METHOD FOR MANUFACTURING RECTANGULAR-BOTTOMED PACKAGING BAG, DEVICE FOR MANUFACTURING RECTANGULAR-BOTTOMED PACKAGING BAG, METHOD FOR MANUFACTURING PACKAGING BODY, AND DEVICE FOR MANUFACTURING PACKAGING BODY

摘要

A method for manufacturing a rectangular-bottomed packaging bag has: an expansion step in which a pair of opening/closing plates (13) inserted into a flat bag are caused to separate from each other along the thickness direction of the flat bag, thereby expanding the flat bag; and a gusset formation step in which, after the expansion step, folding plates (11, 12) are thrust between the pair of opening/closing plates (13) from the exterior of the bag toward the interior of the bag, thereby forming a side-part gusset and a bottom gusset.