D21B—FIBROUS RAW MATERIALS OR THEIR MECHANICAL TREATMENT
D21B1/00—Fibrous raw materials or their mechanical treatment
D21B1/04—Fibrous raw materials or their mechanical treatment by dividing raw materials into small particles, e.g. fibres
D21B1/12—Fibrous raw materials or their mechanical treatment by dividing raw materials into small particles, e.g. fibres by wet methods, by the use of steam