In this blog post, we will focus on the operating principles of FDM 3D printers, the advantages of additive manufacturing technology, and the characteristics of PLA and ABS—two of the most common filament materials.

Overview and Use Cases of FDM 3D Printers

Recently, 3D printing technology has been actively utilized in the medical field to provide patient-specific treatments. For example, there have been reports of cases where CT and MRI data from kidney cancer patients are used to print life-size models of individual kidneys and tumor structures, which are then utilized in surgical planning. Medical staff can use these printed models to more accurately identify the areas that need to be resected and the healthy tissue that should be preserved, thereby enhancing the precision and safety of surgery. As such, 3D printing technology is being utilized not only in the medical field but also in various other sectors, including manufacturing, construction, design, education, and the aerospace industry. Recently, with the growing popularity of home 3D printers, interest in and the need for related technologies have been increasing.

How FDM Works

FDM (Fused Deposition Modeling) 3D printers are a representative additive manufacturing method that creates structures by heating solid filament in the nozzle to melt it, extruding it, and layering it to build a structure.
The process begins by preparing the build plate, which serves as the base for the printed object. The build plate must provide adequate adhesion to prevent the object from shifting or lifting during the printing process. Filament wound onto a spool is loaded into the printer, and the 3D model data to be printed is input. Once the nozzle is heated to the set temperature, the filament melts into a semi-fluid state and is extruded in thin layers through the nozzle.
The nozzle and build plate move precisely according to the input design data, building up the structure layer by layer, starting from the bottom. The extruded filament cools rapidly and solidifies, allowing the next layer to be formed stably on top of it. As this process repeats, the final 3D shape is completed.
The machine’s main components include a filament spool, an extruder that feeds the filament, a nozzle that melts and extrudes the filament, a bed that supports the printed object, and a drive mechanism and control system that regulate the movement of each component.

Advantages of Additive Manufacturing

Additive manufacturing technologies, such as FDM, offer several advantages over traditional subtractive machining methods like CNC milling.
Subtractive machining involves removing material from a large block to leave only the desired part, resulting in material waste. In contrast, additive manufacturing builds up material layer by layer in the exact locations and quantities needed, leading to high material utilization and minimal waste.
Furthermore, while subtractive machining faces limitations when producing internal structures or complex shapes that are difficult for tools to access, additive manufacturing—which builds up layers one by one—can relatively easily create complex internal channels or organic curved surfaces. Thanks to these advantages, FDM 3D printers are widely used in various fields, including prototyping, the production of custom parts, and the creation of educational models.

Filament Requirements and Key Materials

Filaments used in FDM 3D printers must meet several important criteria.
First, they must possess thermoplastic properties, meaning they melt when heated and solidify again upon cooling. They must also maintain a uniform diameter and density to ensure stable movement within the nozzle and consistent extrusion.
Immediately after extrusion, the filament must have appropriate viscosity to prevent excessive sagging, and after cooling, it must possess the strength, heat resistance, impact resistance, and flexibility required for the intended use of the printed object. In particular, properties such as strength, heat resistance, and flexibility refer to the performance of the filament once it has solidified after printing.

PLA (Poly Lactic Acid)

PLA stands for Poly Lactic Acid. It is a thermoplastic resin produced by polymerizing lactic acid, which is obtained through the fermentation of starch or sugars derived from plant-based raw materials such as corn or sugarcane.
Because it is produced from plant-based resources, it has a relatively lower environmental impact compared to petroleum-based plastics and is biodegradable under appropriate conditions in industrial composting facilities. Additionally, it has little odor and is easy to print, making it one of the most popular 3D printing materials among beginners.
PLA generally has excellent surface quality and a glossy finish, and it is easy to achieve a wide range of colors. With a low shrinkage rate, it experiences minimal warping during printing and has a high success rate, making it widely used for home-use models, educational models, and prototyping. It also has a relatively fast print speed, which is advantageous when producing large models.
On the other hand, it is relatively more brittle than ABS, so it is prone to breaking when subjected to strong impacts. Another drawback is its low heat resistance; it may warp if exposed to high temperatures for extended periods.

ABS (Acrylonitrile-Butadiene-Styrene)

ABS is a representative engineering plastic named after the initials of acrylonitrile, butadiene, and styrene.
It offers excellent strength and impact resistance, and its relative flexibility makes it easy to process. It is suitable for manufacturing products that consist of multiple assembled parts, as well as machine components and electronic device casings. Furthermore, since it can retain its shape at higher temperatures than PLA, it is highly versatile in environments requiring heat resistance.
Therefore, ABS is considered a suitable material for applications likely to be exposed to high temperatures or impact, such as industrial prototyping, automotive parts, and electronic device casings.
However, since it is manufactured from petroleum-based raw materials, ventilation is required during the printing process due to the potential for a distinctive odor and the emission of volatile organic compounds (VOCs). Furthermore, its relatively high shrinkage rate makes it prone to warping during printing, and it is generally more challenging to print than PLA. While it offers superior flexibility and impact resistance compared to PLA, its surface quality and ease of printing may be somewhat inferior.

Metal 3D Printing Technologies and Limitations

Currently, various 3D printing technologies using metal materials are also being commercialized. Notable examples include Selective Laser Melting (SLM), Direct Metal Laser Sintering (DMLS), and Binder Jetting, which are utilized in industrial settings; some of these technologies are implemented using metal powders or filaments containing metal.
Metal 3D printing offers the advantage of being able to produce metal parts with complex geometries and to create internal structures that are difficult to achieve with conventional manufacturing methods. In particular, its scope of application is expanding in the aerospace, medical implant, and automotive industries.
However, high-power lasers and expensive equipment are required to melt or sinter metal materials, and post-processing steps such as heat treatment and machining are also necessary after printing. Furthermore, securing cost-effectiveness remains a key challenge due to the high equipment costs and operating expenses. Nevertheless, related technologies are continuously advancing, and it is expected that the scope of metal 3D printing will expand further as costs are reduced and productivity improves.

Conclusion

So far, we have examined the operating principles of FDM 3D printers, the advantages of additive manufacturing, and the characteristics of the representative filaments PLA and ABS. FDM is an additive manufacturing process that builds objects layer by layer, reducing material waste and enabling the creation of complex shapes, resulting in a very wide range of applications. PLA is easy to print with and offers excellent surface quality, making it suitable for home and educational applications, while ABS, with its superior impact resistance and heat resistance, is ideal for manufacturing industrial parts. Furthermore, metal 3D printing technology is also continuously advancing, and it is expected to play an increasingly important role across the manufacturing industry as costs are reduced and the technology becomes more sophisticated.