A MOIST-LIBERATION PROCESS FOR PRODUCING DRY SECONDARY FIBERS

This study verified the feasibility of liberating secondary fibers fro m wastepaper webs by weakening interfiber hydrogen bonds of paper webs with water, and processing with an atmospheric pressure single-rotati on disc refiner and a fiber separator and dryer. The intent was to lib erate secondary fibers from paper webs while retaining most fiber inte grity without employing the highly water-dependent hydropulping operat ion that characterizes the wet-liberation process widely used by the p ulp and paper industry. Eliminating the hydropulping would eliminate t he need for water-pollution-abatement operations. The effectiveness of this moist-liberation process (no hydropulping) was indirectly verifi ed by the fact that flexural strength and water-related physical prope rties of moist-liberated old corrugated container (OCC) secondary fibe r composites (bonded with a very high polyisocyanate resin level using a dry-consolidation process) are comparable to those of wet-liberatio n processed (hydropulped) OCC secondary fibers.