Influence of continuous ramie yarn content on printability and mechanical properties of in situ impregnation <scp>3D</scp> printed biocomposites

Abstract The present work aimed to study the printability and tensile behaviors of ramie yarn‐reinforced PLA‐based composites fabricated by an in situ impregnated fused filament fabrication (FFF) process. The dimensional error analysis was conducted to evaluate the printability of biocomposites with different processing variations and continuous ramie yarns. The effect of yarn volume fraction ( Y f ) caused by processing variations and ramie yarn characteristics on the mechanical properties was also studied. The results showed that the dimensional accuracy of the biocomposites with different ramie yarns could be adjusted by process parameter optimization. On the basis of ensuring printability, the Y f was within the range of 6.80% to 23.32% in the current study. With the increase of Y f , the tensile strength and the tensile modulus of the biocomposites significantly increased. When the Y f was 23.32%, the tensile strength and the tensile modulus increased by 60.78% and 382.35%, respectively, compared to pristine PLA. In addition, an analytical model considering the influences of Y f and microstructural characteristics such as interfacial void content ( V p ) on the tensile strength of the 3D printed biocomposites was derived, and the theoretical predictions were in good agreement with experimental measurements.