Multilayer Technique: the addition of the plastic film was step one to produce brick containers impermeable to liquids and heat-sealable. From the nineteen sixties, an aluminum foil began to be added to the cardboard container to be sure far better security and lengthen the shelf lifetime of the packaged products. https://ecofriendlypackagings.blogspot.com/2025/05/smart-packaging-for-smarter-brands.html