Multilayer Process: the addition of a plastic film was the initial step for making brick containers impermeable to liquids and heat-sealable. Within the nineteen sixties, an aluminum foil started to be additional to the cardboard container to make certain superior security and extend the shelf lifetime of the packaged solution. https://share.evernote.com/note/75719569-11d6-20b6-ab6d-9596498907fc