a device produces containers having an inner space divided into separate container chambers by at least one separating wall . an extruder extrudes a tube of a plasticized synthetic material from an annular gap between an outer nozzle ring and an inner nozzle core . the nozzle core is provided with a guide for synthetic material that is branched off from the annular gap . at at least one outlet port at one nozzle end , the branched - off synthetic material is issued and forms a continuous separating wall that extends within the extruded tube . the guide for the branched - off synthetic material is positioned in a zone of the annular gap located upstream of and at a distance form the outlet end of the outlet port .