POST-CONSUMER WASTE CORRUGATED BOARD - SUPPLEMENT TO VIRGIN KRAFT IN LINERBOARD

New process technology and equipment are described which have enabled the successful utilization of low-quality post-consumer waste corrugated board as a supplement to virgin kraft in fourdrinier linerboard. In addition to considerable savings in furnish costs, runnability and felt life on the paper machine have improved. After adding a secondary-fiber stock preparation system rather than expanding kraft pulping facilities, one mill has raised total post-consumer waste corrugated board capacity to 272 metric tons/day or up to 30% of total production. The paper describes this stock preparation system, which consists of a newly developed pulping system having large extraction holes in the pulper followed by pressure screens with 0. 46-mm slotted baskets and a full-flow reverse centrifugal cleaning system. Capital investment and operating costs are compared to those for virgin kraft.