This paper discusses efforts to characterize the rheological properties of pulps that include low-grade wastepapers and papermill sludges to determine their potential for extrusion andconversion into useful products. We investigated apparent changes in viscosity associated with the addition of typical inorganic paper fillers to "clean" pulps. Addition of calcium carbonate significantly increased apparent pulp viscosity, but clay and titanium dioxide had minimal effects. When high molecular weight sodium carboxymethyl cellulose was added to the pulps, fillers had a minimal effect on visocsity. We detrmined that a non-cleaned recycled magazine pulp makes a suitable model sludge for extrusion purposes. Various levels of OMG were added to a variety of clean pulps and the pulps were extruded. As the ratio of OMG in the feed composition increased, the extrusion conditions were reduced significantly, as were tensile proprties.
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