Mechanical Recycling of Polyurethane Foam Waste by Compression Roller Milling for the Production of Recycled Viscoelastic Polyurethane Foams

The REFOAM project aims to promote the circular use of polyurethane foam waste through its mechanical recycling and reincorporation into the production of new viscoelastic polyurethane foams. In this work, flexible polyurethane foam waste was processed by compression roller milling to produce fine recycled powder suitable for reuse as a polyol filler. Particle size distribution analysis demonstrated that the milling process was effective in producing a fine powder. At room temperature, 90% of the particles presented diameters below 180 µm, with a maximum particle size of 395 µm. When the milling process was performed at 60 °C, the corresponding values increased to 232 µm and 517 µm, respectively, indicating the influence of processing temperature on particle size reduction. The recycled powder was subsequently incorporated into a commercial polyol at contents of 10, 20 and 30 wt.%, followed by reaction with isocyanate to produce viscoelastic polyurethane foams. The mechanical performance of the resulting foams was evaluated through compression testing in order to assess the effect of recycled powder incorporation on compressive behaviour. The results demonstrate the feasibility of producing recycled polyurethane powder with controlled particle size by compression roller milling and its successful incorporation into new viscoelastic polyurethane foams. This approach contributes to the valorisation of polyurethane waste, supporting more sustainable and circular manufacturing strategies for the polyurethane industry.