Multilayer Program: the addition of the plastic film was the first step to help make brick containers impermeable to liquids and warmth-sealable. In the 1960s, an aluminum foil began to be additional on the cardboard container to ensure much better protection and lengthen the shelf lifetime of the packaged item. https://ecofriendlywaterpackaging.blogspot.com/2025/05/driving-sustainability-through.html