A high strength tensile resistant optical cable and a method of making the same

Abstract

The application belongs to the field of optical communication transmission, and specifically discloses a high-strength tensile-resistant optical cable and a preparation method thereof. The optical cable comprises a cable core body and a sheath body. The sheath body is wrapped on the outside of the cable core body. The cable core body comprises a multi-layer stranded center reinforcing structure and a plurality of optical fiber units. The outer periphery of the multi-layer stranded center reinforcing structure has a thread groove. The plurality of optical fiber units are arranged around the multi-layer stranded center reinforcing structure. The cable core body further comprises a water-blocking layer wrapped on the outside of the multi-layer stranded center reinforcing structure and the optical fiber units. The sheath body comprises an inner layer co-extrusion sheath and an outer layer co-extrusion sheath arranged in sequence from inside to outside. The inner layer co-extrusion sheath is coaxially sleeved on the outside of the water-blocking layer. The multi-layer stranded center reinforcing structure and the optical fiber units are used to form the cable core body, and the sheath body adopts a double-layer structure, so that the strength and tensile resistance of the optical cable can be effectively improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of optical communication transmission, and more particularly relates to a high-strength tensile-resistant optical cable and a preparation method thereof. BACKGROUND

[0002] An optical cable is an indispensable part of the communication field, which is a cable manufactured to meet the performance specifications of optics, mechanics or environment, a communication cable assembly using one or more optical fibers as transmission media and can be used alone or in groups. The optical cable is mainly composed of a cable core composed of a plurality of optical fibers and an outer sheath layer covering the outside of the cable core.

[0003] With the development of the information society, the demand for related communication equipment is increasing, and the laying range is also wider and wider. The communication network continues to expand to remote areas, the deep sea and complex industrial scenes, and the traditional optical cable structure exposes many drawbacks. The optical cable is easily damaged by the pulling caused by strong winds and landslides when overhead laid in mountainous areas; the submarine optical cable is easily damaged by ocean current impact and fishing boat anchoring dragging; the optical cable in the industrial automation production line is easily damaged by the repeated bending and dragging stress of the mechanical arm.

[0004] Due to the structure of the traditional optical cable, its strength and tensile resistance are weak. When subjected to a large tensile force, the optical fiber inside the optical cable is easily damaged, affecting the signal transmission effect. At present, the strength of the optical cable is usually enhanced by setting a reinforcing layer inside the outer sheath, but because some optical cables need to remove the outer sheath during laying, the strength and tensile resistance of the internal cable core are still weak, and the optical fiber is easily damaged. Some optical cables have a central reinforcing member in the middle of the cable core, but due to the poor combination between the central reinforcing member and other parts of the cable core, the strength of the cable core is still weak. SUMMARY

[0005] In view of the defects of the prior art, the present application provides a high-strength tensile-resistant optical cable and a preparation method thereof, aiming to solve the problem of poor strength and tensile resistance of the existing optical cable.

[0006] The high-strength tensile-resistant optical cable provided by the present application specifically includes a cable core body and a sheath body, the sheath body covers and fits the outside of the cable core body, wherein the cable core body includes a multi-layer twisted center reinforcing structure and a plurality of optical fiber units, the outer periphery of the multi-layer twisted center reinforcing structure has a thread groove, and a plurality of optical fiber units are arranged around the multi-layer twisted center reinforcing structure; the cable core body further includes a water-blocking layer, and the water-blocking layer covers the outside of the optical fiber unit; the sheath body includes an inner layer co-extrusion sheath and an outer layer co-extrusion sheath arranged in sequence from inside to outside, and the inner layer co-extrusion sheath is coaxially sleeved outside the water-blocking layer.

[0007] Compared with the prior art, the cable core body in the optical cable conceived by the present application is composed of a multi-layer twisted central strengthening structure and an optical fiber unit, the thread groove generated in the twisting process of the multi-layer twisted central strengthening structure can play a role in assisting the positioning of the optical fiber unit, so that the stability of the cable core body is better and the strength is higher, meanwhile, due to the twisting structure of the multi-layer twisted central strengthening structure, when the optical cable is stretched, the multi-layer twisted central strengthening structure can offset part of the stress by means of its own torsion, has good tensile resistance, and through the double-layer structure of the sheath body, the strength of the optical cable can be further improved, and the beneficial effects of effectively improving the strength and tensile resistance of the optical cable can be achieved.

[0008] As a further preferred, the optical fiber unit is a tight-buffered optical fiber.

[0009] By adopting the above technical scheme, the tight-buffered optical fiber is soft and easy to peel, and has a small bending radius, excellent mechanical and environmental performance, and the combination of the tight-buffered optical fiber and the multi-layer twisted central strengthening structure to form the cable core of the optical cable further improves the strength and tensile resistance of the optical cable.

[0010] As a further preferred, the multi-layer twisted central strengthening structure comprises aramid yarn bundles and a plurality of glass fiber reinforced plastic rods, the glass fiber reinforced plastic rods are spirally twisted on the outer periphery of the aramid yarn bundles, and the thread grooves are formed between adjacent two glass fiber reinforced plastic rods.

[0011] By adopting the above technical scheme, the aramid yarn bundle with high strength is used as the axis to improve the initial tensile core force, and the glass fiber reinforced plastic rods are spirally twisted on the outer periphery of the aramid yarn bundle to form the thread grooves, so as to improve the combination stability between the multi-layer twisted central strengthening structure and the optical fiber unit.

[0012] As a further preferred, the twisting angle of the glass fiber reinforced plastic rod is 15°-25°.

[0013] By adopting the above technical scheme, when the twisting angle of the glass fiber reinforced plastic rod is between 15° and 25°, the glass fiber reinforced plastic rods can interact with each other to effectively transfer stress, so that the overall structure after twisting has high tensile strength and fatigue resistance.

[0014] As a further preferred, the surface of each glass fiber reinforced plastic rod is coated with a wear-resistant coating.

[0015] By adopting the above technical scheme, the wear-resistant coating can protect the glass fiber reinforced plastic rod, avoid mutual friction between adjacent two glass fiber reinforced plastic rods, and affect the overall structural strength of the multi-layer twisted central strengthening structure.

[0016] As a further preferred, the cable core body further comprises a buffer layer, the buffer layer is filled between the optical fiber unit and the multi-layer twisted center reinforcing structure.

[0017] By adopting the above technical scheme, when the optical cable is subjected to impact force, the buffer layer can absorb energy through deformation, thereby playing a certain buffering protection effect on the optical fiber unit, and avoiding extrusion between the optical fiber unit and the multi-layer twisted center reinforcing structure to cause damage to the optical fiber unit.

[0018] As a further preferred, the buffer layer adopts a thermoplastic elastomeric buffer material, which is any one of polyurethane thermoplastic elastomer, thermoplastic polyester elastomer, styrene-based thermoplastic elastomer and dynamic vulcanized thermoplastic elastomer.

[0019] By adopting the above technical scheme, the buffer layer can be made of several materials according to actual processing needs, and the number of optional materials is large, the processing cost is low, and the appropriate material can be selected according to the required elastic properties, so that the performance of the optical cable is better and suitable for laying requirements.

[0020] As a further preferred, the sheath body further comprises a metal tape armor layer, and the metal tape armor layer is located between the inner layer co-extrusion sheath and the water blocking layer.

[0021] By adopting the above technical scheme, the metal tape armor layer can further protect the optical fiber unit, avoid the influence of the optical cable outer wall torsion and side pressure on the optical fiber unit, and make the optical fiber unit have good long-term communication function.

[0022] A preparation method of a high-strength tensile optical cable, comprising the following steps:

[0023] S1: a plurality of optical fiber units are arranged around the outer periphery of a multi-layer twisted center reinforcing structure to form a communication unit with a circular cross section, and the multi-layer twisted center reinforcing structure is located at the center of the communication unit;

[0024] S2: wrapping a water blocking layer outside the communication unit;

[0025] S3: after the water blocking layer is wrapped outside, an inner layer co-extrusion sheath and an outer layer co-extrusion sheath are simultaneously extruded and cooled, and the preparation of the high-strength tensile optical cable is completed.

[0026] As a further preferred, in step S3, before the inner layer co-extrusion sheath and the outer layer co-extrusion sheath are extruded, a metal tape armor layer is wrapped outside the water blocking layer.

[0027] Overall, compared with the prior art, the above technical scheme conceived by the present application mainly has the following technical advantages:

[0028] 1. The cable core body is composed of a multi-layer twisted center reinforcing structure and an optical fiber unit. The thread groove on the multi-layer twisted center reinforcing structure can assist in positioning the optical fiber unit, improve the bonding effect, make the stability of the cable core body better, and have higher strength. Meanwhile, due to the twisted structure of the multi-layer twisted center reinforcing structure, when the optical cable is stretched, the multi-layer twisted center reinforcing structure can resist part of the stress by its own torsion, has better tensile resistance, and through the double-layer structure of the sheath body, the strength of the optical cable can be further improved, effectively improving the strength and tensile resistance of the optical cable.

[0029] 2. In the multi-layer twisted center reinforcing structure, the aramid yarn bundle with high strength is used as the axis to improve the initial tensile core force, and the glass fiber reinforced plastic rod is spirally twisted around the aramid yarn bundle to form a thread groove, so as to improve the bonding stability between the multi-layer twisted center reinforcing structure and the optical fiber unit. Meanwhile, the glass fiber reinforced plastic rods are arranged at a certain range of twisting angles, and can effectively transfer stress by mutual cooperation between the glass fiber reinforced plastic rods, so that the overall structure after twisting has high tensile strength and fatigue resistance.

[0030] 3. The optical fiber unit and the multi-layer twisted center reinforcing structure are provided with a buffer layer. When the optical cable is subjected to impact force, the buffer layer can absorb energy through deformation, so as to have a certain buffering protection effect on the optical fiber unit, and avoid extrusion between the optical fiber unit and the multi-layer twisted center reinforcing structure to cause damage to the optical fiber unit. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 is a cross-sectional structure schematic diagram of a high-strength tensile-resistant optical cable provided by the embodiment of the application;

[0032] Figure 2 is a front view structure schematic diagram of a multi-layer twisted center reinforcing structure provided by the embodiment of the application.

[0033] In all the drawings, the same reference signs are used to represent the same elements or structures, wherein:

[0034] 1, cable core body; 11, multi-layer twisted center reinforcing structure; 111, aramid yarn bundle; 112, glass fiber reinforced plastic rod; 113, wear-resistant coating; 114, thread groove; 12, optical fiber unit; 13, water-blocking layer; 14, buffer layer; 2, sheath body; 21, inner layer co-extrusion sheath; 22, outer layer co-extrusion sheath; 23, metal belt armor layer. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not to limit the present application.

[0036] In order to make the optical cable applicable to various extreme environments, the present application provides a high-strength tensile-resistant optical cable, which is a new type of optical cable with all-round reinforced tensile resistance, bending resistance and protection performance.

[0037] With reference to Figure 1 The high-strength tensile-resistant optical cable disclosed by the present application comprises a cable core body 1 and a sheath body 2, the sheath body 2 is wrapped and attached to the outside of the cable core body 1, and the cross section along the optical cable axis is circular.

[0038] In this embodiment, the cable core body 1 comprises a multi-layer twisted center reinforcing structure 11 and a plurality of optical fiber units 12, wherein the optical fiber unit 12 is a tight-fitting optical fiber, the outer periphery of the multi-layer twisted center reinforcing structure 11 has a thread groove 114, the plurality of optical fiber units 12 are arranged around the multi-layer twisted center reinforcing structure 11, and the thread groove 114 on the multi-layer twisted center reinforcing structure 11 can play an auxiliary positioning role for the optical fiber unit 12, so that the stability of the cable core body 1 is better; when the optical cable is stretched, the multi-layer twisted center reinforcing structure 11 can resist part of the stress by means of its own torsion, has good tensile resistance, and has a spring-like buffering mechanism.

[0039] In the present application, the tight-fitting material of the tight-fitting optical fiber is high-elasticity polyurethane, and nano-silica microspheres are added to improve the hardness and wear resistance. The tight-fitting outer diameter is optimized according to the number of optical fiber units 12 to ensure compact arrangement while reserving micro-deformation space. When the number of optical fiber units 12 is 2 to 4, a smaller tight-fitting outer diameter can be used, such as 1.0 to 1.5 mm, to ensure compact overall structure of the optical cable, while reserving 0.1 to 0.2 mm of micro-deformation space between the tight-fitting optical fibers, facilitating the free movement and deformation of the optical fibers to a certain extent. For the case of 8 to 12 optical fiber units 12, the tight-fitting outer diameter can be between 1.5 to 2.0 mm, and the micro-deformation space between each optical fiber unit 12 can be controlled to be 0.15 to 0.25 mm, which can ensure compact arrangement and also provide enough space for the optical fiber units 12 to move and deform slightly when the optical cable is subjected to external force, avoiding mutual extrusion. When the number of optical fiber units 12 reaches 16 or more, the tight-fitting outer diameter can be increased to 2.0 to 2.5 mm or even larger, while the micro-deformation space can be about 0.2 to 0.3 mm to adapt to the compact arrangement of more optical fiber units 12 and provide enough buffer space.

[0040] Specifically, the multi-layer twisted center reinforcing structure 11 includes aramid yarn bundles 111 and a plurality of glass fiber reinforced plastic rods 112 (GFRP rods) twisted at a twist angle of 15°-25° on the outer periphery of the aramid yarn bundles 111. The adjacent two glass fiber reinforced plastic rods 112 twisted on the outer periphery of the aramid yarn bundles 111 form a thread groove 114. The multi-layer twisted center reinforcing structure 11 provides an initial tensile core force by adopting a multi-layer multi-layer twisted center reinforcing structure 11, with the central high-strength aramid yarn bundle 111 as the axis. The aramid yarn bundle 111 is treated by silane coupling agent immersion to enhance the affinity with the surrounding material and ensure uniform stress transmission. When the concentration of the silane coupling agent is too low or too high, the surface of the aramid yarn bundle 111 may not form sufficient chemical bonds or physical adsorption or may form agglomeration on the surface, resulting in uneven stress transmission and affecting the surface performance of the yarn bundle. If the temperature is too low, a long time is needed for the immersion process to achieve the desired effect, reducing production efficiency. If the temperature is too high, the silane coupling agent may not react sufficiently with the surface of the aramid yarn bundle 111, affecting the strength and damaging the fibers. If the immersion time is too short, it cannot form sufficient chemical bonds or physical adsorption, and the immersion effect is not ideal. If the immersion time is too long, it may cause over-immersion, making the silane coupling agent layer too thick, affecting its bonding effect with the surrounding material, and also increasing production cost and production cycle. Therefore, when the aramid yarn bundle 111 is treated by silane coupling agent immersion, the general control is that the mass concentration of the silane coupling agent is between 1% and 5%, the immersion temperature is between 40°C and 80°C, and the immersion time is usually between 1 hour and 4 hours.

[0041] In this embodiment, the surface of each glass fiber reinforced plastic rod 112 is coated with a nano-ceramic wear-resistant coating 113, and other wear-resistant materials can also be used in other embodiments. The nano-ceramic wear-resistant coating 113 can be formed by sol-gel method, through hydrolysis and polycondensation reaction of metal alkoxide or inorganic salt, forming a stable sol, and then drying, sintering and other treatments to form a nano-ceramic coating on the surface of the substrate. This method has relatively low cost, relatively simple equipment requirements, can use various simple and easy coating methods such as dipping, spraying, etc., is easy to operate, has high production efficiency, and can reduce labor cost. The coating thickness is generally between 20μm and 60μm, which can meet the requirements of wear resistance and corrosion resistance in use, and will not greatly affect the flexibility and other properties of the GFRP rod.

[0042] Further, the overall size of the multi-layered stranded central reinforcing structure 11 is generally determined according to the actual application scenario and transmission requirements, such as an optical cable for long-distance backbone communication network, the overall diameter of the multi-layered stranded central reinforcing structure 11 can be about 10 to 30 millimeters; for an optical cable for short-distance communication within a city, the overall diameter can be about 5 to 15 millimeters. The size of the aramid yarn bundle 111 as the central high-strength tensile core is generally about 10% to 30% of the overall diameter of the multi-layered stranded central reinforcing structure 11, for example, for a multi-layered stranded central reinforcing structure 11 with an overall diameter of 20 millimeters, the diameter of the aramid yarn bundle 111 can be between 2 to 6 millimeters. The diameter of the GFRP rod is relatively small, and a plurality of GFRP rods are stranded around the aramid yarn bundle 111, and the diameter of a single GFRP rod can be about 1 to 3 millimeters, and the specific size needs to be determined according to the overall design of the optical cable, the tensile index, and the number of optical fiber units 12. The ratio range of the overall diameter of the multi-layered stranded central reinforcing structure 11 to the diameter of the optical cable, considering that the outermost layer of the optical cable also has a sheath body 2, the ratio range of the overall diameter of the multi-layered stranded central reinforcing structure 11 to the final diameter of the optical cable is about 60% to 80%, for example, the overall diameter of the multi-layered stranded central reinforcing structure 11 is 16 millimeters, and the final diameter of the optical cable can be about 20 to 26 millimeters.

[0043] Further, during the laying process of the optical cable, strong wind can cause the optical cable to be impacted by a transverse force, causing the optical cable to swing, stretch or bend; when a landslide occurs, objects such as rolling stones can impact the optical cable from different directions, and the impact direction is mostly oblique or vertical; when an earthquake occurs, the ground will shake violently, causing the optical cable to be impacted by forces from all directions, including up and down, left and right, and stretching and extrusion; during the laying, maintenance and reconstruction of the optical cable, the improper operation of construction tools, the collision of equipment and the like can cause the optical cable to be impacted, and the impact direction is difficult to determine and can be in any direction. Therefore, the buffer layer 14 is arranged between the optical fiber unit 12 and the multi-layer twisted center reinforcing structure 11 in the present application, and the buffer layer 14 needs to meet the conditions of being elastically deformed to absorb energy in an instant of impact, maintaining a stable form at room temperature, not flowing at high temperature, not brittle cracking at low temperature, adapting to an environment of-40℃-85℃, and specifically forming the buffer layer 14 by filling a thermoplastic elastic buffer material, which is any one of a polyurethane thermoplastic elastomer, a thermoplastic polyester elastomer, a styrene thermoplastic elastomer and a dynamic vulcanized thermoplastic elastomer. When the optical cable is impacted, the buffer layer 14 can absorb energy through deformation, and can have a certain buffering protection effect on the optical fiber unit 12, so as to avoid extrusion between the optical fiber unit 12 and the multi-layer twisted center reinforcing structure 11 and damage to the optical fiber unit 12. The polyurethane thermoplastic elastomer (TPU) has excellent properties such as high elasticity, high strength, wear resistance, oil resistance and chemical corrosion resistance, has a wide hardness range, can adjust the formula to obtain different hardnesses as needed, has good flowability and formability at room temperature, and is convenient and fast for injection molding; the thermoplastic polyester elastomer (TPEE) has both the elasticity of rubber and the strength of engineering plastic, has excellent fatigue resistance, weather resistance, chemical resistance and thermal stability, can be stably injection molded at room temperature, and has good dimensional stability of the molded product; the styrene thermoplastic elastomer (TPE-S) has good elasticity, softness, weather resistance and processing performance, has good melt flowability at room temperature, is easy to injection mold, and can be blended and modified with various materials to meet different performance requirements; the dynamic vulcanized thermoplastic elastomer (TPV) has excellent high and low temperature resistance, chemical resistance, aging resistance and oil resistance, has good elasticity and strength at room temperature, has good flowability during injection molding, and has the characteristics of short molding cycle.

[0044] More specifically, the cable core body 1 further includes a water-blocking layer 13, which is wrapped outside the optical fiber unit 12. In the present embodiment, a water-blocking tape or other water-blocking material is wrapped outside the optical fiber unit 12 to prevent water from entering the inside of the optical cable, so as to protect the optical cable from water erosion and improve the service life of the optical cable.

[0045] Further, the sheath body 2 comprises an inner layer co-extrusion sheath 21 and an outer layer co-extrusion sheath 22 arranged in sequence from inside to outside, the inner layer co-extrusion sheath 21 is coaxially sleeved on the outside of the water-blocking layer 13, wherein the inner layer co-extrusion sheath 21 is weather-resistant polyethylene containing ultraviolet stabilizer and antioxidant, resisting sunlight and chemical corrosion; the outer layer co-extrusion sheath 22 is low-friction coefficient polyurethane, facilitating the laying of the optical cable, and the surface has raised anti-slip texture, and the special texture direction is optimized according to stress simulation, helping to disperse the lateral friction force. In order to further improve the strength of the sheath body 2, the sheath body 2 further comprises a metal tape armor layer 23, which is located between the inner layer co-extrusion sheath 21 and the water-blocking layer 13. The metal tape armor layer 23 improves the strength of the optical cable as a whole, and can further protect the optical fiber unit 12, avoiding the influence of the torsion and lateral pressure of the outer wall of the optical cable on the optical fiber unit 12.

[0046] The application also discloses a preparation method of the high-strength tensile-resistant optical cable.

[0047] S1: a plurality of optical fiber units 12 are arranged around the outer periphery of the multi-layer twisted central reinforcing structure 11 to form a communication unit with a circular cross section, and the multi-layer twisted central reinforcing structure 11 is located at the center of the communication unit; before the optical fiber units 12 are arranged, the multi-layer twisted central reinforcing structure 11 needs to be prepared, wherein the aramid yarn bundle 111 is customized according to the design tensile index of the optical cable, and the number of yarns and the twist are accurately controlled; for example, under the design tensile index of 1500N, the number of aramid yarn bundles 111 is 1500D, and the twist is 20 twists per meter; in actual application, the number of aramid yarn bundles 111 and the twist are comprehensively adjusted and determined according to the specific design tensile index of the optical cable, the use environment, the cooperation of other materials and other factors; when the GFRP rod is twisted with the aramid yarn bundle 111, the twisting equipment is used to ensure that the size tolerance is ±0.05mm; the tight-fitting optical fiber preparation adopts a double-layer co-extrusion process, the inner layer is coated with nanometer silica microsphere doped polyurethane, and the outer layer is coated with an ultrathin polyethylene protective film; the whole tension and temperature closed-loop monitoring is carried out according to the actual production needs, which is not described in detail here.

[0048] By adopting an automatic 3D twisting device, aramid yarn bundles 111, GFRP rods and optical fiber units 12 are uniformly and accurately twisted according to a preset program, the twisting tension and angle are monitored in real time, and an alarm is immediately given for adjustment if the parameters do not meet the standards; the buffer layer 14 material is filled by high-pressure injection, the mold is provided with multiple pressure partitions to ensure uniform filling without bubbles, and after injection, X-ray detection is performed for sampling inspection. In the preset program of the GFRP rod twisting tension and angle, the parameters are as follows: the tension size is generally between 50N and 500N, for the twisting of GFRP rods with smaller diameter and fewer quantity, the tension may be around 50N to 200N; and for the twisting of GFRP rods with larger diameter and more quantity, the tension may need to reach 200N to 500N; the tension uniformity requires that the tension fluctuation range be controlled within ±5% to ±10%; the twisting angle range is generally between 15° and 25°; the angle accuracy generally requires to be controlled within ±1° to ±2° to ensure the uniformity and stability of the twisting, and the above parameters can be adjusted manually as needed during actual preparation.

[0049] S2: wrapping the water-blocking layer 13 outside the communication unit, completing the preparation of the cable core body 1; by wrapping the water-blocking tape outside the optical fiber unit 12 to prevent moisture from entering the interior of the optical cable, the optical cable is protected from water erosion, and the service life of the optical cable is improved.

[0050] S3: after extruding the inner layer co-extrusion sheath 21 and the outer layer co-extrusion sheath 22 outside the water-blocking layer 13 and cooling, the preparation of the high-strength stretch-resistant optical cable is completed; before extruding the inner layer co-extrusion sheath 21 and the outer layer co-extrusion sheath 22, the metal tape armor layer is wrapped outside the water-blocking layer 13; specifically, the metal tape armor layer 23 is first wrapped outside the water-blocking layer 13, and then a double-layer co-extrusion head is adopted, the inner layer co-extrusion sheath 21 polyethylene and the outer layer co-extrusion sheath 22 polyurethane raw materials are fed by the loss weight type metering, and the proportion is accurately controlled; the head temperature is set according to the gradient of the material rheological property to ensure uniform melting and plasticization; after extrusion, the optical cable is vacuum shaped, sprayed and cooled, the traction wheel is intelligently adjusted in distance and speed according to the optical cable specifications, the finished product is measured in diameter, inspected and tested in performance, the data is input into the quality traceability system, and the specific processing parameters can be adjusted manually as needed during actual preparation. This step is prior art, and the present application will not be described in detail.

[0051] In the present application, the optical cable is tested in a simulated complex environment, and it is found that the tensile strength is improved by 80% compared with the traditional one, the attenuation is only 0.1dB after 10000 times of repeated bending, and there is no loss of transmission performance after 30 days of salt spray and acid and alkali immersion.

[0052] The high-strength stretch-resistant optical cable of the present application is compared with the ordinary loose-jacketed twisted optical cable according to the test results as follows:

[0053] Tensile resistance: The optical cable of the present application has a central high-strength aramid yarn bundle as the axis and combines with a spiral tightly twisted GFRP rod, and its tensile strength can reach more than 1500N. The ordinary loose-jacket stranded optical cable mainly relies on the simple strengthening of steel wire or ordinary aramid yarn, and its tensile strength is generally about 800N. In the tensile test simulating overhead laying, the internal structure of the optical cable of the present application has no obvious displacement and damage when bearing 1200N tension, and the signal transmission is stable. The optical fiber unit of the ordinary loose-jacket stranded optical cable has a slight displacement when the tension is 800N, and when the tension is 1000N, some steel wires begin to break, and the signal fluctuates.

[0054] Bending resistance: The tight-jacketed optical fiber of the optical cable of the present application is specially designed to reserve a micro-deformation space, and there is a high-performance thermoplastic elastomer buffer material between the optical fiber unit and the GFRP rod. After 10000 times of bending, the attenuation is only 0.1dB. The ordinary loose-jacket stranded optical cable lacks these designs, and after 5000 times of bending, the attenuation can reach more than 0.5dB, and the tight-jacketed optical fiber is prone to cracking, affecting the signal transmission quality.

[0055] Protection performance: The double-layer co-extrusion sheath of the optical cable of the present application has an inner layer of weather-resistant polyethylene to resist chemical corrosion and an outer layer of low-friction coefficient polyurethane to facilitate dragging and has anti-slip texture to disperse lateral friction. The transmission performance is not damaged after 30 days of salt spray and acid and alkali soaking. The sheath protection of the ordinary loose-jacket stranded optical cable is relatively single, and after about 15 days of soaking in the same environment, the sheath may appear corrosion and aging phenomena, thereby affecting the transmission performance of the internal optical fiber.

[0056] The following compares the high-strength tensile optical cable of the present application with the central tube type optical cable according to the test results:

[0057] Tensile resistance: The multi-layer twisted structure design of the present application makes its tensile resistance far exceed that of the central tube type optical cable. The tensile strength of the optical cable of the present application can reach more than 1500N, while the tensile strength of the central tube type optical cable is usually between 600N and 800N due to the relatively simple structure. For example, in the test simulating the impact of ocean current on submarine cable, the optical cable of the present application can withstand a larger tension without being damaged, while the central tube type optical cable is prone to optical fiber breakage or structural damage under a smaller tension.

[0058] Bending resistance: The buffer material and special tight-jacket design inside the optical cable of the present application make its bending resistance excellent. After 10000 times of bending test, the performance of the optical cable of the present application remains good, while the central tube type optical cable may have a large attenuation after 3000 times of bending, such as the attenuation rising from the initial 0.2dB to about 1dB, and the mechanical properties of the optical fiber are also greatly affected.

[0059] Protection performance: the sheath and the internal layers of the optical cable of the present application provide all-round protection. In the protection performance test, the optical cable of the present application can effectively protect the internal optical fiber when subjected to external impact, wear and chemical corrosion. The center tube type optical cable has weak buffering capacity when facing the same intensity impact, which can easily cause damage to the internal optical fiber; in the chemical corrosion environment, the durability of its protective layer is not as good as that of the optical cable of the present application, and the transmission performance may decrease earlier.

[0060] In summary, the high-strength tensile-resistant optical cable provided by the present application has all-round reinforced tensile resistance, bending resistance and protection performance compared with the existing optical cable, and can be applied in different extreme environments and has good use effect.

[0061] It should be understood that the expressions such as "include" and "may include" used in the present application indicate the existence of the disclosed functions, operations or constituent elements, and do not limit one or more additional functions, operations and constituent elements. In the present application, terms such as "include" and / or "have" can be interpreted to mean that a specific feature, number, operation, constituent element, component or combination thereof is present, but cannot be interpreted to exclude the presence or addition of one or more other features, numbers, operations, constituent elements, components or combinations thereof.

[0062] It should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0063] In addition, the terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0064] In this application, unless otherwise clearly indicated and limited, the terms "mounting", "connection", "connecting", "fixing" and the like should be interpreted broadly, for example, can be fixed connection, can also be detachable connection, or integrally connected; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0065] Those skilled in the art can understand that the above only describes the preferred embodiments of the present application, and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A high strength, tensile resistant optical cable characterized by, The cable core body (1) comprises a multi-layer twisted central reinforcing structure (11) and a plurality of optical fiber units (12), the outer periphery of the multi-layer twisted central reinforcing structure (11) has a thread groove (114), and the plurality of optical fiber units (12) are arranged around the multi-layer twisted central reinforcing structure (11); the cable core body (1) further comprises a water-blocking layer (13) wrapped outside the optical fiber units (12); The sheath body (2) comprises an inner layer co-extrusion sheath (21) and an outer layer co-extrusion sheath (22) arranged in sequence from inside to outside, and the inner layer co-extrusion sheath (21) is coaxially sleeved outside the water-blocking layer (13); The multi-layer twisted central reinforcing structure (11) comprises aramid yarn bundles (111) and a plurality of glass fiber reinforced plastic rods (112), the glass fiber reinforced plastic rods (112) are spirally twisted on the outer periphery of the aramid yarn bundles (111), and the thread groove (114) is formed between adjacent two glass fiber reinforced plastic rods (112). The optical fiber unit (12) is a tight-fitting optical fiber.

2. A high strength, tensile resistant fiber optic cable of claim 1 wherein, The twisting angle of the glass fiber reinforced plastic rod (112) is 15°-25°.

3. A high strength, tensile resistant fiber optic cable of claim 1 wherein, The surface of each glass fiber reinforced plastic rod (112) is coated with a wear-resistant coating (113).

4. A high strength, tensile resistant fiber optic cable of claim 1 wherein, The cable core body (1) further comprises a buffer layer (14) filled between the optical fiber units (12) and the multi-layer twisted central reinforcing structure (11).

5. A high strength, tensile resistant fiber optic cable of claim 1 wherein, The buffer layer (14) is made of thermoplastic elastomer, which is any one of polyurethane thermoplastic elastomer, thermoplastic polyester elastomer, styrene-based thermoplastic elastomer and dynamic vulcanized thermoplastic elastomer.

6. A high strength, tensile resistant fiber optic cable according to claim 5, wherein, The sheath body (2) further comprises a metal tape armor layer (23) located between the inner layer co-extrusion sheath (21) and the water-blocking layer (13).

7. A high strength, tensile resistant fiber optic cable of any of claims 1-6, wherein, The method comprises the following steps:

8. A process for the preparation of a high strength tensile resistant optical cable as claimed in any one of claims 1 to 7, characterised in that, S1: a plurality of optical fiber units (12) are arranged around the outer periphery of the multi-layer twisted central reinforcing structure (11) to form a communication unit with a circular cross section, and the multi-layer twisted central reinforcing structure (11) is located at the center of the communication unit; S2: wrapping a water-blocking layer (13) outside the communication unit; S3: after the inner layer co-extrusion sheath (21) and the outer layer co-extrusion sheath (22) are simultaneously extruded and wrapped outside the water-blocking layer (13), cooling is performed to complete the preparation of the high-strength tensile optical cable. In step S3, before the inner layer co-extrusion sheath (21) and the outer layer co-extrusion sheath (22) are extruded, a metal tape armor layer (23) is wrapped outside the water-blocking layer (13).

9. The production method according to claim 8, wherein ​

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