Automated AM System Looks Toward Future of Industrial Production

You might know BigRep as a manufacturer of large-scale fused-filament fabrication (FFF) 3D printers. Headquartered in Berlin, Germany, the company currently offers two FFF models, including the BigRep One with a build volume of 1 cubic meter. Applications for its printers have included large 3D-printed prototypes, models and molds.

But BigRep has a larger vision for 3D printing as a manufacturing technology. In 2016, the company announced a partnership with TNO, a Dutch research organization, to advance 3D printing for industrial production. BigRep is a young company, established in 2014, but this partnership allows it to tap into the resources and 15-plus years of experience provided by the AM Systems Center, the additive manufacturing group formed by TNO and the Technical University of Eindhoven.

Together BigRep and the AM Systems Center are currently developing an automated system to enable continuous additive manufacturing. The self-contained system connects 3D printing heads with pre- and postprocessing technologies as well as inspection to form a closed-loop, fully digital production solution.

A number of technologies have had to come together to make this happen. In the system being developed, parts can be 3D-printed in multiple materials; postprocessed and polished; and compared to CAD data via laser scanning. The various processes are separate from each other but connected via automation, explains Jochem Borren, BigRep project manager for the partnership. A continuous conveyor belt moves parts throughout the system, and a robotic arm removes them once complete.

With all of these components together, the integrated system currently in development is roughly 4 meters long by 2 meters wide, and more than 1.5 meters tall. But this system will serve as the basis for future development. Ultimately, manufacturers will be able to purchase custom configurations tailored to their needs, from the size of the build plates to the number of integrated stations and technologies. Possible applications could be small volumes of parts for medical, automotive or aerospace.

According to Borren and Erwin Meinders, managing director of the AM Systems Center, the benefits of this approach to AM could include:

• Flexible AM processes. BigRep's current commercial printers use FFF technology, while the continuous AM system in development is based on selective laser sintering (SLS) because the partners decided it was the best choice for functional parts, says Meinders. However, it would be possible to integrate other existing AM technologies within this system, alone or in combination.
• Quality control. The closed design of the system and the continuous printing model make the system well-suited to quality control, says Meinders. The system can integrate inspection technologies that allow for bad parts to be rejected, but it could also offer in-line process monitoring that could check parts after each layer is printed, for example.
• Mass customization. Combining processes into a single system and incorporating automation can help speed production, but it’s not just about the mass production of one part, says Borren. The same approach will also be used to produce multiple small series at the same time.
• Parts with increased functionality. Because the system could support multiple print stations, there’s no need for 3D printing to happen all at once. A part could be built up in station, move to the next to have sensors or other electronics placed inside, and then printing could continue in another station. Additively produced “smart parts,” for example, could be manufactured with the built-in capability to predict their own maintenance.