Cable Bedding Composition Flame Retardancy
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Solution Overview
Problem
Cables with insulated conductors lack effective flame retardant properties due to the combustible nature of polymeric materials used in their construction, particularly in the bedding composition, which affects their safety and mechanical integrity.
Innovation Solution
A cable design featuring insulated conductors embedded in a bedding composition comprising a polymer resin with a weight average molecular weight of 10,000 g/mol or more and a molecular weight distribution of 5 or lower, combined with an inorganic filler, such as aluminium trihydroxide, to reduce combustible volatile species and enhance flame retardancy, while maintaining low production costs and good processability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If polymeric materials are used in cable construction, then mechanical properties and processability are improved, but flame retardant properties deteriorate due to combustible nature of the polymers
Solution Approach 1:
The patent applies composite materials by combining polymeric materials with inorganic flame retardant additives (such as aluminium trihydroxide, magnesium hydroxide, or boron compounds) to create a bedding composition that maintains mechanical properties while achieving flame retardancy. The composite formulation allows the cable bedding to resist combustion while preserving flexibility and structural integrity.
Solution Approach 2:
The patent modifies the chemical composition parameters of the bedding material by controlling the molecular weight distribution (MWD ≤ 5) and incorporating specific inorganic fillers. These parameter changes transform the bedding from a purely combustible polymer into a flame-retardant composite that meets safety standards (heat release rate ≤ 80 kW) while maintaining processability.
2Object-affected harmful factors
If inorganic filler is added to improve flame retardancy, then flame retardant properties are improved, but production cost increases
Solution Approach 1:
The patent applies local quality by selectively concentrating flame retardant inorganic fillers (such as aluminium trihydroxide or magnesium hydroxide) in the bedding layer where they are most needed for fire safety, rather than uniformly distributing them throughout the entire cable structure. This targeted approach optimizes flame retardancy while minimizing material costs.
Solution Approach 2:
The patent employs cost-effective inorganic flame retardant additives that can be readily incorporated into the bedding composition during manufacturing. These inexpensive inorganic fillers (such as metal hydroxides or boron compounds) provide effective flame retardancy without significantly increasing production costs, making the solution economically viable.
3Object-affected harmful factors
If molecular weight distribution is reduced to improve flame retardancy, then flame retardant properties are improved, but processability deteriorates
Solution Approach 1:
The patent optimizes the molecular weight distribution parameter of the polymer resin to MWD ≤ 5, which is a specific parameter range that balances flame retardancy and processability. This controlled MWD ensures uniform distribution of inorganic fillers and consistent melting behavior during extrusion, maintaining good processability while achieving the desired flame retardant performance.
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 proposed solution significantly improves the flame retardant properties of the cable by limiting the heat release rate to 80 kW or less within 200 seconds, as measured by cone calorimetry, thereby enhancing safety and mechanical performance without increasing production costs.
Implementation Method 1
an inorganic filler with improved flame retardant properties
Data Source
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AI summary
The present invention relates to a cable comprising one or more insulated conductors which are embedded in a bedding composition, which comprises a) a polymer resin (A) and b) an inorganic filler (B), wherein the polymer resin (A) comprises an olefin homo- and/or copolymer (A.1) which has a weight average molecular weight Mw of 10,000 g/mol or more and a molecular weight distribution MWD of 4.5 or lower and, in a second aspect, to a cable comprising one or more insulated conductors which are embedded in a bedding composition, which comprises a) a polymer resin (A) and b) an inorganic filler (B), wherein the heat release rate HRR of the composition at any time within the period from 0 s to 200 s after ignition does not exceed a maximum of 80 kW measured with cone calorimetry according to ISO 5660-1.