February 12, 2026 12:51

The Milan-based Cannon Group has outlined the POSSIBLE (PrOduce SuStainabLE Industrial Bodies) research project for the mechanical recycling of glass fibre-reinforced polyurethane, to be presented in March at JEC World in Paris.

Co-funded under Italy’s strategic plan for the EU recovery fund NextGenerationEU, the project involved Italian converter MAP and the University of Bergamo.
It lays the groundwork for the recovery and reuse of polyurethane parts and polyurethane–glass fibre composites, which researchers have successfully incorporated into new composite formulations.

The partners opted not to pursue chemical recycling. According to Cannon, existing technologies operate at laboratory scale and are often too slow, too costly or incompatible with current PU manufacturing processes. Instead, the project focused on a more direct route, reintegrating rigid PU scrap—both neat and composite—through two complementary processes, each compatible with the company’s high-pressure equipment.

“The underlying idea was not to disrupt the system’s chemistry, introduce complex process steps, or require completely new lines - said Dario Pigliafreddo, Mobility and Specialties Sales Manager at Cannon -, but to apply to a well-known and well-performing application of glass fiber impregnation flexibility and modularity to add both recycled granulate and powder, adapting a high-pressure foaming platform that some PU manufacturers already use.”

The first process converts rigid foam waste into micrometric powders with different particle-size distributions. These are dispersed in the polyol to form a slurry and metered as a liquid component through a mixing head. Using this approach, insulating panels were produced with a homogeneous distribution of recycled powder. Thermal conductivity increased by around 4% compared with conventional panels, “which allows for maintaining valid insulating performance even with 3% recycled content in the foam.”

In the second process, granules of rigid PU and PU–glass fibre composites are introduced as a solid filler into the formulation using dedicated dosing systems combined with Cannon’s FPL 36 IW mixing head with Interwet-LFI (Long Fiber Injection) technology, already used to process polyurethane with chopped glass fibres.

To determine the most suitable feeding system, the company tested both pneumatic fluid-bed conveying and a flexible screw conveyor. The former delivered good results with dense, regular granules but proved unstable with light or powdery materials. The flexible screw system was more versatile, enabling flow rates from a few grams to more than 100 g/s without pulsation or bridging, making it suitable for scrap-derived GFRP granules. With this configuration, panels containing up to 40 wt% recycled granules were produced, with uniform distribution across the thickness.

Subsequent trials by the Italian machinery manufacturer showed that recycling rigid polyurethanes and GFRP composites can be integrated into production lines without invasive modifications or radical formulation changes. On this basis, Cannon is developing PU and GFRP recycling technologies for market introduction in the near term.

“This is a concrete step towards circularity in thermosets, a family of materials for which recycling was previously considered almost impossible,” the company said.

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