Bending-resistant optical fiber communication cable and preparation method thereof
By designing multiple micro-tube fiber units surrounding the central reinforcement, a spiral non-metallic support, and an irregularly shaped water-blocking strip in the optical fiber communication cable, combined with a buffer layer and an outer sheath, the problems of signal attenuation and water-blocking performance degradation of optical fiber communication cables under repeated bending are solved, achieving efficient transmission and lightweight design with a small bending radius.
Patent Information
- Application Number
- CN202510908869.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-02
- Publication Date
- 2025-11-04
AI Technical Summary
Existing fiber optic communication cables are prone to cumulative micro-bending loss under repeated bending conditions, resulting in significant signal attenuation. Metal reinforcements cause stress concentration during bending rebound, water-blocking tape loses its sealing performance during bending, multi-layer metal composite structures increase weight and have low production efficiency, and the mismatch between rigidity and flexibility causes fluctuations in transmission performance.
The design employs multiple micro-tube fiber units surrounding the central reinforcement, combined with a spiral non-metallic support and an irregularly shaped water-blocking strip, an external buffer layer and an outer sheath. By offsetting bending stress with reverse torque, a dynamic pressure buffer and triple protection structure is designed, utilizing silicone microspheres and an elastic polymer matrix to form an adaptive deformation mechanism.
It reduces micro-bending loss at small bending radii, improves resistance to repeated bending, disperses mechanical stress, maintains water-blocking performance, reduces cable weight, improves production efficiency, and avoids fluctuations in material properties.
Smart Images
Figure CN120895307A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of optical communication transmission technology, specifically to bend-resistant optical fiber communication cables and their manufacturing methods. Background Technology
[0002] With the development of fiber-to-the-home and high-density data center cabling, communication cables often need to be laid in confined spaces with multiple bends. Although traditional bend-resistant cables use G.657 grade bend-insensitive optical fiber, they still have the following bottleneck problems: Existing structures often rely on increasing the thickness of the sheath or the elasticity of the fiber coating to resist bending stress. Under repeated bending conditions, cumulative micro-bending loss is easily generated. In particular, when the bending radius is small, the signal attenuation is significantly aggravated. Although metal reinforcement can improve stiffness, it leads to the concentration of bending rebound stress and accelerates fiber fatigue. Conventional water-blocking tapes are mostly planar structures, which lose their water-blocking and sealing properties when bent due to the concentration of lateral pressure. At the same time, the difference in modulus between the metal armor layer and the polymer sheath can easily cause interfacial peeling, causing the cable's water-blocking and mechanical protection performance to deteriorate simultaneously in dynamic bending environments. To balance bending resistance and water resistance, cables often adopt a multi-layer metal composite structure, such as corrugated steel pipe and aluminum-plastic tape, which increases the weight of the cable and reduces production efficiency due to the complex process. In addition, the mismatch between the rigid structure and the deformation of the flexible optical fiber can also cause fluctuations in transmission performance. Therefore, it is essential to design and manufacture bending-resistant optical fiber communication cables. Summary of the Invention
[0003] The purpose of this invention is to provide a bend-resistant optical fiber communication cable and its manufacturing method, in order to solve the problems mentioned in the background art. Existing structures mostly rely on increasing the sheath thickness or the elastic resistance of the optical fiber coating to bending stress. Under repeated bending conditions, they are prone to cumulative micro-bending loss, especially when the bending radius is small, the signal attenuation is significantly aggravated. Although metal reinforcement can improve rigidity, it leads to the concentration of bending rebound stress, which accelerates optical fiber fatigue. Conventional water-blocking tapes are mostly planar structures, which lose their water-blocking and sealing properties due to the concentration of lateral pressure when bending. At the same time, the difference in modulus between the metal armor layer and the polymer sheath can easily cause interface peeling, causing the cable's water-blocking and mechanical protection performance to deteriorate simultaneously in dynamic bending environments. In addition, in order to balance bending resistance and water-blocking performance, cables often adopt multi-layer metal composite structures, such as corrugated steel pipes and aluminum-plastic tapes, which increases the weight of the cable and reduces production efficiency due to complex processes. Furthermore, the mismatch between the rigid structure and the deformation of the flexible optical fiber can also cause transmission performance fluctuations.
[0004] To achieve the above objectives, the present invention provides the following technical solution: In the first aspect, a bend-resistant optical fiber communication cable is provided, comprising a central reinforcing member, an optical signal transmission unit, a support member, a water-blocking strip, a buffer layer, and an outer sheath arranged sequentially from the inside to the outside. The optical signal transmission unit is a multi-micro-tube optical fiber unit spirally twisted around the central reinforcing member, and each micro-tube contains 2-12 bend-insensitive optical fibers. The support is a helical non-metallic component, which is embedded in the gap between adjacent microtube units at a helical angle opposite to the twisting direction of the microtube bundle, and offsets the bending stress by reverse torque. The water-blocking strip covers the outside of the optical signal transmission unit, and its cross-section has a periodic wave-like convex structure, forming a dynamic pressure buffer cavity between the convexities. The buffer layer is composed of alternating layers of silicone microspheres and an elastic polymer matrix, which covers the outside of the water-blocking strip and absorbs local deformation by the rolling displacement of the microspheres. The outer sheath covers the buffer layer, forming a mechanical protective barrier.
[0005] As a further technical solution of the present invention, the spiral non-metallic support is made of glass fiber reinforced polypropylene material, and its spiral pitch is 1.2-1.8 times that of the micro-tube stranding pitch, to ensure dynamic matching between the radial elastic support and the stranding structure.
[0006] As a further technical solution of the present invention, the wave protrusion height of the water-blocking strip is 0.3-0.8mm, the spacing between adjacent protrusions is 2-5mm, and a longitudinal guide groove is provided on the top of the protrusion to achieve stress dispersion and water blocking performance synergistic improvement.
[0007] As a further technical solution of the present invention, the diameter of the silicone microspheres in the buffer layer is 50-200μm, the volume ratio is 15%-35%, and the elastic polymer matrix is thermoplastic polyurethane, forming a gradient deformation response mechanism.
[0008] As a further technical solution of the present invention, the inner wall of the outer sheath is provided with annular limiting ribs at intervals, and the spacing of the ribs matches the helical pitch of the support member to prevent the support member from moving axially.
[0009] As a further technical solution of the present invention, the ratio of the stranding pitch of the micro-bundle fiber unit to the cable diameter in the optical signal transmission unit is 8:1-12:1, which optimizes the free expansion and contraction space of the optical fiber.
[0010] As a further technical solution of the present invention, the central reinforcing member is a glass fiber reinforced plastic rod with a diameter accounting for 8%-15% of the total diameter of the cable, balancing tensile strength and flexibility.
[0011] Secondly, a method for preparing a bend-resistant optical fiber communication cable is provided, comprising the following steps: S1. Stranding process: Multiple micro-bundle fiber units are stranded in reverse around the central reinforcement at a pitch of 8:1-12:1 to the cable diameter to form an optical signal transmission unit, and the fiber strain rate is controlled to be ≤0.15%. S2, Support Embedding: Supports are embedded synchronously in the stranding gap of the microtube units to achieve a stress self-balancing structure; S3. Water-blocking tape shaping: The water-blocking tape is wrapped and the corrugated convex structure is shaped by hot pressing process. The hot pressing temperature is 110-130℃ and the pressure is 0.5-1.2MPa. S4, Buffer Layer Composite: A buffer layer is formed by extrusion, and silica microspheres are uniformly dispersed in the matrix; S5. Outer sheath molding: The outer sheath material is molded and an annular limiting rib is simultaneously formed on the inner wall. The height of the annular limiting rib is 0.2-0.5mm.
[0012] As a further technical solution of the present invention, in step S4, a twin-screw co-extrusion process is used to extrude silicone microspheres and molten polyurethane matrix to form a buffer layer, with a screw speed of 80-120 rpm and a temperature control of 170-190℃.
[0013] As a further technical solution of the present invention, in step S5, the spacing between the annular limiting ribs matches the pitch of the spiral support, with a tolerance control of ±5%.
[0014] Compared with existing technologies, the beneficial effects of this bend-resistant optical fiber communication cable and its manufacturing method are: Through the synergistic effect of the reverse spiral layout of the support components and the microsphere dynamic response mechanism of the buffer layer, the micro-bending loss of the cable is reduced at a smaller diameter bending radius, and the resistance to repeated bending is improved compared with the traditional structure. The wave-shaped convex design of the irregular water-blocking strip simultaneously disperses mechanical stress, reduces local pressure, and blocks water longitudinally. Combined with the annular limiting ribs of the outer sheath, it forms a triple protection system, which greatly improves the adaptability to complex environments. The lightweight design of the non-metallic support and adaptive buffer layer reduces the weight of the cable, while the twin-screw co-extrusion process ensures uniform distribution of silicone microspheres, improving production efficiency while avoiding fluctuations in material properties. Attached Figure Description
[0015] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 for Figure 1 Enlarged view of the local structure of region A in the middle; Figure 3 This is a schematic diagram showing the position of the annular limiting rib in this invention; Figure 4 This is a schematic diagram of the method flow of the present invention; In the figure: 1. Central reinforcement; 2. Optical signal transmission unit; 3. Support; 4. Water barrier; 41. Longitudinal guide channel; 5. Buffer layer; 6. Outer sheath; 61. Annular limiting rib. Detailed Implementation
[0016] 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.
[0017] Please see the appendix Figure 1 -Appendix Figure 3 The present invention provides an embodiment of a bend-resistant optical fiber communication cable, comprising, from the inside out, a central reinforcing member 1, an optical signal transmission unit 2, a support member 3, a water-blocking strip 4, a buffer layer 5, and an outer sheath 6. The central reinforcing member 1 is a glass fiber reinforced plastic rod with a diameter accounting for 8%-15% of the total cable diameter, balancing tensile strength and flexibility. The optical signal transmission unit 2 consists of multiple micro-tube optical fiber units spirally twisted around the central reinforcing member 1. Each micro-tube contains 2-12 bend-insensitive optical fibers. The twist pitch of the micro-tube optical fiber units in the optical signal transmission unit 2 is 8:1-12:1 to optimize the free expansion and contraction space of the optical fibers. The support 3 is a helical non-metallic component, which is embedded in the gap between adjacent microtube units at a helical angle opposite to the twisting direction of the microtube bundle. The bending stress is offset by the reverse torque. The helical non-metallic support 3 is made of glass fiber reinforced polypropylene material, and its helical pitch is 1.2-1.8 times the twisting pitch of the microtube bundle, ensuring that the radial elastic support and the twisting structure are dynamically matched. The water-blocking strip 4 covers the optical signal transmission unit 2. Its cross-section has a periodic wave-shaped convex structure. A dynamic pressure buffer cavity is formed between the convex structures. The height of the wave-shaped convex structure of the water-blocking strip 4 is 0.3-0.8mm, the spacing between adjacent convex structures is 2-5mm, and a longitudinal guide groove 41 is provided on the top of the convex structure to achieve a synergistic improvement in stress dispersion and water-blocking performance. The buffer layer 5 is composed of alternating layers of silicone microspheres and an elastic polymer matrix, which are wrapped around the water-blocking band 4. The microspheres absorb local deformation by rolling displacement. The silicone microspheres in the buffer layer 5 have a diameter of 50-200μm and a volume ratio of 15%-35%. The elastic polymer matrix is thermoplastic polyurethane, forming a gradient deformation response mechanism. The outer sheath 6 covers the buffer layer 5, forming a mechanical protective barrier. The inner wall of the outer sheath 6 is provided with annular limiting ribs 61 at intervals. The spacing of the ribs matches the helical pitch of the support 3 to prevent the support 3 from moving axially.
[0018] Please see the appendix Figure 4 The present invention provides an embodiment of a method for preparing a bend-resistant optical fiber communication cable, comprising the following steps: S1. Stranding process: Multiple micro-bundle fiber units are stranded in reverse around the central reinforcing member 1 with a pitch ratio of 8:1 to 12:1 to the cable diameter to form optical signal transmission unit 2, and the fiber strain rate is controlled to be ≤0.15%. S2, Support 3 Embedded: Support 3 is embedded synchronously in the twisting gap of the microtube unit to achieve a stress self-balancing structure; S3, Water-blocking strip 4 shaping: The water-blocking strip 4 is wrapped and the corrugated convex structure is shaped by hot pressing process. The hot pressing temperature is 110-130℃ and the pressure is 0.5-1.2MPa. S4, Buffer Layer 5 Composite: Using a twin-screw co-extrusion process, silicone microspheres are compositely extruded with molten polyurethane matrix to form buffer layer 5. The screw speed is 80-120 rpm, the temperature is controlled at 170-190℃, and the silicone microspheres are uniformly dispersed in the matrix. S5, Outer Sheath 6 Forming: Molding the outer sheath 6 material and simultaneously forming annular limiting ribs 61 on the inner wall. The height of the annular limiting ribs 61 is 0.2-0.5mm. The spacing of the annular limiting ribs 61 matches the pitch of the spiral support 3, with a tolerance control of ±5%.
[0019] In summary, through the synergistic effect of the reverse spiral layout of the support component 3 and the microsphere dynamic response mechanism of the buffer layer 5, the micro-bending loss of the cable is reduced under a smaller diameter bending radius, and the resistance to repeated bending is improved compared with the traditional structure. The wavy protrusion design of the irregular water-blocking strip 4 simultaneously disperses mechanical stress, reduces local pressure, and blocks water longitudinally. Combined with the annular limiting rib 61 of the outer sheath 6, it forms a triple protection system, which greatly improves the adaptability to complex environments. The lightweight design of the non-metallic support 3 and the adaptive buffer layer 5 reduces the weight of the cable, and the twin-screw co-extrusion process ensures uniform distribution of silicone microspheres, improving production efficiency while avoiding fluctuations in material properties.
[0020] 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 its spirit or essential characteristics. 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, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.
Claims
1. A bend-resistant optical fiber communication cable, comprising, from the inside out, a central reinforcing member (1), an optical signal transmission unit (2), a support member (3), a water-blocking strip (4), a buffer layer (5), and an outer sheath (6), characterized in that: The optical signal transmission unit (2) is a multi-micro-tube optical fiber unit spirally twisted around the central reinforcing member (1), and each micro-tube contains 2-12 bend-insensitive optical fibers. The support member (3) is a spiral non-metallic material, which is embedded in the gap between adjacent microtube units at a spiral angle opposite to the twisting direction of the microtube bundle; The water-blocking strip (4) covers the outside of the optical signal transmission unit (2), and its cross-section has a periodic wave-shaped convex structure; The buffer layer (5) is composed of alternating layers of silicone microspheres and elastic polymer matrix, and is wrapped around the water-blocking strip (4); The outer sheath (6) covers the buffer layer (5).
2. The bend-resistant optical fiber communication cable according to claim 1, characterized in that: The spiral non-metallic support (3) is made of glass fiber reinforced polypropylene material, and its spiral pitch is 1.2-1.8 times that of the micro-tube stranding pitch.
3. The bend-resistant optical fiber communication cable according to claim 1, characterized in that: The wave protrusion height of the water-blocking strip (4) is 0.3-0.8mm, the spacing between adjacent protrusions is 2-5mm, and the top of the protrusion is provided with a longitudinal guide groove (41).
4. The bend-resistant optical fiber communication cable according to claim 1, characterized in that: The buffer layer (5) contains silica microspheres with a diameter of 50-200 μm and a volume percentage of 15%-35%, and the elastic polymer matrix is thermoplastic polyurethane.
5. The bend-resistant optical fiber communication cable according to claim 1, characterized in that: The inner wall of the outer sheath (6) is provided with annular limiting ribs (61) at intervals, and the spacing of the ribs matches the helical pitch of the support (3).
6. The bend-resistant optical fiber communication cable according to claim 1, characterized in that: The ratio of the twist pitch of the micro-tube optical fiber unit to the cable diameter in the optical signal transmission unit (2) is 8:1-12:
1.
7. The bend-resistant optical fiber communication cable according to claim 1, characterized in that: The central reinforcing member (1) is a glass fiber reinforced plastic rod with a diameter accounting for 8%-15% of the total diameter of the cable.
8. A method for preparing a bend-resistant optical fiber communication cable, characterized in that: Includes the following steps: S1. Stranding process: Multiple micro-tube optical fiber units are stranded in reverse around the central reinforcing member (1) with a pitch of 8:1-12:1 to the cable diameter to form an optical signal transmission unit (2). S2, support member (3) embedding: support member (3) is embedded synchronously in the twisting gap of microtube unit; S3, Water-blocking strip (4) shaping: Cover the water-blocking strip (4) and shape the wave-shaped convex structure through hot pressing process; S4, Buffer layer (5) composite: extrusion to form buffer layer (5); S5, Outer sheath (6) molding: Molding the outer sheath (6) material and simultaneously forming annular limiting ribs (61) on the inner wall.
9. The method for preparing the bend-resistant optical fiber communication cable according to claim 8, characterized in that: In step S4, a twin-screw co-extrusion process is used to extrude silicone microspheres and molten polyurethane matrix to form a buffer layer (5).
10. The method for preparing the bend-resistant optical fiber communication cable according to claim 8, characterized in that: In step S5, the spacing of the annular limiting rib (61) matches the pitch of the spiral support (3).