Additive Manufacturing The Startup Has Grown Up
/ Nicole Kareta
What is corporate success? When a startup can celebrate its 25th birthday, for example. The SME ACTech from Freiberg in the German federal state of Saxony celebrated this anniversary in early summer 2020. The secret of its success? Rapid prototyping based on additive manufacturing processes. A company history follows.
Reunified Germany in 1995. None of the company’s founders could have guessed that a quarter of a century later the economically successful company called ACTech would be able to celebrate its jubilee. The main driver of this success was foundry engineer Dr. Florian Wendt. “There was a clear deficiency at that time: how could single castings be produced quickly at a reasonable price?” Norbert Demarczyk, now one of the three managing directors of the SME and responsible for production, explains the motivation at the time: “The technologies of the serial foundry were too inflexible and too complicated to rapidly produce an occasional casting for test purposes.”
Dr. Wendt’s Patent is Part of Company Pre-History
Wendt worked, researched and patented. His patent for the laser sintering of Croning mold material, and the implementation of this invention by EOS GmbH in Munich, Germany, is indivisible from ACTech’s pre-history. For the first time a technology was available – the EOSINT-S-technology – that permitted the production of cores and mold parts from a dataset without a previous pattern. The method is a layer-building process in which phenolic resin is hardened using heat energy selectively applied by laser. At the time one spoke of rapid prototyping technologies; now we call it additive manufacturing or even just 3D printing. The group term selected for the technology makes it clear which need is to be served – that of rapid prototype production. The demand first became a market because, due to a previous lack of suitable technology, no really rapid prototype production was possible, particularly not for more complex castings. Pattern and tool construction was the predefined path with predetermined duration and costs.
A young team consisting of a CAD designer, a foundry engineer and a machine expert was rapidly put together in 1995 and got to work with pioneering spirit. It was necessary to overcome the teething problems of the technology, and to prove the suitability of the mold parts and cores for producing different geometries in a variety of casting materials.
Freiberg, the location of a training facility for foundry engineers, was a logical site for the company’s headquarters, and the Institute’s testing ground provided the initial operational base for producing castings using the new type of mold parts.
This new miracle technology was a marvel for the entire sector. New freedoms of design were possible, undercuts and demanding angles were no longer obstacles or restrictions – enabling the casting of hitherto impossible geometries.
Molds were even sent to Japan; transport of the fragile mold parts posing another challenge that had to be overcome. Later, two-meter long molds for casting in magnesium would be flown to Canada as air freight.
ACTech Increasingly Strong in Engine Development
The technology-friendly automotive groups ordered EOSINT plants for their internal foundries, though few others trusted themselves to master the technology and make the investment. ACTech thus saw an opportunity for commercial development as a group-independent service provider offering prototype castings with minimum delivery periods. This enabled, and still enables, the provision of customers worldwide with efficient and rapid development of the products of tomorrow. The business grew steadily. The company was already in the black in its second year of activity.
ACTech prototypes were increasingly supplied for more and more engine development projects and gained a reputation for rapid availability and dependability. Many important engine development projects worldwide could progress with castings from ACTech. Whereby this mainly involved cylinder heads and cylinder crankcases in a variety of aluminum and cast iron materials.
During the early years, ACTech achieved its foundry performance solely through collaborations with foundries and the nearby foundry laboratory of the Technical University Bergakademie Freiberg. Consistent investments were undertaken in the key competence: the additive manufacturing of cores and mold parts.
Milling Molding Materials Since 1999
The first generation EOSINT-S350 was followed by EOSINT-S700, a machine with a larger assembly space – exploiting the world’s first strategy of using two laser fields. Nevertheless, the size limit remained an inhibition. The company’s own ideas resulted in the technology of molding material milling in 1999, followed by patenting and implementation. The basic principle involves milling out the contour from a prefabricated block of molding material. This enabled mold sizes of more than two meters. A high level of freedom of design was provided when milling-out was combined with cores and mold segments from the laser sintering process.
The company’s involvement in mechanical processing was guided by market requirements to not only convert rapidly produced castings to speedily available prototypes, but also provide the finished part. 5-axle CNC milling technology was used here right from the start.
The Original Three Became More Than 100 Employees
Despite the expansion of foundry capacity with its own personnel and equipment, the lack of its own foundry and consolidation of all the production sites became increasingly urgent. The constant growth and profitable business provided the necessary tailwind for investing in its own “integrated production facility”. The opportunity arose in 1999 when the town of Freiberg was looking for someone to take over the property of an old industrial bakery. This industrial wreck was reanimated and converted and, after commissioning in spring 2001, the new production site started manufacturing molds. The site also accommodated the foundry laboratory, mechanical processing (now with four CNC machines) and a pattern construction operation (as a tenant), as well as all the administration. The number of employees rose to more than 100 and sales reached 6.2 million euros. This was followed by ISO-certification, a 3-shift system, and building expansions.
Specific to the foundry is its location upstairs, above the ground floor , with the neighboring aluminum, iron and steel casting groups. ACTech’s engineers developed special patented casting processes in reaction to the need for the prototypes to have properties comparable to subsequent serially produced parts – made using die casting or permanent mold casting. It was possible to improve the mechanical properties of aluminum castings, particularly by using active cooling during the hardening process. The melt capacity was designed for 400 kilograms of cast iron and steel per batch and 500 kilograms of aluminum using two induction or four resistance-heated furnaces. Small in foundry terms, but highly flexible: market requirements best met by this equipment.
ACTech Can Also Do Investment Casting
In addition to sand casting, ACTech also exploits the possibilities of rapid production in investment casting, based on patterns made using additive manufacturing. This started as a joint venture, Rapid Metal, founded in 2000 in Pegau (south of Leipzig). Initially, the plaster compact mold process was used for production, exploiting residue-free burn-out lost patterns made with additive manufacturing. The limitation of using aluminum, and the impractically long cooling rates in the plaster mold required for good mechanical properties, led to the introduction of ceramic bowl technology. The protracted drying process of one day per ceramic layer was optimized in order to make this technique suitable for rapid production. The result led to a patented drying plant that achieved a drying time of just 90 minutes per layer. The effect of this was correspondingly magnified because 10 to 13 layers are applied. Following the merging of Rapid Metal with ACTech GmbH, the Pegau production site was moved to a specially built location in Freiberg in 2008. Large investments were made in catalytic cleaning of the waste gases so that the Flashfire burn-out technology could be applied in an environmentally friendly way.
The Investment Phase After 2007
Optical measurement is the key to the accuracy of individual pieces. The company has been increasingly accompanying production with this measurement method since 2004. Eight such systems are used at present. It began with the classic dimensional inspection of the blanks. This was followed by measurements while setting up for mechanical processing, for adjusting the individual mold parts relative to one another in the mold assembly area, for accompanying straightening processes in post-processing and, last but not least, increasingly in measurement of the finished part. Here, too, collaboration with the system producer to find appropriate solutions paid off. The live tracking of mold assembly has thus become one of the hand-held tools for accurate working methods in the foundry.
The change in owner in 2007 enabled implementation of an investment package in the mechanical production department. The newly built production hall required was gradually occupied with 21 processing centers. Competences and the depth of performance were steadily built up. The company’s entry into processing cylinder heads in 2007 was a milestone. A team of twelve CAM programmers was put together for the mechanical processing department – to enable rapid reaction to the most varied of parts and their requirements.
The results of processing are measured and inspected in ACTech’s “Group measurement room”, as it was once described by an ACTech advisory board with industrial experience in response to its size and equipment. Five coordinate measurement machines are used here, assisted by optical roughness measurement and a variety of hand-held measuring devices.
The world of additive manufacturing for mold parts continues to develop. ACTech accompanied the development of binder jetting technologies right from the start. New binder systems were promptly tested and compared with established technologies. Printed furan resin cores increasingly became an alternative for bulky mold parts and solid cores, and ACTech invested in the first printer with this technology. The great tensile strength of the laser sintered cores made of EOSINT S, however, proved to be a major challenge regarding conversion to more productive printing of the highly demanding core geometries that ACTech parts require. Can printed cores keep up in this regard? Not if made of furan resin, it was found, so ACTech used the phenol resin process and got involved in ExOne’s development process for cold-hardening phenol as a beta customer in 2016. It was a success. The laser sintering technology, particularly intricate in post-processing, was replaced. More complex cores can be constructed; several individual cores are combined to become one. Productivity and accuracy, often opposing criteria, were improved.
What is the Spirit of ACTech?
The development of technology and corporate equipment is one thing, but what about the inner mechanics of the company which has grown from three to almost 400 employees in 25 years? What really characterizes it? And what are the terms with which ACTech itself would describe its DNA. Demarczyk does not need to think for long about this. “We are all informal at ACTech – a kind of large family,” says the Managing Director, who has been on board since 1997 and has thus helped shape almost the entire course taken by the Freiberg-based company since its founding. “Our employees appreciate the collegiality and supportive working atmosphere. And, of course, the fascination of working on innovative and demanding products of the future – every day.” It is logical that topics such as internal communication and organizational development are also matters of interest for a company with a modern positioning that operates at the peak of technical development. “We question ourselves, our structure, our methods – and continuously develop them,” says Managing Director and Commercial Manager Cornelia Bahr. This includes, for example, agile working methods. In 2018, ACTech risked taking the first steps in an agile work structure for which employees themselves are responsible. Several teams are testing and continuously adjusting agile working methods in pilot projects, and the lessons learned are being passed on to other areas of ACTech. The company is currently further expanding these agile methods and establishing them in more departments.
In line with its philosophy of sustainability, ACTech does its own training – to gain specialist staff to meet the company’s own requirements. Training is characterized by intensive collaborations with local vocational colleges and external training centers. In addition, each trainee has an experienced mentor at their side in the company – a personal contact for the duration of the training and afterwards. ACTech supports its trainees in a cross-company understanding of collaboration, and creates projects in which interdisciplinary thinking can be learned. So far 114 young people have received such training in professions such as foundry mechanic, cutting machine operator, industrial mechanic, specialist in metal technology, and specialist in material testing. 26 trainees are currently undergoing training in nine different professions.
Speed Remains the Top Trump
The whole company always did, and still does, aspire to achieve speed in all processes: a sales department that makes offers within 48 hours, a powerful CAD design team, more than 20 engineers from the foundry and processing to support customer projects and immediately get involved when the customer places their order. The parts are made a reality by the highly qualified and experienced employees involved in the 3D printing of molds, the foundry, CNC processing, and quality assurance. “We have reached a super level here by combining technical mastery with state-of-the-art technology. Our ‘all-in’ strategy, having the important processes in-house and mastering them, pays off – we do not want to see any decline in this,” Managing Director Ray Wünsche defines a very important strength, and quotes the company’s investment in the latest S-Max Pro printer from ExOne as an example.
The Future After the Jubilee
“We see the expansion of additive manufacturing in the foundry as an important aspect for the future,” Demarczyk looks ahead. “It can further increase the design variety of foundry technology regarding geometry and materials.” After all, prototype parts ultimately lay the foundation for subsequent series, and they can be efficiently produced by casting. With this consistent use of additive manufacturing technologies, ACTech is in harmony with the parent company Materialise, an internationally active Belgian company that bought ACTech in 2017 and is a trailblazer of 3D printing in many sectors. ACTech can approach the coming years with this investor at their back – for another successful quarter century.