Effect Of Nanoparticles In Wood Containing Furnishes, 2002 Technology Summit Proceedings

Duncan S. Carr

Microparticle technology has for 20 years provided a tool to increase paper machine efficiency. First generation systems based on colloidal silica and cationic starch found greatest acceptance in coated and uncoated freesheet grades. More recently the latest generations of silica-based nanoparticle systems have found acceptance in the production of lightweight wood containing grades produced on demanding high-speed machines. Although the same classic characteristics of improved retention, dewatering, drying, and sheet strength are now seen on wood containing grades as have been seen on wood-free grades for many years, there are some differences in how these characteristics manifest on the paper machine. These differences are related to not only the choice of nanoparticle but also to the equilibrium fines content in the headbox resulting from the retention strategy employed on the respective paper machines. Criteria for determining the optimum operating retention levels on lightweight wood containing machines have been established.