contrary to the first flow direction at least substantially so that the tubular valves close at least substantially by coming together for example in the direction of the supporting fabric 18 the supporting fabric 18 hereby serves as an impact protection so that the depressions 34 and the tubular valves do not turn inside out and extend in an extension direction contrary to an extension direction shown in fig3 whereby they would then facilitate a flow of the air in the second flow direction and would at least substantially prevent a flow of the air in the first flow direction whereby this would constitute an undesirable valve functionality contrary to the previously described valve functionalities the passage openings of the depressions 34 are formed for example in such a way that a respective bottom 36 of the depressions 34 is cut away after the valve device 12 has been removed from the deep drawing tool 10 it can also be provided that the bottoms 36 are removed from the remaining film 14 while the film 14 and the valve device 12 are still in the deep drawing tool 10 in this connection the lower part 14 is formed for example in two parts and comprises an upper part 40 and a lower part 42 so that a clearance 38 is created that facilitates a relative movement between the upper part 40 and the lower part 42 a corresponding section to separate the bottoms 36 then takes place within a gap that results when the two parts.