The Cannon Group will present the Possible project at Jec World 2026 in Paris, focused on the mechanical recycling of rigid polyurethane foams and polyurethane-glass fiber composites (GFRP). The developed solutions are intended to enable the reintroduction of rigid PU and PU/GFRP composite waste into the production stream without fundamentally changing the system chemistry and without the need to build completely new processing lines. The project has been carried out in cooperation with polyurethane processor MAP S.p.A. and the University of Bergamo, with co-funding from the Italian strategic plan for the EU recovery fund NextGenerationEU. The work has demonstrated the possibility of using ground foam and granulated parts as secondary reinforcement materials in new composite formulations.
Thermoset plastics account for around 12% of global plastics production, which translates into more than 40 million tons per year. Of this, polyurethane foams alone represent approximately 17 million tons, or more than 42%. These materials are valued for their mechanical and thermal resistance, stability and the possibility of incorporating reinforcing fibers, but the cross-linked chemical structure combined with the fibers makes conventional recycling practically unfeasible. Scientific research has identified potential chemical recycling routes, but so far they operate mainly at laboratory scale and are often too slow, too costly or incompatible with existing PU manufacturing processes. For this reason, Cannon focused on a more direct approach, based on reusing rigid PU foam waste, both pure and composite, by methods fully compatible with the company’s high-pressure systems.
Objective of the Possible project and market context
According to Maurizio Corti, Corporate R&D Director at the Cannon Group, sustainability and end-of-life issues are moving to the forefront in the plastics industry, in particular with regard to thermoset composite materials. Rigid polyurethane foams and glass fiber reinforced polyurethane composites (GFRP) nevertheless remain key materials for achieving energy efficiency goals in the automotive and building sectors and in technical equipment, even though they belong to the group of the most difficult materials to recycle.
The reason for this difficulty is exactly their cross-linked structure, which ensures stability and durability but prevents remelting and reprocessing. Currently, landfilling and incineration are the predominant solutions for the end-of-life management of such foams and composites, approaches that are increasingly unacceptable from both regulatory and environmental perspectives. In this context, the Possible project was launched with the aim of developing practical methods for recycling rigid PU foams and PU/GFRP composites at industrial scale.
Two complementary mechanical recycling routes
As explained by Dario Pigliafreddo, responsible for sales in the mobility and specialties segment at Cannon, the Possible project created a framework for targeted research on the recycling of rigid foams and PU/GFRP composites. The intention was not to interfere with the system chemistry, introduce complex process steps or force the construction of entirely new lines, but to build on a well-known and proven application of glass fiber impregnation and extend it to the dosing of recyclate in the form of granules and powder. Modifications were implemented on a high-pressure foaming platform already used by part of the polyurethane manufacturing industry.
During the project, two complementary approaches were tested. The first involved converting rigid foam waste into micrometer-scale powder, which was then dispersed in polyol as a slurry and dosed as a liquid component using a mixing head. The second route assumed the use of PU granulate and polyurethane-glass fiber composite granulate, introduced into the system as a solid filler via dedicated dosing devices operating with the FPL 36 IW mixing head for the Interwet-LFI (Long Fiber Injection) technology patented by Cannon.
Powder recyclate in polyol dispersion
In the first route, rigid foam waste was processed into two types of powder. The first, designated as PU-A, was a fine fraction in which most particles had a size below 75 µm. The second, PU-B, was a coarse powder with a fraction in the 300–500 µm range. After drying, the powders were fed into a reactor with polyol, forming a slurry with a concentration of up to 20% by weight relative to the polyol stream, corresponding to about 5% content in the final foam.
To enable processing of such dense slurries, Cannon split both isocyanate and polyol into two parallel streams, a “clean” stream and a stream “loaded” with recyclate. This solution maintains high mixing energy and stable system operation even at viscosities exceeding 10,000 mPa·s. The slurry was dosed using a scraper cylinder. The panels obtained showed a homogeneous structure and good distribution of the recycled powder.
Analysis of the insulation properties showed that thermal conductivity increased by only about 4% compared to the reference material. This means that the required thermal insulation performance can be maintained even with around 3% recyclate content in the foam structure. According to Cannon, powder recycling can be applied where thermal properties and uniform cell structure are particularly important.
PU and GFRP granulate as solid filler in Interwet-LFI technology
The second route consisted of converting PU waste, including polyurethane-glass fiber composite waste, into granulate. The resulting particles were dosed as a solid filler directly into the Interwet-LFI head. This technology has been used for years to combine polyurethane with chopped glass fiber and allows the incorporation of recycled granulate into the reactive mixture flow.
To determine the most efficient feeding method for the granulate, two types of conveying systems were tested: pneumatic fluid bed transport and a flexible screw conveyor. Pneumatic transport delivered good results with dense, regular granules but became unstable for light or dusty materials. The flexible screw conveyor proved to be a more universal solution, enabling feed rates from a few grams up to more than 100 g/s without pulsation or bridging. For this reason, it was considered particularly suitable for feeding GFRP granulate obtained from waste.
With such a configuration, panels containing up to 40% by weight of recycled granulate were produced, with a uniform distribution of particles across the full thickness of the product. This allows granulates of rigid foams and GFRP composites to be treated as an additional reinforcing material in new compositions, without the need for fundamental changes to the existing production infrastructure.
The Cannon FPL 36 IW high-pressure mixing head dispenses polyurethane filled with rigid PU granules onto a mold. (photo: Cannon Group)
Integrating recycling into PU production lines
Tests carried out by Cannon confirmed that recycling rigid polyurethanes and GFRP composites can be integrated directly into existing production lines. The approaches developed do not require invasive processes or radical formulation changes, and waste is converted into a secondary raw material that can be reused in the same process. From the manufacturers’ perspective, this means potential economic benefits through reduced disposal costs and lower consumption of virgin raw materials, as well as environmental benefits arising from reduced volumes of waste sent to landfills or incineration.
The solutions developed within the Possible project represent a concrete step towards greater circularity for thermoset materials, which have so far been considered particularly problematic in terms of recycling. Based on the research results, Cannon is now working on commercial recycling solutions for PU foams and GFRP composites, which are expected to enter the market in the coming years. At Jec World 2026, the company will present these technologies at booth 5M72.
