Optical cable for lightweight communication and method for filling cable jelly with modified hollow microbeads

Abstract

The application discloses a light-weight communication optical cable and a fiber paste cable paste filling method containing modified hollow microbeads, and sequentially comprises an optical fiber unit, a loose tube, a filling rope, a reinforcing member, a cable core tape and an outer sheath from inside to outside. The loose tube is filled with the fiber paste containing the modified hollow microbeads, and the cable core gap is filled with the cable paste containing the modified hollow microbeads. The application relates to the technical field of optical fiber manufacturing. The light-weight communication optical cable and the fiber paste cable paste filling method containing the modified hollow microbeads have the advantages that the weight of the optical cable per unit length is reduced by more than 30%, the transportation cost is reduced by more than 20%, the erection efficiency is improved by 15%, and the application is especially suitable for complex terrain construction scenes. The application can stably work in an environment of-40 DEG C to 85 DEG C and 100% humidity, the service life is prolonged by 50%, the application boundary of the traditional optical cable is broken, the signal attenuation rate is less than or equal to 0.2 dB / km in an extreme environment, the transmission quality is significantly improved, the application is far superior to the traditional optical cable, and the information transmission quality is ensured.

Description

Technical Field

[0001] This invention relates to the field of optical fiber manufacturing technology, specifically to lightweight communication optical cables and a method for filling fiber optic cable paste containing modified hollow microspheres. Background Technology

[0002] With the rapid development of communication technology, optical cables, as the core carrier of information transmission, are finding increasingly diverse applications. They not only need to meet the demands of conventional environments such as cities and plains, but also adapt to the stringent requirements of extreme environments such as plateaus, deserts, and polar regions. However, traditional optical cables and their accompanying filling materials (fiber grease / cable grease) suffer from numerous technical limitations, severely restricting their application scope and performance. The existing optical cable structure has the following defects: 1. Heavy weight: Traditional optical cables rely on steel reinforcement (density 7.8g / cm³) and high-density filler materials, resulting in heavy weight per unit length, which increases transportation, installation costs and energy consumption; 2. Poor adaptability to extreme environments: The sheath is prone to cracking at low temperatures (≤-40℃), and the material aging is accelerated at high temperatures (≥60℃), increasing the fiber optic signal attenuation rate by more than 30%. 3. Insufficient synergy between structural materials: The optical cable structure design is not deeply matched with the performance of the filling materials, making it difficult to achieve both lightweight and resistance to extreme environments at the same time.

[0003] Referring to a cold-resistant stranded OPGW optical cable with prior art publication number CN213780481U, by setting a heat insulation layer inside the aluminum tube, it can prevent high temperature damage to the optical fiber when the line generates a large amount of heat during a short circuit or lightning strike. By setting hollow glass microspheres, the advantages of insulation, flame retardancy and low temperature stability are improved. Therefore, the optical cable filled with hollow glass microspheres has good insulation, flame retardancy and cold resistance performance. Referring to a fiber optic cable reinforcement component and its manufacturing method disclosed in prior art (CN114924368B), the ultra-lightweight characteristics of the reinforcement component, combined with its internal filling of special energy-absorbing microspheres, achieve both lightweighting and enhanced impact resistance. The filled energy-absorbing microspheres can absorb stress through hardening, and when the external force increases to a certain extent, they will further absorb the external force through "fracture," thus achieving a good impact buffering effect.

[0004] Existing fiber optic paste or cable grease is the core protective material for communication cables, and it needs to have properties such as waterproofing, cushioning, and resistance to high and low temperatures, but it has the following key drawbacks: 1. Heavy weight: The density of existing products is generally 1.0-1.3g / cm³, resulting in a high overall weight of the cable, which increases transportation, installation costs and energy consumption; 2. Poor high and low temperature performance: It is easy to soften and flow at high temperatures (≥60℃), losing its waterproof and buffering effect; at low temperatures (≤-40℃), the viscosity increases sharply (>1000Pa·s). 3. Poor temperature adaptability: The thermal conductivity is relatively high (0.2-0.3 W / (m·K)), and fluctuations in ambient temperature are directly transmitted to the optical fiber, causing signal attenuation; 4. Difficulty in cost control: It relies on expensive synthetic oils and special thickeners, resulting in low filling efficiency and insufficient cost-effectiveness.

[0005] To address the aforementioned issues, existing technologies often employ single-dimensional improvements (such as optimizing only the optical cable structure or only modifying the filling material), failing to achieve deep synergy between structure, materials, and processes. This results in a trade-off between lightweight design and resistance to extreme environments, and unsatisfactory signal stability and cost control. Therefore, this invention, through multi-dimensional collaborative innovation, addresses the issues of weight, extreme environment adaptability, signal stability, and cost in optical cables and related filling solutions, fulfilling a pressing need in this field. Summary of the Invention

[0006] (a) Technical problems to be solved To address the shortcomings of existing technologies, this invention provides a lightweight optical cable for communication and a method for filling fiber optic cable paste containing modified hollow microspheres. Through a three-dimensional collaborative mechanism of "lightweight structural design + material formulation optimization + precise process matching", it achieves a dual breakthrough in lightweighting and resistance to extreme environments, while improving signal stability and reducing costs, thus solving the problems of traditional optical cables being heavy, having poor adaptability to extreme environments, and having poor signal stability.

[0007] (II) Technical Solution To achieve the above objectives, the present invention is implemented through the following technical solution: a lightweight optical cable for communication, comprising, from the inside out, an optical fiber unit, a loose tube, a filler rope, a reinforcing member, a cable core wrapping tape, and an outer sheath. The loose tube is filled with fiber grease containing modified hollow microspheres, and the gaps between the cable cores are filled with cable grease containing modified hollow microspheres. The modified hollow microspheres in the cable grease and fiber grease are dried at 120°C for 2 hours, then soaked in a 2wt% silane coupling agent solution for 30 minutes, and then pretreated by drying at 80°C for 1 hour. The silane coupling agent is either KH-550 or KH-560. The fiber paste, by weight percentage, comprises: 65-85% base oil, 5-8% composite thickener, 8-15% modified hollow microspheres, 0.5-1.0% antioxidant, 1.0-2.0% rust inhibitor, and 0.3-0.5% dispersant; The cable paste, by weight percentage, comprises: 55-75% base oil, 8-12% composite thickener, 15-22% modified hollow microspheres, 0.5-1.0% antioxidant, 1.0-2.0% rust inhibitor, and 0.3-0.5% dispersant; The modified hollow microspheres have a particle size of 5-50 μm, a bulk density of 0.3-0.5 g / cm³, and a compressive strength ≥50 MPa.

[0008] Preferably, the optical fiber unit uses G.652D or G.657A optical fiber, and the optical fiber is covered with a UV coating layer with a temperature resistance range of -60℃ to 120℃ and a coating layer thickness of 20-40μm. The loose sleeve is made of modified polybutylene terephthalate (PBT), with a wall thickness of 0.4-0.6 mm, an impact strength of ≥5 kJ / m², and an elongation at break of ≥150%.

[0009] Preferably, the filler rope is a high-density polypropylene (PP) filler rope with a density of 0.9 g / cm³, a diameter deviation from the loose sleeve ≤ ±0.1 mm, and a tensile strength ≥ 150 MPa; The reinforcing member is a carbon fiber reinforced plastic (CFRP) core with a density of 1.5 g / cm³, a tensile strength of ≥2000 MPa, and a diameter of 2-3 mm. The reinforcing member and the filler rope are symmetrically distributed and twisted at the center of the cable core with a twisting pitch of 100-150 mm.

[0010] Preferably, the cable core wrapping tape is flame-retardant polypropylene (PP) wrapping tape with a thickness of 0.05-0.1 mm, an oxygen index ≥32%, a tensile strength ≥25 MPa, and the cable core is bundled using a wrapping method with an overlap rate ≥20%. The outer sheath is made of cross-linked polyethylene (XLPE), with a thickness of 1.0-1.2 mm, a temperature range of -40℃ to 85℃, an elongation at break of ≥300%, and an environmental stress cracking time of ≥1000 h.

[0011] Preferably, the base oil of the fiber paste is a mixture of PAO and mineral oil in a mass ratio of 3:1, while the base oil of the cable paste is a mixture of PAO and mineral oil in a mass ratio of 2:1.

[0012] Preferably, the composite thickener of the fiber paste is a mixture of organic bentonite and polyurea at a mass ratio of 1:1, while the composite thickener of the cable paste is a mixture of organic bentonite and polyurea at a mass ratio of 1:2.

[0013] Preferably, the antioxidants in both the fiber paste and the cable paste are a mixture of BHT and Irganox 1010 in a mass ratio of 2:1, and the rust inhibitors in both the fiber paste and the cable paste are barium petroleum sulfonate, and the dispersants in both the fiber paste and the cable paste are polyisobutylene succinate.

[0014] This invention also provides a method for filling fiber optic cable with modified hollow microspheres, used in the aforementioned lightweight communication optical cable, specifically including the following steps: S1. Directional pretreatment of modified hollow microspheres: Select modified hollow microspheres with a particle size of 5-50μm, dry them in a 120℃ forced-air oven for 2h to remove adsorbed moisture and impurities from the surface of the microspheres, then immerse the dried microspheres in a 2wt% silane coupling agent ethanol solution and stir and soak them at 25℃ for 30min to allow the coupling agent molecules to be fully grafted onto the surface of the microspheres. Finally, place the treated microspheres in an 80℃ oven to dry for 1h to constant weight for later use. S2, fiber paste and cable paste are prepared stepwise: First, the thickener and base oil are stirred at 50°C and 1200 rpm for 30 min. Then, the pretreated modified hollow microspheres are added and stirred at 1500 rpm for 20 min. After cooling to room temperature, the additives are added and stirred at 500 rpm for 10 min to obtain the finished product. S3. Optical cable directional filling, specifically including the following steps: a1. Filling the loose tube with fiber optic paste: The fiber optic paste prepared in step S2 is injected into the loose tube at a pressure of 0.3-0.5 MPa using a pressure filling machine. The filling speed is synchronized with the fiber insertion speed at 10-15 m / min to ensure that the fiber unit is completely covered and the filling rate is ≥95%. a2. Cable core gap filling with cable paste: The stranded cable core, including loose tubes, reinforcing members and filling ropes, is fed into a crawler-type filling machine. The cable paste prepared in step S2 is preheated at 150℃ (to maintain fluidity) and then injected into the cable core gaps at a pressure of 0.5-0.8MPa. Ultrasonic detection is used during the filling process to ensure no voids and a filling rate of ≥98%. a3. Subsequent molding: After filling, the core is wrapped with cable tape and the outer XLPE sheath is extruded in sequence to obtain the finished optical cable. The wrapping speed is 20-30m / min and the extrusion temperature is 120-150℃. S4. Filling quality verification: Sampling inspections are conducted on the filled optical cable, including the uniformity of fiber paste coating in the loose tube, the density of filling gaps in the cable core, the overall waterproof performance of the optical cable (IP68 level verification), and the stability of the filling material under extreme temperatures, to ensure that it meets the design requirements.

[0015] Preferably, the stepwise preparation of fiber paste and cable paste in step S2 specifically includes the following steps: T1. Construction of the basic system: Weigh the base oil and composite thickener according to the formula of the fiber paste in claim 1, add them to the high-speed stirring tank, and stir for 30 minutes at 50°C and 1200 rpm to completely dissolve the thickener and form a uniform colloidal system. T2, Microsphere Dispersion and Composite: Add the modified hollow microspheres pretreated in step S1 to the colloidal system in step T1 according to the ratio, adjust the stirring speed to 1500 rpm, and continue stirring at 50℃ for 20 min to make the microspheres uniformly dispersed in the system and avoid agglomeration. T3. Functional additive compounding: Cool the system to 20-30℃, add antioxidant, rust inhibitor and dispersant according to the formula of the fiber paste described in claim 1, adjust the stirring speed to 500 rpm, stir for 10 min to fully integrate the additives; T4. Finished product post-processing: The mixed materials are ground once by a three-roll mill to ensure that the particle size of the system is ≤100μm, and then vacuum degassed for 15min (vacuum degree -0.09MPa) to remove air bubbles and obtain the fiber paste finished product. T5. Preparation of cable paste: The cable paste is prepared by following the same preparation process as steps T1-T4 according to the ratio of the cable paste described in claim 1.

[0016] Preferably, in step a1, the ratio of the inner diameter of the filling nozzle of the pressure filling machine to the inner diameter of the loose tube is 0.8-0.9, and in step a2, the glue injection port of the tracked filling machine adopts a multi-directional distribution design to ensure that the gap between the cable cores is filled in all directions.

[0017] (III) Beneficial Effects This invention provides a lightweight optical fiber cable for communication and a method for filling fiber optic cable with modified hollow microspheres. Compared with the prior art, it has the following advantages: (1) The lightweight optical cable for communication and the fiber optic cable filling method containing modified hollow microspheres reduce the weight of the optical cable by more than 30% by using CFRP reinforcement, PP filling rope and fiber optic cable filling containing hollow microspheres, reducing transportation costs by more than 20% and improving installation efficiency by 15%, which is especially suitable for construction scenarios in complex terrain.

[0018] (2) The lightweight optical cable for communication and the fiber grease / cable grease filling method containing modified hollow microspheres can reduce the temperature change of optical fiber by 50% through the dual barrier of XLPE sheath (resistant to -40℃ to 85℃) and fiber grease / cable grease (thermal insulation coefficient 0.12-0.18W / (m·K)). This allows the optical cable to work stably in an environment with humidity of 100% and a temperature range of -40℃ to 85℃. The modified PBT loose tube and CFPR reinforcement can resist impact and tension. The buffering effect of fiber grease and cable grease reduces the micro-bending loss of optical fiber. At the same time, by filling the gap between the cable core with cable grease, sealing the sheath and fully filling the loose tube with fiber grease, the entire cross-section is waterproof, the moisture resistance level reaches IP68, and the service life is extended by 50%, breaking through the application boundaries of traditional optical cables.

[0019] (3) The lightweight optical cable for communication and the fiber grease filling method containing modified hollow microspheres, through the heat-resistant coating of optical fiber, the buffering and heat insulation of fiber grease and the mechanical stability of optical cable structure, the signal attenuation rate under extreme environment is ≤0.2dB / km, the transmission quality is significantly improved, which is far superior to traditional optical cables (≥0.5dB / km), and the information transmission quality is guaranteed.

[0020] (4) The lightweight communication optical cable and the fiber optic cable filling method containing modified hollow microspheres replace expensive synthetic oil with hollow microspheres, and the optical cable structure reduces the use of steel materials. Through material substitution and process optimization, the overall cost is reduced by 10%-15%, and the cost performance is significantly improved.

[0021] (5) The lightweight optical cable for communication and the fiber optic cable filling method containing modified hollow microspheres reduce transportation energy consumption and carbon emissions, which is in line with the trend of green communication development. It is suitable for special extreme environments such as plateaus, deserts, extreme cold or extreme heat, and can also meet the needs of ordinary outdoor communication projects. It has strong practicality and promotion value. Attached Figure Description

[0022] Figure 1 This is a flowchart of the fiber optic cable filling method containing modified hollow microspheres according to the present invention; Figure 2 This is a flowchart of the stepwise preparation method of the fiber paste and cable paste of the present invention; Figure 3 This is a flowchart of the optical cable directional filling method of the present invention. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Please see Figures 1 to 3 The present invention provides three technical solutions: lightweight optical cables for communication and a method for filling fiber optic cables with modified hollow microspheres, specifically including the following embodiments: Example 1: Lightweight optical fiber cable for communication, comprising, from the inside out, an optical fiber unit, a loose tube, a filler rope, a reinforcing member, a cable core wrapping tape, and an outer sheath. The loose tube is filled with fiber grease containing modified hollow microspheres, and the gaps between the cable cores are filled with cable grease containing modified hollow microspheres. The modified hollow microspheres in the cable grease and fiber grease are dried at 120°C for 2 hours, then soaked in a 2wt% silane coupling agent solution for 30 minutes, and then pretreated by drying at 80°C for 1 hour. The silane coupling agent is KH-560. The fiber paste, by weight percentage, comprises: 78.4% base oil, 6.5% composite thickener, 12.5% ​​modified hollow microspheres, 0.7% antioxidant, 1.5% rust inhibitor, and 0.4% dispersant; The cable paste, by weight percentage, comprises: 68.8% base oil, 10% composite thickener, 18.5% modified hollow microspheres, 0.8% antioxidant, 1.5% rust inhibitor, and 0.4% dispersant; The modified hollow microspheres have a particle size of 27 μm, a bulk density of 0.4 g / cm³, and a compressive strength of 65.5 MPa.

[0025] In this embodiment of the invention, the optical fiber unit uses 8-core / group G.657A optical fiber, and the optical fiber is covered with a UV coating layer with a temperature resistance range of -60℃ to 120℃ and a coating layer thickness of 30μm. The loose tubes are made of modified polybutylene terephthalate (PBT), with a wall thickness of 0.5 mm, an impact strength of 5.9 kJ / m², and an elongation at break of 166%. Six loose tubes are used to fit six sets of G.657A optical fibers.

[0026] In this embodiment of the invention, the filler rope is a high-density polypropylene (PP) filler rope with a density of 0.9 g / cm³, a diameter deviation from the loose sleeve ≤ ±0.1 mm, and a tensile strength of 171.3 MPa. In this embodiment, three filler ropes are used. The reinforcing element is a carbon fiber reinforced plastic (CFRP) core with a density of 1.5 g / cm³, a tensile strength of 2438.1 MPa, and a diameter of 2.5 mm. The reinforcing element and the filler rope are symmetrically distributed and twisted at the center of the cable core with a twist pitch of 130 mm. In this embodiment, one CFRP reinforcing core is used.

[0027] In this embodiment of the invention, the cable core wrapping tape is a flame-retardant polypropylene (PP) wrapping tape with a thickness of 0.07 mm, an oxygen index of 33.8%, and a tensile strength of 27.9 MPa. The cable core is bundled using a wrapping method with an overlap rate of 23%. The outer sheath is made of cross-linked polyethylene (XLPE) with a thickness of 1.1 mm, a temperature range of -40℃ to 85℃, an elongation at break of 328.4%, and an environmental stress cracking time of 1093.7 h.

[0028] In this embodiment of the invention, the base oil of the fiber paste is made by mixing PAO and mineral oil in a mass ratio of 3:1, while the base oil of the cable paste is made by mixing PAO and mineral oil in a mass ratio of 2:1.

[0029] In this embodiment of the invention, the composite thickener of the fiber paste is a mixture of organic bentonite and polyurea at a mass ratio of 1:1, while the composite thickener of the cable paste is a mixture of organic bentonite and polyurea at a mass ratio of 1:2.

[0030] In this embodiment of the invention, the antioxidants of both fiber paste and cable paste are made by mixing BHT and Irganox 1010 at a mass ratio of 2:1, and the rust inhibitors of both fiber paste and cable paste are barium petroleum sulfonate, and the dispersants of both fiber paste and cable paste are polyisobutylene succinate.

[0031] This invention also provides a method for filling fiber optic cable grease containing modified hollow microspheres for lightweight communication optical cables, specifically including the following steps: S1. Directional pretreatment of modified hollow microspheres: Select modified hollow microspheres with a particle size of 27μm, dry them in a 120℃ forced-air oven for 2h to remove adsorbed moisture and impurities from the surface of the microspheres, then immerse the dried microspheres in a 2wt% silane coupling agent ethanol solution and stir and soak them at 25℃ for 30min to allow the coupling agent molecules to be fully grafted onto the surface of the microspheres. Finally, place the treated microspheres in an 80℃ oven to dry for 1h to constant weight for later use. S2, fiber paste and cable paste are prepared stepwise: First, the thickener and base oil are stirred at 50°C and 1200 rpm for 30 min. Then, the pretreated modified hollow microspheres are added and stirred at 1500 rpm for 20 min. After cooling to room temperature, the additives are added and stirred at 500 rpm for 10 min to obtain the finished product. S3. Optical cable directional filling, specifically including the following steps: a1. Filling the loose tube with fiber optic paste: The fiber optic paste prepared in step S2 is injected into the loose tube at a pressure of 0.4 MPa using a pressure filling machine. The filling speed is synchronized with the fiber insertion speed at 13 m / min to ensure complete coverage of the fiber unit and a filling rate of 97.5%. a2. Cable core gap filling with cable paste: The stranded cable core, including loose tubes, reinforcing members and filling ropes, is fed into a crawler-type filling machine. The cable paste prepared in step S2 is preheated to 150°C (to maintain fluidity) and then injected into the cable core gaps at a pressure of 0.65MPa. Ultrasonic detection is used during the filling process to ensure no voids, with a filling rate of 98.8%. a3. Subsequent molding: After filling, the core is wrapped with cable tape and the outer XLPE sheath is extruded in sequence to obtain the finished optical cable. The wrapping speed is 25m / min and the extrusion temperature is 135℃. S4. Filling quality verification: Sampling inspections are conducted on the filled optical cable, including the uniformity of fiber paste coating in the loose tube, the density of filling gaps in the cable core, the overall waterproof performance of the optical cable (IP68 level verification), and the stability of the filling material under extreme temperatures, to ensure that it meets the design requirements.

[0032] In this embodiment of the invention, the stepwise preparation of fiber paste and cable paste in step S2 specifically includes the following steps: T1. Construction of the basic system: Weigh the base oil and composite thickener according to the formula of the fiber paste in claim 1, add them to the high-speed stirring tank, and stir for 30 minutes at 50°C and 1200 rpm to completely dissolve the thickener and form a uniform colloidal system. T2, Microsphere Dispersion and Composite: Add the modified hollow microspheres pretreated in step S1 to the colloidal system in step T1 according to the ratio, adjust the stirring speed to 1500 rpm, and continue stirring at 50℃ for 20 min to make the microspheres uniformly dispersed in the system and avoid agglomeration. T3. Functional additive compounding: Cool the system to 25°C, add antioxidant, rust inhibitor and dispersant according to the formula of fiber paste in claim 1, adjust the stirring speed to 500 rpm, stir for 10 min to fully integrate the additives; T4. Finished product post-processing: The mixed materials are ground once by a three-roll mill to ensure that the particle size of the system is ≤100μm, and then vacuum degassed for 15min (vacuum degree -0.09MPa) to remove air bubbles and obtain the fiber paste finished product. T5. Preparation of cable paste: The cable paste is prepared according to the ratio of the cable paste in claim 1, and the same preparation process as steps T1-T4 is carried out to prepare the finished cable paste.

[0033] In this embodiment of the invention, the ratio of the inner diameter of the filling nozzle of the pressure filling machine to the inner diameter of the loose tube in step a1 is 0.85, and the glue injection port of the tracked filling machine in step a2 adopts a multi-directional distribution design to ensure that the gap between the cable cores is filled in all directions.

[0034] The properties of the finished fiber paste are as follows: density 0.85 g / cm³, viscosity 485 Pa·s at -40℃, and weight loss rate of 0.2% at 65℃ for 72 hours.

[0035] The finished product properties of the cable paste are: density 0.76 g / cm³, thermal conductivity 0.16 W / (m・K), no softening or loss at 65℃ for 72 hours, and no cracking at -40℃.

[0036] Performance testing: Weight per unit length 113.6g / m, no cracks after 100 bends at -40℃, signal attenuation rate of 0.18dB / km at 65℃ / 72h, waterproof rating IP68 (no water leakage after 24h immersion), comprehensive cost 2.3 yuan / meter.

[0037] Example 2: Fabrication of a 48-core lightweight extreme-resistance optical cable: Fiber Optic Unit: 8-core G.652D optical fibers are inserted into a modified PBT loose tube and filled with the fiber grease of this invention; Cable core assembly: 6 loose tubes + 1 CFRP reinforcing core + 3 PP filler ropes twisted together and tied with flame-retardant PP tape; Sheath extrusion: An XLPE sheath is extruded outside the cable core, with the outer diameter controlled at 10.0 mm; Performance testing: Weight per unit length 115g / m, no cracks after 100 bends at -40℃, signal attenuation rate of 0.18dB / km at 65℃ for 72 hours.

[0038] Preparation of matching fiber paste and cable paste: Preparation of fiber paste: Raw materials: PAO-40 (70.5%), mineral oil (10%), organobentonite (3%), polyurea (2%), modified microspheres (12%), BHT (0.5%), barium petroleum sulfonate (1.5%), dispersant (0.5%). Process: Following the above preparation process steps, the finished product has a density of 0.85 g / cm³, a viscosity of 480 Pa·s at -40℃, and no loss at 65℃.

[0039] Cable grout preparation: Raw materials: PAO-60 (60%), mineral oil (10%), organobentonite (4%), polyurea (4%), modified microspheres (20%), Irganox 1010 (0.5%), barium petroleum sulfonate (1.0%), dispersant (0.5%). Process: Same as fiber paste preparation, finished product density 0.78 g / cm³, thermal conductivity 0.15 W / (m·K).

[0040] Compatibility verification: After the fiber optic cable was filled with fiber optic paste, the optical fiber showed no micro-bending loss at -40℃. After the cable core gaps are filled with cable paste, the overall waterproof performance of the optical cable reaches IP68, and there is no water seepage after 24 hours of immersion.

[0041] Example 3: Fabrication and filling of a 48-core lightweight extreme-resistance optical cable: Materials preparation: Fiber unit: G.652D fiber (8 cores / group), UV coating temperature resistance -60℃ to 120℃; Loose sleeve: Modified PBT, wall thickness 0.5mm, impact strength 6kJ / m²; Filler rope: PP filler rope, density 0.9g / cm³, diameter 2.0mm; Reinforcing component: CFRP reinforcing core, diameter 2.5mm, tensile strength 2200MPa; Cable core wrapping: Flame-retardant PP wrapping, 0.08mm thick, oxygen index 33%; Outer sheath: XLPE, 1.1mm thick, temperature resistant from -40℃ to 85℃; Raw materials for fiber paste and cable paste: PAO-40, mineral oil, organic bentonite, polyurea, modified hollow microspheres (particle size 20μm), BHT, Irganox 1010, barium petroleum sulfonate, polyisobutylene succinate, KH-550 silane coupling agent.

[0042] Pretreatment of modified hollow microspheres: Processed according to step S1 in Example 1, dried at 120℃ for 2h → soaked in 2wt% KH-550 ethanol solution for 30min → dried at 80℃ for 1h, ready for use.

[0043] Preparation of the fiber paste: Weigh out PAO-40 (70.25%), mineral oil (10%), organobentonite (3%), polyurea (2%), pretreated microspheres (12%), BHT (0.5%), Irganox 1010 (0.25%), barium petroleum sulfonate (1.5%), and dispersant (0.5%) according to the specified ratio; prepare the paste according to step S2 in Example 1. The finished product has a density of 0.85 g / cm³, a viscosity of 480 Pa·s at -40℃, and a weight loss rate of 0.3% at 65℃ for 72 h.

[0044] Cable paste preparation: Weigh PAO-60 (60%), mineral oil (10%), organic bentonite (4%), polyurea (4%), pretreated microspheres (20%), BHT (0.33%), Irganox 1010 (0.17%), barium petroleum sulfonate (1.0%), and dispersant (0.5%) according to the formula; prepare according to the process of step S2 in Example 1. The finished product has a density of 0.78 g / cm³, a thermal conductivity of 0.15 W / (m·K), and no loss at 65℃ / 72h.

[0045] Optical cable filling and molding: Loose tube filling: Fiber grease is injected at a pressure of 0.4 MPa and a speed of 12 m / min, with a filling rate of 96%; Cable core filling: The cable paste is preheated to 150℃ and injected at a pressure of 0.6MPa, with a filling rate of 99%; Bag strap wrapping: speed 25m / min, overlap rate 25%; Sheath extrusion: temperature 130℃, outer diameter 10.0mm.

[0046] Performance testing: Weight per unit length 115g / m, no cracks after 100 bends at -40℃, signal attenuation rate of 0.18dB / km at 65℃ / 72h, waterproof rating IP68 (no water leakage after 24h immersion), comprehensive cost 2.8 yuan / meter.

[0047] Control group test (traditional optical cable solution): The method used conventional steel reinforcement (density 7.8 g / cm³), standard fiber paste (density 1.2 g / cm³, without hollow microspheres), and a PE sheath (temperature resistance -20℃ to 60℃). Other structural parameters were consistent with those in Example 3. The test results are as follows: Weight per unit length: 180g / m; After bending 100 times at -40℃, the sheath showed 3-5 micro-cracks. Signal attenuation rate at 65℃ / 72h: 0.52dB / km; The viscosity of the fiber paste at -40℃ is 1650 Pa·s; Cable paste loses 5% of its weight at 65℃ for 72 hours; Waterproof rating IP67 (minor water seepage after 24 hours of immersion); The total cost is 3.2 yuan per meter.

[0048] The comparative experimental data of Examples 1-3 and the control group are shown in Table 1.

[0049] Table 1 Comparative Experimental Data As shown in Table 1, the lightweight optical cables for communication prepared by the fiber optic paste filling method containing modified hollow microspheres in Examples 1-3 of this invention are superior to existing conventional optical cables in terms of unit length weight, state after 100 bends at -40℃, signal attenuation rate at 65℃ / 72h, fiber optic paste viscosity at -40℃, cable paste stability at 65℃, overall waterproof rating, and comprehensive cost. Furthermore, the scheme in Example 1 is superior to that in Examples 2 and 3.

[0050] In summary, this invention achieves triple weight reduction by employing CFRP reinforcement, PP filler rope, and fiber optic / cable grease containing hollow microspheres, resulting in a reduction of over 30% in the weight per unit length of optical cable, a reduction of over 20% in transportation costs, and a 15% increase in installation efficiency. It is particularly suitable for construction scenarios in complex terrain. The dual barrier of XLPE sheath (resistant to -40℃ to 85℃) and fiber optic / cable grease (thermal insulation coefficient 0.12-0.18 W / (m·K)) against environmental temperature fluctuations reduces fiber temperature variation by 50%, enabling the optical cable to operate stably in environments ranging from -40℃ to 85℃ and 100% humidity. The use of modified PBT loose tubes and CFRP reinforcement provides resistance to impact and tension, while the buffering effect of fiber optic and cable grease reduces fiber micro-bending loss. Furthermore, the cable grease fills the gaps between the cable cores, and the sheath seals the cable. The loose tube is fully filled, achieving full-section waterproofing with a moisture-proof rating of IP68 and a 50% extended service life. This breaks through the application boundaries of traditional optical cables. Through the synergistic effect of the fiber optic heat-resistant coating, the buffering and heat insulation of the fiber optic paste, and the mechanical stability of the optical cable structure, the signal attenuation rate in extreme environments is ≤0.2dB / km, significantly improving transmission quality far superior to traditional optical cables (≥0.5dB / km), ensuring the quality of information transmission. By replacing expensive synthetic oil with hollow microspheres, the optical cable structure reduces the use of steel materials. Through material substitution and process optimization, the overall cost is reduced by 10%-15%, significantly improving cost-effectiveness. It reduces transportation energy consumption and carbon emissions, conforming to the trend of green communication development. It is suitable for special extreme environments such as plateaus, deserts, and extreme cold or heat, and can also meet the needs of ordinary outdoor communication projects, possessing strong practicality and promotional value.

[0051] Furthermore, any content not described in detail in this specification is existing technology known to those skilled in the art.

[0052] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0053] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A lightweight optical fiber cable for communication, characterized in that: From the inside out, the cable consists of an optical fiber unit, a loose tube, a filler rope, a reinforcing member, a cable core wrapping tape, and an outer sheath. The loose tube is filled with fiber grease containing modified hollow microspheres, and the gaps between the cable cores are filled with cable grease containing modified hollow microspheres. The modified hollow microspheres in the cable grease and fiber grease are dried at 120°C for 2 hours, then soaked in a 2wt% silane coupling agent solution for 30 minutes, and then pretreated by drying at 80°C for 1 hour. The silane coupling agent is either KH-550 or KH-560. The fiber paste, by weight percentage, comprises: 65-85% base oil, 5-8% composite thickener, 8-15% modified hollow microspheres, 0.5-1.0% antioxidant, 1.0-2.0% rust inhibitor, and 0.3-0.5% dispersant; The cable paste, by weight percentage, comprises: 55-75% base oil, 8-12% composite thickener, 15-22% modified hollow microspheres, 0.5-1.0% antioxidant, 1.0-2.0% rust inhibitor, and 0.3-0.5% dispersant; The modified hollow microspheres have a particle size of 5-50 μm, a bulk density of 0.3-0.5 g / cm³, and a compressive strength ≥50 MPa.

2. The lightweight optical cable for communication according to claim 1, characterized in that: The optical fiber unit uses G.652D or G.657A optical fiber, and the optical fiber is covered with a UV coating layer with a temperature resistance range of -60℃ to 120℃ and a coating layer thickness of 20-40μm. The loose sleeve is made of modified polybutylene terephthalate (PBT), with a wall thickness of 0.4-0.6 mm, an impact strength of ≥5 kJ / m², and an elongation at break of ≥150%.

3. The lightweight optical cable for communication according to claim 1, characterized in that: The filler rope is a high-density polypropylene (PP) filler rope with a density of 0.9 g / cm³, a diameter deviation from the loose sleeve ≤ ±0.1 mm, and a tensile strength ≥ 150 MPa; The reinforcing member is a carbon fiber reinforced plastic (CFRP) core with a density of 1.5 g / cm³, a tensile strength of ≥2000 MPa, and a diameter of 2-3 mm. The reinforcing member and the filler rope are symmetrically distributed and twisted at the center of the cable core with a twisting pitch of 100-150 mm.

4. The lightweight optical cable for communication according to claim 1, characterized in that: The cable core wrapping tape is flame-retardant polypropylene (PP) tape with a thickness of 0.05-0.1mm, an oxygen index ≥32%, and a tensile strength ≥25MPa. The cable core is bundled using a wrapping method with an overlap rate ≥20%. The outer sheath is made of cross-linked polyethylene (XLPE), with a thickness of 1.0-1.2 mm, a temperature range of -40℃ to 85℃, an elongation at break of ≥300%, and an environmental stress cracking time of ≥1000 h.

5. The lightweight optical cable for communication according to claim 1, characterized in that: The fiber paste components: The base oil of the fiber paste is made by mixing PAO and mineral oil in a mass ratio of 3:1, while the base oil of the cable paste is made by mixing PAO and mineral oil in a mass ratio of 2:

1.

6. The lightweight optical cable for communication according to claim 1, characterized in that: The composite thickener of the fiber paste is a mixture of organic bentonite and polyurea at a mass ratio of 1:1, while the composite thickener of the cable paste is a mixture of organic bentonite and polyurea at a mass ratio of 1:

2.

7. The lightweight optical cable for communication according to claim 1, characterized in that: The antioxidants in both the fiber paste and cable paste are made by mixing BHT and Irganox 1010 at a mass ratio of 2:1, and the rust inhibitors in both the fiber paste and cable paste are barium petroleum sulfonate. The dispersants in both the fiber paste and cable paste are polyisobutylene succinate.

8. A method for filling fiber optic cable paste containing modified hollow microspheres, characterized in that: The lightweight communication optical cable according to any one of claims 1-7 specifically includes the following steps: S1. Directional pretreatment of modified hollow microspheres: Select modified hollow microspheres with a particle size of 5-50μm, dry them in a 120℃ forced-air oven for 2h to remove adsorbed moisture and impurities from the surface of the microspheres, then immerse the dried microspheres in a 2wt% silane coupling agent ethanol solution and stir and soak them at 25℃ for 30min to allow the coupling agent molecules to be fully grafted onto the surface of the microspheres. Finally, place the treated microspheres in an 80℃ oven to dry for 1h to constant weight for later use. S2, fiber paste and cable paste are prepared stepwise: First, the thickener and base oil are stirred at 50°C and 1200 rpm for 30 min. Then, the pretreated modified hollow microspheres are added and stirred at 1500 rpm for 20 min. After cooling to room temperature, the additives are added and stirred at 500 rpm for 10 min to obtain the finished product. S3. Optical cable directional filling, specifically including the following steps: a1. Filling the loose tube with fiber optic paste: The fiber optic paste prepared in step S2 is injected into the loose tube at a pressure of 0.3-0.5 MPa using a pressure filling machine. The filling speed is synchronized with the fiber insertion speed at 10-15 m / min to ensure that the fiber unit is completely covered and the filling rate is ≥95%. a2. Cable core gap filling with cable paste: The stranded cable core, including loose tubes, reinforcing members and filling ropes, is fed into a crawler-type filling machine. The cable paste prepared in step S2 is preheated to 150°C and then injected into the cable core gap at a pressure of 0.5-0.8MPa. Ultrasonic testing is used during the filling process to ensure that there are no gaps and the filling rate is ≥98%. a3. Subsequent molding: After filling, the core is wrapped with cable tape and the outer XLPE sheath is extruded in sequence to obtain the finished optical cable. The wrapping speed is 20-30m / min and the extrusion temperature is 120-150℃. S4. Filling quality verification: Sampling inspections are conducted on the filled optical cables, including the uniformity of fiber paste coating in the loose tube, the density of filling gaps between cable cores, the overall waterproof performance of the optical cable, and the stability of the filling material under extreme temperatures, to ensure that it meets the design requirements.

9. The method for filling fiber optic cable paste containing modified hollow microspheres according to claim 8, characterized in that: The stepwise preparation of fiber paste and cable paste in step S2 specifically includes the following steps: T1. Construction of the basic system: Weigh the base oil and composite thickener according to the formula of the fiber paste in claim 1, add them to the high-speed stirring tank, and stir for 30 minutes at 50°C and 1200 rpm to completely dissolve the thickener and form a uniform colloidal system. T2, Microsphere Dispersion and Composite: Add the modified hollow microspheres pretreated in step S1 to the colloidal system in step T1 according to the ratio, adjust the stirring speed to 1500 rpm, and continue stirring at 50℃ for 20 min to make the microspheres uniformly dispersed in the system and avoid agglomeration. T3. Functional additive compounding: Cool the system to 20-30℃, add antioxidant, rust inhibitor and dispersant according to the formula of the fiber paste described in claim 1, adjust the stirring speed to 500 rpm, stir for 10 min to fully integrate the additives; T4. Finished product post-processing: The mixed materials are ground once by a three-roll mill to ensure that the particle size of the system is ≤100μm, and then vacuum degassed for 15 minutes to remove air bubbles, and the fiber paste finished products are obtained respectively. T5. Preparation of cable paste: The cable paste is prepared by following the same preparation process as steps T1-T4 according to the ratio of the cable paste described in claim 1.

10. The method for filling fiber optic cable paste containing modified hollow microspheres according to claim 8, characterized in that: In step a1, the ratio of the inner diameter of the filling nozzle of the pressure filling machine to the inner diameter of the loose tube is 0.8-0.9, and in step a2, the glue injection port of the tracked filling machine adopts a multi-directional distribution design to ensure that the gap between the cable cores is filled in all directions.

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