IMPROVED DUPLEX LINERBOARD FORMED FROM OLD CORRUGATED CONTAINERS
An improved duplex linerboard is formed from old corrugated containers (OCC) (10) by first repulping (12) the OCC and screening (16) it to provide a fine fraction (26) and a coarse fraction (18). NaHSO3 or H2O2 (30) is applied to the fine fraction and the fine fraction produces a chemically treated fine fraction which is then refined (34). Coarse fraction is separately refined (22) and the refined coarse fraction pulp (24) is then used to form the bottom ply of a multi-ply board and the refined fine fraction pulp (36) used to form the top ply of the multi-ply board.