Multilayer procedure: the addition of the plastic movie was step one to generate brick containers impermeable to liquids and heat-sealable. While in the nineteen sixties, an aluminum foil started to be added to the cardboard container to make sure greater protection and lengthen the shelf lifetime of the packaged merchandise. https://www.tumblr.com/sustainablemilkcartons/780356031291293696/sustainable-solutions-through-gable-top-milk?source=share