Method of forming a mat for making particleboard

A method of forming a mat of elongated mainly wood particles on a horizontal and horizontally displaceable conveyor surface with a spreading head having an array of parallel interedigitated disks forming longitudinally extending spaces and rotatable about coplanar axes above said conveyor surface, said method comprising the steps of:

• (a) continuously displacing said conveyor surface in a longitudinal transport direction generally perpendicular to said axes;
• (b) feeding said elongated mainly wood particles onto said array of disks while rotating said disks to orient said particles in said transport direction and deposit said particles onto said conveyor surface as a mat having underneath said array a generally planar upper mat surface having relative to said transport direction upstream and downstream portions and forming with said conveyor surface a deposition angle;
• and
• (c) orienting the plane of said axes at an acute angle to said upper mat surface with said array so much closer to said upper surface at its said upstream portion than at its said donwstream portion that said particles fall a relatively short distance and are deposited on said conveyor generally parallel to said direction underneath said upstream portion and fall a relatively long distance and are deposited generally randomly underneath said downstream portion, whereby the mat thus formed has a lower layer of parallel particles covered by an upper layer of randomly arranged particles.