Offset Printing

Innovative approaches to barrier solutions for the circular economy

Friday 31. January 2020 - First presented at the Open House Barrier Solutions last October, BOBST vacuum metallizing division is focusing on three key areas in relation to sustainability and the circular economy.

Sustainability and the Metallizer
Due to the various sustainability pledges from leading brand owners and retailers, the packaging industry needs to evolve and move toward a circular economy. This is leading the industry to look to use sustainable mono material or bio-based substrates as well as paper based substrates. The use of these new high barrier sustainable substrates and requirements from the market to process more heat sensitive, extensible and functionally less performing materials means the metallizer design has had to change to improve the processing ability of these materials. Key changes include improved heat management for more thermally sensitive materials, improved web handling for extensible/stretchy olefin based materials, patented rewind gas wedge to assist with layer separation for “sticky” substrates and to boost the dyne level of non-polar olefins, an inline plasma pre-treatment system.
High Transparency AlOx on BOPP
Due to demand in the market for metallized PET type barrier performance on mono-material polyolefin based substrates; BOBST has further developed its well established AlOx process. The next generation AlOx process gives better barrier performance at reduced optical density, enables production of higher transparency AlOx films with increased transparency straight off the machine and offers increased benefits for polypropylene based film structures. By combining the right BOPP base film with the BOBST next generation AlOx process it is possible to achieve metallized PET type barrier performance on mono-material polyolefins as well as offering benefits for recyclability.
AluBond on BOPP
As well as providing excellent adhesion levels on all substrates, when the BOBST AluBond process is applied to BOPP it provides enhancement of oxygen (OTR) and water vapour (WVTR) barrier performance. Typically when metallized film is tested under tropical test conditions, some corrosion of the metal layer occurs and the WVTR levels drop; this does not occur with AluBond coated film meaning that the process also produces a more stable and less corrosion sensitive metallized layer.
In addition AluBond has also been shown to significantly increase dyne level retention, even at times of high humidity, which translates in improved ink wettability during printing and enhances structure stability during lamination.