Multilayer Program: the addition of a plastic film was step one to make brick containers impermeable to liquids and heat-sealable. While in the 1960s, an aluminum foil began to be additional into the cardboard container to be certain far better defense and lengthen the shelf life of the packaged item. https://sustainablesoappackaging.blogspot.com/2025/10/water-in-paper-bottle-future-of-eco.html