PACKAGING BAG WITH SELF-CLOSEABLE OUTFLOW PORT, AND METHOD OF MANUFACTURING THE PACKAGING BAG

摘要

A packaging bag and a method of manufacturing the packaging bag, the packaging bag formed by heat-sealing plastic films and having an outflow port (3) formed of a heat seal part (2) and a non-heat seal part (6), wherein the inner surfaces of the films forming the non-heat seal part (6) side of a boundary part (Y) between the heat seal part (2) and the non-heat seal part (6) of an outflow port passage (4) come into contact with each other without providing a clearance in closed state, whereby contents can be prevented from oozing out of the outflow port (3); the method comprising the steps of transferring a valve material (103) limiting the movement of filled material after a bag is formed according to the transfer of web-like body materials (101, 102) forming the packaging bag, and heat-fusing the body materials (101, 102) to the valve material (103) in the state of a seal obstructing member (106) provided on the passing side of the filled material, whereby the packaging bag having a valve function such as a reverse flow prevention function can be continuously manufactured.