Abstract: An apparatus for making plastic handle bags from an advancing flat tubular web includes a knife supported above the moving web and reciprocated transversely by a cam roller to produce a sinusoidal-wave-like cut longitudinally of the web. A support guide having a slot at least as wide as the wave amplitude is positioned beneath the web so that in the event of an interruption of feed the guide lowers, withdrawing the web from the knife, which continues to reciprocate, thereby avoiding start-up inertial friction or chatter. Downstream of the cutting station a detour assembly phase shifts one of the half-tubes 180.degree. to align the transversely extending bag edges for heat sealing. The cutting support assembly is longitudinally movable of the web.