Abstract: In apparatus for manufacturing tubular container sleeves, a blank is wrapped around a fixed mandrel by means of a pair of sweeper arms that are swingable and movable in translation. In each sleeve forming operation the sweeper arms are displaced from a position in which both are wholly at one side of the mandrel to a position in which they embrace the mandrel, each having an inner pivoted end at that one side of the mandrel and an outer swinging end at the other side of the mandrel. During at least the final half of each such displacement the outer ends of the sweeper arms maintain constant engagement against the mandrel through the blank. During the first half of that displacement the blank is progressively engaged against the mandrel by a sweeper band extending under tension between the outer ends of the sweeper arms.