Abstract: An extruder forms shaped bodies from plastics-filler mixtures having a filler content of more than 50% by volume. The extruder comprises a product feed device, an outer mouthpiece and two barrels arranged coaxially between the product feed device and the outer mouthpiece. The first barrel (input cone) having an inside wall provided with grooves essentially parallel to the longitudinal extent of the barrel is connected with the product feed device. The second barrel (output zone) is connected with the outer mouthpiece. A screw arranged in the first barrel conveys material into the second barrel. Separate tempering arrangements for the first barrel, for the second barrel and for the mouthpiece control the desired operation temperatures in the extruder. Preferably, the extruder additionally includes a mandrel connected with the screw and arranged in the second barrel.