Tieteestä & Tekniikasta
Review on recent advancements in composite recycling projects
Authors: Jason Govilas, Jesse Savolainen, Anni Lahti and Essi Sarlin, Tampere University
Since 2017, the Plastics and Elastomer Technology research group at Tampere University has been invol- ved in various projects focusing on composite recycling. During this time, the European perspective on the cir- cular economy of composites has shifted from questio- ning whether recycling should be implemented at an industrial scale to focusing on how it can be achieved. In the case of recycling reinforcing fibres by pyroly- sis or solvolysis the key criteria are sufficient residual mechanical properties, fibre length and purity. The most critical property to verify, however, is the adhesion of the recovered fibres to a new matrix. At Tampere Universi- ty, this is characterized using a state-of-the-art high- throughput microbond device developed by the spin-off company Fibrobotics Oy, which separates picolitre-sized microdroplets from individual fibres to measure fibre– matrix adhesion. For recyclates containing both fibre and matrix phases, the methodological approach involves fib- re fraction analysis, followed by compounding with ther- moplastics and injection moulding into new materials, whose performance can then be characterized. RECREATE, 2022-2026, funded by EU The RECREATE project developed innovative techno- logies to unlock the potential of end-of-life complex composite waste, combining advances in dismantling, reuse, remanufacturing, and recycling with digital tools
for sustainability assessment. The technological soluti- ons targeted high-value applications for second-genera- tion composites. Nine demonstrators showcased these technologies across different sectors, ranging from skis and rackets to airplane seats and wind turbines (Figu- re 1). To enable the reuse of composites, modular design, reversible adhesives, and laser dismantling were deve- loped to allow the replacement of composite parts during active use or the separation of complex structures into reusable or recyclable components. In addition, tempera- ture-assisted reshaping methods were explored to adapt composite geometries for new applications. Catalyst-as- sisted low-temperature green solvolysis was studied to recycle glass and carbon fibres assessing the fibre quality as a function of solvent, curing agent, textile architectu- re, and resin-to-curing-agent molar ratio. Microbond stu- dies demonstrated that solvolysis can preserve their abi - lity to bond with a new matrix, making them well suit- ed for second-generation composites and supporting a closed-loop composite lifecycle (Figure 2.a). Furthermo- re, the use of the depolymerized resin fraction in corro- sion resistant coatings was successfully demonstrated. Mechanical recycling and high-voltage fragmentation were investigated as more mature and upscaled recy- cling routes. Among others, it was shown that high fib- re fraction feedstocks can be produced in an energy effi-
Segmentable wind turbine blades
Modular structures for mobility
Sports equipment
Reshaped panels for transportation
Aircraft interiors
Different reuse and recycling strategies and demonstrators of the RECREATE project. (Credits of the Figure: Jason Govilas)
34 MUOVIPLAST 3/2026
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