Multilayer process: the addition of a plastic film was the first step to help make brick containers impermeable to liquids and warmth-sealable. From the 1960s, an aluminum foil began to be added towards the cardboard container to make certain greater safety and prolong the shelf lifetime of the packaged products. https://gabletoppackaging.tech.blog/2025/09/23/water-in-paper-bottle-redefining-purity-with-every-pour/