Multilayer Process: the addition of a plastic film was step one to help make brick containers impermeable to liquids and heat-sealable. From the nineteen sixties, an aluminum foil started to be added to the cardboard container to make sure greater defense and increase the shelf life of the packaged product. https://durablegabletopcontainers.blogspot.com/2025/05/revolutionizing-dairy-with-eco-friendly.html