Method and apparatus for guiding a zippered film in form, fill and seal package making machines

A forming shoulder for a forming and filling tube of a form, fill and seal machine, comprising

• said forming shoulder having an upwardly slanting body joining at a crest edge a downwardly extending skirt for shaping a package making material sheet about the filling tube, and said skirt having means thereon arranged to face toward said tube for guiding a longitudinal zipper area of said package making material sheet as the sheet runs downwardly from said crest edge and between said skirt and said tube;
• said guiding means retaining said zipper area and thereby said sheet against lateral drifting between said skirt and said tube.

A method of restraining a running sheet of package making material against drifting laterally relative to a forming shoulder structure and an associated forming and filling tube of a form, fill and seal machine surrounded by the shoulder structure, comprising:

• guiding a longitudinal zipper area of said material along means through a channel in a skirt of said shoulder structure facing said tube.

A method of retaining a sheet or package making material against lateral drifting as the material is directed upwardly along a slanting body of a forming shoulder associated with a forming and filling tube of a form, fill and seal machine, and then over a crest edge from which a skirt of said forming shoulder extends downwardly about the filling tube and shapes the sheet tubularly about the tube, comprising:

• running a longitudinally extending zipper area on said sheet through guide means on said skirt and which guide means faces toward said tube.