[3D Printing Knowledge] An Introductory Guide to Carbon Fiber Materials: A Thorough Comparison of PLA-CF, PAHT-CF, PET-CF, and PETG-CF
When considering 3D printing materials, we usually evaluate them based on print performance and mechanical properties. Print performance is a key factor, as it determines whether a material is suitable for 3D printing and influences the final appearance and dimensional accuracy of the printed parts. On the other hand, while mechanical properties are often overlooked, they play a crucial role in determining whether a material is suited for specific applications.
When printing items like drones, race cars, or mechanical components, products require basic mechanical properties such as rigidity (resistance to deformation), strength (resistance to breakage), toughness (resistance to failure from impact), and heat resistance (property of remaining resistant to deformation at high temperatures). These mechanical properties are vital and significantly dictate the lifespan of a printed object in a given environment. The better the mechanical properties, the wider the range of demanding applications a material can accommodate. Materials with such superior mechanical properties are known as "high-performance materials."
Until now, due to certain limitations in the price and performance of 3D printers, high-performance materials have not received much attention. The Bambu Lab X1 series is an excellent solution that supports common high-performance materials. At the same time, Bambu Lab aims to provide comprehensive system solutions—including printers, print materials, and print parameters—enabling users to enjoy a unique 3D printing experience.
When printing items like drones, race cars, or mechanical components, products require basic mechanical properties such as rigidity (resistance to deformation), strength (resistance to breakage), toughness (resistance to failure from impact), and heat resistance (property of remaining resistant to deformation at high temperatures). These mechanical properties are vital and significantly dictate the lifespan of a printed object in a given environment. The better the mechanical properties, the wider the range of demanding applications a material can accommodate. Materials with such superior mechanical properties are known as "high-performance materials."
Until now, due to certain limitations in the price and performance of 3D printers, high-performance materials have not received much attention. The Bambu Lab X1 series is an excellent solution that supports common high-performance materials. At the same time, Bambu Lab aims to provide comprehensive system solutions—including printers, print materials, and print parameters—enabling users to enjoy a unique 3D printing experience.
What is Carbon Fiber?
One common way to create high-performance materials is to add fibers to a polymer matrix. This is similar to adding steel rebar to concrete. Without the rebar, concrete has poor mechanical properties and is prone to cracking when external force is applied. By adding high-strength rebar, concrete becomes a structure capable of withstanding external forces. Following the same principle, fibers can be used to improve the mechanical properties of 3D printing materials. The key is incorporating high-strength fibers into the base matrix.
Carbon fiber is one of the representative reinforcing fibers, along with glass fiber and Kevlar. Carbon fiber is a carbon-based material with a very fine diameter, possessing excellent mechanical properties such as high rigidity, strength, low weight, chemical resistance, and heat resistance. Because of these characteristics, it is widely used in fields such as aerospace, military, racing, and competitive sports. However, because it is difficult to manufacture and costly, there are certain limitations to its widespread use in large-scale applications.
If 3D printing materials could possess some of the superior mechanical properties of carbon fiber, it would bring significant changes to many industries. Currently, the common method for creating final 3D printing materials is by finely chopping carbon fiber and extruding it along with a base matrix for 3D printing.
What are the pros and cons of this composite material composed of a 3D printing matrix and carbon fiber? Benefits include improved mechanical properties (such as rigidity and strength), enhanced heat resistance, better dimensional accuracy, and the unique appearance and texture of carbon fiber. However, the degree of improvement in these properties varies when carbon fiber is added to different matrices. Some properties may see significant improvement, while others may see little. This difference is largely related to the properties of the base matrix itself. Carbon fiber materials with mechanical properties improved to a very high level are called "high-performance carbon fiber materials." Others can be considered entry-level carbon fiber materials.
What are the pros and cons of this composite material composed of a 3D printing matrix and carbon fiber? Benefits include improved mechanical properties (such as rigidity and strength), enhanced heat resistance, better dimensional accuracy, and the unique appearance and texture of carbon fiber. However, the degree of improvement in these properties varies when carbon fiber is added to different matrices. Some properties may see significant improvement, while others may see little. This difference is largely related to the properties of the base matrix itself. Carbon fiber materials with mechanical properties improved to a very high level are called "high-performance carbon fiber materials." Others can be considered entry-level carbon fiber materials.
Disadvantages to Consider
1. High-performance carbon fiber materials demand higher print performance from 3D printers. A closed print chamber is required to ensure a higher, uniform chamber temperature. Also, a nozzle capable of handling higher printing temperatures, made of high-wear-resistant materials such as hardened steel, tungsten carbide, or ruby, is necessary. Furthermore, because high-performance carbon fiber materials are generally high in rigidity, they are difficult to bend during printing and tend to wear down components like the filament path.
2. Since carbon fiber remains in the material at a certain length (approximately 0.05–0.2 mm) and does not melt at the material's printing temperature, it is prone to causing nozzle clogs during printing.
Bambu Lab 3D printers currently meet the basic requirements for using carbon fiber materials, overcoming the first disadvantage mentioned above. This was one of the goals of the Bambu Lab 3D printer from its initial design phase. The Bambu Lab X1-Carbon is equipped with a fully enclosed print chamber, a hardened steel nozzle, a nozzle temperature of up to 300°C, and a 110°C heatbed.
Regarding the second disadvantage, Bambu Lab has optimized both the print material and print parameters to provide a more stable printing experience. On one hand, Bambu has optimized and improved the formula of its carbon fiber materials to reduce the likelihood of clogging during printing.
On the other hand, print parameters have also been optimized for the materials. When printing carbon fiber materials, using a lower print speed and a larger nozzle diameter is recommended.
Representative Carbon Fiber Materials
Until now, while carbon fiber 3D printing materials could improve appearance and mechanical properties, they were considered difficult to print. However, when carbon fiber is added to base materials like PLA, PETG, and PA, the degree of improvement varies. Depending on the characteristics and performance, Bambu Lab primarily classifies them into two types: "High-Performance" and "Entry-Level." First, let's take a look at Bambu Lab's two types of high-performance carbon fiber materials.
-High-Performance Carbon Fiber Materials-
PA-CF
PA-CF is a carbon fiber material based on nylon. Nylon is one of the representative engineering plastics and possesses excellent overall mechanical properties. It is widely used in various industrial applications such as gears and automotive parts via injection molding. When carbon fiber is added to this material, the mechanical properties are significantly improved.
PA-CF is also suitable for 3D printing, enabling overall performance that far exceeds common PLA prints, making it one of the most representative high-performance materials for 3D printing. However, nylon materials have a significant drawback: they have high water absorption and are very sensitive to moisture during 3D printing. If nylon material absorbs moisture, it is prone to issues like stringing and oozing, which can lead to clogs and print failures. Also, if a nylon print absorbs moisture, its strength and rigidity decrease while toughness increases. For this reason, Bambu Lab recommends thoroughly drying the material and storing it in a sealed environment when using this material.
In reality, there are many types of PA (polyamide), and their performance varies greatly. PAs often used in 3D printing include PA6, PA12, and special nylon materials. While PA6 has excellent mechanical properties, its main disadvantage is that its water absorption rate is approximately 3%, much higher than the approximately 0.3% of PA12. On the other hand, in a dry state, the mechanical properties of PA12 do not reach those of PA6, and there is also a significant difference in cost between the two. In other words, a good PA-CF (carbon fiber reinforced polyamide) formula requires a comprehensive balance of multiple factors, such as mechanical properties, water absorption, and cost.
Bambu Lab has developed a proprietary PA-CF filament to achieve low water absorption and high heat resistance. In addition, its rigidity has been optimized for smooth use with the AMS (Automatic Material Supply) system. This enables it to be used with the AMS Automatic Material Supply System (Related article: [3D Printing News] A Thorough Explanation of the Bambu Lab AMS! The Secret to Multi-Color Printing!) and can also be used for printing support material. Bambu Lab names this material "Bambu PAHT-CF."
In summary, Bambu PAHT-CF is AMS-compatible and possesses overall mechanical properties, low water absorption, and high heat resistance. It is a high-performance carbon fiber material that can be used in a wide range of applications such as industrial jigs, fixtures, automotive parts, and drone components. It can also handle various demanding applications in daily life.
PET-CF
Bambu Lab has developed a carbon fiber material with even higher rigidity than PAHT-CF to cater to applications requiring exceptionally high rigidity. That is Bambu PET-CF.
Bambu PET-CF is composed primarily of PET (polyethylene terephthalate) and CF (carbon fiber). PET is a type of crystalline plastic widely used in various fields such as plastic bottles and automotive parts. It possesses high mechanical properties, heat resistance, and chemical resistance. Adding carbon fiber to PET significantly improves mechanical properties, especially rigidity. Furthermore, compared to nylon-based carbon fiber materials, PET-CF has the major advantage of extremely low water absorption (approximately 0.3%). Therefore, even when exposed to moisture, the mechanical properties of the printed parts can be maintained at almost the same level. This makes it suitable for use in high-humidity environments.
The disadvantage of PET-CF is that it is relatively brittle and has low interlayer adhesion strength. To solve this problem, Bambu Lab has adjusted the formula of Bambu PET-CF to increase the Z-axis impact strength to approximately 4.5 kJ/m² (other PET-CF on the market is usually around 2–3 kJ/m²). By selecting appropriate printing conditions and usage methods, one can avoid the weaknesses of this material. For example, when creating structural parts with PET-CF, it is best to avoid usage methods where force is applied in the direction of interlayer adhesion and prevent excessive impact or collisions, allowing you to leverage the benefits while mitigating the weaknesses.
In summary, Bambu PET-CF features higher rigidity and extremely low water absorption, while being characterized by relatively low interlayer adhesion strength and being somewhat brittle. Depending on the application, you can choose the appropriate material from these two types of high-performance materials. PAHT-CF is suitable if you need an AMS-compatible filament. PET-CF is not compatible with the AMS. Please see the chart below for a performance comparison between Bambu PET-CF and Bambu PAHT-CF.
Comparison of PAHT-CF and PET-CF
-Entry-Level Carbon Fiber Filaments-
Next, to meet the carbon fiber printing needs of more users, we will introduce two entry-level carbon fiber materials from Bambu Lab: Bambu PLA-CF and Bambu PETG-CF. Adding carbon fiber does not significantly improve the performance of the PLA or PETG base matrix itself. However, compared to standard PLA or PETG, the addition of carbon fiber makes the material easier to print and provides an excellent appearance, while slightly improving strength and rigidity. Both PLA-CF and PETG-CF are compatible with AMS printing.
PLA-CF
Bambu PLA-CF is a filament with a matte carbon fiber texture that maintains printing performance on par with PLA while significantly enhancing the appearance of the product. To further optimize the printing experience, Bambu Lab has reduced the carbon fiber content, reducing the risk of clogging even during high-speed printing. Although the carbon fiber content is not as high as in high-performance carbon fiber materials, its rigidity is improved by more than 30% compared to standard PLA. Additionally, carbon fiber improves printing accuracy by suppressing warping caused by shrinkage during printing. A disadvantage of PLA-CF is that the carbon fiber may affect interlayer adhesion strength. However, from a different perspective, support structures printed with this filament may be easier to remove.
In summary, Bambu PLA-CF has higher rigidity and dimensional accuracy than standard PLA, features a matte carbon fiber texture, and is easy to print. It is suitable for various daily applications such as small tools, functional prototypes, and structural parts that require rigidity. Performance comparison with standard PLA is as follows.
Comparison of PLA and PLA-CF
PETG-CF
Another entry-level carbon fiber material is Bambu PETG-CF. Composed mainly of PETG and CF, it has a glossy carbon fiber texture. Its mechanical properties are not as high as PET-CF. A major feature of PETG is that the "G" stands for Glycol. PETG is a material modified with glycol, containing a small amount of glycol as a copolymer monomer. Adding glycol lowers the crystallinity of PETG, increasing transparency while lowering strength and rigidity.
Adding carbon fiber to PETG slightly improves its strength and rigidity. Its rigidity is not as high as PLA-CF, so it possesses better toughness. Additionally, it has superior interlayer adhesion strength. Under special conditions, the high rigidity of PLA-CF can lead to print failures, but that risk is lower with PETG-CF. In terms of ease of printing, it may be slightly superior to PLA-CF in some cases. PETG-CF also has excellent water resistance, UV resistance, and weather resistance, providing higher durability and suppressing degradation and aging for applications exposed to outdoor environments.
In summary, Bambu PETG-CF possesses higher toughness, interlayer adhesion strength, and heat resistance, and is also suitable for outdoor applications. It features a glossy carbon fiber texture and is easy to print. You might consider Bambu PETG-CF if your print requires higher toughness or interlayer adhesion strength. If higher rigidity is required, Bambu PLA-CF is more suitable.
Comparison of PETG, PETG-CF, and PLA-CF
Many people likely associate carbon fiber materials with a black appearance. For entry-level carbon fiber materials like PLA-CF and PETG-CF, Bambu Lab offers a wider variety of colors, expanding the range of applications.
For more detailed parameters, please check the Filament Guide and the TDS/MSDS documentation for each filament.
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3DMart Japan Co., Ltd.
407 Center Bldg., Tokyo Distribution Center, 6-1-1 Heiwajima, Ota-ku, Tokyo 143-0006
Web: https://www.3dmart.co.jp/
TEL: 03-4332-9828
Email: client@3dmart.co.jp