The friction washers are mounted on an inclined frame. The material enters at the lower end of the washer with vertical in-feed. The special angular flights in conjunction with the high rpm of the shaft transport the material in an inclined direction toward the top of the unit and simultaneously executes the washing phase. Fines, water and soaked fiberous paper are separated through the perforated screen cage which surrounds the high speed shaft and allows the separated material to flow down through the friction washer housing to the lower discharge pipe.
The device is equipped with water injection nozzles which spray the fresh water or recycled water directly at the screen cage to assist in screen cage cleaning and prevent clogging. In conjunction with the water spray the friction washer is manufactured with a pneumatically operated mechanical screen cleaner.