Certainly one of the most popular and recognizable 3D printing technologies in the world is Material Extrusion. Endearingly referred to as a frozen yogurt machine or hot glue gun on a gantry, Extrusion 3D printing was invented in the late 80s by Scott Crump of Stratasys, and its patent expiration led to the modern maker movement as we know it.
Extrusion 3D printing has matured a lot through the years such that today Extrusion 3D printing supports the manufacturing of not only thermoplastic, but also composite and metal parts. In this blog post, we will briefly review the Extrusion 3D printing options available through the ProdEX engineering and procurement platform.
Thermoplastic Extrusion 3D printing
The “OG” of Extrusion printing is plastic Extrusion 3D printing. Originally termed fused deposition modeling in a patent filing by Stratasys, the subsequent evolutions on that original branded process have carried a variety of different names, most commonly fused filament fabrication.
Originally, printing was done in PLA plastic which stands for polylactic acid. This is a biodegradable material that melts easily and is readily processed by Extrusion 3D printing systems. After a period of time, ABS 3D printing was the standard for engineering plastics given its higher melting temperature and better durability. Over the course of the last few years as increased attention has been paid to ecological tolls of plastic and news has arisen about the danger of fumes from ABS 3D printing, PLA has come back into vogue as well as the rise of a collection of new composite materials that strike a balance between PLA and other materials to provide additional strength. More on that below in the composites section. In addition to enablement of PLA composites, there are also a range of other thermoplastics that can now be utilized like Acrylic Sytrene Acrylonitrile (ASA), Polycarbonate (PC), Polyethermide (PEI, commonly known as Ultem), nylon, and others. Other materials like polypropylene (PP), polyethylene (PE), polyurethane (TPU), Polyetherketoneketone (PEKK), Polyaryletherketone (PEAK), and Polyphenylsulfone (PPSF) are also printed using extrusion, although less commonly, in part because they are more challenging to process using extrusion systems than other technologies. Each of these materials carry unique properties that lend their used to varying applications, and each of these materials is available through the ProdEX engineering and procurement platform. Typically, plastic prints are less than a meter cubed, although for particular applications we do offer options up to 3 meters x 10 meters.
Composite Extrusion 3D Printing
As Extrusion 3D printing systems grew in robustness, their ability to process more challenging materials increased. At the end of the previous paragraph, We highlighted some of the new polymers that are now processable by Extrusion 3D printing systems. But in addition to Pure thermoplastics or thermoplastic urethane, composite filaments have also been introduced. As we touched on earlier, some of these composite variants are hybrid materials that mix one material into another in a single filament spool. Examples of this include abs-pla, PC abs, Carbon filled nylons and glass filled nylons. In addition to these multi polymer elements, markforged also led the charge in integrating continuous strands of carbon fiber inside Parts made of other composites or thermoplastics. This was most commonly seen in the case of Onyx Parts (which are a nylon carbon fiber composite in the first place) Reinforced by a continuous carbon fiber strand throughout the body of the part. Such an approach has also been used with materials like Kevlar and fiberglass to reinforce parts made out of nylon or onyx. Such an approach has allowed for significant improvements in the strength and durability of parts while accommodating the capabilities of Extrusion 3D printing. Typically, composite prints are less than a meter cubed, although for particular applications we do offer options up to 3 meters x 10 meters.
As with the polymers listed in the previous section, all of these composite options are available through the ProdEX engineering and procurement platform.
Metal Extrusion 3D Printing
The final form of material Extrusion 3D printing is metal extrusion 3D printing. Metal Extrusion printing is a bit different than printing with polymers or Composites in the sense that it is actually a two-step process. With metal Extrusion 3D printing, processing a wire of pure metal directly through an extrusion nozzle would result in regular blockages and an ineffective process. That is why processes such as wire additive additive Manufacturing perform their melting process outside the machine itself. Emerging Technologies like Joule 3D printing utilize electrical current running through a wire to enable melting outside the nozzle On the printing surface. As it relates to the most commonly understood versions of metal Extrusion printing, what actually takes place is that is a polymer jacket impregnated with a significant density of metal is processed through a more traditional Extrusion 3D printing system. The system melted polymer jacket just enough to allow for the material to be laid down on the printing platform as with traditional polymer or composite extrusion 3D printing processes. At this point, we have what’s referred to as a green part. This is a roughly 80% dense part That is basically the desired final part built 1.25 times as big in every dimension. This green part is then put into a centering furnace to achieve higher density levels. The sintering furnace, or oven as you might also hear it referred to as, Heats up the temperatures that will melt the polymer jacket and only leave the metal remaining. Moreover, it will raise the metal to a temperature that the molecules will sinter together and result in a shrunken part ranging from 92 to 98% density. Efforts are underway everyday to see if density levels can be raised even higher coming out of the sintering furnace. Additionally, efforts are underway to expand the size of metal Extrusion systems and their corresponding centering ovens. In the present day, Sintered Parts generally don’t go larger than the size of an adult fist due to some of the warpage challenges associated with sintering bigger parts.
With that bit of context in mind, there are a relatively limited but steadily growing list of materials now available for extrusion metal 3D printing. Among those metal impregnated filaments are 17-4 PH stainless steel, copper, inconel 625, h13 tool steel, A2 and D2 tool steel, among others.
Again, these metals are available to you through the ProdEX procurement platform, although being the most recent advancement in extrusion 3D printing, their market penetration is not yet as deep as polymers and composites.
Material Extrusion 3D Printing in Conclusion
Extrusion 3D printing arguably the signature manufacturing process of the additive manufacturing Revolution. With its ability to access a broad range of materials that can be stored without major air filtration and material handling investments, Extrusion 3D printing is one of the most user-friendly and commonly adopted Technologies in the 3D printing Market. Whether your needs call for a plastic, composite, or metal part, there is an extrusion technology More than likely capable of delivering what you need. while extruded parts sometimes may not deliver the most beautiful surface finishes or in the case of metal printing, the density or size required, this process is never the last a force to be reckoned with in the additive manufacturing world.
We are proud at 3Diligent to offer support for a tremendous range of Extrusion 3D printing platforms. If you are seeking to procure extrusion printed parts, please submit an RFQ through our ProdEX engineering and procurement platform. Or if you are a provider of Manufacturing Services, extrusion or otherwise, we encourage you to sign up for shop management software and lead generation services from Shopsight.