Bonala Kondal: Polymer Banknotes

Polymer banknotes are made from a polymer such as biaxially oriented polypropylene (BOPP). Such notes have many security features such as metameric inks and these notes lasts two and a half times longer than paper notes. Modern polymer banknotes were first developed by the Reserve Bank of Australia (RBA), CSIRO, which is Australia’s national science agency, and The University of Melbourne and first issued as currency in the country in 1988.

The (BOPP) substrate is processed through the following steps:

Opacifying: Two layers of ink (usually white) are applied to each side of the note, except for an area(s) deliberately left clear for creating on OVD.

Sheeting: The substrate is cut into sheets suitable for the printing press.

Printing: Traditional offset, intaglio and letter press printing – three different printing techniques/process are used.

Overcoating: Notes are coated with a protective varnish. BOPP is a non-fibrous and non-porous polymer. Compared to paper banknotes, banknotes made using BOPP are harder to tear, more resistant to folding and soiling, are waterproof, easier to machine process and are shreddable and recyclable at the end of their lives.

Security Features:

The security features include intaglio, offset and letterpress printing, latent images, micro-printing and intricate background patterns. Polymer notes can be different olours on the observe and reverse sides. Like paper currency, polymer banknotes can incorporate a watermark in the polymer substrate. Shadow images can be created by the application of optically variable ink, enhancing its fidelity and colour shift characteristics. Security threads like magnetic, fluorescent, phosphorescent, micro-printed or clear text-or windowed can be embedded while paper production process.

Polymer banknotes are easily identifiable, difficult to counterfeit and transparent window where the OVD is located is a key security feature.