Multilayer method: the addition of a plastic movie was the first step for making brick containers impermeable to liquids and heat-sealable. From the 1960s, an aluminum foil started to be included on the cardboard container to be certain far better defense and extend the shelf life of the packaged solution. https://waterincarton.sport.blog/2025/08/26/water-in-sustainable-pak-eco-packaging-that-protects-the-planet/