Process for preparing a sealed laminated vessel

A process for the preparation of a sealed laminated vessel, which comprises (i) applying to a laminate comprising a paper substrate and a metal foil and having heat-sealable resin layers on both the surface portions of the substrate and the foil a heat-sealable resin layer over at least that portion of the laminate to be formed into an inner side of a seam to cover a cut edge of the paper substrate, (ii) forming the laminate into a cylinder so that the metal foil is located on the inner side and the paper substrate is located on the outer side and lap-bonding an inner end of the laminate to an outer end of the laminate by heat sealing to form a barrel having a straight seam on the side surface thereof, (iii) bending outwardly the laminate on at least one open end of the barrel and bending inwardly a part of the bent portion so that it is lapped on the lower side of the remaining part of the bent portion to form a flat circumferential end portion on at least one open end of the barrel, (iv) fitting a lid member on the circumferential end portion of the barrel, said lid member being composed of a laminate comprising a heat-sealable resin layer and a metal foil, said lid member having a peripheral portion for engagement with the circumferential end portion through the heat-sealable resin layer, said lid member having a vertical rim-like inner wall and a horizontal flange wall, (v) heat sealing the lid member and the circumferential end portion of the barrel, and (vi) engaging the lid member and the circumferential end portion of the barrel with a molding roller having a section conforming to the final shape of the sealed portion to downwardly bend the flange wall of the lid member together with the circumferential end portion of the barrel heat-sealed thereto.