Welcome to “discovering the truths and myths of 3D printing”
In the last few years we were all able to observe how news about 3D printing have moved from technology magazines to the normal news papers. Here you can see an extract of different titles from different newspapers of the last few months. Some of you who are following the news might recognize some of the different titles.
Before being able to understand the truths and myths around 3D printing we will need to get an overview of the 3D printing technology. This will support us in understanding where it comes from and what the potentials and limits of this technology are.
Therefore we will discuss a short introduction of the definition of additive manufacturing, and we will take a look at a brief history, as well as at an overview about the technology and the involved processes.
We will see how products are developed for AM and how they are manufactured, including preparation, creation & finishing of the parts produced with AM.
Additionally we will take a look at the different applications showing the potential of this technology. Further, we will discuss which limits needs to be taken into account.
Finally the streams that are currently pursued by High Tech within the group will be presented, with the hope to inspire more colleagues to come and join the High Tech journey in alliance with our customers.
What is additive manufacturing?
First of all 3D printing uses several processes to create three-dimensional structures (e.g. extrusion, jetting, sintering, …)
It is an additive process, that builds parts layer by layer. Hence, it is most often also termed as ALM which means Additive Layered Manufacturing.
The part is produced from a digital input in a certain format that is created with a specific software.
Of course, the printer itself is clearly a robot.
In the late 80’s additive manufacturing was mainly referred to as rapid prototyping. The aim of the technology was to create cost efficient prototypes in a rapid manner.
The first known patent application was filed by Dr. Kodama in May 1980 in Japan. Unfortunately for him the full patent specification was subsequently not filed one year after so that his exclusive rights to this technology ceased. Considering that he was a patent lawyer makes this fact a little bit funny or maybe dramatic … depending on the point of view.
The first apparatus was based on the stereolithography (abbreviated as SLA) and invented by Charles Hull (a co-funder of 3D Systems Corp.) in 1983. The patent was implemented in 1986 and the first commercial RP was relaesed for sale in1987.
In 1987 a new patent was filed by Carl Deckard introducing selective laser sintering (SLS). The patent was issued in 1989 and was acquired by 3D-Systems. In the same year Scott Crump (a co-funder of Stratasys Inc.) introduced a patent for fused deposition modeling (FDM). This patent was issued in 1992.
In Europe, the German company EOS GmbH (founded by Hans Langer in 1989) focused on the laser sintering (LS) process. The company sold its first machines to BMW. Together with Electrolux Finland they have created the direct metal laser sintering (DMLS) process.
During these years additional additive manufacturing technologies emerged:
Ballistic particle manufacturing (BPM) by William Masters
Laminated object manufacturing (LOM) by Michael Feygin
Solid Ground Curing (SGC) by Itzchak Pomerantz
& finally three dimensional printing by Emanual Sachs
In the early nineties a good number of companies in the field of rapid prototyping emerged and began competing in the market, but only three of them where clearly dominating the market:
3D Systems
EOS
Stratasys
Between the 1990’s and the early 2000’s several new technologies emerged, and industrial solutions for tooling, casting and direct manufacturing applications were established. This created the necessity of new terminologies, namely rapid tooling (RT), rapid casting and rapid manufacturing.
Several companies continued to introduce additional technologies like electron beam welding (EBW), so that over time a more general definition was needed. As a consequence, additive manufacturing (AM) or 3D printing was born. Both terms are in use today and actually refer to the same technology.
A large number of additive manufacturing processes are nowadays available.
The main differences between the individual processes are in the way the layers are deposited to create parts and in the materials that are used. Some methods melt or soften material to produce the layers, e.g. selective laser melting (SLM) or direct metal laser sintering (DMLS), selective laser sintering (SLS), fused deposition modeling (FDM) or fused filament fabrication (FFF), while others cure liquid materials using different technologies, e.g. stereolithography (SLA).
With laminated object manufacturing (LOM), thin layers are cut to shape and joined together (e.g. paper, polymer, metal).
Each method has its own advantages and drawbacks, which is why some companies consequently offer a choice between powder and polymer for the material used to build the object.
The main considerations in choosing a machine are generally speed, cost of the 3D printer, cost of the printed prototype, cost and choice of materials, and color capabilities.
Printers that are able to process metals are rather expensive. In some cases, however, less expensive printers can be used to make a mould, which is then used to make metal parts.
In the table you find a categorization provided by Gartner who performed an intensive survey of the technology. There you will find the processes and the current printer prices.
Now that we understand the origins, the general scope and the different processes of 3D printing , let’s see how to develop such parts.
Let us start from a fictitious situation where we have to integrate a structure that connects water pipes with the main structure of a product. This is represented in the first figure.
If we would manufacture such a connecting part in a traditional way we would use standard parts from the supply chain that we can assemble together in order to install the water pipes. In this case we would choose a sheet metal construction in order to provide a light-weight structure. You can see such a classical structure in the second figure.
In a second phase we might think about creating even an optimized version by reducing the assembly parts and thus also improve the manufacturing chain. This you can see in third picture.
However, if an AM part is desired we will have to take some steps back and review the development of this structural part. In fact classical manufacturing constraints as they come along with sheet metal manufacturing can be entirely be neglected. When using AM the design engineer takes up the role of a sculptor who is following the flow of the energy transfer due to the loading through available space.
As a consequence, first of all we need to define the space that is available and that can be used according to the requirement of the installation. This is also called the design space, and this is depicted in the fourth figure. It is clear that we are now talking about structural optimization.
Once the design space is fixed we have to decide which parts of the design space can be changed and which parts may not be altered (e.g. due to load introductions, attachments, joints, or similar). In the fifth figure you will see several constraints being applied to the design space which is where the structure under investigation will be attached to the actual product.
Lastly we will have to define the applied loads as well as the introduction points of the loadings which is represented in the sixth figure.
Once the model has been established it is submitted to a topology optimization package of your choice. Typically, the results of a topology optimization lead to raw structures that resemble a bionic design and actually very often have much in common with structures as they evolve in nature.
It is then the task of the designer to interpret the results and to come up with a design solution that follows the optimization results as closely as possible, however weeding out sharp corners, notches, and the like during this process step, as they are typical for topology optimization results. The above figures show two different design solutions established by two different individuals using two different design software packages. While the design solutions are very similar as could be expected they nevertheless contain some detail deviations, which goes to show that the AM design process is highly susceptible to personal interpretation and is thus difficult to automate, also due to the general complexity of topology optimization results.
Afterwards you use mechanical structure simulation and/or hand calculation tools to verify if the given requirements concerning stresses, displacements, vibrations, and so on are fulfilled. Generally it will be necessary to repeat the process steps of optimization and design several times before a design is established that satisfies all given requirements.
It is interesting to remark that the given example here mainly consists of hollow tubes that were found to be the ideal solution in the light of the specific constraints that were given in this problem. It is clear that if such a structure was manufactured by using classical means, it would be much more expensive and would take much longer to be manufactured, which again shows the clear advantages of 3D printing when it comes to highly optimized and sophisticated designs.
Nonetheless, even though 3D printing has many distinct advantages over classical manufacturing processes, during the development of parts you have to take also the limits of the 3D printing process, the systems and the materials that you want to use for production into account, just like when you want to use a classical manufacturing method. Also here you have to clearly understand what needs to be prepared, how the part is produced and what needs to be done during finishing of the part.
Let us imagine that you want to create the developed part with direct metal laser sintering. You will have to take into account that you need to add cooling supports (e.g. GPI protype in the picture) to ensure that the strains/stresses within the structure produced by the heat of the laser are dissipated during the cooling phase. Additionally, you will need to consider that the powder that sticks within the hollow tubes need to be removed after the part has been manufactured. So you will need to drill holes to evacuate the powder and you will also have to take into account the cutting phase of support structures (if any), and also additional surface finishings to ensure the quality that is expected for the structure. During the manufacturing it is important to ensure that the production space within the printer fulfils the adequate requirements like maximum volume, positioning of the structure, evacuation of the powder during the production phase, and many others.
What is very clear is that you cannot simply change the process (3D printing method), system (3D printer) and material without having a clear impact on the way you manufacture your part. It is not the case that just because you use the best material that you will automatically achieve the best result expected with the different printer or 3D printer processes.
On this slide you can find some interesting links to understand the different processes and also what kind of materials are available today.
I believe that most of you might have already read about or maybe even sees a 3D printed application. As already mentioned in the history introduction, the automotive industry was one of the first users of this technology for their rapid prototyping topics as you can see as example from 3D Systems. But over the years, medical and dental applications have emerged rapidly and have been strongly industrialized with a strong standard approach and high quality products. Furthermore, in the last months you could see a lot of movement concerning 3D printing around the aerospace industry sector, considering the significant investments by renowned players like General Electrics, Airbus, Ruag, and other OEMs in the aeronautical field.
But 3D printing has not only found its place in the traditional industry. It is moving to fashion, art & jewellery as well.
And finally the high potential of such a way of thinking has made it’s way to the Biotech industry where you can find solutions for traditional medical applications and even in the food industry.
I can only recommend you to watch some of the TED talks that are really very interesting, informative and also inspiring. Anthony Atals is talking about how to print organs, and Andras Forgacs elaborates on how to print a steak in the future.
In the amount of news that are produced during the day around additive manufacturing it is difficult to distinguish between truth and myth or as I would call it “VISION”.
As I already mentioned Garner has done a very intense survey around 3D printing. They clearly see an increase of the printer sales in the next 5 years. But despite what most popular scientists believe, it will be not be home printers before the next 10years in my opinion …
During the last few years a strong has been pushed by the media around this topic. It was proclaimed that 3D printing offers no limits for your ideas and business models. The hype is still present (though already declining and slowly reaching more realistic outlooks) and pushes manufacturers to buy a printer without really knowing which return of invest they can hope to expect by investing in this technology.
After having such a machine in the production hall, the manufacturer starts to understand and discovers that this technology can not produce whatever you want, easy and rapid. Yes, there are limits that need to be understood and clarified. From that point they focus on the value that they discover and exchange a lot to learn from leaders, experts and the 3D printing community in general.
Passing through this phase they begin to produce their first ideas by trying to build the same products or maybe already optimized structures. They test the structures and discover the differences they have to take into account. They start to build standards, adapt the production, and manage the lessons learned.
Only they are able to really buy more printers and rollout a revolutionary industrialization.
The opportunities are really clear through the several processes a manufacturer can use, he is able to produce revolutionary designs adapted to the new production process, understood, adapted and implemented.
A good example for one of the strengths of democratization of manufacturing is the community 3Dhubs started in the Netherlands and spread over the over world.
Every person is able to get access to 3D printed parts. It does not matter if you are an enthuisiastic hobbyist or an entrepreneur who wants to start with a small production.
So you are able to:
upload your 3D design
choose your print location
get in contact with your local 3D printer service supplier.
This community keeps growing more and more with a strong sense of cooperation.
A second example is a pilot project that UPS has started with 6 locations at the end of 2013. They wanted to test 3D printing services like the are doing for 2D printing. Instead of transporting the parts from one place to the other, UPS receives directly the digital information and prints the part. They were successful so that one year after they decided to open 100 additional locations in United States.
We also wanted to give the community a small overview of the ongoing streams we are following with the High Tech division in France, Germany, India, Spain & UK.
We are focusing on improving the methods and also the tools, by creating new processes taking into account all the different aspects of the (pre-) development, manufacturing,
To show our strength in structural analysis for the development for AM we are creating several pilots parts for our customers and we participate at industrial different awards.
Additionally to this stream we are building a strategic partnership with 3D printer builders to speed up the phases from early adoption over rollout to industrialization … Therefore we need to support structural testing and material qualification.
In the know how management stream we want to use our strength in create a culture of centralizing and spreading know how. We are used to train colleagues to become trainers and be able to create trainings that inspire and activate the own motivation.
The colleagues to contact here are:
Christian Mittelstedt (High Tech Germany)
Frank Pacou (High Tech France)
Pierre-Yves Meyer (High Tech France)
Jeff Lake (Hightech Uk)
Finally you will find here a small collection of the communities we are following, articles, videos that should inspire you to get more know how around the topic.
And for all the internal Sogeti & High Tech colleagues feel free to join join our teampark community around AM.
