US Patent 7223260 Collecting bag having an improved closure

The collecting bag has a bag member formed by a first and a second film blank, and a discharge portion that is foldable and unfoldable to bring the discharge portion from an open unfolded condition to a closed folded condition and vice versa. A first plate member is positioned on the first film blank and a second plate member is positioned on an extension of the second film blank Each plate member is formed from a relatively stiff material, and the distance between the distal edge of the first plate member and the proximal edge of the second plate member is smaller than the thickness of the first plate member. When folding the discharge portion, the distal edge of the first plate member acts as a pivot, and a stretching effect is created on the second film blank to effectively seal the discharge opening without deformation of the plate members.