According to an aspect of the present disclosure, a method for producing a multi-layer plastic may include coextruding a first laminate with a substrate layer having an HDPE content of at least 60% by volume; a barrier layer having a barrier polymer and having a thickness of at most 20% of a total thickness of the first laminate; and a connecting layer between the substrate layer and the barrier layer; stretching the coextruded first laminate in a machine direction only; and connecting a second laminate having a polyethylene content of at least 80% by volume to the barrier layer of the stretched first laminate.