Influence of manufacturing parameters on the mechanical properties of nano-reinforced CFRP by carbon nanofibers

One of the most relevant problems of nano-reinforced resins is the uniform dispersion of nanoparticles. This problem is even more relevant when they are involved in the production of laminated composites. In this case, in addition to the agglomeration of nanoparticles, air bubbles are also very frequent during the manufacturing process of laminated composites with nano-reinforced resins. These air bubbles are even more frequent in the manual lay-up process. In this context, this study intends to study some manufacture parameters in order to maximize the mechanical properties. For this purpose, the mixer rotation speed, the dispersion time of the nanoparticles and the vacuum time applied to the system were analyzed in detail. It was found that the mixing time is very dependent on the rotation speed used and there is an ideal vacuum time. A short vacuum time allows air bubbles to exist in the resin, while a long time promotes a decrease in mechanical properties due to the removal of resin in the laminates and, consequently, the fibers are not fully wet.