The flat bag is the classic of flexible packaging. Already machine-processed in the thirties of the 20th century, e.g. for the packaging of seeds, the flat bag is still a "hit" today.
The flat bag is created by simply folding the film in the direction of film travel. Depending on requirements, the flat bag can be designed as a three-edge sealed bag or a four-edge sealed bag. While the three-side sealed pouch is only sealed on the sides and the top side, the four-side sealed pouch has an additional sealed seam on the bottom side. This gives the four-side sealed pouch the same external dimensions but with a smaller volume than the three-side sealed pouch.
The following machine types can be used for processing these bags, depending on your requirements: