Halogen-Free Cable Fire Resistance via Glass Fabric Tape
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Solution Overview
Problem
Existing cables lack effective fire resistance and low-temperature resistance, particularly failing to meet standards for flame retardance and flexibility in cold conditions, as demonstrated by the cold impact test according to EN60811-1-4.
Innovation Solution
A single-core cable design featuring a copper conductor surrounded by halogen-free crosslinked polymer layers, metallic shielding, and high-temperature-resistant glass fabric tape, with an outer jacket composed of a halogen-free EVA-based polymer mixture, ensuring rotational symmetry and adherence to stringent fire and temperature resistance standards.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional cable structures are used, then manufacturing simplicity is maintained, but fire resistance and low-temperature flexibility are insufficient
Solution Approach 1:
The cable employs multiple specialized layers including halogen-free crosslinked polymer insulation, glass fabric tape banding, and metallic shielding. Each layer is made from composite materials designed for specific functions: the glass fabric tape provides fire resistance and structural integrity, while the halogen-free polymer layers ensure low smoke emission and chemical resistance. This composite structure resolves the contradiction by achieving superior fire resistance through material composition rather than simple structural complexity.
Solution Approach 2:
The cable is divided into distinct functional segments: conductor, inner conductive layer, insulating layer, second conductive layer, first banding, metallic shielding, second banding, and outer jacket. Each segment is independently optimized for its specific function. The segmentation allows fire resistance to be achieved through specific layers (glass fabric tape, halogen-free polymers) without requiring the entire cable structure to be complex, thus resolving the contradiction between reliability and device complexity.
2Reliability
If conventional polymer insulation is used, then ease of manufacture is maintained, but resistance to low temperatures and flexibility in cold conditions deteriorate
Solution Approach 1:
The insulating layer uses crosslinked halogen-free polymers with specifically adjusted compositional parameters to achieve flexibility at -40°C. The crosslinking degree and polymer composition are optimized to maintain elasticity in cold conditions while resisting fuel and chemicals. This parameter optimization allows the cable to meet low-temperature flexibility requirements without significantly complicating the manufacturing process, as the materials are applied using standard extrusion and banding techniques.
3Object-affected harmful factors
If halogen-free polymers are used throughout, then fire safety is improved, but manufacturing precision requirements increase
Solution Approach 1:
Different layers of the cable have different quality characteristics optimized for their specific functions. The insulating layer uses halogen-free crosslinked polymers for fire safety and chemical resistance, while the outer jacket uses halogen-free EVA-based polymer mixture for flexibility and fire resistance. The glass fabric tape banding provides localized reinforcement for fire resistance and structural stability. This local optimization allows each layer to meet its specific requirements without requiring excessive precision across all layers, as each material is selected for its inherent suitability to its 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 cable achieves superior flame resistance, low flame propagation, and flexibility at -40°C, meeting EN standards for fire safety, fuel resistance, and cold impact tests, making it suitable for high-voltage applications and flexible routing in harsh environments.
Implementation Method 1
an insulating layer made of a crosslinked halogen-free Polymer layer based on EPR
Implementation Method 2
banding made of glass fabric tape, preferably made of halogen-free glass fabric tape made of silica glass with woven edges, heat-resistant up to 1,000 °C
Implementation Method 3
metallic shielding, for example made of a stranded copper wire or copper strands
Implementation Method 4
an outer jacket made of a halogen-free polymer mixture based on EVA
Data Source
Figure 1
AI summary
The line has an electrical conductor (1) with a halogen-free isolating layer (3) that includes a metallic shielding (6) and an outer sheath (9). The metallic shielding is rested on a first electrically conductive band (5) that is made up of fiber, and provided with second electrically conductive band (7) to be made up of fiber. A third electrically conductive band (8) is comprised of glass fiber and surrounded by the second band, where the metallic shielding includes a copper wire. The third electrically conductive band includes a halogen-free glass fiber tape made up of silica glass. The insulating layer and the electrical conductor are separated by an inner conductive layer (2) of a cross-linked halogen-free electrically conductive polymer shielding. An independent claim is also included for a method for manufacturing a cable line.