Multilayer procedure: the addition of the plastic film was the initial step for making brick containers impermeable to liquids and heat-sealable. During the nineteen sixties, an aluminum foil started to be included towards the cardboard container to be sure greater security and extend the shelf lifetime of the packaged product. https://www.tumblr.com/gabletoppak/776465426420989952/water-in-carton-gable-top-paks-sustainable?source=share