The Dutch firm Stork Prints and Spraylat GmbH, a German producer of silver coatings, have developed a method of using rotary screen printing to mass produce RFID circuits with speed and accuracy. It uses Stork’s familiar 16" wide RSI (Rotary Screen Integration) unit to print 6"x1" di-pole antennae using new types of conductive inks formulated by Spraylat. The top speed of 100 fpm is said to represent a significant improvement over previous productivity levels using screen printing.
The collaborative project took place at Stork’s Boxmeer facility and was commissioned by Rake Security Label in Germany. It had been chosen by Metro, a large retailing group, to supply 20,000 labels to test the effectiveness of RFID in managing pallets and cases within the retailer’s supply chain.
Rake carried out subsequent conversion processes at its Witzhave works, inserting the inlays with a 2,024-bit microchip on a Muehlbauer “pick and place” Tag Module Assembler (TMA) machine. It was found that the inlay designs could operate effectively over a wide range of pallet contents, locations and angles. The UHF labels operate at 868 MHz with a read/write functionality of just over nine feet. Antenna inks were 5 microns thick and printed on a 60-micron PET pearlescent substrate. Stork’s pure nickel RotaMesh 215 screen, which can be reused or re-engraved up to 15 times, was employed.
“To meet the high-growth demand for RFID, label industry players have to pool resources and explore ways of increasing productivity,” says Thorsten Wischnewski, head of the RFID-technology group at Rake Security Label. “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.” Stork printed the 20,000 batch of antennae in two hours.