Fused Deposition Modeling (FDM), also referred to as material extrusion additive manufacturing, employs polymers as its primary material in the form of filament. The filament undergoes heating to reach a molten state and is subsequently extruded through the printer's nozzle. This nozzle, capable of movement in three dimensions, deposits the molten polymer onto the build plate according to instructions encoded in G-code. The filament is continuously supplied through the extruder and nozzle via counter-rotating rollers. Layer-by-layer deposition occurs until the desired shape and size of the product are achieved. Throughout this process, the printer nozzle traverses back and forth based on spatial coordinates derived from the original CAD model within the G-code files. In certain FDM systems, multiple nozzles may be utilized, particularly when producing components with compositional gradients. The quality and precision of extrusion primarily hinge on the properties of the thermoplastic filament, leading to the design of specialized 3D printers tailored to specific filament materials. Many low-cost FDM printers are limited to processing a single type of thermoplastic, with polylactic acid (PLA) being the most prevalent. Printed components are typically adhered to the build plate and can be detached by snapping or soaking, depending on the thermoplastic used. Post-processing techniques such as cleaning, sanding, painting, or milling may be applied to enhance both the appearance and functionality of the printed parts.
