An inflatable-cushion inflation and sealing device, comprising: an inflation assembly that inflates a cushion cavity disposed between overlapping portions of first and second plies of a film with a fluid, wherein the plies cooperatively form a flexible structure; a sealing mechanism comprising: a first compression element having a curved surface operable to bend the flexible structure thereabout; a second compression element positioned against the first compression element to pinch the flexible structure therebetween at a first pinch area; a heating element disposed adjacent the first pinch location to heat the film sufficiently to seal the plies to each other to produce a longitudinal seal as the film is moved past the first pinch area; and a third compression element positioned against the first compression element to pinch the flexible structure therebetween at a second pinch area downstream of the first pinch area, the curved surface of the first compression element forming a path between the first pinch area and the second pinch area, such that the second, and third compression elements (161, 163) hold the flexible structure against the first compression element along a cooling path between the first and second pinch areas (176, 178) with a surface of the film opposite from the first compression element free of contact with the sealing mechanism while the film is sufficiently retained against the curved surface of the first compression element to hold the fluid in the cushion cavity while the longitudinal seal cools; characterized in that the first compression element is a first nip roller. an inflation assembly that inflates a cushion cavity disposed between overlapping portions of first and second plies of a film with a fluid, wherein the plies cooperatively form a flexible structure; a sealing mechanism comprising: a first compression element having a curved surface operable to bend the flexible structure thereabout; a second compression element positioned against the first compression element to pinch the flexible structure therebetween at a first pinch area; a heating element disposed adjacent the first pinch location to heat the film sufficiently to seal the plies to each other to produce a longitudinal seal as the film is moved past the first pinch area; and a third compression element positioned against the first compression element to pinch the flexible structure therebetween at a second pinch area downstream of the first pinch area, the curved surface of the first compression element forming a path between the first pinch area and the second pinch area, such that the second, and third compression elements (161, 163) hold the flexible structure against the first compression element along a cooling path between the first and second pinch areas (176, 178) with a surface of the film opposite from the first compression element free of contact with the sealing mechanism while the film is sufficiently retained against the curved surface of the first compression element to hold the fluid in the cushion cavity while the longitudinal seal cools; a first compression element having a curved surface operable to bend the flexible structure thereabout; a second compression element positioned against the first compression element to pinch the flexible structure therebetween at a first pinch area; a heating element disposed adjacent the first pinch location to heat the film sufficiently to seal the plies to each other to produce a longitudinal seal as the film is moved past the first pinch area; and a third compression element positioned against the first compression element to pinch the flexible structure therebetween at a second pinch area downstream of the first pinch area, the curved surface of the first compression element forming a path between the first pinch area and the second pinch area, such that the second, and third compression elements (161, 163) hold the flexible structure against the first compression element along a cooling path between the first and second pinch areas (176, 178) with a surface of the film opposite from the first compression element free of contact with the sealing mechanism while the film is sufficiently retained against the curved surface of the first compression element to hold the fluid in the cushion cavity while the longitudinal seal cools; characterized in that the first compression element is a first nip roller.