In medium- and high-voltage cable manufacturing, effective electromagnetic interference (EMI) shielding combined with high electrical conductivity is essential for signal stability, fault current handling, and overall system reliability. Copper Tape for Cable — also known as Copper Foil Tape or Soft-Annealed Copper Shielding Tape — is a high-purity, precision-slit copper foil engineered specifically for the cable industry. Produced from 99.9%+ pure electrolytic tough pitch (ETP) copper and soft-annealed to O temper, it delivers near-100% IACS conductivity, excellent formability, and superior mechanical properties for longitudinal or helical wrapping applications.
As a trusted B2B supplier of complete cable materials and technical solutions with decades of global project experience, we recognize copper tape as the premium choice for manufacturers requiring maximum shielding effectiveness, fault-current capacity, and long-term durability in power cables, XLPE-insulated cables, transformers, and busway systems.
Why Copper Tape Is Specified for Cable Shielding
Copper tape delivers continuous metallic coverage when applied helically with a minimum 10–25 % overlap (typical 12.5–25 % on MV cables). This creates a Faraday-cage effect that equalises the electric field over the semi-conducting insulation screen, suppresses external electromagnetic interference (EMI), and carries short-circuit fault current to the earthing system. In XLPE-insulated cables rated 6–35 kV (IEC 60502-2 constructions), the copper tape screen is applied directly over the extruded insulation screen.
Key performance data (annealed soft temper):
- Conductivity: ≥96–100 % IACS (TU1 ≥100 %, T2 ≥98 %)
- Volume resistivity at 20 °C: ≤0.017–0.0176 Ω·mm²/m
- Tensile strength: 200–300 MPa (soft annealed)
- Elongation: ≥25–35 % (ensures crack-free wrapping on high-speed lines)
- Surface: bright, clean, free of oxide that would impair conductivity or soldering
These values comply with the latest Chinese national standard GB/T 11091-2024 (Copper strip and foil for cables, implemented November 2024) and are consistent with IEC 60502, ASTM B152 and related cable construction requirements.
Composition & Engineered Manufacturing Process
Copper Tape for Cable is manufactured from high-purity copper strip that undergoes precision cold rolling, annealing, and slitting. Key characteristics include:
- Base material: Electrolytic tough pitch (ETP) copper with ≥99.9% purity
- Temper: Soft-annealed (O temper) for maximum flexibility and wrapability
- Surface finish: Bright, clean, and burr-free edges for smooth high-speed processing
The tape is available in thicknesses from 0.05 mm to 0.20 mm and widths from 10 mm to 1000 mm, with optional adhesive backing or copolymer coating for enhanced bonding and moisture resistance.
Key Technical Advantages & Performance Benefits
Near-100% IACS Electrical Conductivity Copper tape provides the highest conductivity among common shielding materials, enabling excellent EMI/RFI attenuation and low transfer impedance — critical for maintaining signal integrity in sensitive power and communication cables.
Superior Formability & High-Speed Processability Soft-annealed temper combined with high elongation ensures wrinkle-free longitudinal or helical wrapping on high-speed lines without cracking or spring-back, reducing production defects and scrap rates.
Excellent EMI Shielding & Fault-Current Capacity The high-purity copper core delivers near-100% optical coverage and high fault-current carrying capability, making it ideal for metallic shielding layers in MV/HV cables and grounding applications in transformers and busway systems.
Mechanical Strength & Durability
- Tensile strength: High (typically 200–300 MPa in annealed condition)
- Elongation: Excellent (≥30–45%)
These properties ensure the tape withstands mechanical stresses during manufacturing, installation, and service life.
Versatile & Customizable Available in bare, adhesive-backed, or copolymer-coated versions to suit different cable designs, with custom widths and thicknesses for precise matching to your production equipment and performance requirements.
Copper Tape vs. Aluminum Tape for Cable Shielding
| Feature | Copper Tape for Cable | Aluminum Tape for Cable | Best For |
|---|
| Conductivity | ~100% IACS | ~61% IACS | High-fault-current & low-impedance applications |
| Weight | Heavier | Significantly lighter | Weight-sensitive long-distance cables |
| Cost | Higher material cost | Lower | Budget-optimized large-scale projects |
| EMI Shielding Effectiveness | Superior (lower transfer impedance) | Excellent for high-frequency | Critical power & data cables |
| Fault-Current Capacity | Excellent | Moderate | MV/HV power cables |
| Formability & Coverage | Excellent | Excellent | High-speed longitudinal wrapping |
Copper Tape vs. Alternative Shielding Methods
| Feature | Copper Tape (CTS) | Copper Wire Braid / Concentric Wire Screen | Aluminium Foil / Al-Mylar |
|---|
| Optical coverage | Near 100 % | 60–95 % | 100 % |
| High-frequency EMI | Excellent | Moderate | Excellent |
| Low-frequency / magnetic | Good | Excellent | Moderate |
| Fault-current capacity | Moderate (thickness-limited) | High (customisable cross-section) | Low |
| Flexibility / bend radius | Good for fixed installation | Excellent for flexing | Poor (fragile) |
| Weight & diameter impact | Low | Higher | Lowest |
| Cost | Moderate | Higher | Lowest |
| Typical use | MV power, XLPE, fixed runs | High-fault or mobile cables | Data / high-frequency only |
Application & Selection Guide for Engineers and Procurement
Primary applications
- Medium-voltage XLPE power cables (6/10 kV to 18/30 kV) – helical copper-tape screen over insulation screen (IEC 60502-2).
- Frequency-conversion (VFD) and special control cables requiring high EMI attenuation.
- Communication, radio-frequency and instrumentation cables where conductivity and solderability matter.
- Transformers, busbars and grounding layers where soft-annealed copper provides both conductivity and formability.
Selection logic
- Determine system earthing and prospective fault current. Low-to-moderate fault current → copper tape of 0.10–0.15 mm is usually sufficient.
- Confirm voltage class and insulation type. MV XLPE almost always uses copper tape (or copper wire) metallic screen.
- Specify temper (soft annealed / O60 preferred for high-speed wrapping) and surface condition (bright, oxide-free).
- Verify dimensional tolerances against GB/T 11091-2024 or project specification (thickness tolerance typically ±0.005–0.015 mm depending on grade and thickness).
- For hybrid constructions, copper tape can be combined with a drain wire or outer braid when both coverage and mechanical robustness are required.
Installation and failure-prevention notes
- Maintain minimum overlap (normally ≥12.5 %) and uniform tension during application to avoid gaps or wrinkling.
- Ensure the tape is in continuous electrical contact with the semi-conducting insulation screen; any oxide or contamination raises transfer impedance.
- Terminate the copper-tape screen with a 360° connection or soldered/bonded earth braid at joints and terminations to preserve shielding integrity.
- Avoid sharp bends or repeated flexing after installation; copper tape has lower fatigue life than braid in highly mobile applications.
- Store rolls in dry conditions; surface oxidation reduces conductivity and solderability.
Technical Specifications
For Shielding of Power Cable
| Thickness (mm) | Width (mm) | Tensile Strength (MPa) | Elongation at Break (%) | Resistivity (Ω·mm²/m) | Hardness (HV) | Grade |
|---|
| 0.05 – 0.09 | 10 – 50 | ≥180 | ≥12 | ≤0.017241 (100% IACS) | 45–70 | T2 |
| 0.10 – 0.20 | 10 – 50 | ≥180 | ≥18 | ≤0.017593 (98% IACS) | 45–70 | T2 |
For Transformer and Busway Applications
| Thickness (mm) | Width (mm) | Tensile Strength (MPa) | Elongation at Break (%) | Resistivity (Ω·mm²/m) | Hardness (HV) | Grade |
|---|
| 0.1 – 4.0 | 10 – 1200 | ≥180 | ≥30 | ≤0.017241 | 45–120 | T2, TU1 |
| Parameter | Typical Value | Test Condition / Standard |
|---|
| Conductivity | Up to 100% IACS | High-purity copper |
| Tensile Strength | High | Suitable for high-speed wrapping |
| Elongation | Excellent | Soft-annealed temper |
| Thickness Range | 0.05–0.20 mm | Precision slitting |
| Width Range | 10–1000 mm | Clean edges, no burrs |
| Standards | IEC 60502, ASTM B152 | International compliance |
(Custom thicknesses, widths, and tempers available upon request.)
Manufacturing Standards & Quality Assurance
Copper Tape for Cable complies with:
- IEC 60502 (Power cables with extruded insulation)
- ASTM B152 (Copper sheet, strip, plate, and rolled bar)
Every batch undergoes rigorous testing for conductivity, mechanical properties, dimensional accuracy, and surface quality to ensure consistent performance and full traceability.
Packaging & Logistics
Supplied in rolls with standard inner diameters of 76 mm, 102 mm, or 150 mm. Coils are securely packed in wooden cases or on pallets for safe global transportation and storage.
Premium Conductivity & Shielding for Demanding Cable Applications
Copper Tape for Cable combines near-100% IACS conductivity, superior formability, and excellent EMI shielding performance to deliver a high-reliability shielding and conductive solution for modern power, XLPE, transformer, and busway systems. Its precision engineering and compliance with IEC 60502 and ASTM B152 make it the technical upgrade for manufacturers seeking maximum performance and long-term cable integrity.
For cable manufacturers and EPC contractors focused on reliable quality, customized technical solutions, and long-term partnership value, this tape ensures your cables meet the highest conductivity and shielding standards while optimizing production efficiency.
Inquiry Now to request detailed technical data sheets, samples, custom specifications, or competitive bulk quotations tailored to your production line and cable designs. Our expert team provides full technical consultation and one-stop material solutions that strengthen your competitive advantage in global cable markets.
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