Multilayer method: the addition of the plastic film was the first step to help make brick containers impermeable to liquids and warmth-sealable. From the nineteen sixties, an aluminum foil began to be extra towards the cardboard container to guarantee improved security and extend the shelf lifetime of the packaged products. https://sustainablemilkcartongabletop.blogspot.com/2025/06/a-greener-sip-revolutionizing-hydration.html