Abstract: The present invention relates to a method for producing a polymer material filled with longer fibers, wherein the fibers, which typically have a residual moisture content of approximately 5 to 8% and a minimum length of more than 2 mm, and the carrier material are mixed and heated in a reactor or cutter-compacter, constantly moving them and optionally comminuting the carrier material, and constantly maintaining the pourability and/or lumpiness. According to the invention, the conditions, and particularly the temperature, in the reactor are adjusted so as to dry the fibers to the lowest residual moisture possible, at which the fibers are just barely sufficiently flexible so as not to break during processing in the reactor, or during an optionally following compression step, for example extrusion.