Patent ID: 8317975

Claim:
A process of pulping lignocellulosic materials consisting of the steps of: (a) contacting a charge of a lignocellulosic material with water, the lignocellulosic material containing an initial amount of xylan, the water and charge of lignocellulosic material maintained at a temperature in the range of between about 20° C. and about 200° C. and lowering the pH to between about 3.0 and about 6.9 by producing acetic acid from the reaction of the water and lignocellulosic material for a period of about 90 minutes to about 120 minutes, wherein an aqueous extract and extracted lignocellulosic materials are obtained, the aqueous extract containing about 65% of the initial amount of xylan present in the charge of lignocellulosic material; (b) pulping a portion of said extracted lignocellulosic materials wherein individual fibers and fiber bundles are produced and have a kappa number of at least 7 in less than 150 minutes; and (c) bleaching said product of said step (b).