Patent ID: 8182564

Claim:
A multi-layer bag assembly for use with a housing having an external structure for collecting particles from air flowing through said multi-layer bag assembly, said multi-layer bag assembly comprising: at least two bags arranged one inside the other and having an innermost bag, each of said at least two bags having an open end portion facing in one and the same direction, the respective open end portions being movable between a wide open condition and a closed condition, a closed end portion, and a closed side portion interconnecting said respective closed end portions and said open end portions, each of said bags being composed of an air permeable filtering material for collecting particles carried by air flowing through the material, the air permeable filtering material being the same or different for the respective at least two bags; structure for holding the respective open end portions of said at least two bags in a wide open position, said structure comprising an integral collar composed of removable collars attached to the respective open ends of said at least two bags, said removable collar of said innermost bag being separable from the remaining portion of said integral collar for enabling the withdrawal and disposal of said innermost bag with said removable collar of said innermost bag remaining attached to said innermost bag.