Multilayer system: the addition of the plastic film was the first step to create brick containers impermeable to liquids and warmth-sealable. Inside the 1960s, an aluminum foil began to be added towards the cardboard container to be certain much better protection and increase the shelf lifetime of the packaged solution. https://share.evernote.com/note/06681a59-fb97-a7da-c16b-8caf2dd9f085