Aluminium-Polyester
Electromagnetic shielding for data, signal and communications cables
Aluminium-Polyester
The aluminium-polyester laminate (AL/PET) combines the electrical conductivity of aluminium with the mechanical strength of polyester film, bonded with an oven post-cured polyurethane adhesive. This structure delivers effective electromagnetic shields without compromising material integrity during high-speed taping or throughout the cable's service life.
In data-cable construction, AL/PET is applied as an individual shield over each twisted pair or as an overall shield over the bundle, providing attenuation against electromagnetic (EMI) and radio-frequency (RFI) interference. The polyester layer adds dimensional stability and tensile strength, while the aluminium — facing the cable core and in contact with the drain wire — ensures the electrical continuity of the shield.
Structures range from 9/12 µm (24 µm total) to 50/23 µm (76 µm total), with tensile strength of 75 to 110 MPa depending on configuration. This range allows the optimal balance between shielding level, finished-cable flexibility and behaviour during manufacturing to be selected.
Aluminium thickness directly drives shielding effectiveness: greater thickness means greater interference attenuation. However, high aluminium thicknesses reduce laminate flexibility and increase the risk of cracking during folding. The optimum selection depends on the cable type and the expected installation conditions.
For high-speed extrusion processes, lubricated (LUB) versions are available, reducing friction on the aluminium face by up to 50 %, lowering tool wear and improving process stability.
How to choose the right one?
Selecting the right structure depends on the balance between required shielding level, finished-cable flexibility and behaviour during taping. Thinner gauges offer greater flexibility, while thicker ones provide better EMI attenuation.
| Structure (Al/PET) | Total thickness | Weight | Tensile strength | Elongation | Typical application | When to choose |
|---|---|---|---|---|---|---|
| 9/12 | 24 µm | 44.0 g/m² | 90 MPa | 30% | LAN Cat5/Cat5e cables | Maximum flexibility, basic shielding |
| 9/15 | 27 µm | 48.2 g/m² | 100 MPa | 30% | Pair, instrumentation cables | Flexibility/strength balance |
| 9/23 | 35 µm | 59.3 g/m² | 110 MPa | 30% | Data and signal cables | Greater mechanical support |
| 12/12 | 27 µm | 52.0 g/m² | 75 MPa | 15% | Cat6 cables | Improved shielding, high flexibility |
| 12/19 | 34 µm | 62.0 g/m² | 100 MPa | 30% | High-speed data cables | General use, good behaviour |
| 25/23 | 51 µm | 102.3 g/m² | 95 MPa | 20% | Cat6A/Cat7 cables | High shielding, demanding environments |
| 25/50 | 77 µm | 138.2 g/m² | 90 MPa | 20% | Overall shield, coaxial cables | Maximum mechanical support |
| 40/23 | 66 µm | 143.1 g/m² | 80 MPa | 15% | Industrial cables | Elevated shielding |
Additional structures available on request: 12/15, 12/23, 15/19, 37/12, 37/23, 40/12, 50/12, 50/23.
Technical specifications
The mechanical values shown below come from tests run to ASTM standards and characterise the material's behaviour both during processing and in service.
| Property | Method | 9/12 | 9/15 | 9/23 | 12/12 | 12/19 | 25/23 | 25/50 | 40/23 |
|---|---|---|---|---|---|---|---|---|---|
| Al thickness (µm) | ASTM D374 | 9 | 9 | 9 | 12 | 12 | 25 | 25 | 40 |
| PET thickness (µm) | ASTM D374 | 12 | 15 | 23 | 12 | 19 | 23 | 50 | 23 |
| Total thickness (µm, ±10%) | ASTM D374 | 24 | 27 | 35 | 27 | 34 | 51 | 77 | 66 |
| Weight (g/m²) | — | 44.0 | 48.2 | 59.3 | 52.0 | 62.0 | 102.3 | 138.2 | 143.1 |
| Tensile strength (MPa) | ASTM D882 | 90 | 100 | 110 | 75 | 100 | 95 | 90 | 80 |
| Elongation at break (%) | ASTM D882 | 30 | 30 | 30 | 15 | 30 | 20 | 20 | 15 |
Values shown are typical and do not constitute binding specifications.
Available variants
Laminate configuration
- Simplex (AL/PET) — aluminium on one side, standard
- Triplex (AL/PET/AL) — aluminium on both sides, maximum shielding
Surface treatments
- Natural — standard
- Lubricated (LUB) — up to 50% friction reduction on aluminium face, ideal for high-speed extrusion
Colours
- Neutral — standard
- Custom colours on request — by changing the adhesive, for construction identification
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