PAPERmaking! g FROM THE PUBLISHERS OF PAPER TECHNOLOGY Volume 1, Number 1, 2015
Effects of CPAM and Nanosilver addition on the bulk density of handsheets are shown in Figure 2. It is clear that by increasing the CPAM level, the bulk density was decreased. This is probably due to fines retention between fibres. When dry strength agents such as polyacrylamide adheres to fibres, it forms bridges between fibres and increases bonding among the fibres (Scott 2006). The polyacrylamide, due to its cationic charge, adsorbs fines and Nanosilver. Filling of empty space between fibres with Nanosilver may help account for the observed decline in caliper. Also, cationic polyacrylamide causes hydrogen bonding between fibres and prevents fines from being removed.
Figure 2. Effect of CPAM and Nanosilver on bulk of Banknote paper
Due to Interactions of CPAM and Nanosilver, fines absorb more and by forming of hard and tiny flocks, caliper and subsequently bulk density of paper decrease. These results also confirmed the finding of Ebrahimi (2011). Smoothness Smoothness of paper surface is an important property for printed paper such as Banknotes, which need more smoothness compared to other grades of paper (Scott 2006). As Banknote paper is printed on both sides, there should be little difference between the two sides. Figure 3 shows that by adding CPAM and Nanosilver particles, smoothness of the paper was increased compared to the control. It is worth noting that by adding of CPAM, smoothness appeared to be decreased, but the apparent effect was not statistically significant. Also, the difference between the two sides of paper is decreased by adding CPAM level that it might be related to more absorption of fines (Miyanishi, 1998). Smoothness difference between two sides of paper is decreased with an increasing addition of retention aid.
Page 5 of 12
Article 3 – Hygiene (nanosilver)
Made with FlippingBook - professional solution for displaying marketing and sales documents online