Self-reinforcing Optical Cable Element with Low-Expansion Sheath
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing fiber optic cable structures face issues with increased attenuation due to mechanical stress, difficulty in accessing optical fibers, and high production costs, primarily due to the need for multiple layers with varying mechanical properties.
Innovation Solution
A self-reinforced optical cable with a sheath made of a thermoplastic material having a modulus of elasticity greater than 3 GPa and a low thermal expansion coefficient, allowing easy separation from optical fibers and improved rigidity, manufactured through compression extrusion of an LCP-polyester alloy, which reduces stress and simplifies the manufacturing process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If an inner sheath with high modulus of elasticity is used to increase resistance to buckling, then the mechanical strength is improved, but the attenuation of optical fibers increases due to stress generated by locking the fibers
Solution Approach 1:
The cable structure is divided into multiple functional layers: a first sheath providing mechanical strength, a second sheath providing low-friction surface, and an optional third sheath for additional protection. This segmentation allows each layer to optimize for its specific function without compromising others.
Solution Approach 2:
The invention uses composite material structures with different sheaths having distinct mechanical properties. The first sheath uses high-modulus material for strength, while the second sheath uses low-friction material for easy installation, creating a composite cable structure that balances multiple requirements.
2Stability of the object's composition
If an inner sheath with high modulus of elasticity is used to increase rigidity, then the structural stability is improved, but the ease of accessing optical fibers deteriorates due to difficult removal
Solution Approach 1:
The sheath is divided into multiple separable layers with different removal characteristics. The second sheath is designed to be easily removable to expose the first sheath and optical fibers, while the first sheath remains for structural support during operation.
Solution Approach 2:
The second sheath is designed as a sacrificial layer that can be easily removed (discarded) to access the optical fibers, while the first sheath remains as a permanent structural element. This allows easy fiber access without compromising long-term structural stability.
3Reliability
If multiple layers with different mechanical properties are used to meet performance requirements, then the functional performance is improved, but the production cost increases
Solution Approach 1:
The invention combines multiple functional requirements into a streamlined multi-layer structure where each layer serves specific purposes. The first and second sheaths are extruded in sequence in a single manufacturing operation, integrating protection and low-friction properties without requiring complex assembly of separate components.
Solution Approach 2:
The first sheath serves multiple functions: providing mechanical strength, protecting optical fibers, and maintaining structural integrity. The second sheath provides both protection and a low-friction surface for installation. This multi-functionality reduces the need for additional specialized components.
4Ease of operation
If a low-friction outer layer is used to facilitate blowing installation, then the ease of installation is improved, but the rigidity and crush resistance of the cable deteriorates
Solution Approach 1:
The cable is segmented into a first sheath providing rigidity and crush resistance, and a second sheath providing low-friction surface. This segmentation allows the low-friction property to be achieved without sacrificing mechanical strength, as each layer fulfills its specific function.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution significantly reduces optical fiber attenuation, facilitates easy access to the fibers, and lowers production costs by eliminating the need for multiple layers, while providing sufficient rigidity and crush resistance.
Implementation Method 1
The expression 'compression extrusion' refers to a manufacturing process in which a material is subjected to both compression and extrusion simultaneously
Implementation Method 2
whose coefficient of thermal expansion is less than 10 -5
Data Source
Figure 1~2
AI summary
The invention concerns a self-reinforcing optical cable comprising a jacket (3) surrounding at least one optical fiber (2, 20, 21), wherein said jacket is made of a thermoplastic material the elastic modulus of which is more than 3 PGa and the thermal expansion coefficient of which is less than 10-5/°C, wherein said jacket does not adhere to said at least one optical fiber of which it can easily be separated longitudinally in order to allow for easy access to said at least one fiber.