PlastEurasia opened its doors for the 25th time on 3 December 2015 with over 1300 exhibitors from 55 different nations. Plasmatreat gave a live demonstration of perfect print adhesion on a print-resistant plastic at the largest and most important plastics tradeshow for Turkey, North Africa and Eurasia.
The reliable adhesion of printing inks to non-polar plastics is conditional on the material surface being ultraclean and the surface energy of the solid material being higher than the surface tension of the liquid coating. Various pretreatment methods are available to achieve these two conditions, with wet chemical substances still the most widely used.
Hakan Sağkal (CEO Plasmatreat Turkey and MEA Region) and his team at PlastEurasia 2015 showed how this could be done more easily and more reliably without using chemicals by demonstrating a process for printing polypropylene. The aim was to increase the surface energy of the plastic to > 72 dyne by treating it with Openair® plasma in order to achieve uniform wettability. Complete wettability of the surface guarantees effective, long-time stable adhesion of the printing ink.
The centerpiece of the live demonstration was the new RD2005 plasma unit, a double nozzle system with two separate nozzles which orbit around a shared rotating axis. The plasma beam is emitted from the rotating unit parallel to the rotational access. The new, potential-free Next Generation system works at speeds of up to 35 m/min and treatment widths up to 50 mm. It is particularly suitable for applications which require intensive and homogenous treatment.
For tradeshow demonstrations the double nozzle is mounted on a small PT60 positioning table. Its supporting surface automatically travels back and forth underneath the plasma beam. Tradeshow visitors were able to observe the microfine cleaning and selected activation of polypropylene substrates, which took only a few seconds.
Immediately after plasma treatment, components can undergo further processing – in this case printing in a compact pad printer provided by long-standing system partner Tampoprint.
Visitors were amazed by the clear results of the adhesive tape test: When the tape was removed from the untreated surface, the printing ink came with it, whilst the ink on the activated parts held fast. But that wasn't all; the printed image on the plasma-treated surfaces was significantly brighter in color.
The highly effective use of atmospheric pressure plasma for the pretreatment of non-polar plastics demonstrated here in printing is equally successful with bonding and coating processes. Hakan Sagkal is delighted with the successful outcome of the tradeshow: "This year most of visitors came from the automotive, household appliances/white goods and packaging industries and with more than one hundred and twenty potential leads, we can look back on a very successful show."