METHOD FOR MAKING FLEXIBLE BAGS HAVING ELASTIC-LIKE BEHAVIOUR COMPRISING REGIONS FORMED INTO PLEAT ELEMENTS

摘要

A method of forming flexible bags (10) having elastic-like behavior, wherein asheet material (52) is introduced having one portion of the sheet materialoverlapping another portion of the sheet material. The sheet material (52) isformed into a strainable network. The strainable network includes a pluralityof first regions (64) and a plurality of second regions (66). The firstregions (64) are substantially un-deformed and the second regions (66) areformed into disengageable pleat elements (74). As the overlapped portions ofthe sheet material are formed they engage each other at the pleat elements.The pleat elements of each overlapped portion become engaged within each otherand resist disengagement because of the frictional forces of the sheetmaterial. The overlapped portions of the sheet material are separated using adisengaging means (130) so that the overlapped portions become disengaged andare separated from each other while riding on the disengaging means (130). Thedisengaging means is in the form of either air knife, static opening bar,dynamic opening bar, or suction means, and any combinations thereof.