SIG and Pulpac develop paper-based closures for aseptic cartons

SIG is partnering with Pulpac to develop paper-based closures for SIG’s aseptic cartons. The collaboration supports SIG’s goal of increasing paper content in its aseptic packaging to 90% by 2030, including closures. 

The development program will leverage Pulpac’s Dry Molded Fiber technology, which is based on forming a dry web of fibers. This method reduces water use in the molding process and cuts CO2 emissions while offering design flexibility and scalability. 

Gavin Steiner, chief technology officer at SIG, says: “We believe in Dry Molded Fiber technology, paving the way for innovative and responsible alternatives to plastic closures. It is one of the most scalable fiber-based solutions on the market with great potential to boost progress in the transition from plastic to paper-based closures.”

“In our paper-based closure, both the base and the cap will be paper-based — significantly increasing the already very high proportion of paper in our aseptic cartons. At the same time, we aim to offer consumers the same convenience and first-class opening performance they associate with our existing closure solutions.”

Safe solution for transition

SIG adds the closures after the aseptic carton packs have already been filled with the product. The cartons are sealed inside the aseptic zone of the filling machine.

The company says that its post-application of the closures using closure applicators does not interfere with the aseptic process and ensures the safety of the products. 

This process lays the foundation for a plug-and-play solution of paper-based closures, which will be applied to the closed packaging in the same way as plastic closures, enabling a transition without altering the production process.

This year, SIG plans to achieve a goal of 85% paper content, excluding closures. The company aims to continue reducing fossil-based materials and lowering its packaging’s carbon footprint.

Christoph Wegener, chief markets officer at SIG, says: “For packaging innovations focused on sustainability to have a significant impact, they must be compatible with the installed machinery setup. That is why plug-and-play solutions are a design principle for us at SIG, which we inherently follow across our unique packaging structures without an aluminum layer.” 

“We apply the same approach to our paper-based closures. The combination of aluminum-layer-free packaging materials and paper-based closures will be our path to 90% paper content in our full-barrier aseptic cartons. This would be a real breakthrough in the packaging industry toward a circular economy.”