The fastest tape layup system in the world
“We enjoy a close and longstanding partnership with Fraunhofer ICT,” says Ulf Könekamp, head of industry automation at Dieffenbacher. “And we now work with the institute in its capacity as an independent source of research, on all developments relating to plastics and fiber composite materials.” This was also the case with the evolution of the Fiberforge tape layup system and the new development of the Fibercon, which is used to firmly join (consolidate) individual tape layups with no voids in a vacuum-assisted process.
As a result the existing machine was optimized to make it the fastest tape layup system in the world. Fiberforge produces tape layups made of continuous-fiber-reinforced UD tapes that correspond closely to the final contour. In the process, the glass-fiber or carbon-fiber-reinforced tapes are reeled off, cut to size and set down on a rotary table in a set pattern. The procedure takes just one second for each tape. And as the tapes are set down in a form corresponding closely to their final contour, material waste has been cut to under 5%. The Fiberforge can accommodate a total of four reels, allowing for hybrid layups and laying of tapes with various widths and thicknesses.
Dr. Sebastian Baumgärtner, team leader for thermoplastic processing at Fraunhofer ICT, explains the benefits of the material mix: “Processing various materials within one tape layup and the subsequent process of consolidation produces a completely new material, which can even be used as an economical substitute for metals. Particularly for customers in the automotive or aerospace industries, there is an enormous competitive advantage in being able to use lightweight, yet extremely strong fiber composite materials where previously aluminum, for example, was used.” For one year now, the new and improved version of the Fiberforge has been used for research purposes at the Fraunhofer ICT in Pfinztal. It is also, however, already being used as a large-scale production solution for locally reinforced thermoplastic components for the automotive and aerospace industries. The greatest challenge facing the Fiberforge was how to control and coordinate all of its 27 axes and ensure the smooth interplay of all the components.
The core element of the Fibercon is the I/O system Siplus HCS4300, which controls the Fibercon’s infrared radiators so they can precisely maintain the ideal temperature for consolidation.Dr. Sebastian Baumgärtner, team leader for thermoplastic processing at Fraunhofer ICT
Vacuum-assisted consolidation of the tape layup
Following an in-depth analysis of the entire process chain, from the UD tape to the final thermoplastic fiber composite part, researchers at the Fraunhofer ICT identified a bottleneck process. “Consolidating the tape layup is a necessary step to ensuring the high quality of the final component and achieving reproducibility in forming the tape,” Baumgärtner explains. “We looked closely at a number of technologies, but ended up developing our own vacuum consolidation technology.” As a supplementary process line for the Fiberforge, Dieffenbacher developed Fibercon, which is suitable for large-scale production, last year.
It is used to consolidate the tape layup supplied by Fiberforge to produce a laminate that corresponds closely to the final contour. A vacuum-assisted process minimizes voids and imperfections in the material and suppresses oxidation processes, resulting in an excellent laminate quality. So far, no other system on the market can consolidate tape layups on this functional principle and in such a simple yet reproducible way. Fibercon has a cycle time of around 30 seconds, depending on the type and thickness of the tape layup materials. Here too, all components must remain in perfect interplay – from the controller and the I/O systems to the drive technology and a modern operating concept.
With more than 1,700 employees and 16 production and distribution sites around the world, Dieffenbacher, headquartered in Eppingen, Baden-Württemberg, is a leading manufacturer of press systems and complete production systems for the wood composite, recycling, automotive, and aerospace industries. Dieffenbacher’s business unit Composites specializes in the latter two industries – not only as an expert partner in all matters relating to presses and production systems; it is also involved in developing methods to produce fiber-reinforced plastic parts.
Use of the SIMATIC S7-1517TF technology CPU enabled perfect control of the Fiberforge’s 27 axes: the integrated motion control functions ensure exact positioning of the tape, even at high speeds.Ulf Könekamp, head of industry automation at Dieffenbacher
Use of the SIMATIC S7-1517TF technology CPU enabled perfect control of the Fiberforge’s 27 axes: the integrated motion control functions ensure exact positioning of the tape, even at high speeds. In addition, project configuration is easily possible on TIA Portal and with SIMATIC S7-1517TF, as well as with the further installed systems such as SINAMICS S120, SIMOTICS S servo motors, or the fully IP65-protected SIMATIC Panel PC Pro. Another major advantage of selecting Siemens as the system supplier is the scalability of the SIMATIC S7-1500, allowing machine automation, technology and safety functions to be implemented in one controller.
For the Fibercon, too, Dieffenbacher chose an integrated solution from Siemens: in addition to the SIMATIC S7-1517F, this solution employs elements such as the SIPLUS HCS4300 heating control system, SINAMICS S120, SIMOTICS S servo and servo-driven motors, and the SIMATIC HMI Comfort Panel. Easy engineering of all these systems is also possible on TIA Portal.
The core element of the Fibercon is the I/O system for SIPLUS HCS4300 heating applications, which precisely controls the Fibercon’s infrared radiators. The advantage of this is that they can reach the ideal temperature for consolidation of the tape layups very quickly and then precisely maintain this temperature. “That helps to ensure the high quality of the final product,” says Baumgärtner. As it is digitally connected to the controller, it is also easy to create a temperature profile thanks to the visualization options.
Our machines have long lifetimes, so it is important that faulty components can be reordered and replaced even after many years. That makes Siemens our ideal supplier.Felix Manger, development engineer in the business unit Composites at Dieffenbacher
Full process line for large-scale production
Felix Manger, a development engineer in the business unit Composites at Dieffenbacher, has been working closely with the ICT on the evolution of the Fiberforge system for many years and knows what’s important. “Many customers want the components installed in a system to come from a single source,” he explains. “We therefore offer them a consistent automation concept that is easier to operate and maintain. Our machines also have long lifetimes, so it is important that faulty components can be reordered and replaced even after many years. That makes Siemens our ideal supplier.”
With development of the Fibercon enabling further processing of the tape layup from the Fiberforge, Dieffenbacher was in no doubt about the next evolutionary step for these two systems: they were combined to form a tailored blank line, allowing the machine builder to offer a solution for the large-scale production of locally reinforced thermoplastic components. Together with the downstream systems such as handling robots and forming presses, the production line enables the manufacture of over a million parts a year. In the long run, Dieffenbacher sees a key objective in industrial production for the tailored blank line. “In the future, we will see data exchange that makes it possible to automatically transfer a tape layup from Fiberforge to Fibercon, where it is then consolidated,” Felix Manger explains. “This data exchange provides the Fibercon system with all the required process data, e.g. temperatures and times, as well as all quality-assurance data. In terms of the digitalization process, this will enable very fast product changeovers and processes that can run without the need for machine operators.” Work is already ongoing with the ICT to achieve this level of intelligent system interlinking.