[3D Printing Knowledge] A Beginner's Guide to Carbon Fiber Printing Materials: PLA-CF, PAHT-CF, PET-CF, and PETG-CF - A Final Comparison
When discussing 3D printing materials , we typically evaluate them based on their printability and mechanical properties. Printability is a key factor that determines whether a material is suitable for 3D printing and affects the final appearance and dimensional accuracy of the printed product. Mechanical properties are often overlooked, but they play a crucial role in determining whether a material is suitable for a specific application.
If you're printing drones, racing cars, or mechanical parts, the products will require fundamental mechanical properties such as stiffness (resistance to deformation), strength (resistance to damage), toughness (resistance to impact fracture), and high-temperature resistance (the ability to withstand high temperatures without deforming). These mechanical properties of the printing materials are crucial and can largely determine the lifespan of the printed product in a specific environment. The better the mechanical properties, the more demanding the product can be in a wider range of applications. Materials with superior mechanical properties are called high-performance materials.
High-performance materials have received relatively little attention due to the limited price and capabilities of 3D printers on the market. The Bambu Lab X1 series offers a better solution, perfectly supporting common high-performance materials. Furthermore, Bambu Lab aims to provide multi-dimensional system solutions, including printers, printing materials, and printing parameters, ensuring users can enjoy the unique experience of 3D printing.
If you're printing drones, racing cars, or mechanical parts, the products will require fundamental mechanical properties such as stiffness (resistance to deformation), strength (resistance to damage), toughness (resistance to impact fracture), and high-temperature resistance (the ability to withstand high temperatures without deforming). These mechanical properties of the printing materials are crucial and can largely determine the lifespan of the printed product in a specific environment. The better the mechanical properties, the more demanding the product can be in a wider range of applications. Materials with superior mechanical properties are called high-performance materials.
High-performance materials have received relatively little attention due to the limited price and capabilities of 3D printers on the market. The Bambu Lab X1 series offers a better solution, perfectly supporting common high-performance materials. Furthermore, Bambu Lab aims to provide multi-dimensional system solutions, including printers, printing materials, and printing parameters, ensuring users can enjoy the unique experience of 3D printing.
What is carbon fiber?
A common solution for creating high-performance materials is to infuse fibers into a polymer matrix. Imagine it like adding steel reinforcement to concrete. Without reinforcement, concrete has poor mechanical properties and is prone to cracking under external forces. Adding high-strength reinforcement transforms concrete into a structure resistant to external forces. The same principle applies to enhancing the mechanical properties of 3D printed materials with fibers, the key being the high-strength fibers encapsulated within the substrate.
Carbon fiber is one of the most popular reinforcing fibers, along with glass fiber and Kevlar fiber. Carbon fiber is a very fine-diameter carbon material with excellent mechanical properties such as high stiffness, strength, low weight, chemical resistance, and high-temperature resistance. These characteristics make it highly sought after in aerospace, military, motorsports, and competitive sports. However, production difficulties and high costs limit its large-scale application.
Imagine if 3D printing materials had some of the mechanical properties of carbon fiber—it would be a game-changer for many industries! Current industry practice involves shredding carbon fiber and extruding it together with a 3D printing substrate to create the final 3D printing material.
What are the advantages and disadvantages of this hybrid 3D printing material, composed of a 3D-printed substrate and carbon fiber? Advantages include better mechanical properties (stiffness, strength, etc.), higher heat resistance, higher dimensional accuracy, and the aesthetic appeal of carbon fiber. However, it should be clear that the improvements in these aspects vary significantly depending on the substrate to which carbon fiber is added. Some aspects can be significantly improved, while others can be improved only slightly. This difference is directly related to the substrate itself; carbon fiber materials with significantly enhanced mechanical properties are called high-performance carbon fiber materials. Otherwise, they are considered entry-level carbon fiber materials.
What are the advantages and disadvantages of this hybrid 3D printing material, composed of a 3D-printed substrate and carbon fiber? Advantages include better mechanical properties (stiffness, strength, etc.), higher heat resistance, higher dimensional accuracy, and the aesthetic appeal of carbon fiber. However, it should be clear that the improvements in these aspects vary significantly depending on the substrate to which carbon fiber is added. Some aspects can be significantly improved, while others can be improved only slightly. This difference is directly related to the substrate itself; carbon fiber materials with significantly enhanced mechanical properties are called high-performance carbon fiber materials. Otherwise, they are considered entry-level carbon fiber materials.
Disadvantages to consider
1. High-performance carbon fiber materials place higher demands on printers. A closed printing chamber is required to ensure a higher and more uniform temperature. It also necessitates nozzles with higher printing temperatures, and nozzle materials made of hardened steel, tungsten carbide, ruby, or other ultra-wear-resistant materials. Furthermore, high-performance carbon fiber materials typically have greater stiffness, meaning they are more difficult to bend during printing and may wear down the printing path more easily.
2. Because carbon fibers still retain a certain length (about 0.05-0.2mm) in the material, they cannot melt at the printing temperature of the material, thus making them more prone to clogging during the printing process.
Bambu Lab's printers currently meet the basic requirements for using carbon fiber, overcoming the first drawback, which was one of the original design intentions of Bambu Lab printers . The Bambu Lab X1-Carbon features a fully enclosed printing chamber, hardened steel nozzles, nozzle temperatures up to 300°C, and bed surface temperatures of 110°C.
Regarding the second drawback, Bambu Lab optimized the printing materials and parameters to provide a better printing experience. On one hand, the formulation of Bambu carbon fiber materials was optimized and improved to reduce the possibility of clogging during the printing process.
On the other hand, printing parameters were also matched and optimized. It is recommended to use a lower printing speed and a larger nozzle size for printing carbon fiber materials.
Common carbon fiber materials
To date, carbon fiber 3D printing materials might be considered materials that can improve appearance and mechanical properties but are not easy to print. However, the degree of improvement varies when carbon fiber is added to substrates such as PLA, PETG, and PA. Based on their properties and performance, Bambu Lab has different classifications, mainly divided into high-performance and entry-level carbon fiber materials. Let Bambu Lab start with two 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 most common engineering plastics, possessing excellent overall mechanical properties. It is widely used in industrial applications such as gears and automotive parts through injection molding. When carbon fiber is added to this material, its mechanical properties are significantly enhanced.
Fortunately, PA-CF is also suitable for 3D printing, and the overall performance of printed materials far exceeds that of ordinary PLA prints, making it one of the most common high-performance materials for 3D printing. However, nylon materials have a major drawback – high water absorption, making them very sensitive to moisture during the 3D printing process. When nylon absorbs water, defects such as filaments and leakage are prone to occur, which can lead to clogging and printing failures. Furthermore, when nylon prints absorb water, their strength and stiffness decrease, but their toughness increases. This drawback necessitates that Bambu Lab thoroughly dry and store the material in a sealed environment when using it for printing.
In fact, there are many types of PA (polyamide) materials with significantly different properties. In 3D printing, the most commonly used PA types include PA6, PA12, and some special nylon materials. PA6 has strong mechanical properties, but its main drawback is its water absorption rate (approximately 3%), which is much higher than PA12 (approximately 0.3%). However, under dry conditions, PA12's mechanical properties cannot match PA6, and there is also a significant cost difference between them. In short, an excellent PA-CF (carbon fiber reinforced polyamide) formulation needs to achieve a comprehensive balance in terms of mechanical properties, water absorption rate, and cost.
Bambu Lab has launched a specially formulated PA-CF filament designed to achieve low water absorption and high heat resistance. Bambu Lab has also optimized its stiffness in the design to ensure smooth printing through the AMS automated feeding system (Related article: [3D Printing News] Bambu Lab AMS Explained! The Secret to Multicolor Printing! ), making it suitable for printing support materials . Bambu Lab names it Bambu PAHT-CF.
In summary, Bambu PAHT-CF is suitable for AMS applications, offering the most comprehensive mechanical properties, low water absorption, and high-temperature resistance. It is a multifunctional, high-performance carbon fiber material applicable to industrial fixtures, clamps, automotive parts, drone components, and other fields. It easily meets the demanding application requirements of everyday life.
PET-CF
Bambu Lab aimed to introduce a carbon fiber material with higher stiffness than PAHT-CF to meet the extremely high stiffness requirements of users under certain working conditions; this is Bambu PET-CF.
Bambu PET-CF is primarily composed of PET (a ether-based polymer) and CF (carbon fiber). PET is a crystalline plastic widely used in industries such as plastic bottles and automotive parts. It possesses high mechanical properties, temperature resistance, and chemical resistance. When carbon fiber is added to PET, its mechanical properties, especially in terms of stiffness, are significantly improved. Furthermore, PET-CF has a significant advantage over nylon carbon fiber due to its extremely low water absorption rate (approximately 0.3%), allowing printed materials to maintain almost identical mechanical properties even when exposed to moisture. This makes it suitable for humid environments.
The drawback of PET-CF is its relative fragility and poor interlayer adhesion strength. To address this issue, Bambu Lab adjusted the formulation of Bambu PET-CF, achieving a Z-axis impact strength of approximately 4.5 kJ/m² (compared to approximately 2-3 kJ/m² for other PET-CF products on the market). These shortcomings can also be mitigated through proper printing processes and usage conditions. For example, when using PET-CF structural components, it is best to avoid applying force in the interlayer adhesion direction and to avoid excessive impacts or collisions, thereby maximizing its advantages and minimizing its weaknesses.
In summary, Bambu PET-CF has higher stiffness, ultra-low water absorption, and relatively weak interlayer adhesion, making it somewhat fragile. Depending on the specific application, you can flexibly choose one of these two high-performance materials. If you need to use AMS-compatible wires, then PAHT-CF is the best choice because PET-CF is not compatible with AMS. A performance comparison of Bambu PET-CF and Bambu PAHT-CF is shown in the figure below.
Comparison of PAHT-CF and PET-CF
-Entry-level carbon fiber wire-
In the following sections, Bambu Lab will introduce two entry-level carbon fiber materials, Bambu PLA-CF and Bambu PETG-CF, to meet the carbon fiber printing needs of a wider range of users. The addition of carbon fiber does not significantly improve the performance of PLA and PETG substrates. However, compared to regular PLA and PETG, you can think of the addition of carbon fiber as making them slightly stronger and stiffer, while still being easy to print and aesthetically pleasing. Both PLA-CF and PETG-CF can be used for AMS printing.
PLA-CF
Bambu PLA-CF is a filament with a frosted carbon fiber texture that significantly enhances the aesthetics of products while maintaining printing performance comparable to PLA. To further optimize the printing experience, Bambu Lab reduced the carbon fiber content to ensure no clogging occurs even at higher printing speeds. Although the carbon fiber content is not as high as high-performance carbon fiber materials, its stiffness is still increased by more than 30% compared to regular PLA. Furthermore, the carbon fiber suppresses shrinkage deformation during printing, thereby improving printing accuracy. A drawback of PLA-CF is that the carbon fibers may affect interlayer bond strength. However, on the other hand, support structures printed using this filament may be easier to disassemble.
In summary, Bambu PLA-CF offers higher stiffness and dimensional accuracy than PLA, a matte carbon fiber texture, and is easy to print. It is primarily suitable for everyday applications such as printing small gadgets, functional prototypes, and structural components requiring rigidity. Its performance compared to ordinary PLA is as follows:
Comparison of PLA and PLA-CF
PETG-CF
Another entry-level carbon fiber material is Bambu PETG-CF, which is mainly composed of PETG and CF and has a glossy carbon fiber texture. Its mechanical properties cannot reach the level of PET-CF. The key difference in PETG is that the "G" stands for ethylene glycol. PETG is an ethylene glycol-modified version of PET, containing a small amount of ethylene glycol as a comonomer. The addition of ethylene glycol reduces the crystallinity of PETG, making it more transparent, but also reduces its strength and stiffness.
When carbon fiber is added to PETG, it only slightly increases its strength and stiffness. Compared to PLA-CF, its stiffness is not high, meaning it has better toughness. Furthermore, its interlaminar bond strength is better. In certain special cases, the high stiffness of PLA-CF may lead to printing failure, but PETG-CF does not have this risk. In terms of printing experience, it may be slightly superior to PLA-CF. PETG-CF also has good water resistance, UV resistance, and weather resistance, so it may offer better durability when exposed to outdoor elements, and is less prone to degradation and aging.
In summary, Bambu PETG-CF offers superior toughness, interlayer bond strength, and heat resistance, making it suitable for outdoor use. It also boasts a glossy carbon fiber finish and is easy to print on. If your prints require better toughness and interlayer bond strength, consider Bambu PETG-CF. For higher stiffness, choose Bambu PLA-CF.
Comparison of PETG, PETG-CF and PLA-CF
When people think of carbon fiber materials, they usually associate them with a black appearance. For entry-level carbon fiber materials like PLA-CF and PETG-CF, Bambu Lab offers a wider range of color options, making their applications more versatile.
For more detailed specifications, please refer to the cable guide and the specific TDS and MSDS files for each cable.
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