Additive Manufacturing

Printing by numbers

So far, 3D printers have mainly produced prototypes. There should be a breakthrough in mass production on the horizon, but a lack of standards is holding back this revolution. Certification programs could remove this obstacle.

Text Susanne Widrat Illustration Oliver Burston

The plate slowly rises out of the build cylinder, revealing the initial contours of eight objects, each just under 15 centimeters tall. “Those are guide vanes,” says Christoph Hauck, managing director of MBFZ Toolcraft in Georgensgmünd, Germany. They are used in the energy sector and in aeronautics. What’s special about these particular vanes is that they were printed instead of being cast. For several hours, a laser melting machine applied consecutive layers of gray powdered nickel alloy, intermittently melting them with a laser beam.

Hauck is fascinated by the technology. Yet for him and his around 380 employees, the work doesn’t really get started until after the automatic printing process, also known as additive manufacturing (AM), is completed. Now the supporting structures must be removed: small supports beneath the components that hold the objects in place during printing and dissipate heat. They prevent overhanging areas from collapsing. As important as they are during the printing process, they’re just as superfluous afterwards. CNC machining centers take on part of the tedious work, but at other times, employees have to use pliers and files to remove them.

This piecework annoys Hauck since it means delays and costs money. “A lot of development work still needs to be completed here,” he says. He hopes that parameter optimization will drastically reduce the number of supporting structures or that robots will be able to complete the work. He can also imagine dissolving them with liquid solutions.

However, quite a lot of time may pass before Hauck’s wishes come true. Three-dimensional printing is still stuck somewhere between digital high-tech production and hobbyist handicraft. Enthusiasts in private garage workshops and million-dollar production lines set up according to Industry 4.0 standards are both equally part of this technological revolution. In all of this, manufacturers are compensating for the lack of standards, experience and certifications by using self-developed process guidelines and quality controls.

Revolution in a Holding Pattern

Certification could potentially help in the case of Hauck’s support structures, assisting not only with mapping the printing process through to the finished blank, but also in post-processing. “Printer manufacturers have focused especially on better lasering and layering processes and have neglected post-processing,” Hauck explains. “3D printing is still at square one with respect to certifications and standards.”

More than thirty years after its birth, 3D printing—like any emerging technology—is at a crossroads. Just like the first automobile had to compete against horse-drawn carriages, and light bulbs against gas lighting, now 3D printing must prove itself against established processes such as lathing, milling and casting. The question is whether it can rise to become the new standard with the assistance of certification and testing guidelines and displace traditional techniques, or if it will remain a niche process for specialized products.

The technology has enormous potential. Just four years ago, the estimated worldwide revenues for the segment were 2.6 billion euros. According to forecasts by the consulting firm Deloitte, this figure is expected to rise to 17.5 billion euros by 2020. As a study by PwC has found, the biggest growth potential lies unrealized in the aerospace industry, medical technology and the automotive sector. Retailers are also hoping customized products will bring growth.

The number of possible applications and materials has been increasing for years. At the same time, customers’ goals are shifting. Until now, 3D printing has mainly been used for building prototypes or replacement parts. In these areas using it made sense because the parts were difficult to produce and often had to be made by hand. “Currently, additive manufacturing is increasingly moving away from this prototype stage and becoming interesting for mass production as well,” says TÜV SÜD Head of Additive Manufacturing Gregor Reischle. Reischle has been the innovation manager responsible for setting up the AM specialist field for about a year now. The advantages speak for themselves: resource savings, streamlined production processes, rapid availability.

Yet the crucial step to serial production still presents huge challenges for manufacturers and suppliers. To be able to continue meeting the high quality and safety standards demanded by customers in the future, standards must be defined for materials, production processes and end products. “We’ll need uniform curricula for the newly created job profiles,” Reischle says. “Definitions for production conditions, quality standards for the raw materials and testing under everyday conditions are also just as important.”

„Additive manufacturing is increasingly moving away from this prototype stage and becoming interesting for mass production.“

TÜV SÜD Head of Additive Manufacturing Gregor Reischle

Full Speed Ahead for the Long Term

TÜV SÜD is taking an important step in this direction with the new “Additive Manufacturer” certification. Since fall 2017 the company has been cooperating for the first certifications with, for example, Deutsche Bahn. Central Europe’s largest transport company has already had initial experiences with 3D printing and, since 2015, has printed about six thousand parts, the majority of which were not safety-related. The range of parts includes coat hooks for Intercity train cars, aluminum terminal casings for the Intercity Express high-speed trains, handrail signs in braille for train stations, and segments of turbine blades for a generator installed in a 100-year-old steam engine, to name just a few.

To date, external companies have manufactured 99 percent of these parts, which is exactly what’s so challenging about it. “We must be able to rely on our high quality standards for every part,” says Florens Lichte, who is DB’s point person for their 3D printing project. “Particularly when the parts have been manufactured using a new technology.” The only problem is that previous DIN or ISO standards don’t reflect the requirements for 3D printing.

This is why Deutsche Bahn and TÜV SÜD worked together to develop an independent certification program, the principles of which can be used across industries. The program closely examines almost all the areas of a company: management, procurement, manufacturing and post-processing, as well as order processing and customer service. The program has already successfully completed its pilot phase. Individual AM service providers surveyed the practicabil­ity of the requirements. “Moving forward, all of our suppliers who manufacture non-safety-related parts using 3D printing will have to provide proof of this certification,” Lichte says. “For parts that are safety-relevant, we’ll be checking the use of the testing program after the additional requirements have been fully specified.”

Stamp It

In September 2018, Siemens Mobility became one of the first suppliers to receive the AM certification. “We were certain that the inspection wouldn’t be a problem because our business is industrial manufacturing and we only employ specialists,” says Head of Additive Manufacturing Michael Kuczmik, who supervised the inspection. TÜV SÜD’s experts only criticized a few points in the end, for instance the fact that the job descriptions weren’t available in digital form. Kuczmik admits, “This could have posed a problem, particularly if there were surges in expansion.”

Kuczmik is positive that 3D printing is going to become increasingly important: “The hype will start as soon as the production costs have come down again in a few years.” At that point, secure processes and safe products will be all-important. “If even just a few 3D printed parts fail, then trust in the new technology will quickly be lost,” he says. “A certification is necessary for this reason alone.”

Hauck and Toolcraft in Georgensgmünd have also taken part in the certification. Since 2011, the company has been operating several 3D printing systems that they use to manufacture bone drills for operating rooms and engine suspensions for racing cars, not to forget the abovementioned guide vanes for aircraft turbines. Hauck and his team achieved the certification in September 2018. “We produce for many industries where accuracy and safety are extremely important,” Hauck says. “For us, inspectors are like consultants who scrutinize our production processes and objectively evaluate them.”

Toolcraft completed the certification program in just a few weeks. “We only had to fine-tune a few definitions and some conceptual boundaries in the documentation,” he recalls. TÜV SÜD helped the company to develop further in the direction of their industrial clients when accepting orders. For Hauck, the certification is an important step towards completely digital 3D printing processes—and maybe also finally getting rid of those annoying supports.

Breakthrough By Certification

TÜV SÜD offers eight services in the area of additive manufacturing, including the certification of production processes, certification of materials and products, and training and professional development for employees.


Process Certification

“The TÜV SÜD certification program creates binding standards for 3D printing in industrial contexts for the first time,” says Christophe Blanc, an expert in additive manufacturing at TÜV SÜD. This includes the quality of the raw materials, the exact pathway of the data flows, and the individual work steps for post-processing of the product. Special attention is paid to the material flow during the manufacturing process and the reproducibility of the individual manufacturing steps. For companies that want to obtain certification for their 3D printing processes, Blanc says, “We look at the overarching AM strategy, customer management, order acceptance, production preparation, the printing itself and the downstream work steps.” During several inspections, the company must prove that it fulfills the defined quality and safety standards. The certification is valid for one year and can be extended after that with an annual audit.

Materials Certification

In TÜV SÜD laboratories, all the raw materials, intermediate products and end products of 3D printing are scrutinized using chemical analysis, physical tests, ageing analyses and weather simulations. TÜV SÜD Program Manager Additive Manufacturing Materials Stefanie Sagerer says, “We focus especially on metals and plastics. With certification for their additive manufacturing materials, manufacturers and operators of technical systems send a clear signal to outsiders that they have safe and high-quality products.” Companies that want to voluntarily have their materials tested, or those for which it is a statutory requirement, have three stages they can start with. Like this, the whole process, from the characteristics of the raw material to the end result, can be verified. “Which material properties are actually tested in the individual stages depends on the respective use and the produced component’s function,” Sagerer explains.

Training Offerings

3D printing is continually evolving. There is already an urgent need for skilled workers. To bridge this gap, TÜV SÜD has been offering numerous training and professional development programs since spring 2018. The individual courses cover nine areas—including the basics of 3D printing, order processing, design, quality management, risk evaluation, even health and safety requirements. A maximum of twelve participants per course is necessary to keep the workshop character of the trainings. After presentations by specialists, participants must do the practical and interactive exercises themselves. TÜV SÜD provides many speakers from inside the company and brings in outside experts as necessary, for instance to provide information about legal requirements. “Soon our participants will be able to take exams and, if they pass, they will also receive certification,” says Max Rehberger, an expert in additive manufacturing at TÜV SÜD.

TIME SAVINGS

3D printing is very fast compared to conventional processes. For instance, while injection molding requires the design and manufacture of individual molds and tools, 3D printing needs nothing more than a digital blueprint. The production of a component therefore takes only a few hours or days instead of several weeks.

Customization

Since mass-produced parts are all made with the same mold or same tool, all the products are more or less uniform. 3D printing enables individualized products to be made at manageable additional costs. This benefit is already being fully exploited, particularly in dentistry. Fashion companies and athletic shoe manufacturers are following suit. Replacement parts can also be more easily produced in this way.

Lower Costs

3D printing eliminates the need to create molds, tools or extra programs. This saves both time and development costs. 3D printing is already cheaper than traditional manufacturing processes for small batch production and when using synthetic materials. Traditional methods still surpass 3D printing when it comes to larger-scale production and the use of metals.

Lack of Skilled Workers

There are very few 3D-printing specialists even though the process was created more than thirty years ago. For the majority of jobs requiring training, traditional manufacturing methods still dominate the curriculum. Companies that want to convert their component production to 3D printing must therefore either pay handsomely for specialists or take the time needed to train the employees themselves.

Too Few Standards

Many safety and quality standards haven’t yet been reworked for 3D printing processes. This is why products from 3D printers can often only be certified to a limited extent. Manufacturers must therefore individually inspect components printed in 3D and rely on information from other manufacturers. This process costs both time and money.

Conditional Serial Production

Although the use of 3D printers has become economically feasible for small batches and in the meantime even for limited serial production, it is still far from being able to compete with conventional manufacturing processes for mass-produced goods. For the mass production of plastic parts, for instance, injection molding remains unrivaled.