Abstract: An expander, suitable for use in an expandable bag having a closure, includes a stuffer movable from a collapsed orientation wherein the stuffer is substantially flat to an expanded orientation wherein said stuffer is not substantially flat. The stuffer is biased for movement from the collapsed orientation to the expanded orientation. A tearable band disposed about the stuffer releasably maintains the stuffer in the collapsed orientation, and a tearing mechanism is provided for tearing the tearable band to enable the stuffer to move from the collapsed orientation to the expanded orientation, the tearing means being operable from outside the bag.The stuffer is disposed in the bag in the collapsed orientation with the closure closed, the tearable band being disposed in the bag and the tearing mechanism being disposed partially within the bag and partially without the bag.