| 摘要 |
A packaging material for forming at least a part of a package for a product releasing gasses comprises a one-way pressure relief valve (18) including a first inner film (10), being provided with at least one inlet opening (13,14) therethrough, and a second outer film (11) covering the at least one inlet opening (13, 14) and being bonded to the first inner film (10) to form a channel portion (12) between the inner and the outer film. The channel portion (12) communicates with the surroundings of the package through at least one outlet opening (15) spaced apart from the at least one inlet opening (13, 14). The pressure relief valve (18) further comprises a liquid (19) provided in the channel portion (12) and solid spacer means (17) provided in the channel portion (12) proximate to the at least one inlet opening (13, 14). The outer film (11) is a soft film having such a flexibility or elasticity that in a tensile test a force of less than 5 N is needed for elongating a test piece thereof having a width of 15 mm by 5%. |
