Title
Improving the paper recycling process of old corrugated container wastes
Authors
MEHDI RAHMANINIA and AMIR KHOSRAVANI

Received October 23, 2013
Published Volume 49 Issue 2 February
Keywords paper recycling, nanosilica, cationic starch, OCC, zeta potential, productivity

Abstract
Recycling of waste paper is a reasonable response to continuity of raw material in the paper industry, as well as to environmental concerns. However, the quality of recycled pulp and the efficiency of the process are of great importance. Benefitting from emerging technologies can be of much help. Recent developments regarding the application of nanotechnology in the pulp and paper industry are suggesting new horizons in this area. A full scale applied example of using nanoparticles in papermaking is the well-established system of nanosilica with cationic starch. This system is now successfully used as a drainage/retention aid in plenty of paper mills using virgin pulps. Applying this system in the paper recycling process, which involves more complicated wet end (i.e. higher cationic demand and conductivity), seems to be less favorable, however results show this system can be useful in increasing fines retention up to 39% and drainage up to 42% in high basis weight recycled paper produced from old corrugated container (OCC), therefore improving machine speed, reducing energy consumption (in press or dryer sections) and increasing the productivity of the whole papermaking system. Moreover, the role of zeta potential as an indicator of system interactions was also monitored. Because of the special characteristics and behavior of nanosilica in this system, zeta potential did not show a direct correlation with system efficiency (drainage/retention).