Abstract: The bag of the present invention is formed by extruding an elongated tube of sheet material and forming the tube into a gusseted tube having in-tucked gusseted walls at the lateral edges thereof. After the formation of the gussets, the tube is expanded by means of an air bubble, and the gussets are forced outwardly so that the tube is formed into a nongusseted tube. The creases which formed the original gusset walls remain in the tube and in cross-section form apexes forming outwardly from the front and rear walls of the tube. These apexes provide means for grasping and opening the upper end of the tube when the bag is being filled.

Abstract: A block bottom valve bag comprises an elongated bag tube having opposite ends. One end of the bag is folded to form a block bottom closure comprising first and second side flaps folded toward one another in overlapping relationship and adhered to one another, and a pair of end flaps extending inwardly beneath the side flaps at the opposite ends thereof. An elongated valve member extends between one of the end flaps and overlapped side flaps. The valve member comprises an elongated flexible valve tube collapsed into a flat configuration having upper and lower walls in facing relation. The upper wall is operatively secured to the interior surfaces of the side flaps and the lower wall of the valve tube is operatively secured adjacent one end thereof to the end flap and is detachably secured adjacent the other end thereof to the end flap. A reinforcing sheet member may be interposed between and adhered to the under surface of the side flaps and the upper surface of the valve tube.

Abstract: A vented bag comprising a front wall, a back wall, and opposite end walls forming an enclosed container. Each of the end walls is comprised of first and second side flaps folded towards one another in an overlapping relationship and being adhered to one another. A pair of end flaps extend inwardly beneath the side flaps at the opposite ends thereof. One of the end walls is provided with a valve member which is positioned between one of the end flaps and the overlapped side flaps. A plurality of venting perforations are formed in at least one of the end walls for providing communication between the interior of the container and the atmosphere. A flat member is secured to the exterior surface of the said one end wall and is positioned over the venting perforations so that air from the interior of the container may escape therefrom outwardly through the vent perforations and outwardly between the end wall and the flap member.