Novel three-dimensional printed continuous Zylon yarn reinforced polylactic acid composites utilizing compatible sizing

The field of three-dimensional printing (3D-printing) of continuous fibers is currently growing rapidly, with a focus on increasing productivity and applied research to produce technologically advanced products for real world applications. However, there are many 3D-printed fiber/matrix combinations that have not yet been explored in depth. This research aims to address this gap by examining the mechanical properties of 3D-printed composites made from continuous Zylon yarn reinforced polylactic acid (PLA), which is the first of its kind. A polymer sizing method was also introduced to enhance the mechanical properties of the composites. The Zylon yarn was 3D-printed using material extrusion additive manufacturing technology, which is applicable to a wide range of thermoplastic materials. The effect of PLA sizing on the Zylon yarn was investigated, as it plays a significant role in increasing the tensile strength of the 3D-printed composites. Various grades and concentrations of PLA solution were tested to find the most compatible sizing solution. The findings indicate that using a 5%w/v printing filament PLA (PF-5) solution as a sizing solution on Zylon yarn/PLA led to a 43% increase in tensile strength compared to 3D-printed Zylon reinforcement without sizing.