A New Microparticle to Improve Drainage of a NSSC-Containing Furnish, 2003 Spring Technical Conference Proceedings

This study investigates the use of a new microparticle, a synthetic metal silicate (SMS), for drainage enhancement of a 40% NSSC-containing furnish. The use of cPAM flocculants traditionally improves the fines retention yet causes additional water entrapment in the formed sheet. Because of this, increasing cPAM dosage is unable to improve the gravity drainage of the stock, and vacuum dewatering of this same stock, as measured in the laboratory, worsens. The use of a retention and drainage program composed of a flocculant and SMS yields similar or higher fines retention while improving both the gravity and vacuum drainage of the furnish. Laboratory observations were confirmed with a NSSC-containing corrugated medium machine trial, where a cPAM/SMS program maintained retention and improved drainage compared to the cPAM single component program leading to increased machine speed, establishing two new world speed records on heavy basis weight grades. A 12% increase over the average reel speed for a lighter basis weight grade was also attained. These results will be presented and discussed.