Patent ID: 8038841

Claim:
A method for producing fine paper powder, comprising: a first fine pulverizing step of pulverizing coarsely ground paper powder using a first vertical roller mill equipped with a plurality of first pulverizing rollers, each having helical grooves formed on an outer circumferential surface thereof, in order to obtain a fine paper powder having an average particle diameter of 50 μm or greater and less than 150 μm; and a second fine pulverizing step of pulverizing said fine paper powder obtained in said first fine pulverizing step using a second vertical roller mill equipped with a plurality of second pulverizing rollers, each having helical grooves formed on an outer circumferential surface thereof, in order to obtain a fine paper powder having an average particle diameter of 25 μm or greater and less than 50 μm, wherein an angle of inclination of the grooves of said first pulverizing rollers with respect to axes of rotation of said first pulverizing rollers is smaller than an angle of inclination of the grooves of said second pulverizing rollers with respect to axes of rotation of said second pulverizing rollers.