Researchers at the Fraunhofer Institute for Machine Tools and Forming Technology IWU in Chemnitz have developed a new high-speed printing system for high-performance plastics.
The process is called Screw Extrusion Additive Manufacturing or SEAM and is said to be eight times faster than conventional extrusion-based 3D printing methods, enabling 30cm high plastic components to be printed in 18 minutes.
The technology has been fitted into a new machine which Fraunhofer believes will benefit automotive and aerospace industries, as well as tool manufacturers, for the production of large-volume, fibre-reinforced components that are several metres in size.
The process is said to combine machine tool and 3D printing technologies. Instead of conventional filaments, it leverages a specially designed unit that melts standard plastic granulate and ejects it at a high output rate. The unit is installed above a construction platform that can be turned on six axes using the motion system of a machine tool. The hot plastic is deposited in layers on the construction platform which can be moved at a speed of one metre per second in the X-, Y- and Z-axes and can also be tilted by up to 45 degrees. Fraunhofer says up to seven kilograms of plastic are processed through the 1mm diameter hot nozzle per hour, and with free-flowing plastic granules, allows for potential material costs to be reduced by a factor of 200.
Additionally, SEAM allows researchers to implement complex geometries without supporting structures and also makes it possible to print on existing injection-moulded components.
“As our construction platform can be swivelled, we are able to print on curved structures with a separately moving Z-axis,” says Dr. Martin Kausch, a scientist at Fraunhofer IWU. “In tests, we were able to process a wide variety of plastics. They ranged from thermoplastic elastomers to high-performance plastics with a 50 percent content of carbon fibre. These plastics are materials that are particularly relevant to industry and cannot be processed with traditional 3D printers.”
The system is the latest additive manufacturing technology to come out of the research organisation which has already introduced a low-cost metal powder bed system and most recently, a “TwoCure” resin-based process which enables plastic components to be built without any support structures