Multilayer procedure: the addition of the plastic film was the initial step to make brick containers impermeable to liquids and heat-sealable. During the nineteen sixties, an aluminum foil started to be extra into the cardboard container to be certain superior safety and prolong the shelf life of the packaged product. https://gabletopmilkcarton.art.blog/2025/02/07/innovative-eco-friendly-packaging-solutions-for-a-sustainable-future/