Siegwerk’s new UniNature barrier coating for paper plates

Siegwerk, a global provider of printing inks and coatings for packaging applications and labels, on 24 February announced the successful certification of its new water-based coating UniNature water-oil barrier coating for single-use paper plates. The new functional barrier solution is made from 100% natural content and has proven to effectively reduce the absorption of water, oil and grease on plate stock intended for direct food contact while maintaining its recycling through the paper recovery cycle.

Therewith, the new barrier coating offers a sustainable alternative to replace restricted coatings on single-use paper plates according to Single Use Plastics Directive and other relevant legislation. By enhancing the recyclability of disposable paper plates, Siegwerk’s new solution helps to keep resources in the loop, fully in line with a circular economy.

“Paper packaging with barrier requirements often uses coated or laminated materials, which not only make the packaging hard to recycle, but lead to further environmental problems for example due to microplastics or persistent chemicals,” explains Anna Maier, head of Global WB Coatings Technology Platform at Siegwerk. “Here, the use of sustainable barrier coatings can help to replace these hard-to-recycle paper laminates and thus help keep valuable resources in a circular economy.”

By using the right barrier coating, the functionality of paper-based packaging can be ensured, maintain the highest possible level of safety during food contact, as well as support the circular economy by minimizing the use of resources and maximizing the potential to recover them after use. Moreover, a high share of natural materials in barrier coatings helps to create bio-degradable packaging and avoid issues with microplastics and bio-accumulation, thus adding an indispensable value to the paper packaging’s end-of-life in the sense of a circular economy.

“With UniNature water-oil barrier coating we now offer a 100% natural product certified for short-term direct food contact and independently confirmed as compliant with the requirements of the EU’s single-use plastics directive,” adds Oliver Waddington, business development manager barrier coatings, EMEA, fiber-based material at Siegwerk.

In January 2023, the UniNature water-oil barrier OPV became the first coating solution of its kind to be certified for successfully adding a barrier against grease and liquid to paper plates intended for direct food contact. The coating was comprehensively tested by an independent international testing company performing high-level laboratory analyses looking at its behavior in terms of organoleptic testing as well as inhibitors, total migration, mineral oils, and siloxanes.

The migration test conditions included short-term as well as long-term storage. Siegwerk’s natural barrier coating meets the technical requirements essential for paper plate application. The product showed good oil and grease resistance according to TAPPI T559 as well as some liquid resistance according to the COBB method. In addition, the new solution functions as a standalone barrier coating in single or multiple layers, meaning it does not require a primer, is suitable as an Over-Print Varnish with Siegwerk’s water-based ink systems, and is compatible with all standard water-based printing processes and printing machines.

“Saying so, UniNature is another proof of how inks and coatings add functional properties to renewable materials like paper, enabling their use for an even wider range of packaging applications and thus paving the way for new mono-material structures in the sense of a circular economy,” adds Alina Marm, head of Global Sustainability & Circular Economy.

Siegwerk, a sixth-generation family-owned company, is one of the leading international manufacturers of printing inks and individual solutions for packaging, labels, and catalogs.