Multilayer system: the addition of the plastic film was the first step to create brick containers impermeable to liquids and heat-sealable. Within the nineteen sixties, an aluminum foil started to be added to your cardboard container to make sure improved security and extend the shelf life of the packaged merchandise. https://share.evernote.com/note/875cea69-2ebb-13e9-a1a1-a977e0744f51