is tangentially of the chamber within pressurized fiberizer 13 fiberizer 13 operates under pressure to effect the liberation of fibers from slushed materials delivered therein the pressure in fiberizer 13 is approximately 15 to 40 meters of water 1 5 to 4 atmospheres of pressure an impellor 15 creates a helical turbulence or stream in fiberizer 13 in such a way that the lighter contaminants associated with the comminuted and slushed waste paper are distributed and separated for evacuation through central conduit 16 the separation is generally incomplete in that light contaminants passing into conduit 16 entrain some fibrous cellulosic materials accordingly conduit 16 conveys the light contaminants with fibrous material to a vibratory sieve 25 wherein the light contaminants are separated from the flow and retained on the sieve surface the cellulosic fibrous materials in suspension pass through the sieve 25 and into conduit 26 for recycling to slusher 1 this recycled cellulosic fiber material is then carried through the fiberizer again for reclamation with liberated fibers as shown in the drawing the flow of material through conduit 16 may be controlled by a valve 23 when desired valve 23 may be left open so that the flow of material to sieve 25 is continuous valve 24 entering into conduit 16 may provide water for dilution of the suspension travelling to the sieve 25 in an alternate embodiment the shut off.