A device for preparing a flat profiled element from an elastomeric thermoplastic gel includes: an extruder with at least one feed and a discharge; an extruder die having section configured to be suitable for a profile of the flat profiled element; a liquid cooling bath with a free surface for receiving and cooling the flat profiled element as the flat profiled element is discharged from the extruder die; and a flat moving support for receiving the flat profiled element. The free surface of the liquid cooling bath is arranged in an immediate vicinity of an outlet of the extruder die. Additionally, an angle of inclination of a plane of the extruder die to a horizontal plane is between 20 and 70 degrees.