Multilayer process: the addition of a plastic movie was the first step to make brick containers impermeable to liquids and warmth-sealable. During the 1960s, an aluminum foil began to be included on the cardboard container to make sure far better protection and extend the shelf lifetime of the packaged products. https://wateringabletoppak.wordpress.com/2025/02/07/innovative-eco-friendly-packaging-solutions-for-a-sustainable-future/