Multilayer process: the addition of the plastic movie was the first step to produce brick containers impermeable to liquids and heat-sealable. From the nineteen sixties, an aluminum foil started to be included into the cardboard container to ensure much better security and lengthen the shelf lifetime of the packaged products. https://sustainablewaterpackaging.car.blog/2025/01/09/sustainable-water-packaging-leading-the-change/