| 摘要 |
In the production of bags each having a folded cross-bottom end closure containing two side flaps which are successively folded over and stuck down, the bags consisting of an outer layer of at least one ply and an inner layer having adhesion properties different from those of the outer layer, a longitudinally-fed flattened tubular web consisting of the material for the two layers is produced in a tube-forming machine and divided into individual bag sections, two longitudinal incisions being applied through both layers at least near one end of the bag sections at least on the side adjacent to the side flap that is to be folded over last of all, whereby the corner folds are at least partially separated from the side flaps to define rectangular tongue portions on the side flaps. The cross-bottom end closure is formed at least at one end of each bag section during transverse feeding through a base-forming machine by opening up the or each end of the bag section and foreshortening the outer edge of the tongue portion on the side flap of the inner layer that is to be folded over last of all in comparison with the corresponding edge of the innermost ply of the outer layer, applying a suitable adhesive to the faces of the inner and outer layers that are to be stuck together and successively turning over the side flaps, such foreshortening being effected by severing a correspondingly wide strip from the tongue portion in the base-forming machine. |
