METHOD OF MANUFACTURING STANDING BAG AND STANDING BAG

摘要

PROBLEM TO BE SOLVED: To eliminate the possibility of contamination by bacteria and dust in the closed bag, in a self-supporting standing bag suitable for such applications as medical infusion bags.SOLUTION: There is provided a protruded portion at a position confronting the diameter circumferentially in the lip to form thin belt-like regions in a cylindrical sheet. A gusset portion is formed along the first thin belt-like region, and the surface opposite to the folding part of the gusset portion is fused to form the bottom W1 of a standing bag. The second thin belt-like region is divided in middle, and the divided parts each serve as an opening of the standing bag. When the standing bag is used as an infusion bag, a discharge port 90 is arranged in the opening. Even when the content is hardened by a heat treatment, e.g. sterilization after containment, appropriate flexibility of the bottom of the bag is ensured owing to thinning down, thereby ensuring a smooth collapse of the bag on discharge of the liquid.