| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a pressure relief valve which can be manufactured relatively easily and has a slight opening pressure for discharging gas outside from a packed food such as coffee packed in a packaging container and emitting the gas over the storage time. <P>SOLUTION: When excess pressure is produced within the packaging container, the excess pressure is made to act on a valve diaphragm through a through opening. A space layer 15 is directly combined with a base plate 11 at least partially, and a gap 23 is formed at least partially on the edge side between the valve diaphragm 20 and the space layer 15. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
