Performance of Nano Fibrillated Cellulose (NFC) and Chitosan Bio-polymeric System on Recycled Pulp and Paper Properties of Old Corrugated Containers (OCC)

Application of dry strength additives is regarded as a sustainable strategy toward improvement of recycle paper properties, and Bio-based materials utilization enhanced in this aspect extensively, respecting to different technological and environmental issues. In order to improving products properties, Cellulose and Chitosan as the most abundant biopolymers with unique characteristics, have been focused under ever increasing researches as natural and processed forms. Effects of the biopolymers, chitosan and nano fibrillated cellulose (NFC), individually and combined together on recycled pulp and paper properties showed that density and strength indices of paper (tensile, burst and tear), pulp drainage and retention during sheet formation improved with reduction in the material loss compared to the blank. Chitosan addition caused significant enhancement on all of the strengths, density and pulp retention and also reduction in material loss. Dewatering of the pulp suspension (CSF) was significantly improved by chitosan presence, with decline resulted from the higher addition level. The resulted developments were attributed to polymeric character, structural similarity and high bonding ability of chitosan with cellulosic fibers. Individually addition of NFC produced boost in the pulp retention, paper density, tensile and burst indices and fall in pulp freeness, material loss and tear index. Anionic nature, high specific surface area and hydrogen bonding ability of NFC were ascribed to these. Application of NFC just after chitosan as a complex mechanism in papermaking wet end not only had no increment in density and strength indices of recycled paper (except NFC 0.15%), reduced strengths in some cases. In the complex, the pulp properties were fluctuated compared to chitosan treatment, but were prior compared to nano fibrillated cellulose.