Weyerhaeuser Company Limited

North Pacific Paper Company, LLC

Kaaren K Haynes

Roger O Campbell

Robert T Hamilton

Anthony Parrish

Zeecha L Brooks

A method of making bleached mechanical pulps is disclosed for pulping mills having a primary and a secondary refiner. A first step is to provide cellulosic materials, such as wood chips to refine into the pulp; the wood chips have an initial brightness level. A second step is to provide a bleaching liquor to the refining system of the pulp mill, wherein the liquor comprises an amount of hydrogen peroxide and an amount of alkali having greater than 0% to 100% magnesium hydroxide or soda ash or a combination thereof. A third step is to hold the pulp with the bleaching liquor at a temperature in the range of about 85&deg; to about 160&deg; C. and for about 2 to about 180 minutes. The components of the bleach liquor can be added at the first refiner or interstage between refiners.

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Federal Way, WA, United States of America

Kaaren K Haynes