An apparatus for joining a first film portion and a second film portion together along a seal line. The apparatus includes a horn and anvil. The anvil is positioned close to the horn. The horn or anvil has a face that is rotatable about a rotation axis. The face has a raised profile, and a height thereof has a dimension corresponding to 50% to 150% of a thickness of the first film portion or the second film portion. The face is positioned such that the raised profile extends along the circumference such that continuous running contact is provided between the raised profile and the other of the one of the horn or the anvil when rotated about the rotation axis, to form the seal line without any external structure to control a distance between the horn/anvil. A tapered bonding profile, a traction pattern, and a cut-and-seal feature are also disclosed.