is provided this including an endless knife belt 16 carried by pulleys 17 18 the pulley 18 being driven by a motor 19 by v belt 20 driving a pulley 21 on shaft 22 on which pulley 18 is mounted the pulleys 17 18 being mounted in n frames 2 3 respectively the knife belt 16 operates over an angle plate 23 and under the fingers 24 25 these fingers are mounted for example by clamping or welding or brazing to a plate 26 behind the knife belt 16 to extend across the knife belt 16 with the fingers 24 being longer and extending a short distance past the fingers 25 which protrude just past the cutting edge 27 of the knife belt 16 the cutting edge 27 of the knife belt 16 is bevelled to a cutting edge with the edge being serrated the serrations can be at the edge itself but preferably the bevelled surface is serrated these serrations are of a fine or small nature and one manner of satisfactorily producing such serrations is to form the bevel by applying a coarse rotary grinding wheel to the moving knife belt 16 the fingers 24 and 25 are wirelike and with their pointed ends easily protrude through the wool and it has been found that the serrations on the belt 16 effectively cut the wool fed to the knife by the fingers while it is known that a sharply honed edge will not satisfactorily cut wool.