| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an air venting valve for venting air in a bag, made of plastic, to the outside so that roughage silage can be prepared by using the bag made of plastic. <P>SOLUTION: The air venting valve 5 is provided with: a first hole 6, made in a sidewall sheet 2 of the bag made of the plastic for venting the air in the interior of the bag to the outside; a flexible valve element sheet 7 having the periphery bonded to the outside surface of the sidewall sheet 2, in such a state that the first hole 6 is covered; and a second hole 8 provided in the valve element sheet 7. The second hole 8 is provided at a position so as not to superimpose on the first hole 6, to thereby constitute a valve chest 10 of the sidewall sheet 2 and the valve element sheet 7. Furthermore, the valve element sheet 7 is brought into contact with or is separated from the sidewall sheet 2, according to the pressure difference between the inside and the outside of the bag. When the interior of the bag is kept under overpressure, the valve element sheet 7 is changed into a state of separating from the sidewall sheet 2, to release the air in the interior of the bag to the outside. Meanwhile, when the interior of the bag is kept under a negative pressure. the valve element sheet 7 is brought into contact with the sidewall sheet 2, to close the first hole 6. <P>COPYRIGHT: (C)2009,JPO&INPIT |
