Plant for producing an extruded silicone intermediate, use of a corotating twin-screw extruder, and process for producing a raw silicone extrudate

A plant for producing an extruded silicone intermediate, comprising:

• a mixer/extruder for mixing and subsequently extruding a silicone compound including crosslinker additives, for producing a raw silicone extrudate;
• a feed apparatus for feeding raw materials of the silicone compound and the crosslinker additives to the mixer/extruder;
• and
• a heating apparatus for crosslinking the raw silicone extrudate to produce a crosslinked silicone intermediate,
• wherein the feed apparatus is a co-rotating twin-screw extruder including two extruder screws that taper conically toward a downstream extrusion die,
• wherein the feed apparatus includes
• a feed hopper for receiving the raw materials of the silicone compound,
• a feed screw disposed within the feed hopper, and
• a plurality of feed facilities for feeding the raw materials and/or the crosslinker additives,
• wherein the plurality of feed facilities include
• a first feed facility including a first provision container in fluid communication with an upstream section of the feed screw,
• a second feed facility including a second provision container in fluid communication with a middle section of the feed screw proximal to a conically tapered outlet section of the feed hopper,
• a third feed facility including a third provision container in fluid communication with a downstream section of the feed screw at a screw sleeve, the screw sleeve being in fluid communication with a delivery end of the feed hopper and an addition port of the mixer/extruder,
• a fourth feed facility including a fourth provision container in fluid communication with the addition port, and
• a fifth feed facility including a fifth provision container in fluid communication with an upstream section of the two extruder screws,
• wherein the mixer/extruder is configured such that during mixing and during extrusion a temperature of the silicone compound does not exceed 60° C.,
• wherein the mixer/extruder is configured such that an energy input into the silicone compound during mixing and during extrusion in total is always less than 20 Wh/kg.