For anyone who is afraid of the intellectual and financial investments in 3D printing, experienced contract manufacturers are the obvious choice. These companies rely on different experiences and priorities.
These companies mainly deal with 3D printing and have been doing so for many years. They know their systems, the materials, the processes and the design possibilities offered by additive manufacturing. In short: Contract manufacturers are specialists. In the words of Stephan Kegelmann, Managing Director of Kegelmann Technik: "The economic potential of additive manufacturing is not tapped by a machine, but by functional integration, lightweight construction, individualisation and component complexity that can be achieved free of charge. This takes a lot of know-how and experience.” The number of contract manufacturers specialising in 3D printing is growing. Broadly speaking, they can be divided into service providers, – some of which started with subtractive processes, others with 3D printing – manufacturers of machines or software, who also receive direct input for their development department through the printing service as well as spin-offs of larger companies, for which they already operated as service providers.
Metalworking as a speciality
Solidteq is one of the last-named companies as of 2016. A subsidiary of Rheinmetall Automotive, the young company specialises in 3D printing using metals. Like the mother company, which practices ISO 27001 that regulates data protection and confidentiality, the wholly-owned subsidiary is also subjected to this standard. It has been working with the SLM process for six years and can process both internal and external orders on six machines. Solidteq uses aluminum, 316L stainless steel, Maraging Steel 1,2709 and Inconel for this purpose. "But other materials can also be processed," adds Stefan Pörtner, Head of Production and Technology. Their strength is in post-processing. "We have access to the complete technology spectrum of our parent company that has more than a hundred years of experience in mechanical metalworking," says Pörtner. Depending on the component requirements heat treatment, surface treatment or mechanical processing is carried out. In addition, customers can also have their order refined; the range includes painting, electroplating or different coatings. Solidteq uses computed tomography for component analysis and quality assurance.
Probably largest sand printing system
Voxeljet has extensive expertise in the use of its manufacturing machines. This is where the company's own 3D printers are used. Their process is based on binder jetting in a powder bed, their materials are: Plastics, ceramics, and quartz sand. This is also the special feature of the contract manufacturer: "We offer construction dimensions ranging from 300mm × 200mm × 100mm to 4,000mm × 2,000mm × 1,000mm, allowing us to offer the world's largest commercially available 3D sand printing system," explains Dr. Ingo Ederer, CEO of Voxeljet. One of Voxeljet's main focuses is, therefore, on the production of moulds and casting cores which can be further processed by the co-operating foundry at the customer's request. Plastic is mainly used to print models used in investment casting or for design and functional prototypes. Voxeljet provides advice on the printability of the data, the optimum material and the subsequent processing steps or use. "We can also assist with data creation," says Ederer. "In addition, we finalise each data set and repair it if necessary to achieve optimal printing results." The company opened its service division in 2003 and processes up to 400 tonnes of material per month at its German service centre.
Arguably those contract manufacturers who have dedicated themselves entirely to this business area have the most intensive experience. At the very least, they offer the widest range of processes. On the one hand there is Protolabs with SL, SLS, DMLS, Multi Jet Fusion, and Polyjet. These processes already provide an idea of the material spectrum: Plastic, metal, silicone. The service provider keeps thermoplastics, metals and elastomers in stock. The company has its roots in injection moulding and has been offering 3D printing services since 2014. As a special property, colours can be added to the material, creating individualised coloruing already in the printing process. But Protolabs has also come up with a far-reaching service concept for consulting services - in addition to targeted, individual consulting. "If you want more information, you can access our comprehensive library of online resources, including guidelines, tips, and white papers," said Daniel Cohn, Managing Director of Protolabs. Furthermore, the service provider offers webinars to provide regular insights into the special features and requirements of 3D printing. Protolabs also seems to have the most extensive range of customers, because outside industry there is also “the inventor who needs a single part," says Cohn. In terms of post-processing, the possibilities range from CNC processes to optical design, allowing functional elements such as boreholes to be added or the appearance to be improved by means of paints and metal coatings.
Consulting starts with the purpose of the component
Kegelmann Technik is also experienced in injection moulding. However, the company has also been integrating additive manufacturing for almost 30 years. The contract manufacturer is certified for the automotive industry (IATF16949), the aerospace industry (DIN EN 9100), and meets the quality management standard ISO 9001. A total of thirteen machines are used for SLA, SLS, and SLM processes; the materials used reflect these processes: Accura Extreme and Visijet Clear (polymer resins), PA 11, PA 12, PA12GF (glass bead reinforced), PA12 HST (mineral fibre reinforced) and PP as well as 1.4404 stainless steel, AlS10Mg aluminum. "Our advice begins at the end, i.e., the benefit that the component should yield for the customer or their customer,” explains Kegelmann as the “Connected Prototyping” consulting philosophy. "We accompany our customers throughout the entire process chain from the idea or the respective issues to prototyping and production readiness. Our goal is to integrate sustainability, resilience and sustainability in our customers' components." In addition, they rely on "icebreaker projects", in which quick and major successes are relatively easy to achieve, while generating a significant yield in much less than a year.
Exclusive materials for customers
Fit AG is a special case as such. This contract manufacturer started with 3D printing in 1995 and is exclusively active in this business segment; its subsidiaries, which use conventional methods, are also supported by additive methods. Based on his experience, Carl Fruth, founder and managing director of Fit, makes a simple plea to his clients: "Often our prospective customers do not tell us what their real requirements are, either because they don't even know them or because they consider it a business secret. Of course, the resulting advice may be incorrect, too." Even if customers have already decided on design, materials and processes, it is difficult for specialists to help. "We therefore always recommend involving us in the very early design phase," says Fruth. Reason being: "Experience is imperative. Additive manufacturing does not differ from other complex manufacturing techniques in this respect." Fit utilises ten additive techniques, including EBM, WAAM and multi-material techniques. The selection of materials is correspondingly extensive, including titanium, and in-house developed plastics. The latter are also produced exclusively for a customer. When it comes to data protection and confidentiality, Fit offers an all-round carefree package: from separate security areas to an audited compliance system and insurance policies through to fidelity damage and the separate disposal of data carriers as well as samples and rejects.
The common feature of the contract manufacturers is that they predominantly produce prototypes and small series. The automotive industry is seemingly the industry that is most willing to place orders, but the aerospace industry is also very active. All of them offer intensive customer consulting on construction and design. If one wants comprehensive advice on the choice of processes and materials, one should choose a company with the appropriate expertise. Another thing the companies share is data retention, usually over a period of ten years. In this way, it is possible to react quickly to repeat orders, but changes to the product are also possible.
This article first appeared on www.maschinenmarkt.vogel.de.