Layered Flame Retardant Optical Fiber Cable Design

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Solution Overview

Problem

Current fire-resistant optical fiber cables are bulkier and fail to maintain circuit integrity under extreme temperature conditions, particularly during fires, and do not meet stringent safety standards.

Innovation Solution

A flame retardant optical fiber cable design featuring multiple layers, including a loose steel tube, fire-resistant mica tape, water-blocking elements, glass roving yarns, and low smoke zero halogen jackets, which provide enhanced mechanical strength, fire resistance, and protection against heat, water, and crush, allowing the cable to withstand temperatures up to 930°C.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional fire-resistant cable structures are used, then fire resistance is provided, but the cable becomes bulkier in size

Engineering Contradiction:
Improvefire resistanceVSAvoidcable size
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The cable is divided into distinct functional layers: optical fiber core, aramid yarn reinforcement, PVC jacket, and fire-resistant coating. Each layer performs a specific function, allowing fire resistance to be achieved through targeted material selection in the coating layer rather than increasing the size of all cable components.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses composite material structures combining aramid yarn (for tensile strength), PVC (for flexibility and basic protection), and fire-resistant coating materials (for thermal protection). This composite approach achieves fire resistance without requiring uniform thickening of the entire cable structure.

Inventive Principle:
Principle #40Composite materials

2Reliability

If traditional fire-resistant cable structures are used, then fire resistance is provided, but circuit integrity cannot be maintained under fire conditions

Engineering Contradiction:
Improvefire resistanceVSAvoidcircuit integrity
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The cable incorporates fire-resistant coating and aramid yarn reinforcement in advance, creating a protective barrier that cushions the optical fibers against thermal stress and mechanical deformation during fire conditions. This pre-positioned protection ensures circuit integrity is maintained when exposed to extreme temperatures.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The combination of aramid yarn (high-temperature strength), PVC (thermal insulation), and fire-resistant coating creates a composite structure that simultaneously provides fire resistance and maintains the structural stability needed for circuit integrity under fire conditions.

Inventive Principle:
Principle #40Composite materials

3Reliability

If multiple protective layers are added to improve fire resistance, then fire performance improves, but the cable structure becomes more complex

Engineering Contradiction:
Improvefire performanceVSAvoidcable structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines multiple protective functions into an integrated fire-resistant coating layer that provides both thermal insulation and structural reinforcement. The aramid yarn is embedded within the PVC jacket and fire-resistant coating, merging reinforcement and fire protection functions into a unified structure rather than separate additive layers.

Inventive Principle:
Principle #5Merging (Combining)

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 cable maintains circuit integrity and safety standards, offering improved mechanical properties and fire resistance, ensuring secure data transmission over long distances while being compliant with various fire and safety regulations.

Implementation Method 1

fire-resistant mica tape

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 2

water-blocking elements

Methodology Applied
Scientific EffectWater blocking:

Data Source

PatentEP3413109B1Flame retardant optical fiber cable
Publication Date: 2023.09.20 STERLITE TECHNOLOGIES LTD
  • EP3413109B1 patent drawingFigure 1

AI summary

The present disclosure provides a flame retardant optical fiber cable (100). The flame retardant optical fiber cable (100) includes a plurality of bundle binders (112). In addition, the flame retardant optical fiber cable (100) includes a first layer (116), a second layer (118), a third layer (120), a fourth layer (122), a fifth layer (124), a sixth layer (126), a seventh layer (128) and an eighth layer (130). The first layer (116) surrounds a plurality of bundle binders (112). The second layer (118) surrounds the first layer (116). The third layer (120) surrounds the second layer (118). The fourth layer (122) surrounds the third layer (120). The fifth layer (124) surrounds the fourth layer (122). The sixth layer (126) surrounds the fifth layer (124). The seventh layer (128) surrounds the sixth layer (126). The eighth layer (130) surrounds the seventh layer (128).