Continuous fiber reinforced Additive Manufacturing
Fiber reinforced polymer (FRP) composites are already a go-to engineering material in industries like aerospace or wind energy, but the high cost and complexity associated with the molds needed to make them, discourages the use for small, complexly shaped objects. Combining the excellent mechanical performance with the dimensional freedom provided by additive manufacturing, a novel material can be introduced to fill this gap in production capability.
As this kind of material is still brand new, our research focusses on the correct characterization of samples, and using this information to form new insights in the correlation between the fiber impregnation process, printing parameters and mechanical performance.
Results have shown that reinforcing these composites with polymeric fibers, such as aramid or PBO, is a far easier process than with ceramic materials such as glass and carbon fiber. During the printing process, these fibers experience high abrasion wearing by being pulled through the printing nozzle, meaning that these polymeric fibers with high abrasion resistance have a lower chance to break during composite production. Further research however will focus on adapting the production cycle, so that ceramic fibers can also be used in 3D printing composites.
From this research, it was also shown that pre-impregnation of the fibers, i.e. first making a fiber reinforced polymer filament which is then printed in a standard desktop 3D printing setup, yields better results than in-nozzle impregnation. This is due to the lack of an active force, meaning the polymer is not actively forced into the fiber tow, resulting in a low impregnation quality and bad fiber adhesion.
The mechanical performance of 3D printed composites has so far proven to be quite high in tensile testing, but the imperfect impregnation of fibers results in a lower than expected flexural and delamination resistance.
Further information
Contact
Prof. dr. ir. Karen De Clerck (Karen.DeClerck@UGent.be)