pps proceeding - Abstract Preview
pps proceeding
Symposium: S05 - Fibers, Films and Foams
Oral Presentation
 
 

Recycling of Composites – A New Approach Minimizes Downgrading

Wellekötter Jochen (1)*, Baz Stephan (2), Schwingel Johannes (3), Bonten Christian (1), Gresser Götz (4), Middendorf Peter (3)

(1) Institut für Kunststofftechnik - Baden-Württemberg - Germany, (2) Institut für Textil- und Verfahrenstechnik, Denkendorf - Baden-Württemberg - Germany, (3) Institut für Flugzeugbau der Universität Stuttgart - Baden-Württemberg - Germany, (4) Institut für Textil- und Verfahrenstechnik, Denkendorf - Baden-Württemberg - Germany

Fiber reinforced plastics (FRP) hold considerable potential when it comes to constructing and designing light-weight components. FRP are rapidly gaining importance in various industrial sectors. Although this group of materials combines high strength and stiffness while simultaneously being lightweight, major difficulties still arise at high volume production as well as the return of manufactured components back into the cycle of materials at the end of their life. A new approach at the Institut für Kunststofftechnik of the University of Stuttgart in collaboration with the Institute of Aircraft Design of the University of Stuttgart and the Institute of Textile Technology and Process Engineering of the German Institutes of Textile and Fiber Research Denkendorf follows the idea of producing structural components through the forming and back-injection molding of preforms with a large fraction of recycled fibers and matrix, without drastically compromising the quality of the mechanical properties. To achieve this, the carbon fibers retrieved out of a recycling process are mixed with recycled polyamide fibers and spun into a hybrid yarn. The actual fiber length varies depending on the recycled material used. Subsequently these yarns are processed into preforms by means of Tailored Fiber Placement. This process allows for a precise fiber positioning in accordance with the desired component requirements, which ensures a more efficient deployment of fiber and matrix compared to present practice. Additionally, back-injection molding allows functional integration into the components, aiming for weight reduction and lowering installation effort. Recycled carbon fibers and recycled matrix granules are also utilized for the back-injection molding process using an injection moulding compounder to investigate their influence on mechanical properties of the components. The findings show that recycled preforms and matrix perform well in standardized tests.