Key role of anionic trash catching system on the efficiency of lignocellulose nanofibers in industrial recycled slurries

The processing of recycled paper into packaging materials is becoming one of the most important activities of paper mills. However, the use of recycled paper as a raw material causes an important increase of dissolved colloidal substances in industrial waters, known as anionic trash, which greatly increases water conductivity and cationic demand disturbing the function of commonly used retention agents (cationic starch, cationic polyacrylamides). On the other hand, several investigators showed that lignocellulosic nanofibers (LCNF) can be used as reinforcement in papermaking, but their retention can be affected by anionic trash. This work aims to study the technical viability of the application of triticale straw lignocellulose nanofibers in recycled fiber suspensions at industrial scale. For this purpose, a complex retention system of LCNF was proposed to improve the reinforcement efficiency of LCNF. Results show that, with the addition of only 1.5% (w/w) of LCNF, it is possible to fulfill the physical–mechanical requirements of the commercial test liner, and the addition of 4.5% of LCNF would allow the reduction of basis weight and additives or the development of applications with higher mechanical requirements.