An extrusion machine for the continuous manufacture of profiles from a moldable extrusion material, comprising - a main frame, - at least one friction wheel rotatable about a drive axis, which friction wheel is provided with at least one peripheral groove and is in drive connection with a drive device, - a tool holding device, which is mounted on a pivot axis held on the main frame and can be pivoted about the pivot axis between a working position and a release position, wherein the tool holding device is arranged downstream of the friction wheel, as viewed in the pass-through direction of the profile to be manufactured, - a locking device, which locking device in its locking position holds the tool holding device locked in its working position relative to the main frame, - at least one tool unit, which tool unit is supported on the tool holding device, in particular is accommodated in an accommodation chamber arranged in the tool holding device, and includes or forms at least one stripping area with at least one stripping element for the extrusion material to be molded by the friction wheel, characterized in - that a shielding unit is provided, - that the shielding unit comprises at least one first nozzle and at least one second nozzle, - that the at least one first nozzle and the at least one second nozzle are each formed to emit a gas which is free of gaseous oxygen to minimize or prevent an access of ambient air to the heated extrusion material, - that the at least one first nozzle is directed towards a peripheral portion of the friction wheel, which peripheral portion is provided for contact with the supplied extrusion material, - that the at least one second nozzle is arranged below the stripping area of the tool unit, and - that the shielding unit further comprises at least one butterfly valve, and the at least one butterfly valve of the at least one first nozzle is arranged in the area of the peripheral portion of the friction wheel and, as viewed in the direction of rotation of the friction wheel, upstream of the first nozzle, wherein the butterfly valve is configured to prevent the inflow of ambient air into a working area of the friction wheel defined by the peripheral portion and to reduce the outflow of the supplied gas from the working area. - a main frame, - at least one friction wheel rotatable about a drive axis, which friction wheel is provided with at least one peripheral groove and is in drive connection with a drive device, - a tool holding device, which is mounted on a pivot axis held on the main frame and can be pivoted about the pivot axis between a working position and a release position, wherein the tool holding device is arranged downstream of the friction wheel, as viewed in the pass-through direction of the profile to be manufactured, - a locking device, which locking device in its locking position holds the tool holding device locked in its working position relative to the main frame, - at least one tool unit, which tool unit is supported on the tool holding device, in particular is accommodated in an accommodation chamber arranged in the tool holding device, and includes or forms at least one stripping area with at least one stripping element for the extrusion material to be molded by the friction wheel, - that a shielding unit is provided, - that the shielding unit comprises at least one first nozzle and at least one second nozzle, - that the at least one first nozzle and the at least one second nozzle are each formed to emit a gas which is free of gaseous oxygen to minimize or prevent an access of ambient air to the heated extrusion material, - that the at least one first nozzle is directed towards a peripheral portion of the friction wheel, which peripheral portion is provided for contact with the supplied extrusion material, - that the at least one second nozzle is arranged below the stripping area of the tool unit, and - that the shielding unit further comprises at least one butterfly valve, and the at least one butterfly valve of the at least one first nozzle is arranged in the area of the peripheral portion of the friction wheel and, as viewed in the direction of rotation of the friction wheel, upstream of the first nozzle, wherein the butterfly valve is configured to prevent the inflow of ambient air into a working area of the friction wheel defined by the peripheral portion and to reduce the outflow of the supplied gas from the working area.