Siegwerk offers first NC-free ink systems for front printing to improve the recyclability of polyolefin-based packaging

Siegwerk, one of the world's leading suppliers of printing inks and coatings for packaging applications and labels, has introduced the first nitrocellulose (NC)-free ink range specifically developed for surface printing on polyethylene (PE) and polypropylene (PP) packaging solutions. The new range includes NC-free surface solutions for both flexo and gravure printing and is based on the latest guidelines, for example from RecyClass and CEFLEX, which are intended to actively promote packaging design in the sense of a circular economy. With the introduction of the first available solutions of this kind, Siegwerk is once again underlining its innovative strength and technological expertise when it comes to developing forward-looking solutions to support the circularity of packaging.

“We have been offering NC-free inks for lamination for a long time,” says Björn Ewig, Head of Technology Flexible Packaging EMEA at Siegwerk. The new ink systems for frontal printing will be offered together with the latest generation of Siegwerk's NC-free solutions for lamination in the recently launched NC-free toolbox for flexible packaging, which will initially be available to customers in the EMEA region. “With our new NC-free toolbox, we are enabling printers and converters to better meet the demand for NC-free flexible packaging while ensuring excellent recyclate quality that complies with the latest Design for Recycling (D4R) guidelines, without compromising on print or packaging performance,” adds Ewig.
Nitrocellulose-based inks have long been a commonly used solvent-based ink type in flexographic and gravure printing due to their outstanding printability, high heat resistance, fast drying and excellent adhesion to a wide variety of surfaces. However, NC-based printing inks also pose a major problem for recycling. The limited thermal stability of nitrocellulose can lead to an unpleasant odor, discoloration and lower mechanical strength of the recyclate, which can hinder the material recycling process.

For this reason, more and more players along the value chain are adapting their regulations to further limit the NC content in packaging. “With our latest solutions, we have now developed NC-free ink alternatives specifically for surface printing that offer the same technical and mechanical properties as comparable NC-based inks, but are also recyclable,” says Ewig. All solutions comply with current recycling guidelines and are available either as a ready-to-use ink or as a masterbatch system. For all its NC-free solutions, Siegwerk relies on a range of polyurethane binders developed in-house to replace nitrocellulose, which have already proven their excellent printability and high heat and mechanical resistance. Industrial applications of the new flexo and gravure inks for frontal printing have already demonstrated good sealability and high abrasion resistance, confirming their suitability for frontal printing without the use of an additional OPV. “It is this innovative strength with which we produce pioneering inks and coatings, always with the aim of supporting our customers in the realization of sustainable and efficient packaging solutions that meet existing and upcoming regulatory requirements,” adds Ewig.

As the first of their kind, the new NC-free ink systems for frontal printing complement Siegwerk's portfolio with a sustainable and economical alternative for the realization of NC-free, recyclable packaging solutions. The company is thus expanding its range once again by developing forward-looking solutions that actively support sustainable packaging designs and thus contribute to the company's goal of driving forward a circular packaging industry.