MANUFACTURING METHOD FOR INCREASING BULK AND STIFFNESS OF PAPERBOARD BY USING MECHANICALLY AND CHEMICALLY MODIFIED WOOD PARTICLES INTO PAPERBOARD MIDDLE LAYERS

摘要

A method for manufacturing a pasteboard is provided to increase bulk and bending stiffness of the pasteboard, by using adding woody fiber particles, which are physically reformed, in a middle layer of the pasteboard. A timber chip is beat by defibrators, thereby forming woody fiber particles each having a length weighted mean fiber length of 1.0-3.0 mm and a fiber wall thickness of less than 0.9 mg/m. The formed woody fiber particles are chemically processed by using oxidizers, acid, or alkali. The chemically processed woody fiber particles and chemically unprocessed woody fiber particles are physically processed by using beaters, refiners, or defibrators, thereby forming woody fiber particles each having a length weighted mean fiber length of less than 1.0 mm and a fiber wall thickness of less than 0.9 mg/m.