Highly Flexible Automated Manufacturing of Composite Structures Consisting of Limp Carbon Fibre Textiles 2009-01-3213

Due to the conventional autoclaving of pre-impregnated materials causes high costs in the production of carbon fibre structures, new injection methods have become more and more relevant. The research project “CFK-Tex” focuses on the automated handling and processing of preforms out of dry carbon fibre textiles. Regarding the advantages in quality improvement and process time, an automation of all process steps is getting enforced. The major challenge, in addition to the difficult handling-properties of the materials and high quality demands, is the enormous variety of outline variants caused by small production quantities but many different textile cuts per part.

In the first step the requirements of an automated system are exactly analyzed considering the specific material properties as well as process and product based characteristics. Since the automated processing of the limp material is based on a reliable handling process, one main aspect of the research work focused on physical principles to grip the carbon fibre textiles. Therefore, a broad range of different gripping methods like needle grippers, hydro-adhesive grippers, vacuum-based systems and other innovative possibilities were examined. In addition to experimental tests, also theoretical analyses on the profitability contribute to the choice of a specific vacuum principle with very low pressure but high volume flow rates. Based on this fundamental research work, a first prototype of the later end-effector for the automated sorting of cut parts from the cutter table to the stockyard could be developed, which offers great flexibility regarding different contours and materials by an automized reconfiguration based on CAD-data.

Furthermore, the automation of the preforming process with the defined placing, draping and crabbing of a single carbon fibre textile on special 3D-moulds is a main objective of the research project. Hereby the single process steps are examined separately and proper strategies and principles are analyzed. Through several experimental tests on different possibilities, a capable combination was found, which offers great potentials regarding process reliability and flexibility.