A process for producing an extruded, sulfur-crosslinkable rubber mixture, the process comprising the following process steps:
- A) producing a sulfur-crosslinkable rubber mixture by using a mixer, or providing a sulfur-crosslinkable rubber mixture, wherein temperature of the sulfur-crosslinkable rubber mixture is less than 35° C.;
- B) contactlessly adjusting the temperature of the sulfur-crosslinkable rubber mixture produced or provided in step A) to at least 40° C. in a temperature adjustment unit;
- C) measuring the temperature of the sulfur-crosslinkable rubber mixture, the temperature of which has been adjusted in step B);
- D) feeding the sulfur-crosslinkable rubber mixture, the temperature of which has been adjusted in step B) and measured in step C), into an extrusion unit at a temperature of 35° C. or more and extruding the fed sulfur-crosslinkable rubber mixture with the extrusion unit;
- and,
- E) controlling the temperature of the sulfur-crosslinkable rubber mixture by using the temperature adjustment unit based on closed-loop control as a function of at least one of the following parameters:
- drive power for rotating a screw of the extrusion unit;
- pressure of the sulfur-crosslinkable rubber mixture in the extrusion unit;
- variations in pressure of the sulfur-crosslinkable rubber mixture in the extrusion unit;
- or
- variations in weight per meter of the extruded sulfur-crosslinkable rubber mixture downstream of the extrusion unit,
- wherein the contactlessly adjusting the temperature of the sulfur-crosslinkable rubber mixture in step B) includes heating the sulfur-crosslinkable rubber mixture produced or provided in step A) with thermal radiation from at least one heating unit, wherein the heating is to within a temperature range from (a) 40° C. or more to (b) less than a pre-vulcanization temperature of the sulfur-crosslinkable rubber mixture;
- wherein the temperature adjustment unit and/or the extrusion unit comprises at least one temperature sensor, wherein one or more of the at least one temperature sensor ascertains the temperature of the rubber mixture in step C);
- wherein the at least one parameter from step E) is ascertained during the extruding by using one or more measurement sensors;
- wherein the controlling the temperature of the sulfur-crosslinkable rubber mixture by using the temperature adjustment unit based on closed-loop control in step E) includes cooling or heating the sulfur-crosslinkable rubber mixture in the temperature adjustment unit based upon the at least one parameter ascertained from the one or more measurement sensors;
- and
- wherein, when heating is performed in step E), the heating uses contactless heating via thermal radiation from the at least one heating unit to control the temperature to within a temperature range from (a) 40° C. or more to (b) less than the pre-vulcanization temperature of the sulfur-crosslinkable rubber mixture.