Counterfeiters dye over security measures

Diversion is the process ofmoving products made for one market into another at a profit. This profit goesto the diverter and not the manufacturer. Pharmaceuticals are a good example:Drugs shipped to Mexico aresold far more cheaply than in the United States,so buying pharmaceuticals in Mexicoand diverting them to the results in a tidy profit for the perpetrators. Photo-luminescent dyes areemerging as an important tool in this struggle. Novel dye materials with uniqueproperties are read by special scanners and allow authorities to detect, track,and study the counterfeit trade. The dyes can be placed on products as hiddenor disguised marks, or they can be transparent. The enabling technology hasemerged from photo-luminescent research, in which customized batches of dyewith unique fluorescent properties have been developed. "These chelateddyes are proprietary materials with novel ligands," according to DavePhillips, CEO of PhotoSecure (Boston, MA). "This allows us to change theluminescent properties to best fit the application." A strobed UV lamp in thescanner illuminates the dye in roughly 20-nm wavelength bands, with each bandcorresponding to a specific dye between 250 nm and 380 nm. Emissions range fromultraviolet to infrared wavelengths and are measured at predetermined delaysfor comparison with stored intensity and decay characteristics. Typical decaytimes can be from microseconds to tens of microseconds, and light intensity ismeasured through optical filters by a CCD area scanner connected to amicroprocessor. Libraries of dye signatures can be loaded on the computer forscanner programming, and scanners can be easily reconfigured for differentspectral filtering. These new dyes are morelight stable than conventional dyes, so they have an advantage in documentsecurity because of their resistance to fading and three-year shelf life. Datasuch as bar codes or product batch-and-date information can be encoded, andinformation from the scanners can be reported online or as part of a largerdatabase. The relatively slow decay times allow scanners to be manufactured fora few hundred dollars, unlike the nanosecond delay times of common fluorescentmaterials, which require cost-prohibitive sensors.

Source: oemagazine.comAdded: 20 October 2006

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