FEASIBILITY OF USING RECYCLED NEWSPAPERS AS A FIBER SOURCE FOR DRY-PROCESS HARDBOARDS

Dry-process hardboard represents a favorable option for recycling old newspaper fibers. However, dry-process boards tend to be less dimensio nally stable than boards processed by other methods. Our objective was to determine the mechanical and physical properties of 3-mm and 11-mm dry-process hardboards made from various ratios of wood fiber to old newspaper (ONP) (100:0, 50:50, and 0:100). Two series of 3-mm hardboar ds were made, one with untreated fiber and the other with acetylated f iber. Resin levels were 3 or 7 percent, and all 3-mm hardboards had 0. 5 percent wax. The 11-mm hardboards were made with untreated fiber, 5 .5 percent resin, and 2 percent wax. Boards were tested for static ben ding and tensile strength properties, water absorption, thickness swel l, and linear expansion. As expected, increasing the resin level from 3 to 7 percent generally improved all properties. Acetylation substant ially improved the water absorption, thickness swell, and linear expan sion but decreased the mechanical properties of all boards; increasing the amount of ONP caused a corresponding deterioration in mechanical properties, water absorption, and thickness swell.