Dendrimers: A new retention aid for newsprint, mechanical printing grades,and board

The use of amine-terminated dendrimers as retention and drainage aids in th e production of newsprint, supercalendered mechanical printing grades, and board has been investigated in the laboratory with a dynamic drainage jar. The results suggest that dendrimers can be very effective retention aids fo r fines and ash in all three types of paper. In addition, they are very eff ective at flocculating dispersed resin in newsprint pulp slurries and hence offer promise for pitch control. Because of their exceptionally high posit ive charge densities, dendrimers proved effective in a lab-simulated, highl y-closed papermaking system, and also in newsprint pulps containing recycle d deinked pulp. In addition, they performed well in a peroxide-bleached SC furnish. Used in conjunction with a flocculant, dendrimers gave even higher gains in first-pass retention and drainage.