The easy-open lid gets all the credit, but the real hero is the double seam — the rolled joint where the aluminum end meets the PET can body. Get it wrong and the drink leaks, oxidizes, or goes flat. Get it right and the can stays sealed to its best-by date.
What a double seam actually is
A double seam is two layers of can body curled around two layers of lid flange, rolled in two passes. The result has four thicknesses of metal at the rim. The seam needs the right:
- Seam height and width — too tight cracks, too loose leaks.
- Body hook and cover hook — the overlap that locks the joint.
- Tightness — no gap for gas or microbe ingress.
How we hold it on the line
Because we make both the can body and the lid, the seam is a controlled internal variable, not a cross-supplier gamble. Our line checks seam dimensions per batch and keeps them inside the window our filling partners rely on. For still and lightly carbonated drinks that means a stable shelf life without over-thick walls.
Why buyers should care
- A consistent seam means your contract filler does not re-qualify the package every run.
- It protects the 30% purchase-intent bump you get from a clear, intact can on the shelf.
- It is the difference between a can that survives a container crossing and one that weeps in the carton.
