Ceramifiable Cable Insulation for Fire Resistance

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Solution Overview

Problem

Current halogen-free fire retardant cables face challenges with inferior mechanical properties and inability to pass non-fire propagation tests due to unstable carbon layers formed by traditional flame-retardant systems, and existing methods like mica tape application or silicone rubber extrusion are costly and inefficient.

Innovation Solution

Incorporating hierarchically arranged inorganic phosphates on phyllosilicates, such as sepiolite and attapulgite, into organic polymer matrices to form a ceramic barrier that enhances flame resistance and mechanical properties, while using secondary inorganic fillers to optimize the extruded composition.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional flame-retardant systems with inorganic fillers are used, then flame retardant capacity is improved, but mechanical properties deteriorate and carbon layer stability is insufficient

Engineering Contradiction:
Improveflame retardant capacityVSAvoidmechanical properties
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent employs composite materials by combining organic polymers with hierarchically arranged inorganic phosphates on phyllosilicates. This composite structure creates a synergistic effect where the inorganic phosphate-phyllosilicate combination forms a stable ceramic barrier that maintains both flame retardancy and mechanical integrity, resolving the contradiction between flame protection and structural strength

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent changes the chemical composition parameters by replacing traditional inorganic fillers with specifically arranged inorganic phosphates on phyllosilicate surfaces. This parameter change transforms the protective layer from unstable carbon to a stable ceramic structure that maintains mechanical properties while providing flame retardancy

Inventive Principle:
Principle #35Parameter changes

2Reliability

If mica tape is applied directly to the conductor, then fire resistance is improved, but manufacturing complexity and cost increase

Engineering Contradiction:
Improvefire resistanceVSAvoidmanufacturing process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the fire resistance function directly into the extrudable coating material itself, eliminating the need for separate mica tape application steps. The inorganic phosphate-phyllosilicate composite is integrated into the polymer matrix, allowing fire protection to be applied in a single extrusion process rather than through multiple complex manufacturing steps

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent extracts the fire resistance property from the complex mica tape application process and embeds it directly into the extrudable coating composition. This extraction simplifies the manufacturing process by incorporating the protective function into the base material rather than requiring separate application steps

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If silicone rubber is used for insulation, then fire resistance is improved, but extrusion difficulty and cost increase

Engineering Contradiction:
Improvefire resistanceVSAvoidextrusion ease
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent changes the material parameters by developing a thermoplastic or elastomeric polymer composition that inherently provides fire resistance through its inorganic phosphate-phyllosilicate structure. This allows the material to be extruded under normal conditions without requiring the complex processing needed for silicone rubber, while maintaining superior fire resistance

Inventive Principle:
Principle #35Parameter changes

4Object-generated harmful factors

If halogen-free compounds are used, then environmental safety is improved, but flame propagation resistance deteriorates

Engineering Contradiction:
Improvetoxic smoke emissionVSAvoidflame propagation resistance
Core Design Contradiction:
Object-generated harmful factorsVSReliability

Solution Approach 1:

The patent uses composite materials combining halogen-free organic polymers with hierarchically arranged inorganic phosphates on phyllosilicates. This composite structure creates a protective barrier that effectively suppresses flame propagation while maintaining the environmental safety benefits of halogen-free composition, resolving the contradiction between toxicity reduction and flame resistance

Inventive Principle:
Principle #40Composite materials

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 effectively forms a protective ceramic layer with excellent mechanical and dielectric properties, allowing the cable to maintain functionality and pass fire tests by limiting heat transfer and oxygen diffusion, thus ensuring safer and more reliable performance in extreme conditions.

Implementation Method 1

at least one extruded composition comprising: a) an organic polymer; and b) inorganic phosphate arranged hierarchically on phyllosilicates

Methodology Applied
Scientific EffectCeramifiable composition: Vitrification

Implementation Method 2

forms a protective ceramic layer with excellent mechanical and dielectric properties, allowing the cable to maintain functionality and pass fire tests by limiting heat transfer and oxygen diffusion

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Data Source

PatentEP2797084B1Power and/or telecommunications cables comprising a ceramifiable composition
Publication Date: 2020.04.29 GRUPO GENERAL CABLE SISTEMAS

AI summary

Power cables intended for working under extreme conditions of heat and temperature are prone to deterioration and/or destruction of their protective layers, and it is therefore extremely important, for safety reasons, that said cables be made of fire-resistant materials, which are flame-retardant in the event of a fire. The present invention proposes obtaining a power and/or telecommunications cable which includes at least: an electric and/or optical conductor element, covered with at least one electrically insulating layer, also optionally including a protective layer surrounding one or more insulated conductor elements, having the special feature that the cover and/or insulation of the cable includes: a) an extrusible organic polymer or a mixture of several extrusible organic polymers; b) an inorganic phosphate arranged hierarchically on phyllosilicates; and c) other secondary inorganic fillers.