Multilayer method: the addition of the plastic film was the first step to produce brick containers impermeable to liquids and heat-sealable. From the 1960s, an aluminum foil started to be added for the cardboard container to ensure superior safety and increase the shelf lifetime of the packaged products. This process https://wateringabletop.tech.blog/2025/09/24/water-in-sustainable-pak-a-choice-that-protects-generations/