3D printing of short fiber reinforced polymers: a review of the materials, 3D printers, lattice structures and pre-/post-treatment impact on the mechanical characteristics

Abstract: The demand for lightweight, high-performance materials has propelled the use of 3D-printed short fiber-reinforced polymers. However, research on short fiber-reinforced polymer lattice structures and the impact of pre- and post-printing processing treatments on mechanical performance remains limited. This study investigates the fabrication of short fiber-reinforced polymer lattice structures using material extrusion additive manufacturing method. It explores the effects of both pre- and post-printing treatments on the mechanical properties of the printed components. It was found that PEEK exhibits exceptional properties, while Kevlar demonstrates superior toughness among the synthetic fibers examined. Also, chemical post-treatment effectively increases surface roughness (up to 90%), where pre-printing drying is essential for hygroscopic materials like PA6. The re-entrant lattice structure displays excellent energy absorption and rebound, recovering 80% of its initial height after load removal. A comparative analysis of different composite materials and 3D printers highlights the influence of resin cost on filament price and properties. This review also identifies and discusses key 3D printer brands and their capabilities for printing composite filaments. Finally, knowledge gaps are addressed, and future research directions are suggested within this rapidly evolving field.