An Investigation of Hand Sheet paper properties produced from recycled banknote paper with emphasis on refining Effect

in this study, the effect of refining on the optical and mechanical properties of pulp and paper made from recycled banknote paper was investigated. For this purpose, fifty Rials waste banknote papers were cut into strips with a width of 15 mm. First, retail banknote papers were pretreated with acid under conditions pH=3 and 4 hours treatment time in ambient conditions. After acidic pretreatment, a acidic treatment was done under conditions pH=3 and 1.5 to 2 hours treatment time in 95° C, and the amount of consumed acid was 0.3% for banknote papers weight. To separate ink particles from fiber surfaces, a alkaline treatment was performed after acidic treatment under conditions 2 hours treatment time in 95° C, and 3% NaOH for dry pulp weight. After alkaline treatment, obtained pulp was poured into a laboratory mixer and by mixer was stirred in 2 minutes until the fibers are so far apart. Then, the freeness of pulp was measured. Obtained pulp was refined by PFI refiner in refining intensities of 50, 100 and 150 and then, the freeness of obtained pulps were measured. After refining, for each of the pulps, hand sheet papers were made and the properties of them were determined. The results indicated significant differences between pulp and paper properties made of waste currency papers with 4 different refining intensities in 1% confident level. As increasing of refining intensity and refining revolutions, burst strength, tensile strength, folding strength and brightness of papers increased but tear strength of papers and freeness of pulps decreased.