Researchers have developed a new way to make fused deposition faster, a goal of many vendors in additive manufacturing. Researchers at the Fraunhofer Institute for Machine Tools and Forming Technology IWU have developed Screw Extrusion Additive Manufacturing (SEAM), a technique and process they claim is 8 times faster than conventional 3D printing.

According to the researchers, SEAM technology can 3D print a 30 cm high plastic component in 18 minutes. These results indicate that they can offer process speeds that are eight times faster than other 3D printing methods.

“SEAM achieves these speeds by combining machine tool technology with 3D printing,” says Dr. Martin Kausch, a scientist at Fraunhofer IWU. To process the plastic, the researches use a specially designed unit that melts the raw material and ejects it at a high output rate. This unit is installed above a construction platform that can be swiveled in 6 axes by using the motion system of a machine tool. “So far, this combination is unique,” claims Kausch.

The hot plastic is deposited in layers on the construction platform. The motion system of the machine ensures that the construction panel slides along under the nozzle in such a way that the previously programmed component shape is produced. The table can be moved at a speed of one meter per second in the X, Y, and Z-axes and can also be tilted by up to 45 degrees.

Every hour up to 7 kg of plastic are pressed through a hot nozzle that has a diameter of 1 mm. Comparable 3D printing process, such as FDM or FFF usually achieve 50 gr of plastic per hour. Instead of using FFF filament, SEAM processes free-flowing, standard plastic granulate into resilient, fiber-reinforced components that are several meters in size. The researchers claim this method can reduce materials costs by a factor of 200.
SEAM enables researches to implement complex geometries without the need for support structures. The technology makes it possible to print on existing injection molded components.

“As our construction platform can be swiveled, we are able to print on curved structures with a separately moving Z-axis,” says Kausch. “In tests we were able to process a variety of plastics. They ranged from thermoplastic elastomers to high performance plastics with a 50% content of carbon fiber.”

The printer will be demonstrated at the Hannover Messe 2019.

Fraunhofer-Gesellschaft
www.iwu.fraunhofer.de