Flat non-metallic rod armoured optical cable

Abstract

The application discloses a kind of flat non-metallic rod armoured optical cable, including successively from inside to outside along the radial section of optical cable: center reinforcing member, optical fiber unit, inner sheath, armoured buffer layer and outer sheath, armoured buffer layer includes inner buffer layer and outer buffer layer, inner end spiral of inner buffer layer is provided with inner armoured steel wire layer, outer end spiral of outer buffer layer is provided with outer armoured steel wire layer, flat non-metallic rod is arranged along the radial direction between inner buffer layer and outer buffer layer, shear thickening fluid buffer layer is also filled between inner buffer layer and outer buffer layer, and capsaicin inclusion microcapsule is uniformly dispersed in shear thickening fluid buffer layer.The application is characterized in that shear thickening fluid buffer layer with uniformly dispersed capsaicin inclusion microcapsule realizes dynamic dissipation and active defense to gnawing force of rodent, while mass is greatly reduced by non-metallic rod and buffer layer structure.

Description

Technical Field

[0001] This invention relates to the field of optical cable technology, and in particular to a flat, non-metallic rod armored optical cable. Background Technology

[0002] As fiber optic communication networks extend into complex environments such as mountainous areas, forests, and grasslands, the threat of rodent attack on optical cables is becoming increasingly severe. Traditional metal-armored optical cables (such as steel wire armor and steel tape armor), while possessing excellent mechanical protection, suffer from drawbacks such as heavy weight, susceptibility to corrosion, and strong lightning-induced currents, limiting their application in lightning-prone areas and environments with strong electromagnetic interference. Non-metallic armored optical cables, due to their all-dielectric structure, light weight, lightning resistance, and electromagnetic interference immunity, have become an important choice for laying optical cables in complex environments.

[0003] Existing non-metallic armor technology has the following main shortcomings:

[0004] The structure is simple and lacks gradient design. When the optical cable is bitten by rodents, the rigid rod is prone to brittle fracture due to local stress concentration, while the flexible rod cannot effectively disperse the biting force due to insufficient stiffness.

[0005] The rodent control mechanisms are passive and lack active repellency. Existing technologies mostly rely on the physical hardness of non-metallic rods for passive rodent control, or add chemical repellents to the outer sheath. However, chemical repellents are prone to migration and loss over time, resulting in insufficient long-term effectiveness. Furthermore, the repellents in the sheath are only on the surface of the optical cable, and once the sheath is chewed through, the protection is lost. Summary of the Invention

[0006] The purpose of this invention is to provide a flat, non-metallic rod armored optical cable that achieves dynamic dissipation and active defense against the biting force of rodents through a shear-thickening fluid buffer layer with capsaicin inclusion microcapsules uniformly dispersed, while significantly reducing mass through the non-metallic rod and buffer layer structure.

[0007] The above-mentioned technical objective of the present invention is achieved through the following technical solution: A flat non-metallic rod armored optical cable, comprising, from the inside to the outside along the radial cross-section of the optical cable: a central reinforcing member, an optical fiber unit, an inner sheath, an armored buffer layer, and an outer sheath. The armored buffer layer includes an inner buffer layer and an outer buffer layer. The inner end of the inner buffer layer is spirally wound with an inner armored steel wire layer, and the outer end of the outer buffer layer is spirally wound with an outer armored steel wire layer. A flat non-metallic rod is radially disposed between the inner and outer buffer layers. A shear-thickening fluid buffer layer is also positively pressure-filled between the inner and outer buffer layers, and capsaicin inclusion complex microcapsules are uniformly dispersed in the shear-thickening fluid buffer layer.

[0008] Preferably, the optical fiber unit comprises at least one optical fiber placed inside a PBT loose tube, the PBT loose tube being filled with fiber grease.

[0009] Preferably, the optical fiber unit is provided in multiple sets, all twisted around the central reinforcing member SZ, and the gaps between adjacent optical fiber units are filled with cable grease and water-blocking yarn, and the central reinforcing member is phosphated steel wire or glass fiber reinforced plastic.

[0010] Preferably, the inner sheath covers the outside of the optical fiber unit, and the material of the inner sheath is low smoke halogen-free flame retardant polyolefin with a thickness of 0.8~1.2mm. The material of the outer sheath is high density polyethylene, low smoke halogen-free flame retardant polyolefin or polyvinyl chloride with a thickness of 1.0~2.0mm.

[0011] Preferably, both the inner and outer buffer layers comprise the following components by mass fraction: 40-50 parts linear low-density polyethylene, 45-55 parts EVA resin, 8-12 parts maleic anhydride-grafted EVA, 40-55 parts aluminum hydroxide, 15-25 parts magnesium hydroxide, 5-10 parts zinc borate, and 2-3 parts silane coupling agent KH-550.

[0012] Preferably, the inner buffer layer and the outer buffer layer are provided with threaded grooves, and the cross-sections of the inner buffer layer and the outer buffer layer are both sinusoidal wave structures. The position of each set of tooth peaks in the inner buffer layer corresponds to the position of tooth valleys in the outer buffer layer. The flat non-metallic rod is radially disposed between the tooth peaks of the outer buffer layer and the tooth valleys of the inner buffer layer.

[0013] Preferably, the steel wires of the inner armor steel wire layer are spirally wound along the inside of the tooth peaks of the inner buffer layer, and the steel wires of the outer armor steel wire layer are spirally wound along the inside of the tooth valleys of the outer buffer layer. The diameter of the steel wires of the inner armor steel wire layer is smaller than the diameter of the steel wires of the outer armor steel wire layer, and the number of steel wires in the inner armor steel wire layer, the outer armor steel wire layer, and the flat non-metallic rod is 12 to 24.

[0014] Preferably, the shear-thickening fluid buffer layer comprises the following components by mass fraction: 22-26 parts of nano-silica, 52-56 parts of polyethylene glycol, 12-16 parts of glycerol, 0.5-1.0 parts of silane coupling agent KH-570, 0.3-0.6 parts of anti-settling fumed silica, and 6-8 parts of capsaicin inclusion complex microcapsules.

[0015] Preferably, the capsaicin inclusion complex microcapsules have a core-shell-shell three-layer structure, comprising: The core is a β-cyclodextrin-capsaicin inclusion complex, wherein the mass fraction of capsaicin is 25-35% and the mass fraction of β-cyclodextrin is 65-75%. The intermediate layer is a urea-formaldehyde resin structural support wall with a thickness of 2~3μm; The outer layer is a polyethylene glycol-grafted polysiloxane hydrophobic compatibility layer with a grafting density of 0.8~1.2 chains / nm² and a thickness of 0.5~1.0μm.

[0016] Preferably, the flat non-metallic rod comprises the following components by mass fraction: 100 parts of cashew phenol-modified bisphenol A type epoxy resin, 80-85 parts of curing agent methyltetrahydrophthalic anhydride, 1.5-2.0 parts of accelerator 2-ethyl-4-methylimidazolium, 190-230 parts of alkali-free glass fiber, 8-12 parts of cellulose nanofibers, 3-5 parts of fumed silica, and 1-2 parts of hexagonal boron nitride nanosheets, wherein the thickness of one end of the flat non-metallic rod near the inner buffer layer is less than the thickness of the other end.

[0017] In summary, the present invention has the following beneficial effects: 1. This invention combines capsaicin inclusion complex microcapsules with a shear-thickening fluid buffer layer, which can effectively reduce the possibility of failure due to external exposure. At the same time, in the event of rupture of the outer buffer layer, the liquid release increases the release surface density.

[0018] 2. In order to improve the stability of microcapsules in shear-thickening fluid buffer layers, this invention adds a gaseous SiO2 thixotropic agent to the shear-thickening fluid buffer layer to form a weak gel network and increases the proportion of glycerol to avoid sedimentation and stratification after long-term operation. In addition, the outer layer of the microcapsules adopts a dense urea-formaldehyde resin + polysiloxane double wall, which can effectively reduce the permeability at room temperature and prevent it from penetrating into the inner and outer buffer layers.

[0019] 3. This invention utilizes an inner and outer armored steel wire layer and a flat non-metallic rod arranged in a ring-shaped array at intervals. A mechanical interlock is formed by the sinusoidal wave-shaped tooth structure of the inner and outer buffer layers (the inner layer tooth peaks correspond to the outer layer tooth valleys), allowing the flat non-metallic rods to fit between the outer buffer layer tooth peaks and the inner buffer layer tooth valleys, thus creating a stable radial support system. This structure not only significantly reduces the amount of metal material used and lowers the overall weight of the optical cable, but also significantly improves its resistance to lateral pressure, impact, and torsion. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the cross-sectional structure of the flat non-metallic rod armored optical cable of the present invention. Detailed Implementation

[0021] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings. These embodiments do not constitute a limitation on the present invention.

[0022] Example 1 Step 1: Preparation of capsaicin inclusion complex microcapsules Capsaicin and β-cyclodextrin were mixed at a mass ratio of 30:70 and encapsulated at 60°C for 4 hours using a saturated aqueous solution method. After freeze-drying, a core with an average particle size of approximately 15 μm was obtained. Subsequently, a urea-formaldehyde resin intermediate layer was coated on the surface of the core by in-situ polymerization, with the reaction pH controlled at 4.0–4.5 and the reaction time controlled at 2 hours, resulting in a dense support wall with a thickness of 2.5 μm. Finally, polyethylene glycol grafted with polysiloxane with a molecular weight of 400 was coated on the outside of the intermediate layer by solvent evaporation, with the grafting density controlled at 1.0 chains / nm², forming a hydrophobic and compatible outer layer with a thickness of approximately 0.8 μm. The final capsaicin inclusion microcapsules had an average particle size of 23 μm.

[0023] Step 2: Preparation of a shear-thickening fluid buffer layer Weigh out the following by mass fractions: nano-silica (average particle size 75nm, specific surface area 280m²). 2 24 parts of nano-capsaicin inclusion complex microcapsules ( / g), 54 parts of polyethylene glycol (molecular weight 400), 14 parts of glycerol, 0.8 parts of silane coupling agent KH-570, 0.45 parts of anti-settling agent fumed silica (Aerosil R972, hydrophobic), and 7 parts of the capsaicin inclusion complex microcapsules prepared above. Nano-silica and KH-570 were pre-dispersed in polyethylene glycol and sonicated for 30 minutes. Glycerol and Aerosil R972 were added, and the mixture was stirred at 800 rpm for 1 hour in a vacuum degassing machine. Finally, the microcapsules were added, and the mixture was stirred at a low speed of 200 rpm until homogeneous, forming a stable, weakly gel-like shear-thickening fluid.

[0024] Step 3: Prepare a flat non-metallic rod Weigh the following components by weight: 100 parts cashew phenol-modified bisphenol A type epoxy resin, 82.5 parts methyltetrahydrophthalic anhydride (MTHPA) curing agent, 1.8 parts 2-ethyl-4-methylimidazolium accelerator, 210 parts alkali-free glass fiber (3 mm in length, 13 μm in diameter), 10 parts cellulose nanofibers (CNC, 200~500 nm in length), 4 parts fumed silica, and 1.5 parts hexagonal boron nitride nanosheets (h-BN, 500 nm in diameter). Premix the epoxy resin, accelerator, and filler. After adding the curing agent, inject the mixture into a wedge-shaped mold and cure at 120℃ for 2 hours, followed by curing at 150℃ for 3 hours. The resulting flat non-metallic rod has a wedge-shaped cross-section, with a thickness of 2.0 mm at one end near the inner buffer layer and 3.0 mm at the other end, a width of 8.0 mm, and a length corresponding to the circumference of the optical cable. A total of 6 rods were prepared.

[0025] Step 4: Prepare inner and outer buffer layer granules Weigh the following components by weight: 45 parts linear low-density polyethylene (LLDPE, melt index 2.0 g / 10 min), 50 parts EVA resin (VA content 18%, melt index 3.0 g / 10 min), 10 parts maleic anhydride-grafted EVA (MAH-g-EVA, grafting rate 1.2%), 48 parts aluminum hydroxide (ATH, average particle size 2 μm), 20 parts magnesium hydroxide (MDH, average particle size 3 μm), 8 parts zinc borate, and 2.5 parts silane coupling agent KH-550. Mix the above components in a high-speed mixer for 10 minutes, and then melt-extrude and granulate them through a twin-screw extruder (temperature 160~190℃) to obtain a flame-retardant buffer layer material.

[0026] Step 5: Fiber Optic Cable Assembly A phosphated steel wire with a diameter of 3mm was selected as the central reinforcing member 1.

[0027] Six groups of fiber optic units 2 are SZ stranded around the central reinforcing member 1. Each group of fiber optic units contains six G.652D single-mode optical fibers placed in a PBT loose tube (outer diameter 2.0mm, wall thickness 0.35mm). The PBT loose tube is filled with fiber grease, and the gaps between adjacent fiber optic units are filled with cable grease and water-blocking yarn.

[0028] The stranded optical fiber unit is extruded with a 1.0 mm thick low-smoke halogen-free flame-retardant polyolefin (LSZH) inner sheath 3.

[0029] The aforementioned buffer layer material is extruded onto the outer sheath 3 to form an inner buffer layer 4. The extrusion die is designed with a sinusoidal wave structure, with a peak height of 2.0 mm, a trough depth of 2.0 mm, and a period of 6 mm. Eighteen galvanized steel wires with a diameter of 0.9 mm are used as the inner armor steel wire layer 5, and are spirally wound along the inside of the tooth peaks of the inner buffer layer 4 with a helical pitch of 55 mm, with an interval of approximately 0.5 mm between adjacent steel wires.

[0030] The six flat non-metallic rods 7 prepared in step three are inserted radially between the tooth peaks of the outer buffer layer 8 and the tooth valleys of the inner buffer layer 4, arranged in a 60° interval ring array.

[0031] The weakly gel-state shear-thickening fluid 6 prepared in step two is positively filled into the cavity between the inner buffer layer 4 and the outer buffer layer 8 using a pressure injection device at a pressure of 0.3 MPa to ensure that no air bubbles remain.

[0032] Eighteen galvanized steel wires with a diameter of 1.2 mm are used as the outer armor steel wire layer 9 outside the outer buffer layer 8. They are spirally wound along the inside of the toothed valley of the outer buffer layer 8 with a spiral pitch of 50 mm and the spacing between adjacent steel wires is about 0.6 mm.

[0033] Finally, a 1.5mm thick high-density polyethylene (HDPE) is extruded as the outer sheath 10 to complete the optical cable preparation.

[0034] Finished optical cable structural parameters: outer diameter approximately 19.5mm, unit weight approximately 310kg / km.

[0035] Example 2 The main difference between this embodiment and Embodiment 1 lies in the optimization of the shear-thickening fluid buffer layer and the microcapsule wall structure, in order to further improve long-term stability and increase the density of armored components.

[0036] The formulation of the shear-thickening fluid buffer layer was adjusted to: 25 parts nano-silica, 53 parts polyethylene glycol (molecular weight 600), 16 parts glycerol, 1.0 part silane coupling agent KH-570, 0.6 parts anti-settling agent fumed silica (Aerosil R972), and 8 parts capsaicin inclusion complex microcapsules. Increasing the proportion of glycerol and the content of the thixotropic agent resulted in a denser weak gel network structure and a shear recovery time shortened to less than 5 seconds.

[0037] The capsaicin inclusion complex microcapsules were modified as follows: the capsaicin mass fraction in the core was increased to 35%, and β-cyclodextrin to 65%; the grafting density of polyethylene glycol (molecular weight 600) grafted with polysiloxane in the outer layer was increased to 1.2 chains / nm², and the outer layer thickness was increased to 1.0 μm, further reducing the room temperature permeability.

[0038] The flat non-metallic rods were adjusted to consist of 230 parts alkali-free glass fiber, 12 parts cellulose nanofibers, and 2 parts hexagonal boron nitride nanosheets, with the remainder the same as in Example 1. This enhances radial thermal conductivity and rigidity. The cross-section of the flat non-metallic rods was adjusted to have a thickness of 2.2 mm at one end near the inner buffer layer, a thickness of 3.2 mm at the other end, and a width of 5.5 mm. A total of 20 rods were prepared, arranged in a ring array with 18° intervals.

[0039] The armor steel wire layer was adjusted to: The inner armor steel wire layer consists of 20 galvanized steel wires with a diameter of 0.85mm, spirally wound along the inside of the inner buffer layer tooth peaks with a helical pitch of 52mm, and the spacing between adjacent steel wires is about 0.4mm. The outer armor steel wire layer consists of 20 galvanized steel wires with a diameter of 1.15mm, spirally wound along the inside of the outer buffer layer's toothed valley with a helical pitch of 48mm, and the spacing between adjacent steel wires is approximately 0.5mm.

[0040] The wave structure of the inner and outer buffer layers was adjusted to: wave crest height 1.8mm, wave trough depth 1.8mm, and period 5.8mm, to accommodate the increased number of armored components.

[0041] The remaining structure and preparation process are the same as in Example 1.

[0042] Finished optical cable structural parameters: outer diameter approximately 19.8 mm, unit weight approximately 318 kg / km.

[0043] Example 3 The main difference between this embodiment and Embodiment 1 lies in the lightweight design and adaptation to flame retardant requirements, while adopting a higher density armored layout.

[0044] The central reinforcement 1 was replaced with a glass fiber reinforced plastic (FRP) rod with a diameter of 3.5mm to further reduce weight and eliminate electromagnetic shielding.

[0045] The armor steel wire layer was adjusted to: The inner armor steel wire layer consists of 16 high-strength carbon steel wires with a diameter of 0.8mm, spirally wound along the inside of the inner buffer layer tooth peaks with a helical pitch of 58mm, and the spacing between adjacent steel wires is about 0.8mm. The outer armor steel wire layer consists of 16 galvanized steel wires with a diameter of 1.1 mm, spirally wound along the inside of the outer buffer layer's toothed valley with a helical pitch of 52 mm, and the spacing between adjacent steel wires is approximately 0.9 mm.

[0046] While maintaining tensile strength, the amount of metal used is reduced by approximately 18%.

[0047] The flat non-metallic rods were adjusted to contain 190 parts alkali-free glass fiber, 12 parts cellulose nanofibers, and 5 parts fumed silica, with the remainder the same as in Example 1. The modulus loss due to the reduction in glass fiber content was compensated by increasing the cellulose nanofiber content. The cross-section of the flat non-metallic rods was 1.8 mm thick at one end near the inner buffer layer, 2.8 mm thick at the other end, and 5.0 mm wide. A total of 16 rods were prepared, arranged in a 22.5° interval ring array.

[0048] The outer sheath 10 has been changed to low-smoke halogen-free flame-retardant polyolefin (LSZH), and the thickness has been adjusted to 1.2mm to meet the flame-retardant requirements of enclosed spaces such as rail transit.

[0049] The wave structure of the inner and outer buffer layers was adjusted to: wave crest height 1.6mm, wave trough depth 1.6mm, and period 6.0mm.

[0050] The remaining structure and preparation process are the same as in Example 1.

[0051] Finished optical cable structural parameters: outer diameter approximately 18.8mm, unit weight approximately 265kg / km.

[0052] Example 4 (High-Density Armor Solution) This embodiment uses the highest density armored component configuration, which is suitable for extreme mechanical stress environments (such as directly buried rock areas, mines, etc.).

[0053] Armored steel wire layer configuration: The inner armor steel wire layer consists of 24 galvanized steel wires with a diameter of 0.75 mm, spirally wound along the inside of the inner buffer layer tooth peaks with a spiral pitch of 50 mm, and the spacing between adjacent steel wires is about 0.3 mm. The outer armor steel wire layer consists of 24 galvanized steel wires with a diameter of 1.0 mm, spirally wound along the inside of the outer buffer layer tooth valley with a spiral pitch of 45 mm, and the spacing between adjacent steel wires is about 0.4 mm.

[0054] Flat non-metallic rods: 24 rods, with a cross-section of 1.5mm thickness at one end near the inner buffer layer, 2.5mm thickness at the other end, and 4.5mm width, arranged in a circular array at 15° intervals.

[0055] Wave structure of inner and outer buffer layers: crest height 1.5mm, trough depth 1.5mm, period 5.0mm.

[0056] Central reinforcement 1: Phosphated steel wire with a diameter of 3.2mm.

[0057] Fiber unit 2: 10 groups, each group contains 8 G.652D single-mode fibers, PBT loose tube outer diameter 2.2mm, wall thickness 0.38mm.

[0058] The formulations for the remaining materials are the same as in Example 1.

[0059] Finished optical cable structural parameters: outer diameter approximately 20.5mm, unit weight approximately 335kg / km, such as... Figure 1 As shown.

[0060] Example 5 (Medium-Density Optimization Scheme) This embodiment optimizes the matching relationship between the number and size of armored components based on embodiment 1, pursuing a balance between mechanical performance and process feasibility.

[0061] Armored steel wire layer configuration: The inner armor steel wire layer consists of 12 galvanized steel wires with a diameter of 1.0 mm, spirally wound along the inside of the inner buffer layer tooth peaks with a helical pitch of 60 mm, and the spacing between adjacent steel wires is about 1.0 mm. The outer armor steel wire layer consists of 12 galvanized steel wires with a diameter of 1.3mm, spirally wound along the inside of the outer buffer layer's toothed valley with a helical pitch of 55mm, and the spacing between adjacent steel wires is approximately 1.2mm.

[0062] Flat non-metallic rods: 12 rods, with a cross-section of 2.5mm thickness at one end near the inner buffer layer and 3.5mm thickness at the other end, and a width of 7.0mm, arranged in a circular array at 30° intervals.

[0063] Wave structure of inner and outer buffer layers: crest height 2.2mm, trough depth 2.2mm, period 7.5mm.

[0064] Center reinforcement 1: Phosphated steel wire with a diameter of 2.8mm.

[0065] Fiber unit 2: 6 groups, each group contains 6 G.652D single-mode fibers.

[0066] The formulations for the remaining materials are the same as in Example 1.

[0067] Finished optical cable structural parameters: outer diameter approximately 20.0 mm, unit weight approximately 325 kg / km.

[0068] Comparative Example 1 (Traditional Metal-Armored Optical Cable) A traditional layered armor structure is adopted: the center is a 3.0mm diameter phosphated steel wire, 8 sets of optical fiber units (same as in Example 1) are SZ stranded and then extruded with a 1.0mm thick LSZH inner sheath, followed by a 0.3mm thick stainless steel strip directly longitudinally wrapped as the armor layer, and finally a 1.5mm thick HDPE outer sheath is extruded. This comparative example does not include flat non-metallic rods, shear-thickening fluid buffer layers, inner and outer buffer layer wave structures, or capsaicin microcapsules.

[0069] Finished optical cable structural parameters: outer diameter approximately 19.0 mm, unit weight approximately 420 kg / km.

[0070] Comparative Example 2 (containing shear-thickening fluid but without capsaicin microcapsules) The structure is the same as in Example 1, including an inner and outer buffer layer wave structure, 18 flat non-metallic rods, and inner and outer armored steel wire layers (18 inner steel wires + 18 outer steel wires). The shear-thickening fluid buffer layer formulation is the same as in Example 1, but does not contain capsaicin inclusion complex microcapsules (replaced with an equal volume of polyethylene glycol). This is used to compare and verify the contribution of capsaicin microcapsules to rodent-repellent performance.

[0071] Comparative Example 3 (Shear-thickening fluid containing monolayer wall microcapsules) The structure is the same as in Example 1 (18 inner steel wires + 18 outer steel wires + 18 flat non-metallic rods). The shear-thickening fluid buffer layer contains capsaicin microcapsules, but the microcapsules have only a single-layer wall structure (only a urea-formaldehyde resin intermediate layer, 2.5 μm thick, without an outer polyethylene glycol-grafted polysiloxane hydrophobic compatibility layer). This is used to compare and verify the effect of the double-layer wall structure on room temperature permeability and long-term stability.

[0072] Comparative Example 4 (Traditional steel wire armor without flat non-metallic rods) The structure is the same as the armored steel wire configuration of Example 1 (18 inner steel wires + 18 outer steel wires), but it does not contain flat non-metallic rods, and the space between the inner and outer buffer layers is not filled with shear-thickening fluid, but with conventional cable paste. This is used to compare and verify the contribution of the interlocking structure of the flat non-metallic rods and shear-thickening fluid to the mechanical properties.

[0073] System performance tests were conducted on the optical cable samples prepared in Examples 1-5 and Comparative Examples 1-4. The test methods were based on YD / T 901, GB / T 7424, and custom test methods. The results are as follows: Table 1 Comparison of Structural Parameters

[0074] Table 2 Comparison of Mechanical and Environmental Performance

[0075] As can be seen from Tables 1 and 2 above: Tensile properties: The short-term tensile forces of Examples 1-5 all reached 3400-4250N, significantly higher than that of Comparative Example 1. Example 4, using a configuration of 24 armored steel wires, achieved a maximum tensile force of 4250N. Although Example 3 used an FRP center reinforcement, it still achieved 3400N thanks to the synergy of 16 inner and outer steel wires and 16 flat non-metallic rods, meeting the requirements for conventional laying.

[0076] Flattening and lateral compression performance: The residual deformation after flattening in Examples 1-5 was only 1.2%-1.9%, which is 56%-63% lower than that in Comparative Example 1. The lateral compression stiffness of Example 4 reached 3350N, which is 1.5 times that of Comparative Example 1. This is due to the high-density spacing array of 12-24 flat non-metallic rods and armored steel wires, as well as the overall mechanical system formed by the wave interlocking structure.

[0077] Impact and Torsion: Examples 1-5 remained intact under a 500mm impact from a 2.0kg hammer, while Comparative Example 1 developed cracks after the third impact. Comparative Example 4 (without the flat non-metallic rod) had the same number of wires, but exhibited a 0.5mm wire misalignment during torsion, demonstrating the crucial role of the flat non-metallic rod in structural locking.

[0078] Weight optimization: Example 3 weighs only 265 kg / km, which is 36.9% lower than Comparative Example 1 and 47.8% less metal usage, making it particularly suitable for load-sensitive overhead installations.

[0079] Table 3 Comparison of stability and rodent-repellent properties of shear-thickened fluids

[0080] As can be seen from the table above: Rodent repellency: Examples 1-5, through the synergy of 12-24 flat non-metallic rods and shear-thickening fluid-capsaicin microcapsules, achieved zero damage from rat bites, reducing the number of bites by 92%-97%. Comparative Example 2 (without microcapsules) still had a 40% damage rate, and Comparative Example 4 (without flat non-metallic rods, traditional cable paste filling) had a damage rate of 50%, proving that both physical barriers (high-density flat rods + steel wire) and chemical repellency are indispensable.

[0081] Rupture Response: In Example 4, the 24 flat, non-metallic rods divided the shear-thickening fluid cavity into more independent units, resulting in a capsaicin release areal density of 210 μg / cm³ upon local rupture. 2This is 1.22 times that of Comparative Example 3. The high-density flat rod not only enhances mechanical strength but also increases the local release concentration through a "zoned energy storage" effect.

[0082] Stability: In Example 2, due to the increased thixotropic agent content and grafting density, the permeability decreased to 0.5 μg / g, which is 1 / 22 of that of Comparative Example 3 (single-layer wall). Examples 1-5 showed no stratification after 720h high-temperature aging, while Comparative Example 3 showed a 12% concentration gradient, demonstrating the necessity of a double-layer wall + weak gel network.

[0083] Residual rate: The capsaicin residue rate of Example 2 reached 97.5% during accelerated aging, which means that the microcapsule core still maintains highly efficient repellent activity within the 25-year design life.

[0084] Table 4 Comparison of Structural Interlocking and Technological Performance

[0085] As can be seen from the table above: Interlocking stability: Examples 1-5 showed no misalignment of armored components under 50% radial compression, while Comparative Example 4 (without flat non-metallic rods) showed a misalignment of 1.8mm. The high-density alternating arrangement of 18-24 flat non-metallic rods and armored steel wires, combined with the wavy tooth-shaped mechanical interlocking, forms a composite reinforcement system similar to "reinforced concrete".

[0086] Dispersion uniformity: In Example 4, the 24 flat non-metallic rods subdivided the buffer layer cavity into 24 fan-shaped micro-regions, and the microcapsule dispersion CV value was reduced to 3.5%, which is a further improvement compared to Example 1, indicating that increasing the number of flat rods helps to suppress the local enrichment of microcapsules.

[0087] Process Feasibility: Although the 24-strand configuration in Example 4 slightly reduced the cabling pass rate to 96.5%, it was still within an acceptable range. The 12-strand configuration in Example 5 had the highest pass rate, demonstrating that the structure has good process adaptability within the range of 12 to 24 strands.

[0088] In summary, by optimizing the number of armored steel wires and flat non-metallic rods to a range of 12 to 24, and by adjusting the structural dimensions and wave period accordingly, this invention achieves a higher density mechanical reinforcement array while significantly reducing the weight of the optical cable and the amount of metal used.

[0089] The 18-24 wire configuration is suitable for extreme mechanical stress environments, and the residual deformation after flattening can be reduced to 1.2%-1.6%, while the lateral compression rigidity is increased by more than 50%.

[0090] With a configuration of 12 to 16 wires, the weight can be reduced to 265 kg / km while maintaining excellent mechanical performance, and the metal usage is reduced by 47%, making it suitable for lightweight laying scenarios.

[0091] The synergistic effect of capsaicin inclusion complex microcapsules and shear-thickening fluids achieved zero-breakage rodent-proof effect in all configurations, and the room temperature permeability of double-walled microcapsules was reduced by an order of magnitude compared with that of single-walled microcapsules.

[0092] The sinusoidal wave interlocking structure enables 12 to 24 armored components and flat non-metallic rods to form an integrated mechanical system, avoiding the risk of interlayer slippage and misalignment in traditional armored layers.

[0093] This optical cable structure is suitable for complex geographical environments, areas where rodents are active, and overhead / bridge laying scenarios that are sensitive to weight, and has good prospects for engineering applications.

[0094] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art can make various modifications or equivalent substitutions to the present invention within the scope of its essence and protection. Such modifications or equivalent substitutions should also be considered to fall within the protection scope of the present invention.

Claims

1. A flat, non-metallic, rod-armored optical cable, characterized in that, The optical cable, from the inside to the outside along its radial cross-section, comprises: a central reinforcing member, an optical fiber unit, an inner sheath, an armored buffer layer, and an outer sheath. The armored buffer layer includes an inner buffer layer and an outer buffer layer. The inner end of the inner buffer layer is spirally wound with an inner armored steel wire layer, and the outer end of the outer buffer layer is spirally wound with an outer armored steel wire layer. A flat non-metallic rod is radially arranged between the inner and outer buffer layers. A shear-thickening fluid buffer layer is also positively pressure-filled between the inner and outer buffer layers, and capsaicin inclusion complex microcapsules are uniformly dispersed in the shear-thickening fluid buffer layer.

2. The flat non-metallic rod armored optical cable according to claim 1, characterized in that: The optical fiber unit includes at least one optical fiber placed inside a PBT loose tube, the PBT loose tube being filled with fiber grease.

3. The flat non-metallic rod armored optical cable according to claim 1, characterized in that: The optical fiber unit is provided in multiple sets, all of which are twisted around the central reinforcing member SZ. The gaps between adjacent optical fiber units are filled with cable grease and water-blocking yarn. The central reinforcing member is phosphated steel wire or glass fiber reinforced plastic.

4. A flat non-metallic rod armored optical cable according to claim 1, characterized in that: The inner sheath covers the outside of the optical fiber unit. The material of the inner sheath is low-smoke halogen-free flame-retardant polyolefin, with a thickness of 0.8~1.2mm. The material of the outer sheath is high-density polyethylene, low-smoke halogen-free flame-retardant polyolefin, or polyvinyl chloride, with a thickness of 1.0~2.0mm.

5. A flat non-metallic rod armored optical cable according to claim 1, characterized in that: Both the inner and outer buffer layers comprise the following components by mass fraction: 40-50 parts linear low-density polyethylene, 45-55 parts EVA resin, 8-12 parts maleic anhydride-grafted EVA, 40-55 parts aluminum hydroxide, 15-25 parts magnesium hydroxide, 5-10 parts zinc borate, and 2-3 parts silane coupling agent KH-550.

6. A flat non-metallic rod armored optical cable according to claim 1, characterized in that: The inner and outer buffer layers are provided with threaded grooves. The cross-sections of the inner and outer buffer layers are both sinusoidal wave structures. The position of each set of tooth peaks in the inner buffer layer corresponds to the position of tooth valleys in the outer buffer layer. The flat non-metallic rod is radially disposed between the tooth peaks of the outer buffer layer and the tooth valleys of the inner buffer layer.

7. A flat non-metallic rod armored optical cable according to claim 1, characterized in that: The steel wires of the inner armor steel wire layer are spirally wound along the inside of the tooth peaks of the inner buffer layer, and the steel wires of the outer armor steel wire layer are spirally wound along the inside of the tooth valleys of the outer buffer layer. The diameter of the steel wires of the inner armor steel wire layer is smaller than that of the steel wires of the outer armor steel wire layer. The number of steel wires in the inner armor steel wire layer, the outer armor steel wire layer, and the flat non-metallic rod is 12 to 24.

8. A flat non-metallic rod armored optical cable according to claim 1, characterized in that: The shear-thickening fluid buffer layer comprises the following components by mass fraction: 22-26 parts of nano-silica, 52-56 parts of polyethylene glycol, 12-16 parts of glycerol, 0.5-1.0 parts of silane coupling agent KH-570, 0.3-0.6 parts of anti-settling fumed silica, and 6-8 parts of capsaicin inclusion complex microcapsules.

9. A flat non-metallic rod armored optical cable according to claim 1, characterized in that: The capsaicin inclusion complex microcapsules have a core-shell-shell three-layer structure, including: The core is a β-cyclodextrin-capsaicin inclusion complex, wherein the mass fraction of capsaicin is 25-35% and the mass fraction of β-cyclodextrin is 65-75%. The intermediate layer is a urea-formaldehyde resin structural support wall with a thickness of 2~3μm; The outer layer is a polyethylene glycol-grafted polysiloxane hydrophobic compatibility layer with a grafting density of 0.8~1.2 chains / nm² and a thickness of 0.5~1.0μm.

10. A flat non-metallic rod armored optical cable according to claim 1, characterized in that: The flat non-metallic rod comprises the following components by mass fraction: 100 parts of cashew phenol modified bisphenol A type epoxy resin, 80-85 parts of curing agent methyltetrahydrophthalic anhydride, 1.5-2.0 parts of accelerator 2-ethyl-4-methylimidazolium, 190-230 parts of alkali-free glass fiber, 8-12 parts of cellulose nanofibers, 3-5 parts of fumed silica, and 1-2 parts of hexagonal boron nitride nanosheets. The thickness of one end of the flat non-metallic rod near the inner buffer layer is less than the thickness of the other end.

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