TOMRA and Gualapack have joined forces to test how one of Gualapack’s innovative products, which combines monomaterial laminates and semi-rigid multi-layer components, could be automatically and effectively managed for recycling in the rigid PP stream.
Gualapack
Gualapack and TOMRA collaboration introduces new, full-scale recycling trial
Gualapack, manufacturer of laminates, caps and flexible pouches, has shown its commitment to sustainability, which in the past few years has been its greatest driver for growth and innovation, through the partnership.
Michelle Marrone, Gualapack Sustainability Manager, said: “It was 2018 when I first met Jürgen and TOMRA. At Gualapack, we were busy tackling the challenge of designing a monomaterial spouted pouch that had to resist hot-filling, pasteurisation, and maintain its barrier properties 12 months on the shelf. But at the same time, I knew that to be monomaterial by design was not enough. It was equally important to prove our circularity by demonstrating that our pouch could be correctly identified as PP, sorted, processed and extruded on an industrial line.”
Jürgen Priesters, SVP Business Development TOMRA Circular Economy, added: “After development of the new pouches, and to determine whether these could be sorted with optical sorters, we added a significant amount of them to a combined separate source and mixed waste stream sorting plant for automated sorting. The result was very good detection and accurate separation rate of all pouches. A subsequent washing and recycling trial showed that the Gualapack monomaterial pouches could be easily recycled into standard products.”
As a first step, different percentages of Gualapack pouches were added to rigid PP waste, which was then processed through TOMRA’s AUTOSORT solution. Then, a waste PP bale with five per cent additional pouches and a bale without any pouches were compared, in a back-to-back trial that took them through all the steps of a standard recycling process. First shredded into flakes and hot washed with water and sodium hydroxide at 85°C (185°F), then post-sorted through a second AUTOSORT FLAKE machine to further improve the quality of the material, the two bales were then extruded on an industrial scale extruder and pelletised back to PP.
Ink and adhesives from the pouches has no impact on extrusion, and afforded high thermal stability without odour or volatility issues. Furthermore, the pelletised materials were characterised by third party laboratories and declared comparable to PP copolymer grades suitable for injection moulding.