Way Back When …
The inception of RepRap in 2005 was also the birth of a subsequently increasing trend to make 3D printing more accessible, by way of smaller hardware platforms, lower capital and running costs and ease of use. Obviously, RepRap was, is and likely will continue to be much more than that, with its inherent philosophy of self-replicating machines. However, this trend of increasing accessibility to 3D printing for a much wider audience is, arguably, currently the most impactful consequence of RepRap to date.
Powder Bed Fusion, Otherwise Known as Laser Sintering
Since 2007, a successful sub-sector of the 3D printing industry has continued to grow around smaller, more economical and more accessible hardware. This has been largely dominated by fused filament fabrication (FFF) desktop systems, and later photopolymer platforms (based on the stereolithography [SL] / DLP processes). More recently, however, as patents for polymer Powder Bed Fusion (PBF) processes have expired, a further trend has emerged to make this process more accessible too. The PBF process — also commonly referred to as selective laser sintering (SLS) or just laser sintering and selective laser melting (SLM), as well as other brand labels — as its name suggests, utilizes powdered materials and a whole different approach is required compared with the FFF or photopolymer 3D printing processes.
Advantages and disadvantages of the different additive processes have long been debated. Ultimately, the key to success with any 3D printing process is unlocked by the application(s) it is being used for. Making 3D printing more accessible provides the key benefit of faster and more economical product development through the production of fast and cheap prototype iterations, and with PBF comes greater functionality. Of particular note is how the process works with a constrained bed of powder that represents the build volume. For these smaller systems the average size is around 25cm3. A heat source, typically a laser, is then applied — selectively — to the powder bed to fuse the particles together layer by layer to form the part(s). The powder bed itself acts as a support to the parts as they are being built, meaning that attached support structures are not required, which is often cited as a disadvantage of other processes such as FFF, SL or DLP. This allows for the production of highly complex geometries with relative ease, including parts with overhangs greater than 45 degrees.
Another advantage of the powder bed itself is the ability to nest / stack multiple parts within the same build, whereby virtually the full volume of the build area can be utilized to achieve greater productivity.
Other advantages of the PBF process include superior part strength, and therefore functionality, over FFF, SL or DLP. It is also possible to recycle the powdered materials more efficiently than filament, although resin also has a reasonable recyclability rate.
There are, however, also disadvantages to the PBF process. The most notable of these, particularly for smaller systems developed for outside of a factory environment, is the powder handling / safety aspect. Additional safety equipment is required for plastic powder handling, specifically a respirator and eye and hand protection. Also process understanding is required to maximize success in terms of part orientation, cooling and post processing.
A Brief PBF History
The history of 3D printing using powder bed fusion dates back to 1987, when Carl Deckard at the University of Texas, filed a patent for SLS technology, which was issued in 1989. The technology was later licensed to DTM Inc, but the company was subsequently acquired by 3D Systems in 2001. In Germany, 1989 was the year EOS GmbH was founded by Hans Langer with a focus on the plastic sintering process — the company sold its first Stereos system in 1990. For more than two decades PBF was exclusively used within large, industrial additive systems that cost multiple hundreds of thousands of pounds/dollars/Euro.
Making PBF More Accessible
The first company to attempt to make a polymer additive powder bed system more accessible through a scaled down system at a more economical price was Norge Systems in 2014. As was popular for new entrants into the 3D printing industry at the time, the company’s founders, two young Italian engineers based in London, attempted to raise funding via Kickstarter. Before reaching full commercialization the organization was acquired by French 3D printing company Prodways, which later went on to launch a lower cost professional plastic laser sintering platform the ProMaker P1000, based on the Norge development and priced at under €100,000, which is competing well today. Some might not consider “under €100,000” to be that accessible, however the P1000 system, which became commercially available in early 2018 is performing quite well.
Later that same year (2014), Italian 3D printing company Sharebot also announced it was adding a laser sintering platform to its portfolio of 3D printing systems — the company already had a growing reputation with affordable desktop FFF, SL and DLP platforms. Sharebot went on to commercialize the SnowWhite desktop laser sintering system in 2016 and has a number of global installations.
Another company that arguably was among the first to scale down PBF platforms was Blueprinter, which operated out of Denmark. The company introduced the Selective Heat Sintering (SHS) process – similar to laser sintering but using an alternative heat source to the more commonly used laser. Unfortunately, the company was unable to survive the perils of a hardware start-up, due to a somewhat too slow and unreliable printing process, along with it being perhaps a little ahead of its time.
2014 was also the year that Sinterit, based in Kraków (Poland) was founded. Based on more than a year of R&D (at the time) by its three founders the company developed the Lisa laser sintering 3D printer. Just over a year ago, Sinterit raised over €1 million of funding from FIT AG primarily to promote growth. Today the company reports that its system, which comprises the Lisa printer, sieve, sandblaster and two materials — PA12 and flexa — has been installed globally on all continents. In fact Sinterit is today the clear market leader in this segment, both in terms of its technology’s reliability and overall global sales numbers.
Another company operating in this still small space in the 3D printing industry is Sintratec, based in Switzerland. Again, Sintratec’s proposition is a desktop laser sintering system. Originally, in 2015, the company offered the system in a self-assembly “Sintratec Kit” pack for just under €5k, later introducing the fully assembled Sintratec S1, at a higher specification and price. Both build parts with nylon powder. According to the company, there are in excess of 300 Sintratec systems in operation worldwide, notably at universities and research institutes.
And in 2017 three more companies announced their newly developed offerings for accessible laser sintering — Natural Robotics with the VIT SLS, XYZprinting with the MfgPro230 xS, and Formlabs with the Fuse 1. While all three of these systems have been introduced to the market and are currently out with beta testers, none have started commercial shipments yet.
Spanish company Natural Robotics and US based Formlabs are both coming in at a similar pitch — with both systems (excluding post-processing stations) offered as desktop systems for around €10k / $10k respectively. Expect to double that price and workspace for the full solution. XYZprinting’s new laser sintering system is expected to be prices in a higher market segment, at about $60,000. The system will thus be competing with Prodways’ P1000 as the two companies operate in a similar fashion. XYZprinting is based out of the US, but is a subsidiary of the Taiwanese Kinpo Group, Prodways is a subsidiary of Group Gorgè. Both are large companies with significant marketing power.
There is a clear trend here as larger companies are starting from the $100K mark and going lower through production optimization, while smaller companies are starting from the $10K range and going higher through added features and technological evolution. The ideal meeting point may be in the order of £$€ 40-50K.
The established companies in this space are reporting tremendous interest and steady growth, with the installed based increasing.
According to Sinterit: “We are seeing a growing demand for the Lisa machine. The benchtop size and simplicity makes it an ideal printer for learning this technology and qualifying applications: you do not need [much] space, no expertise in-house and you can verify your applications without investing loads of money. Usually our customers have experienced 3D printing already, with standard FDM or SLA technology, but sometimes they need to create something more complex, with movable parts, tunnels and this is possible with powder-based SLS. We are seeing an increasing trend [of customers] upgrading … and affordable desktop SLS machines makes it a soft entry into this segment.”
Sharebot’s CEO, Arturo Donghi concurs with the projection for steady growth based on the demand they are seeing. “At Sharebot we believe that SLS is an important technology and growth in industrial applications is continuing, including for functional prototypes. Making this technology affordable is the key here and this was the motivation for our SnowWhite SLS 3D printer. It was hard work as we started from a clean sheet but now more than 30 university and R&D centers around the world are using our SLS printer.”
Prodways is also reporting growth for plastic laser sintering. Most recently the company reported that service provider Do’in3D has added a ProMaker P1000 to its service offering. This comes on the back of two other installations at Creabis and Inovsys. Alban d’Halluin,CEO Prodways Technologies commented: “I think the growth potential [for plastic laser sintering] is huge. Whether we are talking about ‘professional’ products (i.e. sub 30k) our ‘industrial’ products (50-100k), I believe we should see a strong increase in the use of these systems. I see two drivers for this growth: first, these reduced prices are mathematically increasing the addressable market and with growing awareness of 3D printing more and more users make the decision to use 3D printing as the ROI is now valid for their business; second, the ecosystem has moved from a prototyping world where significant and complex skills, tools, surrounding equipment or software were required to a more production-oriented approach were everything is mature and integrated for the end user. So, you no longer need to know the black art of the sintering process to operate this new generation of printers and it encourages new comers to embrace this technology. Then when users look to ramp up a production center, they would move to more productive or a larger system to better suit there capacity requirement.
A side effect of the price drop is also that it enables educational entities to more easily purchase these technologies and it enables students to get more familiar with these technologies. Additive manufacturing classes are emerging everywhere, it is important they can run the right technologies. Of course this is more a longer term benefit.”
In terms of the new entrants into the desktop laser sintering space, the fact that three emerged so closely together in 2017 only further confirms that there is a strong market for this technology at an accessible price point. This is specifically reinforced by Formlabs’ Eduardo Torrealba, Director of Engineering for the Fuse 1, who commented: “When we started the Fuse 1 project the goal was to make SLS printing technology significantly more affordable and much easier to use than the traditional machines available. With the Fuse 1, Formlabs is doing to SLS printing what we did to SLA printing with the Form 2 – making it more affordable without sacrificing quality.
The Fuse 1 complements the Form 2 by giving users the power to print Nylon parts. Nylon exceeds the performance of most 3D printed polymers with a combination of strength, durability, flexibility, and environmental stability that makes it possible to print real end use parts. This performance leads to Nylon’s wide use in parts for consumer electronics, athletic equipment, and medical devices. Feedback on parts so far from beta users has been enthusiastic. We see Fuse 1 applications in rapid prototyping, small batch production, hybrid production environments and mass customization.”
While it is evident that there is a definite market for small scale, affordable but capable PBF 3D printers, the market itself is still relatively new and therefore small. But it is growing quickly. The ability to quickly print highly functional laser sintered parts off a machine that does not require a whole room is an attractive proposition for SMEs and large OEMs alike in the race to improve product development lead times and product quality.
Current evidence therefore suggests that there is a huge market available for smaller, more easily accessible plastic laser sintering machines with dominant applications being complex, functional prototypes. This process can now be realistically integrated into the product development cycle without the need for huge capital investment.
Another key application area cited by many of the incumbents in this space is also education, notably for R&D labs, but also for educating students.
As these systems — including from the newcomers this year — become more embedded, it is fairly safe to predict that they will only grow in numbers and application.