by • July 26, 2016 • No Comments
“If you appear at the current conventional 3D printing technologies, initially you can notice that many of them are 20 to 30 years old,” said Robert Swartz, founder of Impossible Objects. “One of the things you can like to improve upon may be the faculty to manufacture things faster, to have advantageous mechanical properties so that you can manufacture functional parts, and the faculty to use a wider range of materials. If you ponder of 3D printing for quite long, you rapidly realize that these issues are largely a materials science problem.”
Swartz’s company, based in Northbrook, Ill., has been developing a new 3D printing innovation that is almany eager for beta purchase. The process, dubbed the composite-based additive producing method (CBAM), is intended to address all of the issues and problems that Swartz described in his interview with ENGINEERING.com. Not quite like any other 3D printing innovation on the market, CBAM is able-bodied to turn it into multimaterial, carbon fiber–reinforced parts at potentially unprecedented rates.
How It Works
Similar to equite other 3D printing innovation, CBAM begins with a CAD file that is sliced into individual layers. In CBAM, those layers are and so converted into bitmaps. Inkjet heads containing an aqueous-based printing solution and so deposit the bitmap layer shapes onto a substrate sheet turn it intod of the reinforcement material of choice, that can frequently be carbon fiber for its high durablity-to-weight ratio, but may be a number of various fiber materials.
The substrate sheet is and so flooded with a thermoplastic powder, that adheres just to the areas where the inkjet solution has been deposited. The excess powder is subsequently blown or vacuumed off, leaving just the plastic sticking to the bitmap layer shape. This process is repeated with every layer until the complete object is transformed into a stack of these sheets.
The sheets are compressed, placed into an oven and heated until the plastic powder fuses together, at that point, the object is removed and the excess reinforcement material is removed either by sand blasting or a chemical bath. The end outcome is a geometrically harsh object turn it intod up of thermoplastic and reinforcement fibers that may be up to ten times stronger than parts turn it intod with plastic extrusion or other 3D printing technologies.
If this almany sounds like an assembly line process, that is for the reason it is, with sheets printed and moved onto a conveyor belt that removes excess powder. Whilst it may seem as yet it requires a number of individual steps, the process is automated and CBAM has a number of advantages over other 3D printing and producing technologies, which include speed.
Unlike a 3D printing process that deposits viscous inks, such as HP’s Multi Jet Fusion (MJF), PolyJet or the new innovation of Rize, Impossible Objects jets a water-based solution. This enable-bodieds the liquid to be deposited onto the substrate rapidly.
The CBAM inkjet head depositing the liquid solution. (Image courtesy of Impossible Objects.) CBAM in addition has advantages over futilized deposition modeling (FDM), that sees thermoplastic extruded through a print head. As CBAM does not rely on melting and forcing plastic through a print head, CBAM has a much wider selection of materials to select of and an operate much additional rapidly. Similar material flexibility can be seen in relation to the fiber composite substrate chosen for the CBAM process, as well.
“The advantage of this approach is significant,” Swartz said. “One, our CBAM innovation can scale to use inkjet heads that run 100 meters per minute so you can get quite high speeds. Two, you can use somehow much any thermoplastic that you want. We’ve done polyethylene, nylon and high-performance materials like [polyether ether ketone], and it’s going to donate you a much wider variety of polymers that you can use. Three, you can use high-performance materials like carbon fiber and get much greater durablity— up to ten times stronger—than you may get of the conventional processes like [selective laser sintering] or FDM.
He introduced, “In addition, for the reason it’s a fiber-based process, we can not just get advantageous material properties but we can in addition use a wide variety of substrates—carbon fiber, fiberglass, polyester, PLA, polyvinyl alcohol, cotton and silk.”
Whilst the innovation as a whole promises infinite geometric harshity, equite 3D printing process has its limitations when it comes to the precise shapes a process can turn it into. For instance, FDM may not be able-bodied to turn it into sure moving parts and is dependent on the faculty to turn it into assist structures for overhanging parts of a create. As selective laser sintering (SLS) is a powder bed process, printed parts require the creation of an exit cavity of that the excess powder within a print can be removed.
When it comes to CBAM, the geometry is partially determined by the chosen substrate material. Removing carbon fiber requires sand blasting, creating much like limitations faced by SLS due to the fact that the sand must be able-bodied to access the interior of the part to remove excess carbon fiber.
But, a chemical process is utilized to remove other reinforcement materials, such as Kevlar and polyester. In those cases, the geometric harshity is additional much like to that possible with FDM, when via soluble assists.
The faculty to blend materials and incorporate fiber reinforcement opens CBAM up to a number of uses. These include the 3D printing of electronics enclosures reinforced with carbon fiber for the reason, due to the material’s conductivity, the enclosure can turn it into a Faraday shield for the electronics within.
A 3D-printed drone propeller turn it intod by Impossible Objects. (Image courtesy of Impossible Objects.) Other applications include 3D printing drone, satellite and Formula One parts as well as producing tooling for injection molding. In addition to working with a significant developer to 3D print custom molds for producing components for consumer goods, Impossible Objects has signed a collaborative research agreement with Oak Ridge National Laboratory (ORNL) to 3D print tooling for producing carbon fiber composites. The research involves improving the thermal coefficient of expansion of an injection mold.
ORNL is in addition already working with Cincinnati Inc. on the Big Area Additive Manufacturing (BAAM) process, that has been utilized to 3D print large-scale structures like entire auto chasses, and Cosine Additive to turn it into a Medium Area Additive Manufacturing machine. In turn, the agreement with Impossible Objects is at very least ORNL’s third carbon fiber 3D printing project. Whereas the BAAM machine 3D prints with of 5 percent carbon fiber and 95 percent ABS, Impossible Objects can bring much higher reinforcement to the U.S. Department of Energy lab.
A 3D-printed femoral stem implant turn it intod with carbon fiber and PEEK. (Image courtesy of Impossible Objects.) Swartz sees his process as positioned between conventional 3D printing and high-end custom carbon fiber layup. The innovation may not be able-bodied to complete the same durablity as carbon fiber layup, but it turn it intos parts stronger than other 3D printing technologies, producing it perfect for fabricating geometrically harsh and durable-bodied parts much additional affordably than—and frequentlytimes not actually possible—with traditional carbon fiber producing methods.
Simultaneously, CBAM is much quicker and additional automated than the labor-intensive and costly carbon fiber layup process. “When it comes to producing, you’ve got a choice of metal, conventional polymers or carbon fiber. There’s quite nothing in between, whereas our process donates you a thing in between but in addition donates you the advantage of the harsh geometries,” Swartz said. “If you require the absolute top possible durablity, and so hand-laid carbon fiber composites are rad. But if you don’t require that absolute most durablity, we represent a much faster, inexpensive alternative.”
Today, there are quite few methods for 3D printing plastic parts with fiber reinforcement. Aside of comparatively weak chopped carbon fiber filaments, the just carbon fiber 3D printing devices on the market are the Mark One and Mark Two of Markforged, that fill FDM parts with strands of continuous carbon fiber.
Due to the lack of soluble assist material, this process cannot turn it into parts that are as geometrically harsh as other 3D printing technologies, and for the reason it relies on FDM methodology it may be complex to scale for significantly greater dimensions or speed.
On the horizon, yet, is the selective lamination composite object producing machine of EnvisionTEC. Unveiled at RAPID 2016, this process stacks huge sheets of woven fiber composites and fuses them with thermoplastic preceding a huge blade cuts the parts out. The use of woven fiber composites can most likely enable-bodied the production of parts that are stronger than those turn it intod by CBAM, but it can most likely be slower than CBAM and limited to easier geometries. Additionally, removing the assist material may be quite labor intensive. More than that, the process is priced at roughly $1 million. With that price tag in mind, Swartz sees EnvisionTEC as targeting a much various market than his own innovation.
In the immediate future, Impossible Objects plans to ship beta pre-production machines at the beginning of future year. The aim is to sell the process at prices that are less than high-end Stratasys and EOS machines and actually HP’s MJF printing devices. The box can most likely include a heating machine that is additional efficient than a conventional oven and may come with specialized equipment for automated post-processing.
With its current prototype machine, Impossible Objects has scaled its innovation to print sheets with a robust dimensions of 12 in x 16 in (304mm x 406mm); yet, Swartz explained that the company envisions scaling up actually additional to print objects the dimensions of a car hood.
“We’re in addition working on high-speed production rates,” Swartz introduced. “We ponder in the long term we may see printing at 100 meters per minute to turn it into parts faster than injection molding of a production rate point of view. If you appear at printing these things on sheets that are 30 in x 40 in, that is not unreasonable-bodied, there are folks who can run those at 18,000 sheets an hour. There are surely lots of inkjet printing devices that can run at 3,000 to 5,000 sheets per hour. So, theoretically, you can have speeds that quite are unprecedented as compared to conventional methods.”
Before we can see geometrically harsh carbon fiber–reinforced parts flying off of the CBAM assembly line at 100 meters per minute, we will have to wait for the beta pre-production machines to ship future year.
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