“Lately brand owners have expressed an increasing interest in PVC-free printing inks to realize complex packaging structures. Our new PUR-based ink system fulfills these requirements, while also incorporating other benefits,” explained Dr. Hanns Martin Kaiser, head of technology Flexible Packaging EMEA at Siegwerk.
The new ink technology - first available for the European market - is optimized to meet high performance requirements such as high bond-strength values in lamination. It allows for use in harsh retort conditions and can also be applied on modern barrier film substrates.
Another benefit is that the PUR ink system is based on ethyl acetate as a solvent to allow utilization in monosolvent setups in combination with solvent recovery systems. But in any case, printers can also use common co-solvents like methyl ethyl ketone (MEK), or ethanol etc. The key polyurethane binders are manufactured in Siegwerk’s own PUR production facilities in Annemasse, France, and Bhiwadi, India.
“After two years of development, the new ink range performed very successful in first extended industrial trials. It showed excellent printability with solid full tone and outstanding half tone reproduction. We optimized it for best dispersion results in order to produce high color strengths,” said Dr. Kaiser.
Under industrial trial conditions, the new PUR inks exhibited very good printability even at high printing speeds above 500 m/min. At the same time, it has been proved that the solvent retention level of the inks is very low.
Furthermore, Siegwerk’s PUR ink solution can also be used for medium performance applications, since it can be supplied in two different versions – either as a master base system in the form of ready-made inks or as a masterbatch system, where the full PUR concentrates are combined with various master compounds (technical varnishes) out of one dispenser.
Siegwerk’s new ink range is a unique combination of a new technology – the polyurethane binder – with a proven concept – the masterbatch system. This creates a universal platform in terms of print performance, efficient handling in the ink room and cost-effectiveness. The inks will be tailored to the specific requirements of each customer to match their individual needs, keep the portfolio simple and avoid overdesign. This contributes to simplify ink room complexity and reduce ink stocks, which at the end improves cost-in-use for customers.
The new ink technology was developed in accordance with the relevant product safety standards. All ingredients are compliant with the stringent Swiss Ordinance and will also comply with the upcoming new German Ordinance. The new system will add to Siegwerk’s broad range of Flexible Packaging solutions – while other ink technologies including PVC-based inks continue to have their merits.