Printed Electronics: RFID in the Packaging Industry

(NPES International E-commerce Website, July 14, 2008) Security experts are amongst the most active of the packaging printers and packaging designers. The buzz word RFID (Radio Frequency Identification) on its own accounts for a whole galaxy of patents, meetings, products and articles. Large service providers have found their own companies concentrating exclusively on the field of high tech security.

Within this field there is a wide range of sub-sectors: with RFID and the special machines for producing the substrates and the transponder labels on the one hand, but also holograms in all their forms, diffraction films, lenticular effects or other techniques.

RFID is a technical system that allows the radio frequency reading of identification data without the need for physical contact.

A reading device generates a magnetic or electromagnetic field that is received by the antenna of the transponder and passed on to the microchip. This allows information such as the item's ID, manufacturer data, logistical commands and other similar data to be transferred. Since the transponder does not generate a magnetic or electromagnetic field of its own, it simply responds to the electronic field altered by the reading device and sends the answer back. The reading device evaluates the answers in fractions of a second.
Not long ago, RFID was a source of great excitement in the printing and packaging industry but this has gradually cooled off. The first showers of cold water were poured in the USA and Germany when the data protection authorities criticized the lack of customer privacy.

The second problem area has been that low-priced labels are neither in prospect nor market ready. In September 2007, prices per label were between five and eighty Euro Cents, depending upon the size and type of RFID label, the kind of application and the run length. This is too much for most products. Experts, however, view the discussion in much more practical terms and what is starting to happen is that RFID labels are exclusively being used in the logistic chains of manufacturers and dealers.

The in-house trial printing plant at Koenig & Bauer AG in Radebeul has been working on the inline production of RFID antenna for packaging printing. Whilst development work is not yet completed, it is a route to achieving more viable prices.
Transponder energy sources
The primary point over which there are differences is the type of energy supply for the RFID transponder. Batteryless RFID transponders with shorter ranges have no energy source of their own, with a potential difference being induced by the radio signal of the base station. The 'tag' of such passive transponders is charged by induction through the antenna and so provided with energy.

RFID transponders with their own source of energy are capable of longer ranges and a long lifespan. The costs per unit are, however, significantly higher. For this reason, such transponders are primarily to be found in transport logistics or in toll logging. These active RFID transponders draw their energy from a battery that has also been laid down and only become active in response to a defined signal. This increases the lifespan of the energy source. The battery cannot be used for generating the return signal. Nevertheless, longer ranges are achieved through high return beam coefficients, due to lower field energy consumption.

Logistics applications
RFID systems can be used in logistics to simplify goods transport and goods transfer (manufacturer, intermediate distributor, final dealer). To achieve this, the item to be tracked must be fitted with a transponder on which a clearly identifiable code has been stored. Based on the Electronic Product Code (EPC) system, this code, which is independently issued for each item, contains product specific information and is registered in a database. The first reading device records the items on loading or departure from the manufacturing company, providing the manufacturer with real time information about what quantities of which items have left the factory by which means of transport. The second reading device could be placed in the transport vehicle in order to automatically record unloading. If the recipient of the goods also uses RFID technology then the EPC must also be communicated to it. This way of proceeding extends right through to the final recipient and the database provides constant monitoring of the goods. The absence of matching data raises the possibility that the goods have been damaged or the destination has not been reached. End to end application from manufacturer to final distributor offers immense potential for savings by reducing time intensive manual data capture.

Sales applications
Provided all goods are fitted with an RFID transponder, reading devices installed on the shelves would be able to record any movement of goods. Sales staff would receive rapid information about stock levels on the shelves and in the event of need could immediately restock with the goods in question.