Interlaminar bonding performance of 3D printed continuous fibre reinforced thermoplastic composites using fused deposition modelling

It was observed that the effect of layer thickness of nylon samples on the interlaminar shear performance was marginally significance. ILSS values decrease as layer thickness increase due to higher porosity. In addition, continuous fibre reinforced samples show higher ILSS values than unreinforced ones but, conversely, the level of increase in ILSS is moderate with continued increase in fibre content, particularly in the case of Kevlar® fibre. Carbon fibre reinforced composites exhibit the best interlaminar shear performance with higher stiffness. On the other hand, Kevlar® fibre reinforced composites have the lowest interlaminar shear performance due to poor wettability of Kevlar® fibre bundles by the nylon, leading to extensive delamination. Finally, the results obtained demonstrate that it is still a challenge to increase shear performance of 3D printed composites with respect to common pre-preg materials. Nevertheless, ILSS values exhibited by 3D printed composites are significantly higher than the usual 3D printed thermoplastics.