Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Plastic Money

08.04.2010
Australia’s plastic bills make life difficult for counterfeiters

Counterfeiting money is the “second oldest profession in the world”—a profession that truly took off with the introduction of paper money. In order to spoil things for counterfeiters, Australia introduced the world’s first banknotes made of plastic in 1988.


David H. Solomon at the University of Melbourne was part of an interdisciplinary team of scientists that developed these bills. In an essay in the journal Angewandte Chemie, he and co-author Emma L. Prime trace the technically challenging route to the development of the plastic banknote.

In 1966, Australia converted its currency from the British Pound to the decimal system. The new banknotes distributed by the Reserve Bank of Australia (RBA) were at the time the most counterfeit-proof bills in the world. However, it was less than a year before counterfeiters tried to put the first forged $10 bills into circulation—ingeniously printed on common office paper. The Governor of the RBA, H.C. (Nugget) Coombs, thus initiated a project to secure banknotes against counterfeiters.

Solomon remembers a photographic expert on the commission, who countered nearly every suggestion with the words, “if you can see it, you can photograph it”—meaning that it was always possible to separate the colors of a banknote, produce printing plates, and forge the bills. “Our idea was to develop materials that could not be photographed,” reports Solomon, “which eventually led to the use of clear plastic films as a substrate in place of paper.” A banknote with a transparent window made of a plastic film is a simple but highly effective security feature. The material selected was a polyethylene/polypropylene/polyethylene film. Two or three of these three-layer films were combined in a hot lamination process to attain the required thickness of 80 to 90 µm.

Another security feature is a small picture in the transparent window that is designed to produce a complex diffraction grating through the diffraction and interference of light. To protect the diffraction grating and to achieve the right “feel”, the entire banknote then had to be covered with a clear polyurethane coating. The team was able to develop a production process that put everything together in a single run: lamination, application of white ink, printing the pattern, hot embossing the diffraction grating, application of the clear coat, and cutting. In stringent tests, the sample banknotes proved to be more durable than the paper banknotes in circulation – to such an extent that the higher production costs were easily balanced out.

In 1988, the RBA first introduced a limited number of a special $10 banknote for the Australian bicentennial celebration (see picture). Between 1992 and 1996, the Note Issue Department then replaced all Australian paper banknotes with plastic ones. “Since that time, other countries have adopted our technology,” says Solomon. “In Romania, New Zealand, and Brazil, the counterfeiting rate went down by over 90 % upon introduction of plastic bills.”

Author: David H. Solomon, University of Melbourne (Australia), http://www.chemeng.unimelb.edu.au/people/staff/solomon.html

Title: Australia's Plastic Banknotes: Fighting Counterfeit Currency

Angewandte Chemie International Edition 2010, 49, No. 21, Permalink to the article: http://dx.doi.org/10.1002/anie.200904538

David H. Solomon | Angewandte Chemie
Further information:
http://pressroom.angewandte.org
http://www.chemeng.unimelb.edu.au/people/staff/solomon.html

More articles from Life Sciences:

nachricht Barium ruthenate: A high-yield, easy-to-handle perovskite catalyst for the oxidation of sulfides
16.07.2018 | Tokyo Institute of Technology

nachricht The secret sulfate code that lets the bad Tau in
16.07.2018 | American Society for Biochemistry and Molecular Biology

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Subaru Telescope helps pinpoint origin of ultra-high energy neutrino

16.07.2018 | Physics and Astronomy

Barium ruthenate: A high-yield, easy-to-handle perovskite catalyst for the oxidation of sulfides

16.07.2018 | Life Sciences

New research calculates capacity of North American forests to sequester carbon

16.07.2018 | Earth Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>