TOMRA and Gualapack join forces to improve bag recyclability

TOMRA has teamed up with bag manufacturer Gualapack to demonstrate that the latter's single-material PP spray bag can automatically manage recycling in rigid PP streams
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The results follow extensive testing at several sites during 2020
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Michelle Marrone, Sustainability Manager at Gualapack, explains: “I first met Jürgen Priesters and TOMRA in 2018.

At Gualapack, we were busy solving the challenge of designing a single-material spray bag that had to withstand Hot-filled, pasteurized, and has a 12-month shelf life barrier
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But at the same time, I also know that it’s not enough to just design as a single material! It’s also important to demonstrate our circularity, to demonstrate that we The bags can be correctly identified as PP and sorted, processed and extruded on industrial lines
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Jürgen Priesters, Senior Vice President, Business Development, TOMRA Circular Economy, explained: "After developing new bags, in order to determine whether they could be sorted with an optical sorter, TOMRA added a large number of bags to a Combined sorting unit of separate sources and mixed waste streams for automatic sorting
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The result is very good detection and accurate separation rates for all pouches
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Subsequent cleaning and recycling trials have shown that small pouches of Gualapack monolayer material can be easily The ground is recycled into the standard product
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”

As a first step, varying proportions of Gualapack bags are added to the rigid PP waste, which is then processed through TOMRA's Autosort, a sensor-based sorter that confirms the bags are PP material, More than 80% of the bags are redirected into the rigid PP stream
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Then, in a back-to-back trial, a waste PP bag with a 5% increase in pouches was compared to a bag without any pouches that went through all steps of the standard recycling process
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It was first cut into flakes and hot washed with water and sodium hydroxide at 85°C, then post-sorted by a second Autosort flake machine to further improve the quality of the material, the two bales were processed in an industrial Extruded on a large-scale extruder and made into PP pellets
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The results were surprisingly good, according to TOMRA, the ink and adhesive in the pouch did not interfere with extrusion, and it was highly thermally stable without any odor or volatility issues
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In addition, third-party labs have characterized these particulate materials and declared them to be comparable to PP copolymer grades suitable for injection molding
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TOMRA explained that this shows that the Gualapack single-material bags are well tolerated in the German DKR rigid PP stream, and that the TOMRA sorting system is a suitable infrastructure for the correct identification and sorting of single-material in real-world scenarios, even if Semi-rigid multilayer structures exist
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