Challenges in making filaments for fused filament fabrication 3D printers

Abstract

Fused filament fabrication (FFF) as one of the most popular and cost-efficient methods for 3D printing of polymeric parts has been at the center of attention in past years. FFF 3D printers melt a filament of polymer material to create the model layer by layer. The evolution of FFF 3D printers has reached an acceptable level during the last few years, while more studies and innovations are needed in the material side of the process which is directly related to filament-shaped material production. The filament must be dimensionally accurate without fluctuations in diameter and should be easy to melt and solidify. The filament is fabricated via a hot melt extrusion process and some processes before and after the extrusion process. The extrusion process of filaments is done with the help of an extruder machine which basically is a device for converting polymer pellets into round-shaped filaments. The process of filament fabrication, from both the material and process equipment viewpoints, may be challenging and tricky. This chapter introduces the filament fabrication process from feeding the pellets to the extruder machine to spooling the fabricated filament in spools. Also, design considerations of a single-screw extruder suitable for filament fabrication are discussed in order to create a clear point of view about the process and help in designing better extruders for filament fabrication. In addition, the raw materials and additives properties and applications, as the base material of filaments, are introduced. In recent years, the lack of high mechanical properties and durability of common filament materials for 3D printing of more practical and mechanical parts, caused the producers to introduce composite filaments which represent composite materials with higher and better mechanical properties. The fabrication of composite filament has some different processes which are discussed in this chapter. Finally, the challenges which can be faced during the filament extrusion process are discussed and possible solutions are mentioned. © 2024 Elsevier Inc. All rights are reserved including those for text and data mining AI training and similar technologies.