JEC COMPOSITES MAGAZINE - Issue #100 - Special JEC Asia - October 2015 - 70

recycling
EPCP) and a DK-Codim injection press were used (Figure 5). The
injected specimens were subjected to monotonic tensile tests (Figure
6). The mechanical tensile properties of the composite made from
recycled fibres (breaking strength: 136 MPa, elastic modulus: 8.4
GPa) are nearly identical to those of the composite made from virgin
fibres (breaking strength: 141 MPa, elastic modulus: 8.9 GPa).

Conclusions and prospects

Fig. 5: DK-Codim injection press

Focus
Alpha Recyclage Composites has been a partner of the Institut Clément Ader and the RAPSODEE research laboratory in Albi since 2009.
Research has focused on the development of a steam thermolysis process to treat carbon fibre composite materials and on the corresponding manufacturing processes for recycling carbon fibres into secondgeneration materials. Thanks to the financial support of the Direction
Générale des Entreprises and the Direction Générale de l'Armement, a
pilot batch reactor for steam thermolysis (internal volume 2m3 or 2000
litres) and four doctoral theses have been funded, including one that
will start in October 2015.

were created from AS4C carbon fibres and Sicomin SR1710LRI
resin using the Liquid Resin Infusion (LRI) process, and subjected
to steam thermolysis. The properties of the virgin carbon fibres
were then compared to those of the recycled carbon fibres from the
composites (Figure 4). No degradation of the recycled fibre properties was observed: the virgin AS4C carbon fibre showed a breaking
strength of 3864 MPa, compared to 3852 MPa for the recycled fibre.
Thanks to the large database acquired with the tow tensile test, the
confidence intervals over an average at 95% are very low at about 20
MPa.

Creating thermoplastic composites from recycled fibres
Virgin AS4C carbon fibres and the above recycled fibres were added
to PA 6.6 matrices in a 6% fibre volume fraction. A LabTech Engineering extruder (in partnership with the University of Pau - IPREM

So far, the research programmes have shown the interest of steam
thermolysis for the treatment of carbon fibre composites. Alpha
Recyclage Composites would now like to demonstrate the industrial
feasibility of such treatment. To this end, the "Rapid" programme,
cofunded by the French Direction Générale des Entreprises and
Direction Générale de l'Armement, has been set up in collaboration
with the Institut Clément Ader (Mines d'Albi) to study new ways to
develop composites from recycled carbon fibres. n
Acknowledgements
The authors would like to thank the University of Lyon -
MATEIS - INSA Lyon (France) and the University of Pau - IPREMEPCP - Pau (France) for their scientific collaboration, and the French
Environment and Energy Management Agency (ADEME) and the
national technical research association ANRT for their financial
support.
References
[1] A. Oliveira-Nunes, Y. Soudais: A steam-thermolysis process to
recover carbon fibers from CFRP waste, JEC Asia 2015, Singapore,
October 2015
[2] M. Boulanghien, M. R'Mili, G. Bernhart, F. Berthet, Y. Soudais:
Fibre characterisation of steam thermal process recycled carbon
fibre/epoxy composites, ICCM 19 proceedings, Montreal, 2013
[3] B.D. Coleman: On the strength of classical fibers and fiber
bundles, Journal of the Mechanics and Physics of Solids, 7:60-70,
1958
[4] M. R'Mili, N. Godin, J. Lamon: Flaw strength distribution and
statistical parameters for ceramic fibers: the normal distribution,
Physical Review E, 85:1-6, 2012
More information:
p.brosson@alpharecyclage.com

Fig. 6: Stress-strain curves obtained for dry specimens and wet (1.02% moisture regain) specimens. Virgin fibre composites (a) and recycled fibre composites (b)

70 jec composites magazine / No100 October 2015

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #100 - Special JEC Asia - October 2015