Siegwerk has developed a new UV offset ink series and UV flexo coatings with excellent deinking properties for packaging printing. The new solutions increase the recyclability of UV-coated paper and cardboard packaging.
For the recycling of paper and virgin fibre board, it is important that ink and varnish films can be broken down into small hydrophobic (water-repellent) particles during the recycling process. Today's standard UV inks are often still difficult to deink as they form a solid, chemically and mechanically resistant layer. This is firmly bonded to the cellulose fibre like an adhesive plastic layer. They can therefore be difficult to remove during the recycling processThis leads to large visible colour fragments, so-called dirt specks, in the recycled paper.
New deinkable UV offset ink series
The new ink series is based on Siegwerk's SICURA Low NRGY UV/ LED UV ink series. It was launched in 2019 as the first UV/LED offset ink system with deinking properties for coated and uncoated paper grades. The experts at Siegwerk have developed the UV offset ink series especially for offset and packaging printing of non-food solutions further developed. The SICURA Plast SP ink series has the best deinking properties. According to the company, these are even comparable to the deinkability of conventional, oil-based sheet-fed offset inks. SICURA Plast SP also offers excellent offset properties, high colour strength and good adhesion to absorbent and non-absorbent substrates. It was specially developed to achieve very high polyvalence on cardboard.
The deinkability of SICURA Plast SP alone and in combination with the new deinkable UV flexo coatings has been proven by applying INGEDE Method 11, the officially recognised industry standard for deinking tests. Today, the entire range of process, basic and special colours of the new ink system is available. It is already being used by various customers. In addition, Siegwerk developers have also launched the first deinkable UV flexo coatings on the market.
"Our new UV flexo lacquers are available after the Standard flotation deinking processwhich is also used for recycling ink-printed paper and virgin fibre cardboard, can be recycled without any adjustments. This enables us to offer commercial and packaging printers the complete package of recyclable UV offset inks plus UV coatings. 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." Thomas Glaser, Head of Technology in the Sheetfed Offset Business Unit at Siegwerk.
The company's new deinkable UV flexo coatings offer the same performance characteristics as standard UV flexo coatings and can be applied in- and offline with standard flexo coating units.
For better recycling
With its deinkable solutions, Siegwerk is improving the recycling of UV-cured packaging prints in particular. This supports the recycling target defined by the EU for paper and cardboard packaging, which is Recycling rate from 60 per cent to 85 per cent by 2030 to increase. "We are continuously working on further improving the deinkability of our printing inks and coatings in order to contribute to the improved recyclability of packaging and to further advance the development of closed-loop solutions in accordance with the principles of the circular economy," adds Thomas Glaser.
Source: Siegwerk
