Aging effect of CMC modification and accelerated ageing on currency notes
G.N. Simonian, R.F. Basalah, F. T. Abd El Halim, F.F. Abd El Latif, A. M. Adel, A. M. El Shafey
Forgery and Counterfeiting Expert, Ministry of Justice, Egypt.
Banknote papers include an extensive range of security features that involve secure complex process such as watermark, security thread, micro printing etc. Security features are very important elements integrated into paper banknotes for facing counterfeiting as without the presence of security features within banknote papers how we can face the counterfeiting crime.
In the present paper, different banknote papers (Egyptian 5 pounds "EGP", Egyptian 10 pounds "EGP", 1 Riyal "SAR", 5 Dirham "AED", 1 Dolar "U$", 5 Euro "€" are coated by different concentrations and different layers of carboxymethyl cellulose (CMC). Accelerated ageing speeds the natural ageing process of paper by subjecting it to extreme conditions. We performed accelerated ageing; thermal ageing at 140 °C for 2 hours and UV-radiation ageing with two different wavelengths (λ1= 256 nm, λ2 = 336 nm). Change CIE (L*, a*, b*) and the total colour difference (colour tolerance); ΔE* values were investigated before and after CMC coating. Change CIE (L*, a*, b*) and the total colour difference (colour tolerance); ΔE* values were measured and calculated before and after accelerated ageing. The security features of banknote papers were examined through transmitted light, UV light and IR. It can be concluded that the effectiveness of security features integrated into banknote papers are marvellous as the accelerated ageing have no effect even small on the security features after CMC modification which reflects in increasing banknote papers durability.
Keywords: Banknote papers, Security features, CIE (L*, a*, b*), The total colour difference (Colour tolerance) "ΔE", Accelerated ageing, CMC.