Fiber composites such as carbon are used primarily in lightweight automotive construction. However, they have not quite made the leap into series production yet, as the manufacturing costs for parts made of carbon fiber-reinforced plastic, or CFRP for short, are still too high. This is now set to change. The press manufacturer Schuler and other partners joined forces in the "iComposite 4.0" research project to solve the problem. Ultimately, they succeeded in reducing the cost of a prototype part by more than 50 percent and the throughput time by over 40 percent.

A floor panel mounted under the engine and passenger compartment of an English sports car served as a reference component. The requirements included that its structure must withstand a frontal impact and be designed for high torsional rigidity and seat load. Previously, the cost of such a floor panel was just under 400 euros. As part of the project, these costs were reduced to around 150 euros. The processing time was reduced from 73 to 46 minutes.

Interlocking processes

The Aachen Institute for Plastics Processing was responsible for the first production step: A robot injects the basic structure made of glass fiber. Next, an algorithm - developed by the Aachen Center for Integrative Lightweight Design (AZL) and CFRP supplier Teijin Carbon - calculates the individual tensile strength. Depending on this, another robot places the carbon fibers using a process developed by Siemens and Broetje Automation Composites, thereby compensating for fluctuations in the component properties. Optical control is carried out by a 3D measuring system from Apodius. A resin is then injected into this mat of composite fibers. This hardens under the high pressure of a hydraulic press from Schuler and is simultaneously molded into the desired shape. The press can specifically influence the deflection of the die to achieve the desired wall thickness. This means that good parts can be produced from a quantity of one, reducing waste to zero. Until now, manufacturers of fiber composite parts have used carbon mats as the starting material, which have to be cut to size. This means that almost half of the expensive carbon fibers become waste. In the research project, the required CFRP is used up completely. At the same time, the throughput time decreases while the output increases.

An RFID chip from ID-Systec ensures traceability. All components of the production line, which runs at the AZL at RWTH Aachen University, are networked with each other. The findings of the research project are now to be put into industrial practice.

According to documents from Schuler / ag