Multilayer system: the addition of the plastic movie was the initial step to generate brick containers impermeable to liquids and warmth-sealable. In the nineteen sixties, an aluminum foil started to be added on the cardboard container to be certain better protection and lengthen the shelf lifetime of the packaged merchandise. https://topcartons.family.blog/2025/09/24/water-pak-pure-hydration-protected-by-smart-layers/