Multilayer process: the addition of the plastic film was the initial step to create brick containers impermeable to liquids and warmth-sealable. From the nineteen sixties, an aluminum foil started to be additional for the cardboard container to be sure greater defense and prolong the shelf lifetime of the packaged product. https://tetrawaterpak.blogspot.com/2025/04/how-gable-top-cartons-and-paper-water.html