Cover for a can-shaped container

摘要

A can comprising a barrel, an upper lid and a lower lid bonded to the barrel. Both the upper and lower lids comprise a gas liquid impermeable barrier layer, preferably aluminum foil, and resin layers heat fused to both sides thereof. Another resin layer is bonded to the exterior of the lids, with the upper lids having a tab and score to be perforated by the tab built into the resin layer. According to the invention, the yield strength of the top lid is made greater than that of the lower lid to prevent breaking of the score if the can is dropped. The differential strength may be accomplished by making the barrier layer of the top lid greater than that of the bottom lid.