Multilayer method: the addition of a plastic movie was the first step to create brick containers impermeable to liquids and heat-sealable. In the sixties, an aluminum foil began to be extra on the cardboard container to be sure greater safety and lengthen the shelf lifetime of the packaged products. This https://www.tumblr.com/sustainablemilkcartons/785842570013130753/innovating-sustainability-with-eco-friendly?source=share