May 2008 Medtec web exclusive:

One concern still found in the medical market is the explosive growth of counterfeit medicines that endanger patient’s health. Germany’s Fraunhofer Institute IGB (Stuttgart) and its industrial partner, identif (Erlangen, Germany), have developed a new approach to anti-forgery security for flexible plastic packaging. “We coat plastics films with fluorocarbon nano-layers, on top of which the metal layer generating the color effect is applied,” explained Michael Haupt, project manager at Fraunhofer IGB, during the Medtec show in mid-March. “The advantage is that the basic characteristics of the material remain unaltered, while the surface of the film is optimized by the nano-coating for further processing.”

The nano-layers are applied in a low-pressure plasma chamber by placing a label in a vacuum chamber where fluorine gases are introduced and ignited. “We can deposit different coatings with defined properties on the label surface, depending on the proportions of electrons, ions, neutrons, and photons in this luminous gas mixture,” said Christian Oehr, department head at Fraunhofer IGB. Subsequently, identif applies an additional layer of thin metal to the polymer surface, with that metal generating color effects. Due to the underlying flurocarbon layer, the color-change effect can be copied only with extreme difficulty, while the label is more easily machine readable, he says. The two organizations introduced this new product during last year’s K2007 trade show.