Air-Blown Micro-Cable Structure for Higher Fiber Density
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Solution Overview
Problem
Traditional air-blowing micro-cables face challenges in maximizing pipeline utilization due to their large outer diameter and low optical fiber density, which limits their competitiveness in urban environments with scarce pipeline resources.
Innovation Solution
The manufacturing process involves multi-layer twisting of optical fibers with a central reinforcing piece made of high modulus FRP, using thin-walled tubes and sheaths, semi-dry filling with factice, and incorporating water-blocking yarns to reduce cable diameter and increase fiber density, resulting in a semi-dry design with improved environmental protection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If traditional layer-twisting air-blowing micro-cable structure is used, then the cable structure is simple and easy to manufacture, but the outer diameter is large and optical fiber density is low
Solution Approach 1:
The patent implements multi-layer nested twisting structure where multiple layers of optical fiber bundles are twisted around a central strength member in concentric arrangements. Each layer is nested within the structure of previous layers, maximizing space utilization and minimizing outer diameter while maintaining structural integrity and manufacturability
Solution Approach 2:
The patent transitions from traditional single-layer or two-layer twisting to multi-layer concentric twisting structure, adding dimensional complexity in the radial direction. This multi-layer arrangement optimizes the packing density of optical fibers and reduces the overall cable outer diameter while preserving manufacturing feasibility
2Ease of manufacture
If traditional layer-twisting air-blowing micro-cable structure is used, then the manufacturing process is straightforward, but the optical fiber density per unit area is low
Solution Approach 1:
The patent employs nested multi-layer twisting where optical fiber bundles are arranged in concentric layers around a central strength member. This nesting approach maximizes the number of optical fibers that can be packed into the cable cross-section, achieving high optical fiber density (up to 89% in 1728-core cables) while maintaining a systematic manufacturing process
Solution Approach 2:
The patent utilizes multi-layer concentric arrangement that extends the packing in the radial dimension, allowing multiple layers of optical fiber bundles to be stacked efficiently. This dimensional approach significantly increases optical fiber density per unit area compared to traditional single-layer configurations
3Productivity
If high optical fiber density is achieved through multi-layer twisting, then pipeline utilization improves, but cable structure complexity increases
Solution Approach 1:
The patent divides the cable structure into standardized modular components including central strength member, multiple layers of optical fiber bundles with buffer tubes, and outer sheath. Each layer follows a consistent twisting pattern and structural configuration, making the complex multi-layer structure manageable through modular design and standardized manufacturing procedures
Solution Approach 2:
The patent employs a universal multi-layer twisting structure that can accommodate different numbers of optical fibers (e.g., 144-core, 864-core, 1728-core cables) by adjusting the number of layers and bundles while maintaining the same basic structural paradigm. This universal design achieves high pipeline utilization without proportionally increasing structural complexity
4Quantity of substance
If thin-walled tube and sheath structure is adopted, then optical fiber density increases and cable weight reduces, but mechanical strength may be compromised
Solution Approach 1:
The patent incorporates a central strength member as the core structural element around which all optical fiber bundles are twisted. This preliminary placement of the strength member provides foundational mechanical support before the multi-layer twisting process, ensuring that thin-walled tubes and sheaths can achieve high optical fiber density without compromising overall cable strength
Solution Approach 2:
The patent employs composite material construction combining central strength member (typically steel or FRP), thin-walled buffer tubes, and outer sheath materials with complementary mechanical properties. This composite structure distributes mechanical loads effectively, allowing thin-walled components to achieve high optical fiber density while maintaining adequate mechanical strength through the synergistic combination of materials
Data Source
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AI summary
The invention provides an ultrahigh-density large-core-number air-blowing micro-cable. The ultrahigh-density large-core-number air-blowing micro-cable comprises loose tubes formed by at most 48 pieces of 200-μm small-size optical fibers, each loose tube is used as a subunit to prepare the ultrahigh-density large-core-number air-blowing micro-cable which is advantageous in terms of low weight, small cable diameter and high optical fiber density. The ultrahigh-density large-core-number air-blowing micro-cable includes a central reinforcing piece, at least one optical unit twisting layer annularly distributed on a periphery of the central reinforcing piece and a relatively outer optical unit twisting layer twisted at a periphery formed by a relatively inner optical unit twisting layer. Each optical unit twisting layer includes a plurality of identical subunits, the subunits in different optical unit twisting layers are the same and a number of the subunits of the relatively outer optical unit twisting layer is larger than that of the subunits of the relatively inner optical unit twisting layer. Each loose tube is filled with factice, and a periphery of an outermost optical unit twisting layer is coated with an outer PE sheath.