FIELD: packaging equipment. SUBSTANCE: method involves pushing annular part of one closed package end into package with U-shaped structure forming; welding annular part at least partly to remainder package along package areas facing each other. Device for carrying out above method comprises members for holding walls of package having at least one closed end; means inserted into members for package walls fixing with the purpose of U-shaped annular part creation, heat-sealing means for U-shaped annular part sealing. EFFECT: simplified package forming process, easy production, possibility of package bottom reinforcement. 10 cl, 12 dwg
