초록 ▼

A sealed container is formed by positioning a length of heat shrinkable film above the open top of a container, grasping a corner of the film, and heat shrinking the peripheral portion of the film into fluid tight compressive engagement with the upper portion of the container while the film corner i

A sealed container is formed by positioning a length of heat shrinkable film above the open top of a container, grasping a corner of the film, and heat shrinking the peripheral portion of the film into fluid tight compressive engagement with the upper portion of the container while the film corner is grasped. The unshrunk gripped corner of the film provides a pull tab for removing the closure, when desired. As the peripheral portion of the film is heat shrunk, the remainder of the film is tensioned across the open top of the container, and minute perforations are then formed in the tensioned film to define frangible sections which may be ruptured by a straw when the contents of the container are to be consumed with the closure in place.

대표청구항 ▼

The method of forming a closure in an open top container comprising the steps of: feeding a length of heat-shrinkable film into superposed relationship with respect to the open top of said container, said length of film being larger than the open top of said container whereby corners of said film pr

The method of forming a closure in an open top container comprising the steps of: feeding a length of heat-shrinkable film into superposed relationship with respect to the open top of said container, said length of film being larger than the open top of said container whereby corners of said film project beyond the periphery of said open top, effecting relative movement between said length of film and said container so that the upper end of the container is positioned in engagement with said length of film with portions of the film being disposed outwardly of the periphery of the open top of the container, grasping only a single corner of the outwardly extending film portion, applying heat to the outwardly extending film portions completely around the periphery of the container to heat shrink the film into compressive engagement with the upper end of the container completely around the periphery thereof to thereby form a closure, said grasping step being performed at least during a portion of said heat applying step whereby heat shrinking of the grasped film corner is retarded, and releasing the grasped film corner to provide a single pull tab for said closure.