With the widespread application of fire-resistant cables in construction engineering, power systems, and rail transit, the wire and cable industry continues to place higher demands on fire resistance performance and material stability. In practical applications, differences in mica tape selection and process control among manufacturers are a major reason for inconsistent fire-resistant cable quality.
During fire-resistant cable development, the industry commonly follows a “sample trial – fire resistance testing – mass production” process. However, practice shows that relying solely on a single fire resistance test is not sufficient to eliminate potential risks. Product consistency must be systematically improved from three key aspects: mica tape materials, conductor structure, and wrapping process.
1. Mica Tape Materials: The Most Critical Cable Materials for Fire-Resistant Cables
Among the fire-resistant cable materials used in fire-resistant cable structures, mica tape is the core material that ensures circuit integrity under flame exposure. Common mica tape types used in fire-resistant cables include: Synthetic mica tape, Phlogopite mica tape, Muscovite mica tape
Based on comprehensive evaluation of high-temperature resistance, mechanical strength, and long-term stability, synthetic mica tape offers the best overall performance in fire-resistant cables, with temperature resistance up to 1100°C. Phlogopite mica tape ranks second, while muscovite mica tape shows relatively weaker long-term fire resistance stability.
Therefore, for small-size fire-resistant cables and fire-resistant power cables and control cables with higher fire resistance requirements, synthetic mica tape is generally preferred as the primary fire-resistant insulation material.
Key Points for Mica Tape Selection and Management
Layered mica tape structures are not recommended, as delamination may occur during wrapping and extrusion
Both synthetic mica tape and phlogopite mica tape are hygroscopic; moisture absorption will negatively affect fire resistance performance
Mica tape should be stored at 20–25°C with relative humidity below 50%
2. Mica Tape Wrapping Process: The Key to Material Performance Realization
In fire-resistant cable manufacturing, the mica tape wrapping process directly determines whether synthetic mica tape and phlogopite mica tape can form a continuous and stable fire-resistant layer.
Key process control points include:
Use wrapping equipment with high tension control accuracy and stable operation
Control wrapping angle within 30°–40° to ensure uniform overlap
All guide rollers and components in contact with mica tape must have smooth, burr-free surfaces
Wrapping tension must be stable to avoid micro-cracks or loose wrapping of synthetic mica tape
Take-up reels must ensure uniform stress distribution on the mica tape layer
3. Conductor Structure: Fire-Resistant Cable Design Matched with Mica Tape
① Round Compacted Conductor
In fire-resistant cable structures, round compacted conductors provide the best compatibility with mica tape—especially synthetic mica tape and phlogopite mica tape. The uniform stress distribution after wrapping makes this structure the recommended conductor design for fire-resistant cables.
② Risks of Bunched Flexible Conductors
Bunched flexible conductors have uneven surfaces, which can easily damage mica tape during wrapping. They are also prone to deformation during extrusion and operation, compromising mica tape integrity. Therefore, bunched flexible conductors are not suitable for fire-resistant cables.
③ Material Consumption Issues with Sector-Shaped Conductors
For the same cross-sectional area, sector-shaped conductors have a perimeter approximately 15%–20% greater than round conductors, significantly increasing mica tape consumption—whether synthetic mica tape or phlogopite mica tape is used. From both fire resistance performance and material efficiency perspectives, round conductors are the superior choice.
4. Conclusion: Systematic Optimization of Mica Tape Materials for Fire-Resistant Cables
In the wire and cable industry, achieving stable fire resistance test results and long-term reliable operation requires systematic optimization of mica tape material selection, mica tape wrapping processes, and conductor structure design.
Practical experience shows that using round compacted conductors, combined with high-quality synthetic mica tape or phlogopite mica tape and stable wrapping process control, is an effective technical approach to achieving a fire resistance test pass rate of over 99.5%.
About ONE WORLD
ONE WORLD specializes in the research and application of mica tape, synthetic mica tape, and phlogopite mica tape for the wire and cable industry. Based on a deep understanding of fire resistance mechanisms and process compatibility, we provide systematic technical support—from mica tape selection to wrapping process optimization—to help manufacturers achieve stable and reliable fire-resistant cable performance.
Post time: Jan-29-2026