Tensile properties of unidirectional thermosetting composites reinforced with ring-spun hybrid yarns including recycled carbon fiber

The study of composites reinforced with aligned recycled carbon fiber (CF) is gaining increasing attention, particularly in light of the circular economy. Hybrid yarns, among other oriented reinforcements, have gained interest from researchers who have already utilized them to produce unidirectional thermoplastic composites. Nevertheless, the evaluation of unidirectional thermosetting composites reinforced with hybrid yarns is still lacking. This article presents their production, leveraging a recently developed process, and mechanical characterization. The results show that the amount of recycled CF and the number of draw frame doublings within the hybrid yarns affect the tensile properties of the composite, while the thermoplastic fiber has no influence, as also suggested by the main effect plots. Two-way interactions exhibit different behaviors depending on the tensile property considered. Overall, the composite material with the best tensile properties was that reinforced with a ring-spun hybrid yarn consisting of 70% recycled CF, 30% polyamide, and five draw frame doublings.

Unidirectional thermosetting recycled CFRPs were produced and characterized;

Recycled CF’s quantity and draw frame doubling’s number affect mechanical properties;

Thermoplastic fiber has no influence on mechanical properties;

Ring-spun hybrid yarn with 70% recycled CF, 30% polyamide, and 5 draw frame doublings provides CFRP with the best mechanical properties;