Siegwerk, one of the leading global providers of printing inks and coatings for packaging applications and labels, has received a RecyClass Technology approval for two of its nitrocellulose (NC) free ink series.

According to the company, the new approval confirms that the flexo ink system UR 62 and the gravure ink system UR 74 meet the recyclability requirements for surface-printed PE and PP flexible packaging in Europe.

Switch to NC-free inks

With their excellent printability, high heat resistance, quick drying capabilities, and excellent adhesion to various surfaces, NC-based inks have long been a commonly used solvent ink type in flexo and gravure printing. At the same time, however, they are increasingly recognized as a critical obstacle to high-quality mechanical recycling of flexible packaging. Due to the limited thermal stability of nitrocellulose, NC-based inks can lead to an unpleasant odor, discoloration and reduced recyclate quality. With ever-evolving design for recycling requirements across Europe and worldwide, the replacement of nitrocellulose has therefore become a key lever for the recyclability of packaging.

Siegwerk has been developing and expanding its portfolio of NC-free ink solutions for flexible packaging. These alternatives to NC-based inks are designed to support recyclable packaging structures while maintaining the high printing and converting performance required in industrial flexographic and gravure applications. While conventional PU-based lamination inks have long enabled reliable NC-free solutions and are fully recognized by RecyClass for their recyclability, they have not been suitable for surface printing – making the development of new NC-free surface systems essential to unlock a broader spectrum of technically demanding applications.. The portfolio is bundled in Siegwerk’s NC-free toolbox, which provides converters and brand owners with a structured approach to implementing NC-free printing solutions across surface and lamination applications.

“Switching to NC-free inks is a decisive step for recyclable flexible packaging, especially in surface printing,” said Björn Ewig, head of technology flexible packaging EMEA at Siegwerk. “Our focus has been to develop NC-free alternatives that work reliably in industrial production and meet recyclability requirements without compromising on print or packaging performance.” Siegwerk said it relies on a set of proprietary, self-developed polyurethane binders as a replacement for nitrocellulose, which has already proven itself in terms of excellent printability and high heat and mechanical resistance.

RecyClass Technology Approval for UR 62 and UR 74

With the RecyClass Technology approval for UR 62 (flexo) and UR 74 (gravure), Siegwerk said it offers brand owners and converters independent proof that these NC-free inks enable recyclable PE and PP flexible packaging. This third-party validation simplifies material and ink selection for designs that meet current and upcoming Design for Recycling requirements, reducing risk and accelerating the transition to circular packaging. “Our customers need solutions that combine print performance with proven recyclability,” said Ralf Leineweber, head of global technology development at Siegwerk. “This approval now gives them the confidence to make the right decisions, supporting the overall trend toward circular packaging concepts.”