Layer thickness and path width setting in 3D printing of pre-impregnated continuous carbon, glass fibers and their hybrid composites

3D printing has been successfully applied in the manufacturing of variety continuous fiber and hybrid fiber reinforced composites. The process parameters have a significant impact on the overall performance of the printed parts. This paper investigates the effects of layer thickness and path width on the bending strength and surface roughness of printed pre-impregnated continuous carbon fiber, glass fiber, and their hybrid composites. Additionally, the microstructures of the fracture surfaces of the printed parts were analyzed. The results indicate that the optimal combination of bending strength and surface accuracy for printed single fiber parts is achieved when the printing layer thickness is set to 30%-40% of the fiber filament diameters. Furthermore, finely matched path width settings significantly improve the surface accuracy of printed hybrid carbon/glass fiber composites. Notably, the bending strength of printed interlayer hybrid fiber composite specimens increased by 35% compared to the specimens uniformly set according to the carbon fiber path width.