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Carbon fiber 3d printer filament strength
All You Need to Know About Carbon Fiber for 3D Printing
Published on May 5, 2020 by Carlota V.
Produced for the first time by Joseph Swan in 1860, carbon fiber is made of a long chain of carbon atoms bonded together. The chain is usually between 5 to 10 micrometers in diameter and varies in length according to the application. Over the years, carbon fiber has become popular across many sectors because it offers interesting properties, including high stiffness, high tensile strength, low weight, high chemical resistance, high temperature tolerance and low thermal expansion. Pure carbon fiber is actually five-times stronger than steel and twice as stiff, yet lighter. As you can imagine, these characteristics make carbon fibers suitable for applications that rely on a material’s properties to optimize performance, which is particularly the case in sectors such as aerospace, automotive, military or civil engineering for example.
As some of you may already know, carbon fibers are rarely used on their own. They are usually combined with other materials to form what we call a composite material – referred to as carbon fiber reinforced materials in this particular case. These composites are made of a matrix material, usually a polymer – even though it is possible to use non-polymer materials such as ceramics – to which carbon fibers are added. The main benefit is you end up with a stronger, yet lighter plastic with an increased level of stiffness.
The body of this bike frame has been made with carbon fiber | Credits: Arevo
Traditionally, carbon fiber composites have been used for structural design, where added weight translates into increased lifecycle costs or unsatisfactory performance. Carbon fiber composites can be used to create many products such as bike frames, aircraft wings, propeller blades, car components, etc. As you can imagine, given the many benefits of carbon fiber, it’s no longer just traditional manufacturing systems that are utilizing it. In recent years, a growing number of 3D printing companies have been offering carbon fiber reinforced materials or technologies developed to work with this composite to enable higher performance applications.
So how is carbon fiber used in additive manufacturing?
3D Printing Applications
In its 3D Printing Composites 2020 – 2030 report, IDTechEx reveals that the global market for composite 3D printing will reach a value of $1.7 billion by the year 2030. This figure includes other composites such as materials that have been reinforced with glass or plastic fibers. Nevertheless, the trend clearly showcases that the 3D printing industry is increasingly using all composites, including carbon, in its manufacturing activities. In 3D printing, there are essentially two ways of using carbon fiber, the first is carbon fiber reinforced filaments and the second is continuous carbon fiber reinforcement.
Carbon Fiber Filament
Carbon fiber filament uses short carbon fibers, consisting of segments of less than one millimeter in length, which are mixed with a thermoplastic known as the base material. There are a number of popular filaments that can be bought with carbon fiber fill including PLA, PETG, Nylon, ABS, and Polycarbonate.
These fibers being extremely strong, they cause the filament to increase in strength and stiffness, and also reduce its overall weight. The 3D printing requirements for carbon fiber filaments should be similar to those of the base material that the carbon fibers were added to. The main difference is that the fibers can clog the nozzles of the 3D printer, therefore experts recommend using a hardened steel nozzle. Additionally, above a certain threshold of fibers, the 3D printed part will lose in surface finish.
Carbon fiber segments are incorporated into the filament to reinforce it | Credits: Markforged
Some companies have developed carbon fiber filaments for more technical applications. These filaments use as the base material high performance polymers (HPPs) such as PEEK or PEKK. Therefore, they not only offer the benefits of HPPs such as durability and strong mechanical and chemical performance, but also an improved strength-to-weight ratio. The printing parameters need to be adjusted since HPPs rely on extruders that can reach around 400°C, and systems that have heated chambers and build plates.
Some of the manufacturers of carbon fiber filaments include Roboze, 3DXTech, ColorFabb, Markforged, Kimya, Intamsys, Zortrax, etc.
Continuous Carbon Fiber Reinforcement
Carbon fiber filament is definitely stronger than a filament that has not been reinforced. However, in order to obtain an even stronger part, another technique can be used, called continuous carbon fiber reinforcement. Since the carbon fiber is not chopped up into smaller pieces, it retains much more of its strength. In fact, continuous carbon fiber 3D printing is strong enough to replace aluminium at half the weight. 3D printer manufacturers claim that it can replace metal 3D printing for some applications – the main advantage being it is cheaper than metal. Finally, by placing the carbon fiber according to DfAM techniques, it is possible to add even more strength to a part whilst reducing material use.
Using DfAM techniques, it is possible to reinforce a part using carbon fiber | Credits: Anisoprint
There are a few actors on the market that offer technologies that can print carbon fibers in a continuous way.
Actors can be divided into two main types, depending on when the carbon fiber is added (it can be added before the 3D printing process or during). When added before, continuous fiber 3D printing is known as prepreg-based, whilst when it is added during extrusion it is known as co-extrusion. In the prepeg technique, you also end up with a composite filament (or tape) but the carbon fibers have not been chopped up, instead they have been impregnated with the polymer thanks to a pultrusion process.
Actors that offer continuous fiber 3D printing on the market include Markforged, Anisoprint, CEAD, etc. More recently, Desktop Metal also joined the race by launching a new system called Fiber. Fiber uses Micro Automated Fiber Placement (μAFP). Additionally, 9T Labs has developed Additive Fusion Technology (AFT) to mass produce carbon composites at lower cost.
Carbon Fiber 3D Printing: Other Technologies
Moving away from the more well-known extrusion process, an interesting technology is AREVO’s proprietary process based on Directed Energy Deposition technology, in which a laser is used to heat the filament and carbon fiber at the same time as a roller compresses the two together.
Impossible Objects and EnvisionTEC have also added systems for carbon fiber 3D printing to their range of machines, the technology however differs a bit. They weave in sheets of carbon fiber into a print by using a lamination process. Last but not least, Continuous Composites uses a hybrid technology where the strand of fiber is soaked with resin and then hardened using UV light, similarly to SLA 3D printing.
This part showcases how continuous carbon fiber 3D printing can add strength to a plastic part | Credits: Markforged
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What is the Strongest 3D Printing Filament That You Can Buy? – 3D Printerly
People used to consider 3D printed objects weak and brittle, but we have made some serious strides in the durability of these models.
We can create a strong 3D printer filament that stands up to very harsh conditions.
This made me wonder, what is the strongest 3D printer filament that you can actually buy?
The strongest 3D printer filament you can buy is polycarbonate filament. Its mechanical structure is unlike many others, where strength tests have shown the excellent resilience and strength of this filament. Polycarbonate is widely used for engineering and has a PSI of 9,800 compared to PLA’s 7,250.
I will describe some interesting details about 3D printer filament strength, as well as give you a researched list of the top 5 strongest 3D printing filament, plus more, so keep on reading.
What is the Strongest 3D Printer Filament?
Polycarbonate (PC) filament is the strongest filament of all the known printing materials in the market. It is used for bullet-proof glass, riot gear, phone & computer cases, scuba masks and much more. The durability and rigidity of PC outweighs other printing materials easily.
The glass transition temperature rate offered by Polycarbonate filament is much higher than most other plastics filaments, meaning it has a high temperature resistance.
One of the tough competitors is ABS filament but you will be amazed to know that Polycarbonate filament can withstand 40°C more than ABS, making it a very strong filament.
Even at room temperature, thin PC prints can be bent without cracking or bending. Wear and tear doesn’t affect it as much as other materials, which is great in many 3D printing applications.
PC has amazing impact strength, higher than that of glass and several times higher than acrylic materials. On top of its incredible strength, PC also has transparent and lightweight qualities which make it a serious contender for 3D printing materials.
The Polycarbonate filament has a tensile strength of 9,800 PSI and can lift weights of up to 685 pounds.
Depending on the different types of 3D printers and its components, Polycarbonate filament has an extruding temperature of almost 260°C and requires a heated bed of around 110°C to print properly.
Rigid.Ink has a great article detailing how to print with Polycarbonate filament.
All these statistics are far better and efficient than any other filament tested until now. In a nutshell, Polycarbonate filaments is the king of the 3D printing filament when it comes to strength.
Top 5 Strongest 3D Printing Filament
- Polycarbonate Filament
- Carbon Fiber Filaments
- PEEK Filaments
- ABS Filament
- Nylon Filaments
Polycarbonate Filament
When it comes to the strongest filaments, polycarbonate filament will always be seen at the top of the list as described above.
Many amazing features and reasons are contributing to making it to float above the other filaments but some of the most appreciated features of Polycarbonate filaments include:
- PLA usually begins to deform at a minor temperature of about 60°C but Polycarbonate filament can resist the heat up to amazingly 135°C.
- It is durable with impact and high shatter resistance.
- Electronically, it is non-conductive.
- It is transparent and highly flexible.
You can’t go wrong with some PRILINE Carbon Fiber Polycarbonate Filament from Amazon. I’d thought it would be a lot pricer but it actually isn’t too bad! It also has great reviews that you can check out.
One user actually tested how much carbon fiber was in the PRILINE Carbon Fiber Polycarbonate Filament and they estimated it was around 5-10% carbon fiber volume to plastic.
You can print this on an Ender 3 comfortably, but an all-metal hotend is recommended (not required).
Carbon Fiber Filament
Carbon fiber is a thin filament composed of fiber that contains carbon atoms. The atoms are in a crystalline structure that provides high strength which makes it an ideal choice for industries like automotive.
Markforged state that their carbon fiber filament has the highest strength-to-weight ratio, where in their flexural strength three-point bending test, illustrated that it is 8x stronger than ABS and 20% stronger than the yield strength of aluminum.
Their carbon fiber has a flexural strength of 540 MPA, which is 6 times higher than their nylon-based onyx filament and it’s also 16 times stiffer than their onyx filament.
You can purchase 2KG of carbon fiber PETG for around $170 from 3DFilaPrint which is very premium for 3D printer material, but a great price for high quality filament.
It is light and has excellent resistance to chemical degradation and corrosion.
Carbon fiber has better dimensional stability because of its strength that helps in mitigating the chances of colliding or shrinking.
The stiffness of carbon fiber make it a top contender for the aerospace and automotive industries.
PEEK Filament
PEEK filament is one of the most reliable and trusted materials in the huge 3D printing industry. PEEK stands for its composition which is Polyether Ether Ketone, a semi-crystalline thermoplastic.
It is well known for its excellent strength and high-end chemical resistance. During its manufacturing, a process is followed known as phased polymerization at a very high temperature.
This process makes this filament highly resistant to organic, bio, and chemical degradation in any type of environment with a useful operating temperature of 250°C.
As PEEK filaments reduce the amount of moisture absorption and make the process of sterilization easy, medical fields and industries are adopting PEEK filaments for 3D printer rapidly.
It does get pretty pricey so keep that in mind!
ABS Filament
ABS comes in the list of the strongest filaments because it is a hard thermoplastic material that can resist impact gracefully.
This filament is widely used in printing processes such as engineering purposes, technical printings, etc. It is one of the most cost-effective as compared to other major types of fiber filaments.
This is the fact that makes this filament ideal for the users who are bound to a budget but want to have a high-quality strong filament for 3D printing.
ABS is a perfect choice if you are going to print things that will have the stress of will include high functionality. As this filament is heat and water-resistant, it provides users with a smooth and attractive finish to the product.
You also have the ability to easily work with the material, whether that’s sanding, acetone smoothing, or painting.
Nylon Filament
Nylon is an excellent and strong material that is used in most of the 3D printers. It has an amazing tensile strength of almost 7,000 PSI which is more than most of the other 3D filaments.
This filament is highly resistant to the chemicals and heat which makes it one of the ideal options to use in industries and major organizations.
It is strong but comes after ABS although, the nylon industry is moving forward to bring improvements using mixtures of particles from fiberglass and even carbon fiber.
These additions can make the nylon filaments more strong and resistant.
NylonX by MatterHackers is a perfect example of this composite material for some amazing 3D printed strength. The video below shows a great visual of this material.
TPU Filament
Although TPU is a flexible filament, it has some serious strength in the impact-resistance, wear and tear resistance, chemical and abrasion resistance, as well as shock absorption and durability.
As shown in the video titled ‘The Ultimate Filament Strength Showdown’ above, it showed to have amazing material strength and flexibility. The Ninjaflex Semi-Flex withstood 250N of pulling force before snapping, which in comparison with Gizmodork’s PETG, gave a force of 173N.
Which Filament is Stronger ABS or PLA?
When comparing the strength of ABS and PLA, the tensile strength of PLA (7,250 PSI) is greater than the tensile strength of ABS (4,700 PSI), but strength comes in many forms.
ABS has more flexible strength since PLA is brittle and doesn’t have as much ‘give’.
If you expect your 3D printer part to bend or twist, you would rather be using ABS over PLA.
The all-famous Legos are made from ABS, and those things are indestructible!
In hotter environments, PLA doesn’t hold its structural strength very well so if heat is a factor in your area, ABS is going to hold up better. They are both strong in their own rights but there is another option.
If you want a filament which meets in the middle of the two, you want to look towards using PETG, which is easy to print like PLA, but has a little less strength than ABS.
PETG has more natural flex than PLA and should keep its shape longer.
PETG can also withstand higher temperatures than PLA, but you want to make sure your 3D printer has the correct capabilities to reach the necessary temperatures to print it.
What is the Strongest 3D Printer Resin?
Accura CeraMax is considered as the provider of the strongest 3D printer resin. It guarantees full capacity temperature resistance as well as the highest strength for heat and water resistance.
It can be used efficiently to print the perfect composite like prototypes, ceramic-like components, jigs, tools, fixtures, and assemblies.
What is the Stiffest 3D Printing Material?
PLA filament is also known as Polylactic Acid and is one of the most used filaments in 3D printers.
It is considered as a standard filament material that is widely being used because it can print clearly at a very low temperature without requiring a high heated bed.
It is the stiffest 3D printing material and is ideal for the beginners because it makes 3D printing easy as well as it is very inexpensive and produces parts to be used for a variety of purposes.
After being the stiffest 3D printing material it is also known as the most environmentally friendly material to be used in 3D printers. As an amazing property, PLA emits a pleasant smell while printing.
What is the Weakest 3D Printing Filament?
As it is mentioned above that simple nylon or some PLA filaments are considered as the weakest 3D printing filaments in the 3D industry. This fact is only valid for previous or old versions of the nylon filaments.
However, the new updates such as filled nylon filaments with Onyx or nylon carbon fiber filaments come in the list of top strongest filaments for the 3D printers.
Carbon Fiber 3D Printing Guide: Printers and Materials
Bicycles, race cars, drones and tennis rackets all have a variety of applications and require high strength and durability without added weight. This combination of properties is typical of carbon fiber composites, which are used in everything from Formula 1 racing car chassis to lightweight road bike frames.
Since many 3D printers commonly use polymer-based materials, including various composites, many people ask the question, "Can a 3D printer print carbon fiber?".
Indeed, there are two methods by which 3D printing can be used to create carbon fiber parts: supporting traditional fabrication methods with 3D printed molds, or direct 3D printing of carbon fiber composites. In this article, we'll look at traditional fabrication methods as well as new workflows for 3D printed carbon fiber molds and direct 3D printed carbon fiber composite parts.
Combining traditional carbon fiber parts with 3D printing
Carbon fiber is a composite material traditionally made by weaving long strands of carbon fibers together and then bonding them with a polymer. The yarns can be woven strategically so that the strength is directed along one specific vector, or so that the final product has multiple strengths in all directions. The resulting material is then molded into the desired end product using one of three processes: wet laid, pre-laminated, or resin transfer molding (RTM).
Wet Laid
Wet laid carbon fiber sheets are cut and pressed in a mould, then dyed with a liquid resin that cures to bind the sheets into the desired final shape. This method requires the least equipment and is the easiest to master for a beginner. Because most of the work can be done by hand, this is one of the cheapest methods, but the trade-off is that the resulting parts are less accurate to the master mold than parts made by other methods.
Prepreg lamination
In this method, the carbon fiber is already impregnated with resin and then placed in a mold that uses pressure and heat to form the final shape. This method is the most expensive due to the need for specialized equipment to store and process the pre-impregnated sheets, as well as a heated and pressurized forming machine. These factors also make it the most repeatable and consistent, and thus the most suitable for serial production of carbon fiber parts.
Resin transfer molding (RTM)
In RTM molding, the dry fiber is inserted into a two-part mold. The mold is clamped, after which high-pressure resin is injected into the cavity. This method is usually automated and is used to produce large volumes of products.
3D printed carbon fiber parts
For each of the three previous methods, 3D printing can be used to reduce costs and improve production times. All three traditional manufacturing methods require the use of a mold or multiple molds, which are traditionally created through labour-intensive subtractive processes such as wood, foam, metal, plastic or wax. 3D printing offers an alternative way to make molds. 3D printed molds are customizable and are more efficient and cost effective for small batch or custom production.
For applications requiring live prototypes, such as the automotive and aerospace industries, the iterative process can require hundreds of different shapes.
Producing such iterations with traditional manufacturing methods can be costly and time consuming, so 3D printing provides an efficient way to produce small batches. Although 3D printed molds are not as suitable for high-volume production as metal molds, they can be created in-house, reducing costs, speeding up product development and validation, and short-term production.
Carbon fiber molds can be made in a variety of ways, but the smooth surface and wide choice of materials for SLA 3D printers make them a common choice for mold making in the factory. SLA-created parts have virtually no layer lines or porosity, so carbon fiber sheets can be pressed tightly into the mold without the fear of creating a textured surface.
Panoz, a manufacturer of racing and sports cars, needed a custom race car cabin duct to bleed the air out of the cabin and cool the temperature inside. In collaboration with DeltaWing Manufacturing, they used a Formlabs SLA 3D printer to print a high temperature resin part and then manually molded that printed part using high temperature epoxy for tooling.
By using 3D printing, DeltaWing avoided outsourcing the costly metal mold for this custom carbon fiber part, reducing overall costs and delivery times.
Carbon fiber wing duct next to two piece mold printed with High Temp Resin made by DeltaWing Manufacturing.
Direct Carbon Fiber 3D Printing
Looking for the best carbon fiber 3D printer? There is a strong demand for workflows that combine the strength, durability and wear resistance of traditional carbon fiber parts with the maneuverability, geometric capabilities and cycling of 3D printing. Therefore, it is not surprising that there are many companies offering 3D printing using carbon fiber, with two methods currently available: printing using chopped or continuous fibers.
Chopped Carbon Fiber 3D Printing
Chopped Fiber refers to 3D printing composite plastic materials that are impregnated with small pieces of carbon fibers.
These crushed fibers add strength to the composite, which can be carbon fiber filament for FDM modeling or nylon powder for SLS 3D printing.
The main advantages of chopped carbon fiber reinforced materials over other types based on polymers are that they are strong, light, heat resistant and less prone to deformation. Compared to traditionally molded carbon fiber parts, chopped fiber 3D printing provides increased geometric flexibility in part design, especially in SLS 3D printing, potentially eliminating the labor involved with traditional molding or opening up innovative new opportunities for users to incorporate this material into the working process.
The Formlabs Fuse 1+ 30W SLS 3D Printer enables this type of carbon fiber 3D printing with Nylon 11 CF Powder, the strongest material in the Formlabs SLS material library. Fuse 1+ 30W is the most affordable high performance SLS printing option for shredded carbon fibers. Although traditional industrial SLS machines also offer some carbon fiber materials, the initial implementation costs negate much of the added value of 3D printing carbon fiber parts over RTM or prepreg lamination methods.
Formlabs Nylon 11 CF Powder is strong, lightweight and heat resistant making it ideal for the automotive, aerospace and manufacturing industries .
Many FDM 3D printers can handle carbon fiber filaments, but these materials are more difficult to print than standard ABS or PLA filaments, resulting in more clogs and more maintenance as the brass nozzles wear out. FDM 3D printers specifically designed to grind carbon fiber filaments are also available but are more expensive.
The main limitation of chopped-fiber printed parts using both SLS and FDM technologies is that they should be considered as more durable 3D printed parts, rather than a true alternative to traditional woven and continuous carbon fiber parts. fibers. They also provide the greatest increase in strength by positioning them in the X-plane direction for SLS printing, and in the XY-plane direction for FDM printing. Traditional methods of creating carbon fiber parts provide multidirectional strength through careful planning and placement of different carbon fiber sheets in a preform.
Carbon Fiber Continuous 3D Printing
Carbon Fiber Continuous 3D Printing is available on some dedicated FDM 3D printers, and the resulting parts are close in strength to traditional carbon fiber parts, but similar to chopped fiber printers FDM, only in the XY plane. In such printers, continuous filaments of carbon fiber are mixed with a thermoplastic and the filaments can be applied strategically to selectively pressurize certain planes or axes. This method can use either a dual extruder nozzle to lay down a combination of carbon fiber and polymer filaments, or a 2-in-1 in which one nozzle lays down the carbon fiber filaments and the other heats and extrudes the filament.
Continuous carbon fiber 3D printing offers an alternative comparable to traditional molded carbon fiber parts, albeit with limited design freedom. While these parts are incredibly strong, strength only appears in the XY planes and the models must be oriented so that their strength matches the direction of the applied force.
In designs where possible, this method can be used to replace aluminum parts, as well as to create durable manufacturing aids or end-use parts.
Applications for 3D printed carbon fiber parts
The high strength, light weight, and impact, heat and chemical resistance of carbon fiber printed parts make them ideal for a variety of applications where 3D printing has never been was not considered. Now, these plastic and carbon fiber composite parts can withstand the heat generated by automotive or aerospace engine components, be used as a replacement for machined aluminum parts and manufacturing fixtures, and produce durable and impact-resistant equipment.
3D printed carbon fiber parts are ideal for rapid prototyping, the production of wear-resistant and durable production fixtures such as tooling and fixtures, and for low-volume production of durable end-use parts with complex geometries.
3D printing technology has opened up new possibilities in design and manufacturing, and 3D printing of carbon fiber composites has further expanded these possibilities, allowing users in the automotive, aerospace, defense, and manufacturing industries to quickly and efficiently produce high-strength, heat-resistant, geometrically flexibility.
By bypassing traditional machining or molding processes, these users can more easily create custom parts, replacement parts and functional prototypes. Although carbon fiber printed parts are not a complete replacement for traditional technologies due to the single plane of added strength, they are still stronger than almost all other plastics, making them exceptionally useful in many applications.
The right process for producing carbon fiber parts by molding or directly by 3D printing depends largely on the specific application and factors such as part design, production volume, and more. SLS 3D printing with shredded fibers offers the best option for those who want to produce parts that are strong, but not necessarily to the same degree as traditional molded carbon fiber parts.
Formlabs Fuse 1+ 30W with Nylon 11 CF Powder enables low-funding, fast-paced businesses to quickly iterate and produce end-parts with strength and better mechanical properties than traditional plastics.
They can also functionally test their parts and then redesign with only minor CAD changes, improving their product performance and getting to market faster.
Everything you need to know about 3D printing carbon fiber
First produced by Joseph Swan in 1860, carbon fiber is made up of a long chain of carbon atoms bonded together. The chain is typically 5 to 10 micrometers in diameter and varies in length depending on the application. Over the years, carbon fiber has become popular in many sectors because it offers interesting properties, including high stiffness, high tensile strength, light weight, high chemical resistance, high temperature resistance, and low thermal expansion. Pure carbon fiber is actually five times stronger than steel and twice as stiff but lighter. As you can imagine, these characteristics make carbon fibers suitable for applications in sectors such as aerospace, automotive, military or civil engineering.
As some of you may already know, carbon fibers are rarely used on their own.
They are usually combined with other materials to form what we call a composite material - in this particular case, these are materials reinforced with carbon fiber. These composites are made from a matrix material, usually a polymer, although it is possible to use non-polymer materials such as ceramics to which carbon fibers are added. The main advantage is that you end up with a stronger but lighter plastic with a higher level of stiffness.
The body of this bike frame is made of carbon fiber | Source: Arevo
Traditionally, carbon fiber composites have been used for structural design, where added weight results in increased life cycle costs or unsatisfactory performance. Carbon fiber composites can be used to create many products such as bicycle frames, aircraft fenders, propeller blades, automotive components, etc. As you can imagine, given the many benefits of carbon fiber, it is already being used by more than just traditional manufacturing systems. In recent years, more and more 3D printing companies are offering carbon fiber reinforced materials or technologies.
They are designed to work with this composite to provide better performance. So how is carbon fiber being used in additive manufacturing?
3D Printing Applications
In its 3D Printing Composites 2020 - 2030 report, IDTechEx reports that the global market for 3D printing composites will reach $1.7 billion by 2030. This figure also includes other composite materials, such as materials reinforced with fiberglass or plastic. However, this trend clearly demonstrates that the 3D printing industry is increasingly using all composites, including carbon, in their manufacturing activities. There are essentially two ways to use carbon fiber in 3D printing, the first is carbon fiber reinforced filaments and the second is continuous carbon fiber reinforcement.
Carbon fiber filament
Carbon fiber filament uses short carbon fibers composed of segments less than one millimeter long, which are mixed with a thermoplastic known as a base material. There are a number of popular filaments available with carbon fiber fill, including PLA, PETG, nylon, ABS, and polycarbonate.
These fibers, being extremely strong, cause an increase in the strength and stiffness of the thread, and also reduce its overall weight. The requirements for 3D printing carbon fiber filaments should be the same as for the base material they were added to. The main difference is that fibers can clog 3D printer nozzles, so experts recommend using a hardened steel nozzle. In addition, when a certain threshold of fibers is exceeded, the part printed on a 3D printer loses its surface quality.
Carbon fiber segments embedded in thread for reinforcement | Source: Markforged
Some companies have developed carbon fiber fibers for more technical applications. These yarns use high performance polymers (HPPs) such as PEEK or PEKK as the base material. Consequently, they not only offer the benefits of HPPs such as durability and high mechanical and chemical performance, but also an improved strength to weight ratio. Print settings need to be adjusted as HPPs require extruders that can heat up to 400°C and systems that have heated chambers and build plates.
Some of the carbon fiber filament manufacturers are: Roboze, 3DXTech, ColorFabb, Markforged, Kimya, Intamsys, Zortrax, etc.
Continuous carbon fiber reinforcement
Carbon fiber thread is definitely stronger than thread that has not been reinforced. However, to get an even stronger part, another method called continuous carbon fiber reinforcement can be used. Since carbon fiber is not cut into smaller pieces, it retains much more strength. In fact, continuous printing on carbon fiber is strong enough to be half the weight of aluminium. 3D printer manufacturers claim that they can replace metal 3D printing for some applications. And the main advantage is that it is cheaper than metal. Finally, by placing carbon fiber according to DfAM techniques, it is possible to increase the strength of the part while reducing material consumption.
Using DfAM methods, it is possible to strengthen a part using carbon fiber | Source: Anisoprint
There are several players on the market that offer technologies that can continuously print carbon fibers.
They can be divided into two main types, depending on when the carbon fiber is added (it can be added before the 3D printing process or during). When added earlier, continuous fiber 3D printing is known as backing prepreg, while when added during extrusion, it is called co-extrusion. In the prepeg technique, you also get a composite thread (or tape), but the carbon fibers have not been cut, instead they have been impregnated with a polymer through a pultrusion process.
Members offering continuous fiber 3D printing include Markforged, Anisoprint, CEAD, etc. More recently, Desktop Metal has also joined the race with a new system called Fiber. Fiber uses Micro Automated Fiber Placement (µAFP). In addition, 9T Labs has developed additive synthesis technology (AFT) to mass-produce carbon composites at a lower cost.
Carbon 3D printing: other technologies
A departure from the better known extrusion process, an interesting technology is the patented AREVO process, based on directed energy deposition technology, in which a laser is used to heat filament and carbon fiber simultaneously as a roller presses them together.
