The new UV flexo varnishes and offset inks developed to improve the recyclability of UV-coated paper and board packaging


Germany’s Siegwerk offers printing inks for customers. (Credit: Siegwerk Druckfarben AG & Co. KGaA)

Germany-based printing inks provider Siegwerk has launched a new UV offset ink series varnishes and UV flexo varnishes inks for commercial and packaging printing.

Featuring deinking properties, the new UV flexo varnishes and offset inks have been developed to help improve the recyclability of UV-coated paper and board packaging.

The firm said that the newly launched solutions also support the material-specific recycling targets while complying with the EU Waste Framework Directive (2008/98/EC) and the Packaging and Packaging Waste Directive (94/62/EC).

Siegwerk technology sheetfed head Thomas Glaser said: “Our new UV flexo varnishes are recyclable by the standard flotation deinking process also used for the recycling of printed ink films on paper and virgin fiber board without any adaption.

“This enables us to offer commercial and packaging printers the complete package of recyclable UV offset inks plus varnishes.

“A very good example of Siegwerk’s Circular Economy strategy, which enables our customers to become more sustainable – in this case by increasing the recyclability of paper.”

For the recycling of paper and fresh fibreboard, the ink and varnish films are initially fragmented into small hydrophobic (water repellent) particles, allowing them to more easily separated from the substrate fibre during the recycling process.

However, standard UV inks often show an extremely poor deinkability as they form a solid resistant layer attached to the cellulose fibre, thus making them difficult to remove during the recycling process.

In a statement, Siegwerk said: “Packaging printing UV offset inks and conventional oil-based inks are often covered with standard UV flexo varnishes. In particular, this problem significantly hampers the recyclability of valuable virgin fiber-based carton board.”

New UV ink series designed for offset and non-food packaging printing

Siegwerk said it has developed UV ink series, SICURA Plast SP, for offset and packaging printing of non-food solutions.

Designed to offer the same performance properties as standard UV flexo varnishes, the new deinkable UV flexo varnishes can be applied in- and offline using standard flexo coating units.

In May 2020, Siegwerk and APK AG, a plastic recyclate producer, have announced the completion of de-inking trials of twofold printed LDPE-films.