EXAX Inc., a South Korean chemical manufacturer, is set to expand into RFID (radio-frequency identification) label production at its Cheonan plant by investing in a dedicated rotary screen printing line from Stork Prints. When installed, the system will print RFID antennae using conductive ink.
When it’s installed this summer, the new line will produce both HF (high-frequency) and UHF (ultra-high frequency) antennae in a single pass, according to the company.
The configuration comprises three of Stork’s 600mm wide PD-IV/RSI units, which are rotary screen printing stacks with drying capabilities. Vertical hot air and infrared drying systems are integrated into the first and third print positions, and a UV curing unit is on the second. The first printing position will apply the conductive silver solvent based ink, specially formulated by EXAX – either as a thick layer of HF coil, or a thinner UHF dipole antenna. The second and third positions are for laying down the two extra components of the HF antenna: the dielectric insulator with UV curable ink, followed by the conductive jumper.
Ger Roza, account manager at Stork Prints, comments: “Rotary screen printing was preferred by EXAX because it is capable of achieving high definition and laying down heavy ink layers needed in HF antenna circuits. The challenge was to devise a concept that afforded the conductive ink a lengthy dwell time, at a relatively fast production speed. This was achieved by devising an accumulator drying system, whereby the web passes up and down the dryer several times.”
The RSI printing line will use Stork’s proprietary pure-nickel electroformed RotaMesh screens, which offer consumable savings because they can be re-engraved several times, and thus be used for many different antenna designs.
EXAX, also a supplier of subcomponents to global electronic manufacturers, sees numerous opportunities in the rapidly growing radio frequency label market. Long distance applications of special interest, normally readable between 5 and 10 m and which require UHF antennae, include track and trace labels in the distribution chain and road toll systems, while booming HF-format labels include chip-based touch-in, touch-out public transport and ID cards.