Fiber depither

An improved depithing device comprising an inlet to permit the flow of fiber into a circular chamber having a perforated wall structure, an outlet from said circular chamber, a rotor carrying an upper plurality of blades and a lower plurality of blades centered for rotation within said circular chamnber, means to rotate said rotor, and a chamber surrounding said circular chamber and adapted to receive material passing through the perforated wall of said circular chamber;

• the improvement comprising said rotor having a separated upper and a lower plurality of blades;
• the uppermost blades of said upper plurality of blades being feeder blades having an end surface area at least 2 times the end surface area of the remaining blades;
• and the lowermost blades of said lower plurality of blades being fan blades wherein the outer end of said blades have a ratio of height to width of at least 5.