Method of producing an easily openable multilayer plastic container

摘要

A multilayer container with a flange for sealing with a lid, wherein the thickness of the inner surface layer at the inner edge of the flange is thinner than that in the sealing area, is produced by a method wherein a circular portion of a multilayer sheet to be the flange is held at a certain pressure while the multilayer sheet is being thermoformed under specified molding conditions, with the other portion than the circular portion being stretched. Even a seal ring having an even surface serves as a means for sealing the resulting multilayer container with a lid while ensuring easy openability.