Multilayer Program: the addition of the plastic film was step one for making brick containers impermeable to liquids and heat-sealable. From the nineteen sixties, an aluminum foil started to be additional on the cardboard container to be certain much better safety and increase the shelf lifetime of the packaged item. https://sites.google.com/view/gabletoppak/how-water-in-sustainable-pak-is-revolutionizing-the-packaging-world