Technology with Potential
No matter whether food, film props, prostheses or bumpers – everyone is talking about additive manufacturing at the moment. No wonder - the technology makes it possible to produce complex parts from a wide variety of materials. And all this in the highest quality.
More and more frequently, three-dimensional printing supplements or replaces conventional manufacturing processes. Not only medical technology, the automotive industry and aerospace benefit from this, but the foundry, steel and aluminium industries have also recognised the potential of 3D printing. From 25 to 29 June, the Düsseldorf trade fair quartet Gifa, Metec, Thermoprocess and Newcast will also be showing what this can look like in concrete terms. A special show will then be devoted to the topic of "Additive Manufacturing".
The greatest advantage of additive manufacturing is the time saved for companies. Since they often use CAD data directly without first having to build a tool. "Especially in the automotive industry, the entire development process runs without tools and is therefore much faster. The products come onto the market more quickly," says Tobias King, Director Marketing & Applications at voxeljet from Friedberg near Augsburg, in Germany. Mould sets for turbochargers, for instance, are printed within a week, then tested and, if necessary, modified again on the computer. With just a few clicks, the developers digitally adapt the associated CAD data.
The corresponding CAD program calculates the various levels, and the 3D printer constructs them layer by layer. Material is only joined where it is needed as a supporting structure. This offers developers, engineers as well as architects a new variety of geometric shapes. In this way, even the smallest quantities or individual parts, for example for prototypes, can be produced cost-effectively, validated and then transferred to series production.
Additive manufacturing and conventional techniques often go hand in hand. "For us, additive manufacturing offers interesting perspectives, especially when it comes to supplementing our manufacturing processes," says Cesare Troglio, Head of Technology and Innovation at the Federal Association of the German Foundry Industry (Bundesverband der Deutschen Gießerei-Industrie, BDG). Many foundries use the process either for the production of moulds and cores or for models and tool inserts. Thereby, they combine additive manufacturing with proven casting processes. The direct metal printing of components is, according to Troglio, still concentrated on the production of prototypes and small series. However, great efforts have been made to further industrialise the process.
Opportunities and Risks through E-Mobility
In particular, electromobility and lightweight construction in the automotive industry present new opportunities and challenges for the industry. For example, a studyinitiated by BDG has discovered that although some motor components for foundry companies will be eliminated by the new drive concepts, the overall production of castings for hybrid and electric drives will initially increase.
And additive manufacturing comes into play here as well. In electric vehicles in particular, thermal management of both the engine and the battery plays a major role. The necessary temperature control channels come from the foundry. "This requires complex cavities that cannot be produced by forming or welding," explains Troglio. Additive manufacturing provides additional potential here for the optimum design of the new components.
No Miracle Weapon
However, 3D printing is not a panacea. "Additive manufacturing," explains production expert Franz-Josef Wöstmann from the Fraunhofer Institute IFAM in Bremen, "is supplementation, not substitution". Troglio also believes that the costs for additively manufactured components are still too high. Many 3D printers reach their limits at the very latest when conventional manufacturing processes can be used to produce large quantities economically. Furthermore, there is also a lack of skilled workers here.
However, additive manufacturing is the ideal playground for founders or young companies. New possibilities are opening up, not only in the area of design, but also in simulation, software or as a service in engineering. Start-ups could help plant manufacturers to further develop their processes. Here, topics such as process control and automation are addressed. Some suppliers sell their printers openly without material, so that on one day it is possible to work with nylon thread and on the next day with foam. Or one can team up with a material manufacturer and develop a completely new product. As a service to ensure cash flow, founders could offer printing as a kind of copy shop. After all, not everyone has to own or can own such a device.
From Spin-Off to Leading Global Manufacturer
voxeljet shows how a start-up can develop into a major player. The company works with inkjet printheads that are very much similar to office printers. Industrial printing modules can be connected in series in order to increase both the printing rates as well as the installation space. Currently, the maximum here is eight cubic metres. "It will take us about two days," says King. However, the "unpacking" of the parts and the removal of unprinted sand still needs to be done by hand. Still. Because if things go according to the Bavarians, there will soon be an end to this. At the GIFA trade fair in Düsseldorf at the end of June, the former spin-off of the Technical University of Munich will present a new concept.
In concrete terms, this is all about water jacket cores. They are used to cast cylinder heads in the foundry. In order to produce them in series using additive manufacturing, the company has developed an even more powerful printhead and coating unit. Instead of 50 seconds shift time, it is now five seconds.
After printing, loose quartz sand material remains between the printed cores. This is now extracted automatically or blown away by suction and compressed air, thanks to a joint partner. A robot cleans and then removes the parts; the machine is set up again and starts the process from the beginning. "A milestone for the additive industry," King is convinced.