| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a packaging bag having a simple structure to discharge a gas, and securing its airtightness. <P>SOLUTION: The packaging bag 10 has both ends in an extending direction of an overlapping portion 12 in which the end edges of a film overlap each other, and transversely sealed portions 20 are formed at both ends. The overlapping portion 12 has longitudinally sealed portions 14 longitudinally sealed air-tightly, and passage forming portions 16 formed with passages 18 for communicating between the inside and outside of the bag, between the films. On the inside of the bag, a nonwoven fabric 24 is bonded across and over the whole length of an inside end edge 12a of the overlapping portion 12. The passage forming portion 16 is filled with silicone oil for closing the passages 18. When the pressure in the bag is increased to a predetermined pressure, the passages 18 closed with the silicone oil is released, and the gas is allowed to be discharged from the passages 18. When the pressure in the bag is reduced, the passages 18 are closed with the silicone oil again. <P>COPYRIGHT: (C)2012,JPO&INPIT |
