The effect of pulp suspension and NFC mixing time on reinforced paper properties

In this study a cellulosic and environmentally friendly nano material has been used as a reinforcing agent of CMP pulp of Mazandaran pulp and paper factory (used for producing liner board). The purpose of this study was to evaluate the influence of the suspension mixing time on the final paper properties. So, the chemi-mechanical pulp suspensions (with concentration of %2 and freeness of 250 CSF) included cellulose nanofiber of 5% wt were prepared and mixed on the magnetic stirrer for 0.5, 1, 4 and 8 hours at 25 oC. The resulted suspensions were drained by means of vacuum filtration. After draining, the wet handsheets were pressed and then dried in the oven at 100 oC for 24 hours. The results showed that at the first phases (around 1 hour) air permeability decreased and strength properties of paper increased with the increase of mixing time. Although, with increasing of mixing time more than 1 hour, the trend of paper properties changed completely inversely. It can be attributed to the change of the interaction between fiber and cellulose nanofiber at longer mixing time.