Why the composites industry will be excited about a carbon fiber 3D printer


Credit: MarkForged

As of this week, you can pre-order a 3D printer that prints in carbon fiber (or fiberglass or Kevlar, if you prefer). The MarkForged Mark One printer is a novelty among the growing ranks of plastic-printing machines on the market, but founder and CEO Greg Mark thinks it’s an even bigger deal than you’d imagine: It will totally change how people think about carbon fiber.

Carbon fiber is made of long strings of carbon atoms that can be woven together to form sheets. It’s strong but flexible, and a good conductor of heat and electricity. However, it’s expensive and time consuming to work with, as, in its whole form, it can only be incorporated into objects by hand.

To fully appreciate the labor intensiveness of working with carbon fiber, watch this video of a cello construction:

Or skip to 3:40 in this video to see how GE builds jet engine blades:

The appeal of 3D printing carbon fiber

Carbon-fiber objects (like Yo Yo Ma’s cello) are generally not made of 100 percent carbon fiber. They’re composites, which means that the carbon fiber is incorporated into another material. You only need a little bit of carbon fiber to add a lot of strength to an object.

A 3D printer is the perfect tool to take advantage of that. Instead of printing objects that are 100 percent carbon fiber, it’s expected that users will consider where exactly their project needs added strength. That way, they only need to add carbon fiber where it is actually necessary. The Mark One has two print heads, so it’s capable of printing carbon fiber within an object made of another material like plastic or nylon.

MarkForged Mark One carbon fiber 3D printer

Carbon fiber can be added to objects more cheaply if you chop it up, which allows it to be made into a powder instead of sheets. Firms like Proto-Pasta have taken advantage of that to produce carbon fiber 3D printer filament in the past.

But cutting carbon fiber causes it to be five teams weaker. Mark said the Mark One uses filament that contains continuous strands of fiber, so it doesn’t lose its strength.

It also frees people from having to stand for hours piecing sheets of carbon fiber onto a project. Instead, the 3D printer does all the work.

“We do it in one shot and there’s no post-processing, no curing,” Mark said in an interview.

Mark emphasized that the whole process cuts down on waste, which right now is an inevitable part of the carbon-fiber manufacturing process. Users of the printer no longer have to trim an object, as the printer lays down exactly what is needed and nothing more.

“Composite fibers give engineers a huge range of levers to pull, we just haven’t used them traditionally because they are so expensive to process,” Mark said. “3D printing itself is hot because it’s an exciting space, but the composites people are just as excited about this.”

Fiberglass may be a bigger draw

But despite its billing as the first carbon fiber printer, Mark said it’s more likely that people will use it to print with another compatible material: fiberglass. It doesn’t have the same conductive properties or strength as carbon fiber, which could be used to print bulletproof vests, airplane parts or electronics, but it’s much cheaper and electrically insulating.

“For 99.9 percent of applications, it’s perfect,” Mark said.

MarkForged will sell carbon fiber filament for $550 a pound, while fiberglass will cost $199 a pound. Nylon and PLA will be available for $99 and $22 a pound, respectively. Details on Kevlar are not yet available. Those carbon fiber and fiberglass prices are very, very high, but the ease of use will still make them appealing to the right people. And Mark holds that production of these types of filaments will go up as demand rises, eventually causing prices to drop.

That Mark One 3D printer itself is available for $4,999, or $8,799 for the developer version. It will ship in the second half of 2014. Mark said the company is limiting the number of orders it will accept.

Mark One 3D printer developer kit

“It’s very important for us that these first machines are built really well,” Mark said. “We’re very happy to sacrifice revenue numbers in order to ensure the machines are built to the quality we would want if we were buying them.”

Mark, who is an aerospace engineer, spent years working on race cars, which gave him a deep respect for the labor that goes into building composite parts. He said that he hopes people use the Mark One to its full potential.

“We’re building a tool and people are going to do crazy things with it,” Mark said. “So far we’ve been overwhelmed with how quickly people got the idea.”


Nik Aed

I agree with the observations. Z shear is similar to the base plastic, there is negligible reinforcement in this plane under loading. What has been shown is continuous laydown around a body of revolution, how this technique would handle overhangs and variable movement along the desired laydown path for evolving irregular shapes would be interesting to observe. A teapot print would demonstrate this (handle). As it stands it could be used as a former to over/underlay reinforcement in the weak plane if requires. This said, doing is the mother of innovation, a very good start. I look forward to the Mk 3. They must of done their homework, they have encapsulated the filament in the polymer or effectively combines binder and filament, (a key enabler), top job. Go MarkForge

Sujith Pillai

What about the strength of the material in the z-direction?

Luke Johnson

This machine will be great for making long objects that are loaded along the direction of the fibers but basically useless in any other direction (think of it as a stiff rope). If this machine had multiple heads and could weave the filaments I would be impressed. The time lapse of that sculpture being printed looked really cool but doesn’t really prove that this product is ready for load bearing applications that significantly exceed the strength of whatever polymer the fibers are encased in.

If any of that is confusing just think of a rope. Rope is really strong when you pull on it, but it is so weak in the other directions that it can’t even hold their own shape. This printer (printing shapes like they showed in the video) essentially coils a bunch of rope up and encases it in plastic. I’m sorry, I know this a mean post but I believe people have a right to know the limitations of this machine if they are planning on buying one for thousands of dollars.

Having said that, this machine is an important step in the direction toward truly effective 3D carbon fiber printing and I applaud the initiative and the ingenuity of the development team.

Andrew Yang

“Carbon fiber is made of long strings of carbon atoms formed by stacking sheets of graphene.”

The sentence implies “how it’s made” versus what it resembles. Carbon fiber certainly isn’t manufactured from sheets of graphene. There isn’t a commercially viable manufacturing method yet for graphene.

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