US Patent 10118736 Bag and method for producing the same

A sack is formed by first transverse sealing seams from a foil tube, and is provided with at least a first vent channel, which runs largely parallel to the axis of the film tube, and whose inner film layer has first vent openings for venting of the sack interior into the first vent channel. A second vent channel is provided, which is connected to the first vent channel by second vent openings, and which, in turn, has third vent openings, which vent the at least one second vent channel.