ETCH: a new etching technique for better joined CFRP/GFRP performances

This project is based on a patented etching process proven to be effective as joint strength enhancer for carbon fiber reinforced polymers (CFRPs) [1].

Previous studies showed that the CFRP surface modification by acid etching resulted in the matrix removal without interruption of the continuity of fibers, thus preserving the CFRP mechanical properties.

Additionally, this technique minimizes the use of acid and the etching solution is reusable, providing low impact on the environment.

The CFRP etched surface provided a better joint strength when mechanically tested.

In case of coating applications, it enables better coating adhesion to the CFRP.

The objective of ETCH project is to extend the know-how on this technology and to demonstrate that the process can be successfully applied on a large variety of FRP. This class of materials find application in several fields because of their outstanding performances due to presence of the reinforcing fibers. Fibers commonly used are made of glass (GFRPs) or carbon (CFRPs).

Both GFRPs and CFRPs will be etched, joined and tested. Finally, two CFRP prototypes will be manufactured: a component for aerospace applications and a small boat to assess the feasibility for nautical use.

The validation of the prototypes will establish the improvement from TRL (Technology Readiness Level) 2 to TRL 5.

The ETCH team is composed by Monica Ferraris, Stefano De La Pierre, Alessandro De Zanet, Frediano De Marco, Valentina Casalegno. Recently, Simone Repetto, a mechanical engineering student, has joined us for his Bachelor’s final project.

Keywords: etching, surface, composites, GFRP, CFRP, joining

Contacts: ,


De La Pierre, S., Giglia, V., Sangermano, M. et al. Etching of Carbon Fiber-Reinforced Plastics to Increase Their Joint Strength. J. of Materi Eng and Perform 29, 242–250 (2020).

Funding: Politecnico di Torino “Proof of Concept” 2020