Multilayer technique: the addition of the plastic film was the initial step to make brick containers impermeable to liquids and heat-sealable. Within the nineteen sixties, an aluminum foil started to be included for the cardboard container to be sure greater defense and increase the shelf lifetime of the packaged product. https://sustainablewaterpackaging.blogspot.com/2024/12/the-future-of-custom-packaging-for.html