Abstract: A method is provided for converting waste paper materials into more useful forms for uses such as plant mulches, lightweight concrete aggregates, fertilizers, animal feeds, chemical food stock and other materials, fuels and uses such as recycling paper processes. Waste paper materials including corrugated box board, paper board, paper of all types, etc. is available as a raw material in a wide variety of forms such as sheets, bales, bundles, boxes, shavings, clippings from box making operations, magazines, newspapers, etc. and these products are much more useful for the purposes and uses mentioned after treatment and conversion into a more useful form. This conversion includes the steps of bale breaking, sorting, trimming and/or cutting these raw materials into pieces of relatively limited size for feeding across a cutter bar into a rotating knife cylinder wherein the raw materials are cut into small pieces.