Abstract: There is provided a method and an apparatus for producing a sleeve from a heat-sealable foil blank, wherein the blank is wrapped around a mandrel by means of a strip of flexible material acting on the side of said blank remote from the mandrel. A strip section engaging the blank is held tensioned between two strip-guides which are movable around the mandrel to successively place strip material, and therewith also the foil blank, against the mandrel until the mandrel is surrounded by said blank and two opposite edge portions of the blank overlap each other. The overlapping edge portions of the blank are welded together by heating a portion of said strip material placed on top of said overlapping blank edge portions.