Copper-Polyester
High-performance electromagnetic shielding for critical applications
Copper-Polyester
The copper-polyester laminate (CU/PET) combines the superior electrical conductivity of copper with the mechanical strength of polyester film, bonded with an oven post-cured polyurethane adhesive. Compared with aluminium, copper offers approximately 60 % higher conductivity, translating into more effective EMI attenuation in applications where the shielding level is critical.
In signal, data and coaxial cable construction, CU/PET is applied as a shield when attenuation requirements exceed the performance of standard aluminium-polyester. Copper purity (>99.5 %) ensures consistent conductivity along the cable length, while the polyester backing provides the mechanical strength needed to withstand taping without deformation or breakage.
The standard 18/23 µm structure (18 µm copper + 23 µm polyester) yields a total thickness of 44 µm and tensile strength ≥100 MPa per ISO 527. This configuration represents the optimum balance between shielding effectiveness, finished-cable flexibility and material cost.
The choice between copper-polyester and aluminium-polyester depends fundamentally on the required attenuation level and the available budget. CU/PET is the technically superior option when cable specifications demand maximum shielding, while AL/PET is more economical for standard applications with moderate interference levels.
During taping, CU/PET behaves similarly to AL/PET: the polyester layer provides dimensional stability and the post-cured adhesive prevents delamination during manufacturing and over the cable's service life.
How to choose the right one?
Selection between copper-polyester and aluminium-polyester is based on the trade-off between shielding requirements and cost. Copper offers superior performance at a higher cost; its use is justified in applications where attenuation is critical.
| Factor | Copper-Polyester | Aluminium-Polyester |
|---|---|---|
| Electrical conductivity | Superior (~60% higher) | Standard |
| EMI shielding effectiveness | Maximum | Good |
| Relative cost | Higher | Lower |
| Typical application | Critical instrumentation cables, medical equipment, high-interference environments | LAN cables, standard data, conventional installations |
| When to choose | Demanding specifications, severe EMI environments, critical medical or industrial applications | Standard requirements, cost optimisation |
Technical specifications
The values shown below correspond to the standard CU/PET 18/23 structure and characterise the material's behaviour both during processing and in service.
| Property | Value | Test method |
|---|---|---|
| Copper thickness | 18 ± 2 µm | DIN 53370 |
| Polyester thickness | 23 ± 2 µm | DIN 53370 |
| Total thickness | 44 ± 4 µm | DIN 53370 |
| Tensile strength | ≥100 MPa | ISO 527 |
| Elongation at break | ≥13% | ISO 527 |
| Copper purity | >99.5% | — |
| Unit weight | 250 ± 10% g/m² | Calculated |
| Bonding type | Polyurethane adhesive, oven post-cured | — |
Values shown are typical and do not constitute binding specifications.
Available variants
Alternative structures
- Other Cu/PET thickness combinations available on request
- Specific configurations per shielding requirements
Colour
- Natural copper — standard
Delivery formats
The supply format directly influences process continuity and taping efficiency. Material can be supplied in different formats and dimensions adapted to each machine type and production speed.
Pad / Roll (pancake)
Flat reel for conventional taping
Spool (TWS / STS reel)
Reel for feeding taping machines
Other formats and dimensions available on request. Custom slitting service available.
Application sectors
Need technical advice?
Our technical team is available to help you select the optimum material for your application.
Custom slitting
Up to 1200 mm width, ±0.50 mm tolerance
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Spooling
Pad to TWS/STS spool conversion
View serviceWe process material from our stock or material supplied by the customer.
Need technical advice?
Our technical team is available to help you select the optimal material for your application.
Local stock in Barcelona · Immediate delivery in Spain and Portugal