Strength Development in OCC and OCC Mixed Paper Furnishes: A Benchtop and Pilot Plant Study, 1999 Recycling Symposium Proceedings

Roger J. Dexter, Dennis W. Barton, Mark E. Laurint, MaryBeth K. Letscher, Michael A. Schuster

Brown recycled fiber mills in the United States are becoming increasingly concerned with quality and strength issues in their finished products. As furnishes experience multiple recycles, the quality of the recycled fiber tends to decline. This leads to strength as well as dirt, yield, and runnability issues. Add the complication of water conservation and the reasons for recycled mills’ concern are obvious.

This study includes benchtop and pilot plant investigations of various physical properties of 100% Old Corrugated Containers (OCC), 100 % Mixed Paper (MP), and mixtures of these two basic furnishes. The furnishes were characterized in detail. The mixing of MP and OCC was used to simulate a general reduction in raw material quality. The pilot studies included the impact of pH changes, different types of refiner plates, fiber fractionation, and chemical (starch and polymer) additions on several strength properties (including STFI and Ring Crush) on these mixed furnishes.

Part I of the paper utilizes both benchtop studies (Valley beater) and Pilot Plant studies (Hercules Pulp and Paper Division Applications Research Laboratory) [1] to investigate refining, pH, and fractionation as means for increasing strength of OCC and mixtures of OCC and MP. Part II of the paper involves the testing of various chemicals (polymers and starches) for strength development on the furnishes generated in Part I.