Additive Manufacturing Bio-based Filaments Reinforced with Cellulose Nanocrystals

Abstract

Additive Manufacturing (AM), commonly known as 3D printing, is a manufacturing technique that is attracting broad attention due to its advantages, tailorability, and low cost. Among the many different types of AM processes, extrusion based systems are commonly used due to its low initial equipment and material costs. Bio-based Polylactic Acid (PLA) is one of the most commonly used materials in this market. However, mechanical properties and final tolerances of 3D printed PLA based parts are in need of improvement for applications that require high strength, stiffness and structural stability. Addition of filler materials such as organic particles can provide the required property improvements. Cellulose Nanocrystals (CNC) are novel bio-based nano-fibers with excellent mechanical properties. These particles have high potential to improve mechanical and thermo-mechanical properties of PLA. The present work investigates production and use of PLA/CNC composite filaments as an attractive option for 3D printing. PLA/CNC filaments were produced via twin-screw extrusion and fed into extrusion-based printers to form 3D printed components. The investigation shows an increase in mechanical properties from plain 3D printed PLA to a CNC reinforced PLA.