High-strength tensile optical cable and preparation method thereof

Abstract

The invention belongs to the field of optical communication transmission, and particularly discloses a high-strength tensile optical cable and a preparation method thereof.The optical cable comprises a cable core body and a sheath body, the sheath body wraps and is attached to the outer portion of the cable core body, the cable core body comprises a multi-layer stranded center reinforcing structure and a plurality of optical fiber units, and the optical fiber units are arranged in the multi-layer stranded center reinforcing structure. The periphery of the multi-layer stranded central reinforcing structure is provided with a thread wire slot, and the plurality of optical fiber units are arranged around the multi-layer stranded central reinforcing structure; the cable core body further comprises a waterproof layer, and the waterproof layer is wrapped outside the multi-layer twisted central reinforcing structure and the optical fiber unit. The sheath body comprises an inner-layer co-extrusion sheath and an outer-layer co-extrusion sheath which are sequentially arranged from inside to outside, and the inner-layer co-extrusion sheath is coaxially sleeved outside the waterproof layer. According to the invention, the cable core body is formed by the multi-layer twisted central reinforcing structure and the optical fiber unit, and the sheath body is of 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 specifically, to a high-strength tensile-resistant optical cable and a preparation method thereof. Background Art

[0002] Optical cable is an indispensable part of the communication field. It is a cable manufactured to meet optical, mechanical or environmental performance specifications. It uses one or more optical fibers as transmission media and is a communication cable assembly that can be used individually or in groups. The optical cable is mainly composed of a cable core composed of several optical fibers and an outer sheath layer covering the outside of the cable core.

[0003] With the advancement of the information society, the demand for related communication equipment is increasing, and the deployment range is also getting wider and wider. Communication networks continue to expand to remote areas, deep seas and complex industrial scenarios, and traditional optical cable structures have exposed many drawbacks. When optical cables are laid overhead in mountainous areas, they are easily damaged by the pulling caused by strong winds and landslides; submarine optical cables are often damaged by the impact of ocean currents and the dragging of fishing boats; optical cables in industrial automation production lines are frequently subjected to repeated bending and dragging stress of robotic arms and are easily damaged.

[0004] Due to its structure, the strength and tensile resistance of traditional optical cables are relatively weak. When subjected to large tensile forces, the optical fibers inside the optical cables are easily damaged, affecting the signal transmission effect. Nowadays, the strength of optical cables is usually enhanced by setting a reinforcement layer inside the outer sheath, but since some optical cables need to remove the outer sheath during laying, the strength and tensile resistance of the internal cable core are still relatively weak, and the optical fibers are easily damaged; some optical cables have a central reinforcement member in the middle of the cable core, but the strength of the cable core is still relatively weak due to the poor bonding between the central reinforcement member and other parts of the cable core. Summary of the invention

[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 cables.

[0006] The present application provides a high-strength tensile-resistant optical cable, which specifically includes a cable core body and a sheath body, wherein the sheath body covers and adheres to the outside of the cable core body, wherein: the cable core body includes a multi-layer twisted central reinforcement structure and a plurality of optical fiber units, the outer periphery of the multi-layer twisted central reinforcement structure has a threaded wire groove, and the plurality of optical fiber units are arranged around the multi-layer twisted central reinforcement structure; the cable core body also includes a water-blocking layer, which covers the outside of the optical fiber unit; the sheath body includes an inner co-extruded sheath and an outer co-extruded sheath arranged in sequence from the inside to the outside, and the inner co-extruded sheath is coaxially sleeved on the outside of the water-blocking layer.

[0007] Through the above technical scheme conceived by the present application, compared with the prior art, since the cable core body in the optical cable of the present application is composed of a multi-layer twisted center reinforcement structure and an optical fiber unit, the threaded wire grooves generated by the multi-layer twisted center reinforcement structure during the twisting process can assist in positioning the optical fiber unit, so that the cable core body has better stability and higher strength. At the same time, due to the twisted structure of the multi-layer twisted center reinforcement structure, when the optical cable is stretched, the multi-layer twisted center reinforcement structure can use its own torsion to offset part of the stress and has good tensile resistance. At the same time, through the double-layer structure of the sheath body, the strength of the optical cable can be further improved, and the beneficial effect of effectively improving the strength and tensile resistance of the optical cable can be achieved.

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

[0009] By adopting the above technical solution, the tight-buffered optical fiber is soft and easy to strip, and at the same time has a small bending radius and excellent mechanical and environmental properties. It is combined with a multi-layer twisted central reinforcement structure to form the cable core of the optical cable, further improving the strength and tensile resistance of the optical cable.

[0010] As further preferred, the multi-layer twisted central reinforcement structure includes an aramid yarn bundle and a plurality of glass fiber reinforced plastic rods, the glass fiber reinforced plastic rods are spirally twisted on the periphery of the aramid yarn bundle, and the thread groove is formed between two adjacent glass fiber reinforced plastic rods.

[0011] By adopting the above technical solution, a high-strength aramid yarn bundle is used as the axis to improve the initial tensile core force, and a glass fiber reinforced plastic rod is spirally twisted on the outer periphery of the aramid yarn bundle to form a threaded groove, thereby improving the bonding stability between the multi-layer twisted center reinforcement structure and the optical fiber unit.

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

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

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

[0015] By adopting the above technical solution, the wear-resistant coating can protect the glass fiber reinforced plastic rods, thereby preventing the friction between two adjacent glass fiber reinforced plastic rods from causing damage and affecting the overall structural strength of the multi-layer twisted center reinforced structure.

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

[0017] By adopting the above technical solution, when the optical cable is subjected to impact force, the buffer layer absorbs energy through deformation, which can provide a certain buffering protection effect for the optical fiber unit, thereby avoiding damage to the optical fiber unit caused by squeezing between the optical fiber unit and the multi-layer twisted center reinforcement structure.

[0018] As further preferred, the buffer layer is made of a thermoplastic elastic buffer material, and the thermoplastic elastic buffer material is any one of polyurethane thermoplastic elastomer, thermoplastic polyester elastomer, styrene thermoplastic elastomer and dynamically vulcanized thermoplastic elastomer.

[0019] By adopting the above technical solution, the buffer layer can be made of several materials according to actual processing needs. There are many types of materials to choose from, and the processing cost is low. At the same time, suitable materials 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 preference, the sheath body further comprises a metal tape armor layer, and the metal tape armor layer is located between the inner co-extruded sheath and the water-blocking layer.

[0021] By adopting the above technical solution, the metal belt armor layer can further protect the optical fiber unit, prevent the optical fiber unit from being affected by the twisting of the outer wall of the optical cable and the lateral pressure, so that the optical fiber unit has good long-term communication function.

[0022] A method for preparing a high-strength tensile-resistant optical cable comprises the following steps: S1: A plurality of optical fiber units are wrapped around the outer periphery of a multi-layer twisted central reinforcement structure to form a communication unit with a circular cross section, wherein the multi-layer twisted central reinforcement structure is located at the center of the communication unit; S2: Wrap a water-blocking layer around the outside of the communication unit; S3: Extruding an inner co-extruded sheath and an outer co-extruded sheath simultaneously on the outside of the water-blocking layer and then cooling the layers to complete the preparation of the high-strength tensile-resistant optical cable.

[0023] As a further preferred embodiment, in step S3, before extruding the inner co-extruded sheath and the outer co-extruded sheath, a metal tape armor layer is wrapped around the outside of the water-blocking layer.

[0024] In general, the above technical solutions conceived by this application have the following technical advantages compared with the prior art: 1. The present application adopts a multi-layer twisted center reinforcement structure and an optical fiber unit to form a cable core body. The threaded groove on the multi-layer twisted center reinforcement structure can play an auxiliary positioning role for the optical fiber unit, improve the combination effect, and make the cable core body more stable and stronger. At the same time, due to the twisted structure of the multi-layer twisted center reinforcement structure, when the optical cable is stretched, the multi-layer twisted center reinforcement structure can offset part of the stress by its own torsion, and has good tensile resistance. At the same time, through the double-layer structure of the sheath body, the strength of the optical cable can be further improved, and the strength and tensile resistance of the optical cable can be effectively improved.

[0025] 2. In the present application, the multi-layer twisted central reinforcement structure adopts a high-strength aramid yarn bundle 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 a threaded groove, thereby improving the combination stability between the multi-layer twisted central reinforcement structure and the optical fiber unit; at the same time, the glass fiber reinforced plastic rods are set with a certain range of twisting angles, and the glass fiber reinforced plastic rods can cooperate with each other to effectively transfer stress, so that the overall structure after twisting has higher tensile strength and fatigue resistance.

[0026] 3. In the present application, a buffer layer is provided between the optical fiber unit and the multi-layer twisted central reinforcement structure. When the optical cable is subjected to impact force, the deformation and energy absorption of the buffer layer can provide a certain buffering protection effect for the optical fiber unit, thereby preventing the optical fiber unit from being damaged due to squeezing between the optical fiber unit and the multi-layer twisted central reinforcement structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic cross-sectional structure diagram of a high-strength tensile-resistant optical cable provided in an embodiment of the present application; Figure 2 It is a front view structural schematic diagram of the multi-layer twisted center reinforcement structure provided in an embodiment of the present application.

[0028] Throughout the drawings, the same reference numerals are used to denote the same elements or structures, wherein: 1. Cable core body; 11. Multi-layer twisted center reinforcement structure; 111. Aramid yarn bundle; 112. Glass fiber reinforced plastic rod; 113. Wear-resistant coating; 114; Threaded wire groove; 12. Optical fiber unit; 13. Water-blocking layer; 14. Buffer layer; 2. Sheath body; 21. Inner co-extruded sheath; 22. Outer co-extruded sheath; 23. Metal belt armor layer. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0030] In order to make the optical cable suitable for 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 enhanced tensile, bending and protection performance.

[0031] Reference Figure 1 The present application discloses a high-strength tensile-resistant optical cable, comprising a cable core body 1 and a sheath body 2. The sheath body 2 covers and fits the outside of the cable core body 1. The cross section along the axial direction of the optical cable is circular.

[0032] In this embodiment, the cable core body 1 includes a multi-layer twisted central reinforcement structure 11 and a plurality of optical fiber units 12, wherein the optical fiber unit 12 is a tight-fitting optical fiber, and the outer periphery of the multi-layer twisted central reinforcement structure 11 has a threaded groove 114, and the plurality of optical fiber units 12 are arranged around the multi-layer twisted central reinforcement structure 11. The threaded groove 114 on the multi-layer twisted central reinforcement structure 11 can assist in positioning the optical fiber unit 12, thereby improving the stability of the cable core body 1. When the optical cable is stretched, the multi-layer twisted central reinforcement structure 11 can offset part of the stress by its own torsion, and has good tensile resistance, similar to the buffer mechanism of a spring.

[0033] In the present application, the tight sleeve material of the tight sleeve optical fiber is high elastic polyurethane, which is doped with nano-silicon dioxide microspheres to improve hardness and wear resistance. The tight sleeve 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 sleeve outer diameter, such as about 1.0 to 1.5 mm, can be used to ensure the compactness of the overall structure of the optical cable, and at the same time, a micro-deformation space of 0.1 to 0.2 mm is reserved between the tight sleeve optical fibers to facilitate the free movement and deformation of the optical fiber to a certain extent. For the case of 8 to 12 optical fiber units 12, the tight sleeve outer diameter may be between 1.5 and 2.0 mm, and the micro-deformation space between each optical fiber unit 12 can be controlled at 0.15 to 0.25 mm, which can not only ensure close arrangement, but also when the optical cable is subjected to external force, the optical fiber unit 12 has enough space for small displacement and deformation to avoid mutual squeezing. When the number of optical fiber units 12 reaches 16 or more, the outer diameter of the tight sleeve may increase to 2.0 to 2.5 mm or even larger, and the micro-deformation space may be around 0.2 to 0.3 mm to accommodate the compact arrangement of more optical fiber units 12 and provide sufficient buffer space.

[0034] Specifically, the multi-layer twisted center reinforcement structure 11 includes an aramid yarn bundle 111 and a plurality of glass fiber reinforced plastic rods 112 (GFRP rods). The glass fiber reinforced plastic rods 112 are twisted at a twist angle of 15°-25° on the periphery of the aramid yarn bundle 111, and a thread groove 114 is formed between two adjacent glass fiber reinforced plastic rods 112 twisted on the periphery of the aramid yarn bundle 111. The multi-layer twisted center reinforcement structure 11 adopts a multi-layer twisted center reinforcement structure 11, with the central high-strength aramid yarn bundle 111 as the axis, to provide an initial tensile core force. The aramid yarn bundle 111 is impregnated with a silane coupling agent to enhance the affinity with the surrounding materials and ensure uniform stress transmission. Among them, when the concentration of the silane coupling agent is low or too high, the surface of the aramid yarn bundle 111 will not be able to fully form chemical bonds or physical adsorption or agglomeration will form on the surface, resulting in uneven stress transmission and affecting the surface properties of the yarn bundle. If the temperature is too low, the impregnation process will take a long time to achieve the expected effect, and the production efficiency will be reduced. Too high a temperature may cause the silane coupling agent to be unable to fully react with the surface of the aramid yarn bundle 111, resulting in reduced strength, fiber damage, etc. If the impregnation time is too short, sufficient chemical bonds or physical adsorption cannot be formed, and the impregnation effect is not ideal. Too long an impregnation time will lead to over-impregnation and make the silane coupling agent layer too thick, affecting its bonding effect with surrounding materials, and also increasing production costs and production cycles. Therefore, when the aramid yarn bundle 111 is impregnated with a silane coupling agent, the general control is: the mass concentration of the silane coupling agent is between 1% and 5%, the impregnation temperature is between 40°C and 80°C, and the impregnation time is usually between 1 hour and 4 hours.

[0035] In this embodiment, the surface of each glass fiber reinforced plastic rod 112 is coated with a nano ceramic wear-resistant coating 113. In other embodiments, other wear-resistant materials can also be used. The nano ceramic wear-resistant coating 113 can use a sol-gel method to form a stable sol through the hydrolysis and polycondensation reaction of metal alkoxides or inorganic salts, and then form a nano ceramic coating on the surface of the substrate through drying, sintering and other treatments. This method has relatively low cost and relatively simple equipment requirements. It can adopt a variety of simple and easy coating methods such as dip coating and spray coating. It is easy to operate and has high production efficiency, which can reduce labor costs. The coating thickness is generally between 20μm and 60μm, which can meet the wear resistance and corrosion resistance requirements in use, and will not have much impact on the flexibility and other properties of the GFRP rod.

[0036] Furthermore, the overall size of the multi-layer twisted center reinforcement structure 11 is usually determined according to the actual application scenario and transmission requirements. For example, for optical cables used in long-distance backbone communication networks, the overall diameter of the multi-layer twisted center reinforcement structure 11 may be around 10 to 30 mm; for optical cables used for short-distance communications within cities, the overall diameter may be around 5 to 15 mm. The size of the aramid yarn bundle 111, as the central high-strength tensile core, generally accounts for about 10% to 30% of the overall diameter of the multi-layer twisted center reinforcement structure 11. For example, for a multi-layer twisted center reinforcement structure 11 with an overall diameter of 20 mm, the diameter of the aramid yarn bundle 111 may be between 2 and 6 mm. The diameter of the GFRP rod is relatively small. Multiple GFRP rods are twisted around the aramid yarn bundle 111, and the diameter of a single GFRP rod may be around 1 to 3 mm. The specific size needs to be determined comprehensively based on the overall design tension index of the optical cable and the number of optical fiber units 12. The ratio range of the overall diameter of the multi-layer twisted center reinforcement structure 11 to the diameter of the optical cable is approximately 60% to 80% taking into account that there is also a sheath body 2 on the outermost layer of the optical cable. For example, for an optical cable with an overall diameter of 16 mm of the multi-layer twisted center reinforcement structure 11, the final diameter of the optical cable may be around 20 to 26 mm.

[0037] Furthermore, during the laying process of optical cables, strong winds may cause lateral impact forces on the optical cables, causing them to swing, stretch or bend; during landslides, falling rocks and other objects may hit the optical cables from different directions, and the direction of the impact forces is mostly oblique or vertical; when an earthquake occurs, the violent vibration of the ground will cause the optical cables to be subjected to impact forces from all directions, including up and down bumps, left and right shaking, stretching and squeezing; during the laying, maintenance and modification of optical cables, improper operation of construction tools, collision of equipment, etc. may cause impacts on the optical cables, and the direction of the impact is difficult to determine and may be in any direction. Therefore, in the present application, a buffer layer 14 is arranged between the optical fiber unit 12 and the multi-layer twisted central reinforcement structure 11. The buffer layer 14 needs to meet the following conditions: it can elastically deform and absorb energy when encountering an impact, maintain a stable shape at room temperature, not flow at high temperature and not crack at low temperature, and adapt to an environment of -40°C-85°C. Specifically, the buffer layer 14 is formed by filling a thermoplastic elastic buffer material, and the thermoplastic elastic buffer material is any one of a polyurethane thermoplastic elastomer, a thermoplastic polyester elastomer, a styrene thermoplastic elastomer and a dynamically vulcanized thermoplastic elastomer. When the optical cable is subjected to an impact force, the deformation and energy absorption of the buffer layer 14 can provide a certain buffering protection effect on the optical fiber unit 12, thereby avoiding extrusion between the optical fiber unit 12 and the multi-layer twisted central reinforcement structure 11 to cause damage to the optical fiber unit 12. Among them, polyurethane thermoplastic elastomer (TPU) has excellent properties such as high elasticity, high strength, wear resistance, oil resistance, and chemical corrosion resistance. It has a wide range of hardness and can adjust the formula to obtain different hardnesses as needed. It has good fluidity and formability at room temperature, and injection molding is convenient and fast. Thermoplastic polyester elastomer (TPEE) has both the elasticity of rubber and the strength of engineering plastics, and has excellent fatigue resistance, weather resistance, chemical resistance and thermal stability. It can be stably injection molded at room temperature, and the size of the molded product is good. Styrene thermoplastic elastomer (TPE-S) has good elasticity, softness, weather resistance and processing properties, good melt fluidity at room temperature, easy injection molding, and can be blended and modified with a variety of materials to meet different performance requirements. Dynamically vulcanized thermoplastic elastomer (TPV) has excellent high and low temperature resistance, chemical resistance, aging resistance and oil resistance, good elasticity and strength at room temperature, good fluidity during injection molding, and short molding cycle.

[0038] More specifically, the cable core body 1 also includes a water-blocking layer 13, which is coated on the outside of the optical fiber unit 12. In this embodiment, a water-blocking tape or other water-blocking material is wrapped around the outside of the optical fiber unit 12 to prevent moisture from invading the interior of the optical cable, thereby protecting the optical cable from water erosion and improving the service life of the optical cable.

[0039] Furthermore, the sheath body 2 includes an inner co-extruded sheath 21 and an outer co-extruded sheath 22 arranged sequentially from the inside to the outside, wherein the inner co-extruded sheath 21 is coaxially sleeved on the outside of the water-blocking layer 13, wherein the inner co-extruded sheath 21 is weather-resistant polyethylene, containing UV stabilizers and antioxidants, and resisting sunlight and chemical erosion; the outer co-extruded sheath 22 is a low-friction polyurethane, which is convenient for dragging and laying optical cables, and has a raised anti-slip texture on the surface, and the special texture direction is optimized according to the force simulation, which helps to disperse the lateral friction force. . In order to further improve the strength of the sheath body 2, the sheath body 2 also includes a metal belt armor layer 23, which is located between the inner co-extruded sheath 21 and the water-blocking layer 13. The metal belt armor layer 23 improves the overall strength of the optical cable, and can further protect the optical fiber unit 12, and prevent the outer wall of the optical cable from twisting and the lateral pressure from affecting the optical fiber unit 12.

[0040] The present application also discloses a method for preparing a high-strength tensile-resistant optical cable, comprising the following steps: S1: A plurality of optical fiber units 12 are wrapped around the outer periphery of a multi-layer twisted center reinforcement structure 11 to form a communication unit with a circular cross section, wherein the multi-layer twisted center reinforcement structure 11 is located at the center of the communication unit; before setting the optical fiber unit 12, the multi-layer twisted center reinforcement structure 11 needs to be prepared first, wherein the aramid yarn bundle 111 is customized according to the tension index of the optical cable design, and the yarn count and twist are precisely controlled. For example, under the customization of the 1500N tension index, the count of the aramid yarn bundle 111 is 1500D, and the twist is 20 twists per meter. In practical applications, The count and twist of the aramid yarn bundle 111 will be comprehensively adjusted and determined according to the specific design tension index of the optical cable, the use environment, the combination 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 the dimensional tolerance of ±0.05mm; the tight-buffered optical fiber is prepared by a double-layer co-extrusion process, and the inner layer is first wrapped with polyurethane doped with nano-silica microspheres, and the outer layer is covered with an ultra-thin polyethylene protective film. According to the actual production needs, the whole process tension and temperature closed-loop monitoring is carried out, which is not explained in detail here.

[0041] By using automated 3D twisting equipment, the aramid yarn bundle 111, GFRP rod and optical fiber unit 12 are twisted at a uniform speed and accurately according to the preset program, and the twisting tension and angle are monitored in real time. If they do not meet the standards, an alarm will be immediately issued for adjustment; the buffer layer 14 material is filled by high-pressure injection, and the mold is set with multiple pressure zones to ensure uniform filling without bubbles. After injection, it is inspected by X-ray flaw detection. In the preset program of GFRP rod twisting tension and angle, the parameters are as follows: the tension is generally between 50N and 500N. For the twisting of GFRP rods with smaller diameters and fewer numbers, the tension may be around 50N to 200N; for the twisting of GFRP rods with larger diameters and more numbers, the tension may need to reach 200N to 500N; tension uniformity: the tension fluctuation range is required to be controlled within ±5% to ±10%; the twisting angle range is usually between 15° and 25°; angle accuracy: generally required to be controlled within ±1° to ±2° to ensure the uniformity and stability of twisting. The above parameters can be manually adjusted as needed during the actual preparation process.

[0042] S2: Wrap a water-blocking layer 13 around the outside of the communication unit to complete the preparation of the cable core body 1; wrap a water-blocking tape around the outside of the optical fiber unit 12 to prevent moisture from invading the inside of the optical cable, thereby protecting the optical cable from water erosion and increasing the service life of the optical cable.

[0043] S3: After the inner co-extruded sheath 21 and the outer co-extruded sheath 22 are extruded on the outside of the water-blocking layer 13 at the same time, the temperature is cooled to complete the preparation of the high-strength tensile-resistant optical cable; before the inner co-extruded sheath 21 and the outer co-extruded sheath 22 are extruded, the metal tape armor layer is wrapped on the outside of the water-blocking layer 13; specifically, the metal tape armor layer 23 is first wrapped on the outside of the water-blocking layer 13, and then a double-layer co-extrusion die is used, and the polyethylene raw materials of the inner co-extruded sheath 21 and the polyurethane raw materials of the outer co-extruded sheath 22 are fed by weightless metering to accurately control the ratio; the die temperature is set according to the gradient of the rheological properties of the material to ensure uniform plasticization of the melt; after extrusion, the optical cable is vacuum-shaped and spray-cooled, the traction wheel is intelligently adjusted in distance and speed according to the specifications of the optical cable, the finished product is measured in diameter, flaw detected, and performance tested section by section, and the data is entered into the quality traceability system. The specific processing parameters can be manually adjusted as needed during the actual preparation process. This step is a prior art and is not described in detail in this application.

[0044] The optical cable in this application has been tested in a simulated complex environment, and the results show that its tensile strength is 80% higher than that of the traditional one. After repeated bending for 10,000 times, the attenuation is only 0.1dB, and the transmission performance is lossless after being immersed in salt spray, acid and alkali for 30 days.

[0045] The following is a comparison between the high-strength tensile-resistant optical cable of the present application and the ordinary loose-tube stranded optical cable based on the test results: Tensile strength: The optical cable of this application uses a central high-strength aramid yarn bundle as the axis, and is combined with a spirally tightly twisted GFRP rod, and its tensile strength can reach more than 1500N. Ordinary loose tube layer-twisted optical cables mainly rely on simple reinforcement of steel wire or ordinary aramid yarn, and their tensile strength is generally around 800N. In the tensile test simulating overhead laying, when the optical cable of this application is subjected to a tensile force of 1200N, there is no obvious displacement or damage to the internal structure, and the signal transmission is stable; under a tensile force of 800N, the optical fiber unit of the ordinary loose tube layer-twisted optical cable has shown slight displacement, and when stretched to 1000N, some steel wires begin to break and the signal fluctuates.

[0046] Anti-bending performance: The tight-buffered optical fiber of the optical cable of this application adopts a special design, which reserves a micro-deformation space, and there is a high-performance thermoplastic elastomer buffer material between the optical fiber unit and the GFRP rod. After 10,000 bends, the attenuation is only 0.1dB. Ordinary loose-buffered layer-stranded optical cables lack these designs, and after 5,000 bends, the attenuation may reach more than 0.5dB, and the tight-buffered optical fiber is prone to cracks, affecting the signal transmission quality.

[0047] Protective performance: The double-layer co-extruded sheath of the optical cable in this application, the inner layer of weather-resistant polyethylene resists chemical erosion, and the outer layer of low-friction polyurethane is convenient for dragging and has a non-slip texture to disperse lateral friction. It has no loss of transmission performance after being immersed in salt spray, acid and alkali for 30 days. The protective performance of the sheath of ordinary loose-tube stranded optical cables is relatively simple. After being immersed in the same environment for about 15 days, the sheath may corrode and age, which will affect the transmission performance of the internal optical fiber.

[0048] The following is a comparison between the high-strength tensile-resistant optical cable of this application and the central tube optical cable based on the test results: Tensile strength: The multi-layer twisted structure design of the present application makes its tensile strength far superior to that of the central tube 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 optical cable is usually between 600N and 800N due to its relatively simple structure. For example, in the test simulating the impact of ocean currents on submarine optical cables, the optical cable of the present application can withstand a large tensile force without being damaged, while the central tube optical cable is prone to fiber breakage or structural damage under a smaller tensile force.

[0049] Anti-bending performance: The buffer material and special tight sleeve design inside the optical cable of this application make it have excellent anti-bending performance. After 10,000 bending tests, the performance of the optical cable of this application remains good, while the central tube optical cable may have a large attenuation after 3,000 bendings, such as the attenuation from the initial 0.2dB to about 1dB, and the mechanical properties of the optical fiber will also be greatly affected.

[0050] Protective performance: The synergy of the sheath and internal layers of the optical cable of this application provides all-round protection. In the protective performance test, the optical cable of this application can effectively protect the internal optical fiber when subjected to external impact, abrasion and chemical corrosion. When facing impacts of the same intensity, the buffering capacity of the central tube optical cable is weak, which can easily cause damage to the internal optical fiber; in a chemical corrosion environment, the durability of its protective layer is not as good as that of the optical cable of this application, and the transmission performance may decline earlier.

[0051] In summary, the high-strength tensile-resistant optical cable provided in the present application has all-round enhanced tensile, bending and protection performance compared to existing optical cables, can be used in different extreme environments and has good use effects.

[0052] It should be understood that expressions such as "include" and "may include" used in this 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 this application, terms such as "include" and / or "have" may be interpreted as indicating specific characteristics, numbers, operations, constituent elements, components or combinations thereof, but may not be interpreted as excluding the existence or possibility of adding one or more other characteristics, numbers, operations, constituent elements, components or combinations thereof.

[0053] It should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0054] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0055] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0056] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A high-strength tensile-resistant optical cable, characterized in that: It comprises a cable core body (1) and a sheath body (2), wherein the sheath body (2) covers and adheres to the outside of the cable core body (1), wherein: The cable core body (1) comprises a multi-layer twisted central reinforcement structure (11) and a plurality of optical fiber units (12); the outer periphery of the multi-layer twisted central reinforcement structure (11) has a threaded wire groove (114); and the plurality of optical fiber units (12) are arranged around the multi-layer twisted central reinforcement structure (11); the cable core body (1) further comprises a water-blocking layer (13), and the water-blocking layer (13) is coated on the outside of the optical fiber unit (12); The sheath body (2) comprises an inner co-extruded sheath (21) and an outer co-extruded sheath (22) which are arranged in sequence from the inside to the outside, and the inner co-extruded sheath (21) is coaxially sleeved on the outside of the water-blocking layer (13).

2. A high-strength tensile-resistant optical cable as claimed in claim 1, characterized in that: The optical fiber unit (12) is a tight-buffered optical fiber.

3. A high-strength tensile-resistant optical cable as claimed in claim 1, characterized in that: The multi-layer twisted central reinforcement structure (11) comprises an aramid yarn bundle (111) and a plurality of glass fiber reinforced plastic rods (112), wherein the glass fiber reinforced plastic rods (112) are spirally twisted on the outer periphery of the aramid yarn bundle (111), and the thread groove (114) is formed between two adjacent glass fiber reinforced plastic rods (112).

4. A high-strength tensile-resistant optical cable as claimed in claim 3, characterized in that: The twisting angle of the glass fiber reinforced plastic rod (112) is 15°-25°.

5. A high-strength tensile-resistant optical cable as claimed in claim 3, characterized in that: The surface of each glass fiber reinforced plastic rod (112) is coated with a wear-resistant coating (113).

6. A high-strength tensile-resistant optical cable as claimed in claim 1, characterized in that: The cable core body (1) further comprises a buffer layer (14), wherein the buffer layer (14) is filled between the optical fiber unit (12) and the multi-layer twisted central reinforcement structure (11).

7. A high-strength tensile-resistant optical cable as claimed in claim 6, characterized in that: The buffer layer (14) is made of a thermoplastic elastic buffer material, and the thermoplastic elastic buffer material is any one of polyurethane thermoplastic elastomer, thermoplastic polyester elastomer, styrene thermoplastic elastomer and dynamically vulcanized thermoplastic elastomer.

8. A high-strength tensile-resistant optical cable according to any one of claims 1 to 7, characterized in that: The sheath body (2) further comprises a metal tape armor layer (23), wherein the metal tape armor layer (23) is located between the inner co-extruded sheath (21) and the water-blocking layer (13).

9. A method for preparing a high-strength tensile-resistant optical cable according to any one of claims 1 to 8, characterized in that: The steps include: S1: A plurality of optical fiber units (12) are wrapped around the outer periphery of a multi-layer twisted central reinforcement structure (11) to form a communication unit with a circular cross section, wherein the multi-layer twisted central reinforcement structure (11) is located at the center of the communication unit; S2: Wrapping a water-blocking layer (13) around the outside of the communication unit; S3: Extruding an inner co-extruded sheath (21) and an outer co-extruded sheath (22) simultaneously on the outside of the water-blocking layer (13), followed by cooling, thereby completing the preparation of a high-strength tensile-resistant optical cable.

10. The preparation method according to claim 9, characterized in that: In step S3, before extruding the inner co-extruded sheath (21) and the outer co-extruded sheath (22), a metal tape armor layer (23) is wrapped around the outside of the water-blocking layer (13).

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