Method for heat sealing
AssigneeReynolds Metals Company
InventorJames L. Hutcheson
Life of this patent
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Abstract
A method and apparatus for hermetically heat sealing flexible containers, and particularly pouch-like containers, is disclosed. A filled pouch is positioned between a pair of heated bars, with the bars being constructed and arranged to maintain a gap therebetween, such that pressure is not applied to the pouch. Thereafter, the pouch is positioned between a pair of chilled sealing bars and the chilled bars are constructed and arranged to apply sealing pressure to the edge of the pouch, where the edge region of the pouch is sealed and cooled. If desired, a plurality of gapped heated bar stations may be provided prior to the chill bar position.
Claims8
In a method of forming a heat seal on the open end of a flexible container after filling of said flexible container and cleaning of said open end of said flexible container, said cleaning producing moisture on said open end of said flexible container, said flexible container comprising a pair of generally planar walls which have been heat sealed to one another, comprising positioning said open end of said flexible container between a pair of heated bars and subsequently positioning said open end of said flexible container between a pair of chilled bars the improvement comprising maintaining a sufficient gap between said heated bars such that no pressure is applied to said open end of said flexible container while said open end of said flexible container is positioned between said pair of heated bars, evaporating said moisture from said open end of said flexible container while said open end of said flexible container is positioned between said pair of heated bars and applying sealing pressure to said open end of said flexible container while cooling said open end of said flexible container while said open end of said flexible container is positioned between said pair of chilled bars to thereby provide a hermetic seal on said open end of said flexible container.
Dependencies are inferred from the claim text.