An extrusion device (1) for manufacturing a product based on a rubber mix, which comprises a rotary roller (5), an inlet orifice (15) for the rubber mix and a vault (6) partially circumferentially covering the external surface (51) of the roller (5), the rubber mix being driven from the inlet orifice (15) into the air gap situated between the vault (6) and the roller (5) towards an extrusion orifice (21) defining the profile of the product. The extrusion orifice is delimited by a wall (20) which cooperates with the external surface (51) of the roller (5), and the vault (6) carries on its internal surface oriented towards the roller projecting threads in order to delimit with the surface (51) of the roller a chamber for plasticization of the mix, at least two of the threads extending substantially axially of the roller.