Thermoplastic Elium Recycling: Mechanical Behaviour and Damage Mechanisms Analysis by Acoustic Emission

This study aims to prove the recyclability of an innovative thermoplastic called Elium resin. It’s the first liquid thermoplastic resin that provides the production of composite materials with an interesting mechanical behavior. Until now, its recyclable character is unjustified. It appeared on the resin market in 2014. But until now, no studies were available concerning how it can be recycled and reused. For this study, a thermocompression recycling process was investigated and applied to Elium resin. Three levels of recycling were carried out on the initial material. The recycled specimens were investigated and tested by means of tensile tests. Also, the acoustic emission (AE) technique was used to characterize microstructural damage events leading to overall failure of the recycled Elium. This study has been further supported by scanning electron microscopy (SEM) micrographs of the fractured face. The results obtained show that the failure tensile properties of Elium resin as well as flax fiber reinforced composites decrease during recycling operations. Conversely, recycling induces a rise in the elastic modulus. Also, the acoustic emission technique associated with SEM observation showed two classes of damage mechanisms. A first “class A” related to “matrix cracking” and a second “class B” associated to matrix/matrix friction.