PAPERmaking! g FROM THE PUBLISHERS OF PAPER TECHNOLOGY Volume 1, Number 1, 2015
Sobtilitis bacteria. By contrast, Nanosilver particles were more efficacious against Staphylococcus aureus and Escherichia coli (Imani et al . 2011). In another investigation to achieve better performance of silver particles, CFGI compound was produced on fibres pretreated with the chelating monomer glycidyl methacrylate-iminodi acetic acid (Gma- ida), and this treatment caused more bonding of Nanosilver particles to the fibres. Antibacterial performance was improved. With increasing concentration of Gma-ida solution, more silver was absorbed to fibres. Nanosilver with a particle size of 75nm was said to have better performance (Chen and Chiang 2008). Also, Nanosilver particles with size of 25nm and concentration of 25 and 50ppm on the basis of ethanol were used for making antibacterial cloth fibres that were added to cloth before and after dyeing. When cloth was examined with an antibacterial test after dyeing, it showed more efficacy. The suitable concentration of Nanosilver suspension to cloth treatment was reported as 50ppm (Lee and Yeo, 2003). Despite the fact that most infectious diseases can be transferred by touching biotic objects such as Banknotes (Pinner and Teutsch 1996), no research has been reported about making antibacterial Banknote paper. So the present study may be unique in its consideration of Nanosilver particles due to antibacterial properties, non-toxicity, and environmental friendly character as an antibacterial agent in Banknote paper production. Industrial cotton pulp was provided with a Schopper-Riegeler ( o SR) value of 51, a consistency of 3.1%, and a pH of 7.2. Also, Nanosilver (with 4000ppm concentration and 50nm particle size made by Rangdane Sharif company) and cationic polyacrylamide (with medium cationic charge with Farinret K325 trademark made by Degussa Co.) were used as antibacterial agent and retention aid, respectively. For antibacterial test of papers, the two bacteria including Gram-negative Escherichia coli ATCC: 25922 and Gram-positive Staphylococcus aureus , ATCC, which were provided by Dr. Ghahari of the medical diagnosis laboratory in Babolsar city, were used. Brain Heart Infusion Broth (BHIB) and Nutrient agar both made by Biolife company were used as liquid and solid culture medium, respectively. Methods The pulp consistency was decreased to 0.3% and stirred to homogenise it for 15 minutes. Cationic polyacrylamide (CPAM) with 1% concentration was added at the levels of 0, 0.3, 0.5, 0.7, and 1%, and then a constant level of 100ppm Nanosilver was added to the pulp. Standard handsheets were made according to ISO 5269/1 and tested to evaluate physical and mechanical properties (Table 1). Surface fibres in Banknote paper must have good bonding so that they will not separate from the paper when the metal surface bearing the tacky ink is separated from it during printing. Hence, a wax test was carried out, in which the end part of a series of wax pieces is softened over a flame and put over the paper. The wax pieces are separated from the paper surface rapidly, after 15 minutes. So the most highest number of wax (representing higher strength) that doesn’t result in damage to the paper is accepted as wax test. EXPERIMENTAL Materials
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Article 3 – Hygiene (nanosilver)
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