SÜDPACK and industrial printing specialist LEIBINGER have joined forces test the suitability of continuous inkjet (CIJ) inks for printing on recyclable films for packaging food that is sterilized following the packaging process.

Packaging films are expected to be resource-saving and recyclable to support a circular economy. The EU Packaging Regulation requires all packaging on the EU market to be recyclable by 2030. As a result, composite materials are being increasingly replaced by monomaterials. If these monomaterials are not equipped with a barrier function that prevents ink components from migrating to food, they may only be printed with harmless ink. This raises the requirements for the production, coding and marking of packaging films.

SÜDPACK is developing monomaterials that are on par with previous composite materials in terms of convenience and protection. For printing and coding this type of food packaging, LEIBINGER offers industrial inkjet printers and develops special CIJ inks together with SIS Ink Solution, a LEIBINGER Group company. The interaction of these components is the focus of the joint project between SÜDPACK and LEIBINGER.

The team printed the single-material solutions based on PE and PP with advanced CIJ ink. During the subsequent steam sterilization, the printed films were heated at 121°C for 30 minutes. Assessment of the print samples before and after sterilization showed that the print was still legible. The inks used are suitable for printing on food contact materials. This means that they only contain raw materials that are approved in compliance with the German Printing Inks Ordinance and the Swiss Commodities Ordinance.

The idea for the joint project between the two family-run Swabian companies SÜDPACK and LEIBINGER originated at a meeting at the PACK EXPO trade fair in Chicago in 2022. Together, the two companies set themselves the goal of providing food manufacturers with a packaging and printing solution that had already been tested for key customer requirements.

“The sterilization resistance of ink is always a major challenge,” says Thomas Paul, ink expert and managing director at SIS Ink Solution. “I am delighted that we have succeeded in developing a food-approved CIJ ink that is this effective when printing on monomaterials.”