PURPOSE: To provide both an improved apparatus and method for treating an animal fiber, especially an unprocessed wool.

CONSTITUTION: This apparatus comprises an inlet 2 for the admission of raw (greasy) wool and a first solvent bowl 3 to which wool is firstly admitted. Wool in the first solvent bowl 3 is wetted by a solvent sprayed from a nozzle 11 and falls into a solvent bath 13. An endless belt 5 transports wool through the solvent bath 13 in the first solvent bowl 3. A co-flow of a solvent through a nozzle 14 is utilized to ensure that wool disposed on the belt 5 travels as the same speed as the belt 5. A pressurized spray from a shower device 7 is directed to wool in the belt 5 to cleanse the wool. The treated wool in the first solvent bowl 3 is transported to an elevated portion of the endless belt 5 where it is subjected to a cascade of solvent from a weir 8.