A transfer unit is configured for use with a form, fill and seal packaging machine. The transfer unit receives a partially erected carton from a first station in a tubular form, conveys the carton to a second station, and conveys the carton from the second station to a third station. The transfer unit includes a hub defining a longitudinal hub axis and configured for rotational movement about the hub axis. A plurality of car pairs are mounted to the hub for longitudinal movement along the hub. Each of the car pairs includes first and second cars, each of which has first and second mandrels mounted thereto. The mandrels are configured to receive a partially erected carton. Each mandrel has a mandrel axis and is rotational about its respective axis. The mandrel axes are perpendicular and tangential to the hub axis. A drive longitudinally moving the car pairs along the hub and rotationally moves the mandrels about their respective mandrel axes, about 90 degrees, between an untwisted position and a twisted position.