Anisotropic Properties of Polylactic acid–carbon Fiber Composites Prepared by Droplet spray Additive Manufacturing

Anisotropic materials are important functional materials in many fields. The use of these materials is currently being expanded through the rapid development of additive manufacturing. However, there is still no universal method for fabricating two-dimensional anisotropic polymer composites. Here, polylactic acid–carbon fiber composites were prepared using the droplet spray method, and their mechanical and friction properties were studied. The tensile strength in the X–Y plane perpendicular to the direction of the droplet spray was significantly higher than that in the direction of droplet ejection. Similar trends were observed for the elongation at breaking and the impact strength. The friction coefficient was smallest in the X–Y plane. Scanning electron microscopy showed that carbon fibers were oriented in the X–Y plane, which enhanced the mechanical and friction properties in this plane.