A process of comminution of wood chips (C) having a grain direction to produce a mixture of wood particles (P), wherein the wood chips are characterized by an average length dimension (LC) as measured substantially parallel to the grain, an average width dimension (WC) as measured normal to LC and aligned cross grain, and an average height dimension (HC) as measured normal to WC and LC, and wherein the comminution process comprises the step of feeding the wood chips in a direction of travel substantially randomly to the grain direction through a counter rotating pair of intermeshing arrays of cutting discs (D) arrayed axially perpendicular to the direction of wood chip travel, wherein the cutting discs have a uniform thickness (TD), and wherein at least one of LC, WC, and HC is greater than TD.