Hexagonal mesh collapsed energy-absorbing ribbon cable and method of making same

Abstract

This invention discloses a hexagonal mesh collapse-absorbing ribbon optical cable and its manufacturing method. The optical cable includes, from the inside out, a core unit, a three-dimensional mesh elastic energy-absorbing layer, a circumferentially wound reinforcement layer, a dry water-blocking layer, and an outer sheath. The three-dimensional mesh elastic energy-absorbing layer is a continuously extruded, integrally formed three-dimensional hexagonal mesh elastomer with a mesh diameter of 0.15-0.20 mm and a porosity of 42-48%. The hexagonal mesh is filled with ultrafine elastic short fibers. The circumferentially wound reinforcement layer is formed by spirally winding polymer fiber yarn around the circumference of the optical cable. This invention achieves controllable collapse, dissipation, and elastic rebound of local point pressure loads through the synergistic cooperation of the three-dimensional hexagonal mesh, ultrafine elastic short fibers, and circumferentially wound reinforcement layer, effectively avoiding micro-bending damage to the ribbon fiber core and significantly improving the ribbon optical cable's resistance to point pressure, impact resistance, and long-term service stability.

Description

Technical Field

[0001] This invention belongs to the field of optical communication cable technology, specifically relating to a hexagonal mesh collapse energy-absorbing ribbon optical cable and its preparation method. Background Technology

[0002] Ribbon optical cables are widely used in backbone communication and structured cabling due to their advantages of high fiber density, neat wiring, and high integration. However, ribbon fiber cores are planar integrated structures, which are extremely sensitive to local point pressure, instantaneous impact, and eccentric extrusion loads compared to traditional bundled optical fibers, resulting in a very low fault tolerance rate.

[0003] Existing ribbon optical cables typically employ solid elastic pads, ordinary planar braided buffers, or conventional foamed buffers for their buffer protection. Their protective principle relies solely on the material's own elastic deformation for passive buffering, lacking active stress relief and load dissipation mechanisms. When the optical cable is subjected to concentrated loads from construction impacts, pipe compression, or stone crushing, the concentrated stress cannot be effectively dissipated and is directly and vertically transmitted to the inner ribbon fiber core. This easily induces micro-bending deformation of the optical fiber, resulting in excessive additional optical transmission loss. In severe cases, it can lead to fiber breakage due to compression, delamination of the ribbon structure, and significantly reduce the cable's service stability and lifespan.

[0004] Currently, a small number of foamed buffer optical cable structures in the industry have defects such as disordered cell structure, uncontrollable pore size, and poor pore uniformity. They are difficult to achieve directional and controllable collapse energy absorption, and the overall structural strength of the buffer layer is insufficient. After repeated pressure, it is prone to permanent collapse and rebound failure, and cannot provide long-term stable protection for the ribbon fiber core.

[0005] In summary, existing ribbon optical cables still have significant shortcomings in resisting local point pressure and instantaneous impact. The buffer protection structure cannot effectively disperse and dissipate concentrated loads, and it is also difficult to balance structural strength and elastic rebound performance, which seriously restricts the application of ribbon optical cables in complex working conditions. Summary of the Invention

[0006] To address the aforementioned technical problems, the present invention aims to provide a hexagonal mesh collapse-absorbing ribbon optical cable and its preparation method. This invention achieves controllable collapse, dissipation, and elastic rebound of localized point pressure loads through the synergistic effect of a three-dimensional hexagonal mesh, ultra-fine elastic short fibers, and a circumferentially wound reinforcing layer. This effectively avoids micro-bending damage to the ribbon fiber core, significantly improving the ribbon optical cable's resistance to point pressure, impact resistance, and long-term service stability.

[0007] To achieve the above-mentioned technical objectives and effects, the present invention is implemented through the following technical solution: This invention provides a hexagonal mesh collapse-absorbing energy-absorbing ribbon optical cable, comprising, from the inside out, a cable core unit, a three-dimensional mesh elastic energy-absorbing layer, a circumferentially wound reinforcement layer, a dry water-blocking layer, and an outer sheath; the three-dimensional mesh elastic energy-absorbing layer is a continuously extruded, integrally formed three-dimensional hexagonal mesh elastomer with a mesh diameter of 0.15-0.20 mm and a porosity of 42-48%; the hexagonal mesh is filled with ultra-fine elastic short fibers; the circumferentially wound reinforcement layer is formed by spirally winding polymer fiber yarn around the circumference of the optical cable.

[0008] Furthermore, the cable core unit includes multiple optical fibers, each optical fiber including a loose tube and a ribbon core located in the loose tube.

[0009] Furthermore, the overall thickness of the three-dimensional mesh elastic energy-absorbing layer is 0.30-0.50 mm.

[0010] Furthermore, the length of the ultrafine elastic short fiber is 0.4-0.7 mm, and the filling volume accounts for 8-12% of the volume of the corresponding mesh cavity.

[0011] Furthermore, the ultrafine elastic short fibers are dispersedly filled inside the mesh, with point contact between fibers and between fibers and the mesh wall, and no continuous force transmission medium is formed.

[0012] Furthermore, the ultrafine elastic short fiber is configured to: dissipate impact energy through interfacial friction between the fiber and the mesh wall when the mesh collapses under load; and assist the mesh wall to return to its original position through the elastic recoil force of the fiber after the load is removed.

[0013] Furthermore, the circumferentially wound reinforcing layer covers the outer surface of the three-dimensional mesh elastic energy-absorbing layer to limit excessive radial deformation of the energy-absorbing layer.

[0014] Furthermore, the dry water-blocking layer is a dry water-blocking tape wrapping structure, and the dry water-blocking tape contains superabsorbent resin particles.

[0015] Furthermore, the outer sheath is a low-smoke halogen-free polyolefin sheath.

[0016] Another aspect of the present invention provides a method for preparing a hexagonal mesh collapse energy-absorbing ribbon optical cable, comprising the following steps: (1) Fabrication of cable core units; (2) A three-dimensional mesh elastic energy-absorbing layer is continuously extruded and integrally formed outside the cable core unit. The three-dimensional mesh elastic energy-absorbing layer is a hexagonal mesh elastomer with a mesh diameter of 0.15-0.20 mm and a porosity of 42-48%. The hexagonal mesh is filled with ultra-fine elastic short fibers. (3) A circumferentially wound reinforcement layer is formed by spirally winding polymer fiber yarn around the circumference of the optical cable outside the three-dimensional mesh elastic energy-absorbing layer; (4) Wrap a dry-type water-blocking layer around the reinforcing layer in a circular pattern; (5) Extrude an outer sheath outside the dry water-blocking layer.

[0017] This invention achieves the following specific technical effects through the synergistic combination of a three-dimensional hexagonal mesh, ultrafine elastic short fibers, and a circumferentially wound reinforcing layer: (1) When the hexagonal mesh is compressed, the mesh wall undergoes relatively uniform collapse deformation along the hexagonal nodes, which disperses the local point load to the surrounding mesh area and reduces the peak stress transmitted to the cable core. Compared with circular, square or random bubble structure, the collapse path of the hexagonal mesh is more regular, which can avoid stress concentration in local positions of the ribbon fiber core to a certain extent and reduce the risk of fiber microbending and additional attenuation.

[0018] (2) The ultrafine elastic short fibers filling the mesh undergo relative sliding and friction with the mesh wall during the mesh collapse process, consuming some of the impact energy; after the load is removed, the elastic recoil of the fibers can help the mesh wall return to its original position, reducing the permanent deformation of the buffer layer. Compared with hollow mesh or foam-filled structures, this filling method helps to improve the rebound stability of the buffer layer after repeated compression and extend its effective protection period.

[0019] (3) A circumferentially wound reinforcing layer covers the outside of the three-dimensional mesh elastic energy-absorbing layer, which constrains the radial deformation of the energy-absorbing layer, prevents the mesh from excessively collapsing or caving under large local loads, and improves the radial compressive and lateral compressive strength of the optical cable. The inner mesh structure is responsible for the collapse and dispersion of local loads, while the outer wound reinforcing layer is responsible for overall strength reinforcement. The combination of the two enables the optical cable to maintain a certain degree of flexibility while having good resistance to point pressure and impact.

[0020] In summary, this invention, through the synergistic cooperation of a three-dimensional hexagonal mesh, ultra-fine elastic short fibers, and a circumferentially wound reinforcement layer, enables the ribbon optical cable to reduce the probability of damage to the ribbon fiber core and the additional attenuation under conditions such as construction bumps, local compression, and instantaneous impacts. This is achieved by dispersing the load through mesh collapse, dissipating energy through fiber friction and assisting rebound, and limiting excessive deformation through the wound reinforcement layer. As a result, the long-term stability of the optical cable in complex laying environments is improved. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the hexagonal mesh collapse energy-absorbing ribbon optical cable of the present invention.

[0022] In the diagram, 10: cable core unit, 101: optical fiber, 102: central reinforcement; 20: three-dimensional mesh elastic energy-absorbing layer; 30: circumferential winding reinforcement layer; 40: dry water-blocking layer; 50: outer sheath. Detailed Implementation

[0023] The technical solutions of the present invention will be clearly and completely described below with reference to specific embodiments. 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] The present invention provides a hexagonal mesh collapse energy-absorbing ribbon optical cable, comprising, from the inside out, a core unit 10, a three-dimensional mesh elastic energy-absorbing layer 20, a circumferential winding reinforcement layer 30, a dry water-blocking layer 40 and an outer sheath 50.

[0025] The cable core unit 10 serves as the core for optical signal transmission. Exemplarily, the cable core unit 10 includes multiple optical fibers 101, each fiber 101 comprising a loose tube and a ribbon fiber core located within the loose tube. The ribbon fiber core can, for example, be formed by bonding multiple single optical fibers side-by-side to form a planar integrated structure, with the loose tube providing mechanical protection for the internal ribbon fiber core. Furthermore, a central reinforcing member 102 is provided at the center of the cable core unit 10, with the loose tubes of the multiple optical fibers 101 twisted around this central reinforcing member 102 to form a cable. The central reinforcing member 102 can, for example, be made of materials with a certain tensile strength, such as phosphated steel wire, stainless steel wire, or glass fiber reinforced plastic rod, to withstand tensile loads during optical cable laying and improve the structural integrity and stability of the cable core unit 10.

[0026] The three-dimensional mesh elastic energy-absorbing layer 20 covers the outside of the cable core unit 10 and is a continuously extruded, integrally formed three-dimensional hexagonal mesh elastomer. Preferably, the mesh diameter is 0.15-0.20 mm and the porosity is 42-48%. This range of pore size and porosity is beneficial for achieving relatively uniform and controllable collapse under local point pressure loads. The hexagonal mesh is filled with ultrafine elastic short fibers. The ultrafine elastic short fibers can be selected from one or more of polyester elastic fibers, polyurethane elastic fibers, polyolefin elastic fibers, and polyamide elastic fibers; preferably, polyester elastic fibers or polyurethane elastic fibers. Preferably, the length of the ultrafine elastic short fibers is 0.4-0.7 mm, and the filling volume accounts for 8-12% of the corresponding internal cavity volume of the mesh. This filling ratio ensures that the mesh has sufficient space for collapse deformation while providing necessary elastic support for the mesh wall. More preferably, the ultrafine elastic short fibers are filled into the mesh in a discrete manner, with point contact between fibers and between fibers and the mesh wall, without forming a continuous force transmission medium. When the mesh collapses under load, relative slippage and interfacial friction occur between the fibers and the mesh wall, thereby dissipating some of the impact energy. After the load is removed, the elastic recoil force of the fibers can help the mesh wall return to near its original position, reducing the permanent deformation of the buffer layer. Preferably, the overall thickness of the three-dimensional mesh elastic energy-absorbing layer 20 is 0.30-0.50 mm.

[0027] The circumferentially wound reinforcing layer 30 is disposed on the outside of the three-dimensional mesh elastic energy-absorbing layer 20, and is formed by spirally winding polymer fiber yarn around the circumference of the optical cable. The polymer fiber yarn can be selected from one or more of aramid fiber yarn, ultra-high molecular weight polyethylene fiber yarn, polyester fiber yarn, glass fiber yarn, and PBO fiber yarn; preferably, it is aramid fiber yarn or ultra-high molecular weight polyethylene fiber yarn. This circumferentially wound reinforcing layer 30 covers the outer surface of the three-dimensional mesh elastic energy-absorbing layer 20, and is used to limit excessive radial deformation of the energy-absorbing layer, thereby improving the radial compressive strength and lateral compressive strength of the optical cable.

[0028] The dry water-blocking layer 40 is disposed on the outside of the circumferentially wrapped reinforcing layer 30, and is a dry water-blocking tape wrapping structure. The dry water-blocking tape contains superabsorbent resin particles, which expand upon contact with water, thus providing a water-blocking and sealing effect. This dry water-blocking layer has a dry structure, and the optical cable is not filled with grease.

[0029] The outer sheath 50 is located outside the dry water-blocking layer 40. It is a low-smoke halogen-free polyolefin sheath with weather resistance, flame retardancy, and environmental protection properties, and can be adapted to various laying environments such as pipelines, direct burial, and overhead installations.

[0030] The present invention also provides a method for preparing the above-mentioned hexagonal mesh collapse energy-absorbing ribbon optical cable, comprising the following steps: (1) Preparation of cable core unit 10. For example, multiple single optical fibers are first bonded side by side to form a ribbon fiber core, and the ribbon fiber core is placed in a loose tube to form an optical fiber 101; a central strengthening member 102 is provided, and multiple optical fibers 101 are twisted around the central strengthening member 102 to form a cable, thereby obtaining cable core unit 10.

[0031] (2) A three-dimensional mesh elastic energy-absorbing layer 20 is continuously extruded and integrally formed outside the cable core unit 10. Exemplarily, an extrusion die is used to continuously extrude the elastomer material to form a three-dimensional hexagonal mesh elastomer, with the mesh diameter controlled at 0.15-0.20 mm and the porosity controlled at 42-48%. During or after extrusion, ultrafine elastic short fibers are filled into the hexagonal mesh. Preferably, the length of the ultrafine elastic short fibers is 0.4-0.7 mm, and the filling volume accounts for 8-12% of the internal cavity volume of the mesh. The filling method can be, for example, airflow dispersion or vibration filling, so that the fibers are distributed discretely inside the mesh.

[0032] (3) Polymer fiber yarn is spirally wound around the optical cable around the three-dimensional mesh elastic energy-absorbing layer 20 to form a circumferential winding reinforcement layer 30.

[0033] (4) A dry water-blocking tape is wrapped around the reinforcing layer 30 to form a dry water-blocking layer 40. The dry water-blocking tape contains superabsorbent resin particles.

[0034] (5) Extrude an outer sheath 50 outside the dry water-blocking layer 40.

[0035] By adopting the above technical solutions, the ribbon optical cable can reduce the risk of micro-bending damage to the ribbon fiber core and improve the long-term service stability of the optical cable under conditions such as local point pressure and instantaneous impact. This can be achieved by dispersing the load through the collapse of the hexagonal mesh, by dissipating energy through friction and elastic recovery of the ultra-fine elastic short fibers to assist the energy absorption layer in recovery, and by limiting excessive deformation through the circumferential winding reinforcement layer.

[0036] The present invention will be further described below through specific embodiments.

[0037] Example

[0038] This embodiment provides a hexagonal mesh collapse energy-absorbing ribbon optical cable. The cable core unit 10 is formed by twisting together a central reinforcing member 102 and six optical fibers 101. The central reinforcing member 102 is made of glass fiber reinforced plastic rod with a polyethylene coating on its surface. The six optical fibers 101 are arranged around the central reinforcing member 102, and each optical fiber 101 includes a loose tube and a ribbon fiber core located inside the loose tube.

[0039] A three-dimensional (hexagonal) mesh elastic energy-absorbing layer 20 is continuously extruded and integrally formed outside the cable core unit 10. The material is thermoplastic polyurethane elastomer, the extrusion temperature is 180-200℃, the mesh diameter is 0.18mm, the porosity is 45%, and the energy-absorbing layer thickness is 0.30mm. After extrusion, ultrafine elastic short fibers are filled into the mesh using an airflow dispersion method. The ultrafine elastic short fibers are made of polyester elastic fibers, with a fiber length of 0.5mm. The filling volume accounts for 10% of the mesh cavity volume. The fibers are distributed in a discrete manner, with point contact mainly between fibers and between fibers and the mesh wall.

[0040] A circumferentially wound reinforcing layer 30 is formed by spirally winding polymer fiber yarn around the circumference of the optical cable outside the energy-absorbing layer. The polymer fiber yarn is made of aramid fiber yarn, and the winding pitch and thickness are determined according to the optical cable specifications. A dry-type water-blocking tape is wrapped around the outer edge of the circumferentially wound reinforcing layer 30, and the water-blocking tape adsorbs superabsorbent resin particles. The outermost layer is an extruded outer sheath 50 made of low-smoke halogen-free polyolefin material.

[0041] After being subjected to a 300N local point pressure load test for 1 minute, the additional attenuation of the ribbon fiber was ≤0.05dB; after unloading, the three-dimensional mesh elastic energy-absorbing layer rebounded well and showed no obvious permanent indentation.

[0042] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0043] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A hexagonal mesh collapse energy-absorbing ribbon optical cable, characterized in that, The cable consists of a core unit, a three-dimensional mesh elastic energy-absorbing layer, a circumferentially wound reinforcement layer, a dry water-blocking layer, and an outer sheath arranged from the inside out. The three-dimensional mesh elastic energy-absorbing layer is a three-dimensional hexagonal mesh elastomer formed by continuous extrusion, with a mesh diameter of 0.15-0.20 mm and a porosity of 42-48%. The hexagonal mesh is filled with ultra-fine elastic short fibers. The circumferentially wound reinforcement layer is formed by spirally winding polymer fiber yarn around the circumference of the optical cable.

2. The hexagonal mesh collapse energy-absorbing ribbon optical cable according to claim 1, characterized in that, The cable core unit includes multiple optical fibers, each of which includes a loose tube and a ribbon core located within the loose tube.

3. The hexagonal mesh collapse energy-absorbing ribbon optical cable according to claim 1, characterized in that, The overall thickness of the three-dimensional mesh elastic energy-absorbing layer is 0.30-0.50 mm.

4. The hexagonal mesh collapse energy-absorbing ribbon optical cable according to claim 1, characterized in that, The length of the ultrafine elastic short fiber is 0.4-0.7 mm, and the filling volume accounts for 8-12% of the volume of the corresponding mesh cavity.

5. The hexagonal mesh collapse energy-absorbing ribbon optical cable according to claim 1, characterized in that, The ultrafine elastic short fibers are discretely filled inside the mesh, with point contact between fibers and between fibers and the mesh wall, and no continuous force transmission medium is formed.

6. The hexagonal mesh collapse energy-absorbing ribbon optical cable according to claim 1, characterized in that, The ultrafine elastic short fiber is configured to dissipate impact energy through interfacial friction between the fiber and the mesh wall when the mesh collapses under load; and to assist the mesh wall in returning to its original position through the elastic recoil force of the fiber after the load is removed.

7. The hexagonal mesh collapse energy-absorbing ribbon optical cable according to claim 1, characterized in that, The circumferentially wound reinforcing layer covers the outer surface of the three-dimensional mesh elastic energy-absorbing layer and is used to limit excessive radial deformation of the energy-absorbing layer.

8. The hexagonal mesh collapse energy-absorbing ribbon optical cable according to claim 1, characterized in that, The dry water-blocking layer is a dry water-blocking tape wrapping structure, and the dry water-blocking tape contains superabsorbent resin particles.

9. The hexagonal mesh collapse energy-absorbing ribbon optical cable according to claim 1, characterized in that, The outer sheath is a low-smoke halogen-free polyolefin sheath.

10. A method for preparing a hexagonal mesh collapsible energy-absorbing ribbon optical cable according to any one of claims 1-9, characterized in that, Includes the following steps: (1) Fabrication of cable core units; (2) A three-dimensional mesh elastic energy-absorbing layer is continuously extruded and integrally formed outside the cable core unit. The three-dimensional mesh elastic energy-absorbing layer is a hexagonal mesh elastomer with a mesh diameter of 0.15-0.20 mm and a porosity of 42-48%. The hexagonal mesh is filled with ultra-fine elastic short fibers. (3) A circumferentially wound reinforcement layer is formed by spirally winding polymer fiber yarn around the circumference of the optical cable outside the three-dimensional mesh elastic energy-absorbing layer; (4) Wrap a dry-type water-blocking layer around the reinforcing layer in a circular pattern; (5) Extrude an outer sheath outside the dry water-blocking layer.

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