Method and device for extruding and labelling a cylindrical product

A method of extruding and labeling a packaging tube by an extrusion-labeling line comprising the steps of:

• (a) forming a partially or totally tubular label from a film in a shaper;
• (b) introducing the tubular label into a calibration element;
• (c) extruding a tubular body on a side of a concave face of the tubular label in an extrusion head;
• and
• (d) bringing an external face of the extruded tubular body into contact with the concave face of the tubular label to produce a labelled packaging tube, by creating a first pressure difference between an interior and the external face of the extruded tubular body by an air jet, the first pressure difference generated by a first floating plug arranged downstream of the shaper that at least partially obstructs an escape of air via the interior of the tubular body,
• wherein the tubular label includes two layers, one of the layers has a melting point that is at least 20° C. higher than a melting point of the extruded tubular body.

An extrusion-labeling device comprising:

• a device for forming a partially or totally tubular label from a film;
• an extrusion device including an extrusion nozzle for forming a tubular body, on a side of a concave face of the tubular label;
• a calibration element, the extrusion nozzle being disposed inside the calibration element;
• a blower device for creating a jet of compressed air in the tubular body to bring the tubular body into contact with the concave face of the tubular label to form a labelled tube;
• a first floating plug located away from the extrusion nozzle;
• and
• a second plug located in proximity to the extrusion nozzle.