Rako team sets new productivity standard for printed RFID antennae

Stork Prints and silver coating producer Spraylat GmbH, based in Aachen, Germany, have demonstrated the effectiveness of rotary screen printing as a means of mass-producing radio-frequency identification (RFID) circuits
with speed and accuracy.

Stork's 16"-wide RSI (Rotary Screen Integration) unit was used to print 150 mm x 25 mm di-pole antennae, at 30 metres per minute, using a specially formulated conductive ink designed by Spraylat. This speed is claimed a significant improvement over previous productivity levels using screen printing process.

The collaborative project, which took place at Stork's Boxmeer Demo Centre, was specially commissioned by Rako Security Label in Witzhave, Germany. The label manufacturer had been chosen by METRO group to supply 20,000 labels to trial the effectiveness of RFID in managing pallets and cases within the retailer's supply chain.

Rako carried out subsequent conversion processes at its Witzhave works, inserting the inlays with a 2024-bit microchip on a Mhlbauer 'pick and place' Tag Module Assembler (TMA) machine. The trial succeeded because the
inlay designs could operate very effectively over a wide range of pallet contents, locations and angles. The labels are ultra high frequency (UHF), operating at 868 MHz, and their read / write functionality works at three metres' distance.

Comments Thorsten Wischnewski, head of the RFID-technology group at RAKO Security Label: 'To meet the high-growth demand for RFID labels label industry players have to pool resources and explore ways of increasing
productivity. The collaboration with Stork Prints and Spraylat had this aim in mind and makes us well placed to offer large-volume RFID label orders with relatively short lead-times.' The 20,000 batch of antennae was printed by Stork in just two hours.

Antenna ink-thicknesses were 5 m thick and printed on a 60 m PET pearlescent substrate. Stork's RotaMesh 215 screen was used. Stork's units achieve a registration within 0.1 mm, accurate enough to ensure the functionality of the RFID label.

Comments Neil Browes, European business development manager for Spraylat's Electronics Material Group: 'The Silver Conductive Ink from Spraylat was formulated to give a homogeneous ink surface, thus providing optimum
antenna performance for RFID applications. The ink was engineered to provide enhanced performance on rotary screen equipment.'

The demand for UHF frequency RFID label as a means of product tracking is expected to increase significantly over the coming years, thanks mainly to the long distance they function at. Many of the world's biggest retailers are beginning to work with this type of RFID label, and some are expecting their top 100 suppliers to have RFID systems in place during the course of 2005. Other possible high-volume applications include automotive tyre-tracking. There are 1.25 billion in use today, and 200 million new tyres are sold each year.