High-throughput extrusion additive manufacturing using electrically resistive preheating

Abstract

Extrusion-based additive manufacturing, commonly known as fused deposition modeling (FDM) or fused filament fabrication (FFF) is incredibly useful in industry for a variety of reasons, including rapid prototyping and the ability to create complex geometries easily. However, its further adoption is limited by relatively slow part manufacturing rates when compared to conventional manufacturing methods. Previous work has identified three modules within the FDM process which are rate limiting: speed of gantry positioning, polymer heating, and extrusion pressure. Advancements in any one module will allow for higher volumetric output, which will in turn allow for higher rates of production using FDM. This work focuses on polymer heating, and demonstrates a new concept for rapid heating of filament by introducing conductive nanoparticles into the polymer resin and resistively heating sections in flow. This technique can improve the volumetric output of FDM printers by at least 20%. First, the resistive properties of the composite filament are characterized. Second, the concept is experimentally validated by demonstrating a decrease in extrusion force required to maintain a given feed rate when using resistive heating.