Polymer banknote

File:Australian $10 note 1988.jpg

The first Guardian® polymer banknote in circulation. Released in 1988 to commemerate Australia's Bicentenary. The optically variable device is in the upper right hand corner.

Polymer banknotes were developed by the Reserve Bank of Australia (RBA) and the Commonwealth Scientific and Industrial Research Organisation (CSIRO) and were first issued as currency in Australia in 1988. Polymer banknotes are made from the polymer Biaxially-oriented polypropylene (BOPP) which greatly enhances durability of the banknotes. Polymer banknotes also incorporate many security features not available to paper banknotes making counterfeiting difficult.

Trading as Securency the RBA and Innovia films a subsiduary the UCB-group market BOPP as Guardian® for countries with their own banknote printing facilities. Note Printing Australia, a subsiduary of the RBA, prints commemorative banknotes and banknotes for circulation and has done so for 19 countires.

An alternate polymer of polyethylene fibers marketed as Tyvek® by DuPont was developed for use as currency by the American Bank Note Company in the early 1980s. Tyvek® did not perform well in trials, smudging of ink and fragility are reported problems. Only Costa Rica, Haiti and the Isle of Man issued Tyvek® banknotes, however they are no longer produced and have become collectors items.

Development of polymer banknotes

Polymer banknotes were developed to increase the security of Australia's paper currency against counterfeiting. In 1967 forgeries of the Australian $10 note were found in circulation and the RBA was concerned about an increase in counterfeitting with the release of color photocopiers that year. In 1968 the RBA started colaborations with the CSIRO and funds were made available in 1969 for the experimental production of distinctive papers.

The insertion of an optically variable device (OCD) created from diffraction gratings in plastic as a security device inserted in banknotes was proposed in 1972. The first patent arising from the development of polymer banknotes was files in 1973. In 1974 the technique of lamination used to combine materials, the all-plastic laminate eventually choosen was a clear, BOPP laminate, in which OVDs could be inserted without needing to punch holes. 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) that is deliberately left clear for creating an OCD;
• Sheeting - the substrate is cut into sheets suitable for the printing press;
• Printing - traditional offset, intaglio and letterpress printing processes are used; and
• Overcoating - notes are coated with a protective varnish.

BOPP is non-fibrous and non-porous polymer, making polymer banknotes more durable than paper, harder to tear, more resistant to folding, notes remain cleaner in circulation, are easier to machine process, and can be shredded and recycled at the end of their useful life.

Security features

The traditional printed security features applied on paper can also be applied on polymer, including intaglio, offset and letterpress printing, latent images, micro-printing, and intricate background patterns. Polymer notes can be different colours on the obverse and reverse sides.

A optically variable 'shadow image' can be incorporated in the polymer substrate, replacing the watermark. Shadow images can be created by the application of Optically Variable Ink (OVI) enhancing its fidelity and colour shift characteristics. Security threads can also be embedded in the polymer note, they may be magnetic, fluorescent, phosphorescent, microprinted, clear text, as well as windowed. The transparent window where the OCD is located in a key security feature of the polymer banknote, it is easily identifiable allowing anyone to be able to authenticate a banknote. The polymer can also be embossed.

Because the polymer is slightly transparent and contains many security features that cannot be successfully reproduced by photocopying or scanning, it is very difficult to counterfeit. The complexities of counterfeiting polymer banknotes are proposed to act as a deterrent to counterfeiters.

Adoption of polymer banknotes

File:PNG $20 note, polymer.jpg

20 Kina note from Papua New Guinea

Countries with notes printed on Guardian® polymer in cirulation include:

• Australia, Western Samoa, Papua New Guinea, Indonesia, Brunei, Thailand, Sri Lanka, New Zealand, Romania, Taiwan, Vietnam, Mexico, Nepal, Bangladesh, Zambia.

Countires that have issued commemorative banknotes (not in circulation) on Guardian® polymer include:

• Singapore, Kuwait, Malaysia, Northern Ireland, Brazil, China, the Solomon Islands

In 1996 Australia was the first country with a full set of circulating polymer banknotes. Zambia is the first African country to adopt polymer banknotes. In 2004 it was estimated that there were over 3 billion polymer notes in service. It has been suggested that the United States and a number of other countires are experimenting with polymer banknotes.

References

• Currency Note Research and Developmet Project, CSIRO, Division of Chemicals and Polymers Guide to Records
• CSIRO-Polymer banknote information sheet
• Note Printing Australia
• Polymer Banknotes of the World
• Securency