Furthermore, this repellent uses a composite chemical composition, avoiding the problem of tolerance that can easily occur with single chemical components, significantly extending the protective effect.

[0025] In the illustrated embodiment, each hollow optical fiber 22 is covered from the inside out with a first buffer layer 23, a second buffer layer 24 and a third buffer layer 25, wherein: the first buffer layer 23 is made of polyurethane acrylate; the second buffer layer 24 is made of silicone rubber; and the third buffer layer 25 is made of polyimide.

[0026] The primary material of the first buffer layer 23 is polyurethane acrylate, which possesses high flexibility, wear resistance, and easy adhesion. During optical fiber processing, a layer of polyurethane acrylate is coated on the outer wall of the hollow optical fiber 22 and tightly bonded to the optical fiber through ultraviolet curing, providing the first layer of elastic protection.

[0027] The second buffer layer 24 is primarily made of silicone rubber, which possesses high elasticity, high buffering capacity, and thermal stability. During optical fiber processing, the silicone rubber is uniformly coated and cured in liquid form onto the surface of the first buffer layer 23, providing a second layer of protection by further buffering stress.

[0028] The third buffer layer 25 is a high-modulus buffer layer, mainly made of polyimide, which has high modulus, high temperature resistance and flame retardant properties. During the processing of optical fibers, the polyimide is coated in liquid form and then subjected to step-heat thermal imidization to form the outermost solid high-modulus buffer layer, which can effectively disperse external stress and isolate high temperature.

[0029] As mentioned earlier, the entire buffer layer outside the hollow fiber 22 follows the principle of "soft inside and hard outside". The hardness of each buffer layer increases from the inside to the outside. Through the progressive layering, stress is absorbed, high temperature is blocked and mechanical damage is blocked, effectively protecting the integrity of the fiber's interior.

[0030] In some embodiments, the wall material of the microcapsule 5 comprises maltodextrin. Maltodextrin has high emulsification stability and good moldability, making it a preferred material for capsule wall materials.

[0031] In some embodiments, the compound biological repellent includes at least one of carvacrol, thymol, cinnamaldehyde, and trimethylpyridine. Carvacrol and thymol are irritant components that rapidly and strongly stimulate the mucous membranes and nerve cells of rodents, producing a burning and stinging sensation, leading to food refusal and avoidance behavior in rodents. Cinnamaldehyde and trimethylpyridine are repulsive components that release irritating and volatile gases that rodents are naturally resistant to, causing them to instinctively avoid the area. Hydroquinone is a predator component that induces fear and instinctive escape behavior in rodents by mimicking threatening chemical signals in the secretions of rodent predators.

[0032] All of the above raw materials have the advantages of heat resistance and environmental friendliness. The optimal ratio is carvacrol: thymol: cinnamaldehyde: trimethylpyridine: hydroquinone = 2:2:3:1:0.1. The composite biological repellent prepared by this ratio has excellent precise repellency and long-lasting sustained release.

[0033] In some embodiments, the solvent for microcapsule 5 includes propylene glycol.

[0034] Compared to traditional rodent repellents, the composite biological repellent provided in this application is composed of irritant, repulsive, and natural enemy components, and can form a complex and precise multi-target repellent system through various formulations.

[0035] The aforementioned microcapsules 5 use maltodextrin as the wall material and encapsulate the composite bio-repellent agent using a microencapsulation method. Then, they are uniformly and stably composited into the inner and outer sheaths via melt blending. The complete molding process is as follows: the entire molding process is divided into a pretreatment stage and an emulsification and drying stage. First, in the pretreatment stage, the composite bio-repellent agent prepared according to the specified ratio is dissolved in food-grade propylene glycol to form a homogeneous oil phase, and a small amount of antioxidant is added to improve storage stability. Second, the oil phase is added to the wall material (maltodextrin) aqueous solution, and a stable emulsion with a particle size of nanometers is formed under high-speed and high-pressure conditions. Spray drying is then performed under high-temperature conditions to obtain microcapsule particles with an outer diameter of 20 μm and good dispersibility.

[0036] The molding process of the outer sheath layer 8 filled with microcapsules 5 is as follows: the sheath molding process is a melt blending method, using halogen-free flame-retardant polyolefin with flame retardancy, rigidity, and environmental friendliness as the matrix particles, and using prepared microcapsule particles as the filler particles; the matrix particles, filler particles, antioxidants, compatibilizers, and lubricants are dry-mixed and then melt-blended using a twin-screw extruder; finally, the outer sheath layer 8 is formed by granulation, extrusion, and coating molding, covering the outside of the cable core. The outer sheath layer 8, as the outermost rodent-proof barrier, has both physical protection and chemical repellency functions.

[0037] Continue to refer to Figure 1 In some embodiments, each loose tube 21 is also filled with a solid optical fiber; in this embodiment, each loose tube 21 is filled with one hollow optical fiber 22 and multiple solid optical fibers, and each loose tube 21 is also filled with water-blocking materials such as fiber grease 26. This application integrates the hollow optical fiber 22 and the solid optical fiber inside the same optical cable. On the one hand, it utilizes the advantages of low latency and low nonlinearity of the hollow optical fiber to carry latency-sensitive high-speed services; on the other hand, it utilizes the characteristics of low cost, good mechanical performance, and convenient operation and maintenance of the solid optical fiber to carry conventional communication services. The solid optical fiber can also form a physical buffer protection for the fragile hollow optical fiber.

[0038] In some embodiments, each loose tube 21 is externally covered with a first shear-thickening fluid layer 27. The shear-thickening fluid layer (i.e., a non-Newtonian fluid layer) is made of silica dispersed in a polyethylene glycol polymer medium, achieving intelligent defense through changes in the physical properties of the material. The working process of the shear-thickening fluid protective layer is dynamic and reversible, and can be cycled multiple times to achieve a long-term effective rodent-proof effect.

[0039] The working mechanism of the shear-thickening fluid layer is as follows: Under normal circumstances, the shear-thickening fluid is in a soft state, and the uniform dispersion of internal particles can maintain the flexibility of the optical cable; when subjected to high-frequency and high-impact biting by rodents, the internal particles are compressed and quickly aggregate to form "particle clusters". Due to non-Newtonian fluid dynamics, a huge flow resistance will be generated instantaneously, causing the material hardness and viscosity to increase sharply, forming a hard protective layer that is difficult for rodents to penetrate; when the external force dissipates, the "particle clusters" will redisperse and return to a uniform fluid state.

[0040] In some embodiments, the cable core further includes multiple filler ropes 3 arranged around the periphery of the central reinforcement 1, each filler rope 3 being covered by an inner sheath layer 4; the inner sheath layer 4 is filled with microcapsules 5. By filling the inner sheath layer 4 and the outer sheath layer 8 with microcapsules 5 respectively, the precise and long-term slow-release chemical repellency against rodents can be further improved, significantly enhancing the reliability and service life of the optical cable containing hollow optical fiber 22 in the field environment.

[0041] In some embodiments, the hollow fiber optic cable further includes a non-metallic armor layer 6, which covers the outside of the cable core and is located inside the outer sheath layer 8. The non-metallic armor layer 6 satisfies the characteristics of being lightweight, low-volume, and free from electromagnetic interference, and is preferably made of non-metallic glass fiber reinforced plastic (GFRP) as the main material. GFRP is composed of high-strength glass fiber and an epoxy resin matrix, possessing physical protective properties such as structural stability, high friction, and resistance to pressure and impact. The non-metallic armor layer 6 is manufactured by rotating and stranding GFRP around the cable core.

[0042] When rodents such as mice gnaw on the non-metallic armor layer 6, firstly, the toughness and hardness of the non-metallic armor layer 6 make gnawing too difficult; secondly, the glass fiber fragments generated inside when gnawing on a portion of the GFRP cause extreme discomfort to their mouths and teeth, thus causing them to actively abandon gnawing. These characteristics effectively resist gnawing by rodents such as mice, meeting the requirements for robust protection of hollow optical fibers and demanding outdoor laying environments.

[0043] In some embodiments, the hollow fiber optic cable further includes a second shear-thickening fluid layer 7, which covers the outside of the cable core and is located inside the outer sheath layer 8. The material and mechanism of the second shear-thickening fluid layer 7 are the same as those of the first shear-thickening fluid layer 27, and will not be described again here.

[0044] This application sets up an inner and outer double-layer shear-thickening fluid protective layer on the optical cable. Utilizing the dynamic and reversible physical properties of non-Newtonian fluids, the optical cable has excellent flexibility under normal conditions, while it instantly hardens into a rigid barrier under high-speed biting and impact, making up for the poor adaptability of traditional static protective layers.

[0045] In the illustrated embodiment, the central reinforcement 1, optical fiber units 2, and filler ropes 3 together constitute the cable core. The central reinforcement 1, composed of high-strength fiber-reinforced composite material, is located in the center of the cable core and is used to enhance the overall strength of the optical cable. The optical fiber unit 2 includes the following components: a loose tube 21; hollow optical fibers 22, solid optical fibers, and water-blocking material all filled within the loose tube 21; and a first shear-thickening fluid layer 27 covering the outside of the loose tube 21. Each loose tube 21 contains at least one hollow optical fiber 22 and multiple solid optical fibers. The hollow optical fibers 22 have a multi-layer buffer layer process, and the loose tube 21 is coated with a first shear-thickening fluid layer 27. The surface of the filler rope 3 is coated with an inner sheath layer 4 containing microcapsules 5. The central reinforcement 1, all optical fiber units 2, and all filler ropes 3 are twisted and wrapped together to form the hollow and solid optical fiber cable core. The entire cable core possesses good water-blocking, rodent-proof performance, and structural stability.

[0046] Furthermore, the cable core is sequentially covered from the inside out with a non-metallic armor layer 6, a second shear-thickening fluid layer 7, and an outer sheath layer 8. The overall optical cable structure is designed with a reasonable progression between each layer, which not only protects the intrinsic characteristics of the hollow optical fiber 22, but also achieves efficient rodent prevention through multiple physical and chemical mechanisms, significantly improving the reliability and service life of the hollow optical fiber cable containing the hollow optical fiber 22 in the field environment.

[0047] This hollow fiber optic cable has both physical protection and chemical repellency functions for rodent control: In terms of the physical protection rodent-proof structure design, the non-metallic armor layer 6 uses the toughness, hardness, and debris stimulation of the material to block rodents from gnawing, while the special material of the shear thickening fluid protective layer will harden instantly when it is bitten, thus forming a protective layer; In terms of the chemical repellency rodent-proof structure design, the inner sheath layer 4 and the outer sheath layer 8 are respectively filled with microcapsules 5, which achieve precise and long-term slow-release chemical repellency against rodents through a composite biological repellent with irritant, repulsive and natural enemy components.

[0048] In summary, this application organically and rationally integrates various mechanisms such as buffer protection, physical barrier, intelligent hardening, and multi-target chemical repellency, systematically and completely solving the key technical problems of optical cables containing hollow optical fibers 22, achieving excellent levels in terms of reliable protection, environmental adaptability, and service life.

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A hollow-core optical fiber cable, characterized in that, It includes a central reinforcement (1), multiple fiber optic units (2), and an outer sheath (8); Multiple optical fiber units (2) are arranged around the outer periphery of the central reinforcing member (1) to form a cable core, and the outer sheath layer (8) covers the outside of the cable core; Each of the optical fiber units (2) includes a loose tube (21) and a hollow optical fiber (22) filled in the loose tube (21). The hollow optical fiber (22) is covered with at least one buffer layer; The outer sheath layer (8) is filled with microcapsules (5), and the microcapsules (5) are filled with a composite biological repellent.

2. The hollow-core optical fiber cable according to claim 1, characterized in that, The hollow optical fiber (22) is covered with multiple buffer layers, and the hardness of each buffer layer increases from the inside to the outside.

3. The hollow-core optical fiber cable according to claim 2, characterized in that, Each hollow optical fiber (22) is covered from the inside out with a first buffer layer (23), a second buffer layer (24), and a third buffer layer (25), wherein: The material of the first buffer layer (23) includes polyurethane acrylate; The material of the second buffer layer (24) includes silicone rubber; The material of the third buffer layer (25) includes polyimide.

4. The hollow-core optical fiber cable according to claim 1, characterized in that, Each of the loose tubes (21) is filled with one hollow optical fiber (22) and multiple solid optical fibers; And / or, each of the loose tubes (21) is externally covered with a first layer of shear-thickening fluid (27).

5. The hollow-core optical fiber cable according to claim 1, characterized in that, The cable core also includes multiple filler ropes (3) arranged around the outer periphery of the central reinforcement (1), and each filler rope (3) is covered with an inner sheath layer (4). The inner sheath layer (4) is filled with the microcapsules (5).

6. The hollow-core optical fiber cable according to claim 1, characterized in that, It also includes a non-metallic armor layer (6), which covers the outside of the cable core and is located inside the outer sheath layer (8).

7. The hollow-core optical fiber cable according to claim 6, characterized in that, It also includes a second shear thickening fluid layer (7), which covers the outside of the cable core and is located inside the outer sheath layer (8).

8. The hollow-core optical fiber cable according to claim 7, characterized in that, The cable core is covered from the inside out with the non-metallic armor layer (6), the second shear thickening fluid layer (7), and the outer sheath layer (8).

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