| 摘要 |
This invention relates to flexible packages (Fig. 1) having an openable and resealable interlocking closure 22 and to methods and apparatus (Fig.7) for making the same from a continuous web of flexible film 25, the closure 22 being formed transversely to the direction of film flow across one end of the package 20 during package formation at line speed. A converter device 29/31 mounted atop or adjacent to standard packaging apparatus 33 forms a small amount of the running packaging film 25 into the resealable closure structure 22 as an integral part of the film 25 extending transversely to the long dimension of the package 20. The converter functions with both horizontal and vertical form/fill/seal wrapping machines and with overwrap packagers, and uses diverse packaging films such as polypropylene, polyester, polyvinyl chloride, high and medium density polyethylene and various film laminations. Package formation begins by feeding the plastic packaging film 25 into the converter 29 where the film is first automatically fanfolded across the entire width of the film to form a stack, the layers of which are immediately heat sealed together forming a multilayered semi-rigid strip 30 of typically one half inch width extending completely across the film width in plane with the film. The number of folds in the stack varies depending on the thermoforming properties and thickness of the particular film being used. The resealable locking feature 22 is next thermoformed at 31 into the multilayered strip 30 which then continues through the packaging machinery 33 in the usual manner, encircling the product 34 and passing through the end sealer 35 where the package ends are sealed, as at 21a and 21b, and cut, and the front and back film panels 23 and 24 are pressed together closing the resealable locking feature 22. <IMAGE> <IMAGE> |
