Extrusion process and extrusion apparatus for realizing this process

摘要

1. An extrusion process for the manufacture of a product from the group of the expanded starch products or the structured protein products, wherein the material supplied is acted on in a single screw extruder (1) having a material inlet (5), pressure build-up and reduction zones (16, 22, 27) and also a discharge nozzle (7, 97) by pressure, friction, and if necessary heat, characterised in that the pressure in the material (5) is rapidly build-up to its maximum value in a range from 100 to 500 bar in a first zone (16) of the extruder (1) arranged directly after the material inlet (5) and representing the single pressure build-up zone, with this maximum value being achieved at the start of an intermediate zone (22) of the extruder (1) where the material is still solid or only liquefied to a small degree ; with the intermediate zone directly following the pressure build-up zone (16) ; in that the material is liquefied in this intermediate zone (22) with gradually falling pressure ; and in that, in a zone (27) of the extruder (1) which directly follows the intermediate or liquefaction zone (22), the pressure in the material is gradually consumed for homogenisation of the same down to a pressure in the range from 10 to 100 bar prevailing in front of the extrusion nozzle (7, 97) which directly follows this zone (27).