Industry partnership drives large-scale rollout of paper-based carton closures

SIG has entered a strategic partnership with PulPac, a company known for its Dry Molded Fiber technology, to jointly develop and scale up production of paper-based closures for aseptic cartons. The collaboration marks a significant step towards SIG’s goal of increasing the paper content of its cartons to 90% – including the closure – by 2030.

As part of its wider ambition to create a regenerative packaging system, SIG is working to enhance the renewability of its materials and reduce reliance on fossil-based inputs. The company expects to reach an interim milestone this year of 85% paper content in its cartons (excluding closures), with a longer-term aim of incorporating paper-based closures to surpass the 90% mark.

PulPac’s patented Dry Molded Fiber technology replaces traditional wet pulp methods by forming dry webs of fibres. This process uses less water and can significantly cut carbon emissions compared to plastic alternatives. The technology is also suited to high-volume manufacturing and allows for considerable design flexibility.

In SIG’s aseptic packaging lines, closures are applied after the product has been filled and sealed in the sterile zone, ensuring the aseptic process remains intact. This post-application method, developed in-house by SIG, enables a seamless transition to paper-based closures in the future without needing to alter existing filling or sealing operations.

Gavin Steiner, Chief Technology Officer at SIG: 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.

The partnership aims to deliver a plug-and-play paper-based closure solution that can be integrated into SIG’s established production systems, supporting the company’s broader sustainability targets.