A Journey from Metallized Labels to Metallized Functional Papers: Challenges and Achievements to Produce the Barrier Papers

Presented by Daniela Mondelli, AR Metallizing

Valeria Rasetto (a), Kurt Gundlach (b), Roghi Kalan (b), Daniela Mondelli (a)
(a) AR Metallizing S.r.l, Via Lombriasco, Casalgrasso, CN 12030, Italy
(b) AR Metallizing Ltd, AR Metallizing Ltd., 24 National Drive, Forge Park, Franklin, MA 02038, United States

In the last few years, an increased interest in functional papers has been observed globally. Both converters and brand owners are pushing the flexible packaging world to match the sustainability targets within 2025-2030. Of course, paper is not a new material for packaging, but it has been mainly used as part of multilayers structures e.g., paper/aluminium foil or extruded coated paper or metallized film laminated to paper.  Today mono-material concept is preferred over the multi-materials and the percentage of paper in the structures is moving from 50% to 95%. The main challenge for mono-material paper-based is to reach high barrier properties which so far have been reached by films or multi material composites. Physical Vapor Deposition (PVD) metallization is largely used on film to supply or boost barrier properties, and it has been natural to think of using it to functionalize the paper as well.

For this reason, AR Metallizing R&D team has been actively working in developing metallized barrier paper for last four years focusing mainly on the high vapor barrier, to reach WVTR around 1 g/m2/day in tropical conditions.
Along our journey, we have learnt that the selection of the raw material is the key to reach the desired final product, both base paper and coatings play significant roles.

The flexibility of the paper and of the coatings, the reduction of the pinholes of the substrate, the good adherence between coatings and base paper, the amount and homogeneity of aluminium layer have been some of the challenges faced to produce a good barrier paper, without forgetting the food compliance and recyclability as outcome.

The achievements are really encouraging. AR Metallizing has been able to develop and scale-up a recyclable metallized barrier paper showing WVTR < 1 g/m2/day in tropical conditions, where the barrier level is slightly increased after folding but still at a good level.

The journey is not finished yet and new challenges have to be overcome. We are currently working to add oxygen barrier coatings to the metallized paper as well as we are testing different metallization technologies (e.g. ALUBOND, ALOX) in collaboration with BOBST.