Details Emerge on The Mark One Carbon Fiber 3D Printer: Prints using continuous fibers in user defined unidirection
This $5,000 3D printer seemed to be something that just about everyone in the 3D printing industry could get excited about. Without a doubt, there are millions of uses for a 3D printer that can print in a material that is 5 times stronger than typical ABS plastic. For those that are wondering ABS is typically stronger than the other most popular material used in 3D printing, PLA.
Today, MarkForged, released more details on their 3D printer.
One of the comments that we heard after our first article, was that it was impossible for a 3D printer to print in carbon fiber that is as strong as the carbon fiber that you see used in manufacturing today.
“If it is carbon fiber powder mixed with polycarbonate / resin, it will not be very strong,” said one 3DPrintBoard member. “Sounds like they added CF powder to a polycarbonate to make a filament. The strength will not be good.”
Today, MarkForged stated that, “The Mark One™ uses continuous fibers as a reinforcement in the printing material. Composites made with continuous reinforcing fibers exhibit substantial increases in strength and stiffness compared to similar materials using discontinuous (chopped) fibers.”
One slight drawback of the Mark One is the fact that it will only allow for the use of specific Mark One composite filament. However, this is understandable, considering that the technology is completely new, and there are patents filed protecting it. However, there are many positives that go into using this technology. According to MarkForged,
“The parts printed on the printer can be designed to be stronger than 6061-T6 aluminum by weight, and up to 1/3 the strength of the best carbon fiber composites made today.”
In order to collect this data, the company utilized 3-point bend testing on an Instron universal testing machine.
The Mark One not only prints in carbon fiber. It can also print using glass fiber, as well as traditional PLA and nylon (polyamide). This means that it can take the place of your current 3D printer, plus add the benefit of being able to print in this new ultra-strong carbon fiber or glass fiber composite filament. The printer features a dual-printhead design, where one head is capable of printing in composite filaments, while the other in traditional filaments.
Another concern that many readers had after first reading about this new 3D printer was the fact that it didn’t seem possible to print in woven sheets.
“As far as I know, a lot of the strength of composites which usually use carbon (or glass) fiber weaves, comes from the way the different fiber patches are placed in the layout,” explained user ‘bringho‘ on 3DPrintBoard. “In a FDM print the fiber will only follow the direction of the print, so in what way would that strengthen the printed part compared to a classic composite weave layout?”
It appears that since the user can determine the orientation of the unidirectional composite in each printed layer, the strength can still remain. It would seem that you could make a “mock” weave simply by alternating the unidirection of the composite in each layer. Users will be able to do this in the free software that ships with the printer.
So, if this is the case, than why are woven fabrics used so often when fabricating composites such as carbon fiber? MarkForged also addressed this concern.
“Woven fabrics offer greater ease-of-use in traditional composite lay-up manufacturing processes while maintaining the desired mechanical properties.”
Another benefit of the Mark One 3D Printer is the fact that there is literally no curing time for printed parts. As soon as they have been finished printing, they are hardened and ready to be used. This is because the printer uses a thermoplastic matrix that solidifies immediately after it is extruded.
The Mark One creates builds of objects in the same way that traditional FDM printers do. It create one layer at a time. Because of this, it is not possible to lay the fibers in the Z-directions. This shouldn’t come as a surprise to anyone that has been using 3D printers. It would simply be impossible to lay down continuous composite strands from the bottom up.
It certainly seems as though this printer is for real. At a price tag of $5,000 it seems almost too good to be true though. Discuss this printer along, with the idea of printing in composite materials at: http://3dprintboard.com/showthread.php?1551-Mark-One-Carbon-Fiber-3D-Printer
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