How to Choose the Right Aluminium Foil Thickness
Thickness decides strength, barrier performance and cost. Here is how to match gauge to your application instead of over-specifying.
Aluminium foil is specified in micrometres, and a few micrometres change both the performance and the price of the finished pack. Buyers who over-specify pay for material they do not need; buyers who under-specify get pinholes and complaints.
Start from the barrier requirement
For moisture and oxygen barrier in flexible packaging, the foil layer is what does the work. Below roughly 9 µm, pinhole counts rise sharply after lamination unless the foil is handled carefully, so most pouch structures sit between 9 µm and 12 µm.
Then consider mechanical load
Container and tray foil is not chosen for barrier at all — it is chosen for formability and rigidity. Trays deeper than 40 mm typically need 60 µm and above, while lidding stock works well between 30 µm and 50 µm.
Then consider the converting process
Printing, coating and heat sealing all apply tension. A foil that is too thin will stretch and register poorly; a foil that is too thick will not form cleanly around tight radii.
A practical starting point
| Application | Typical gauge |
|---|---|
| Household retail foil | 10 – 18 µm |
| Flexible packaging lamination | 7 – 12 µm |
| Blister lidding (PTP) | 20 – 25 µm |
| Container and tray | 50 – 150 µm |
| Cable shielding | 7 – 25 µm |
Send us your end use and we will confirm a workable gauge window, including the tolerance we can hold on the rolling mill.