CarboSteer

The aim is to avoid downcycling by type-appropriate processing and targeted
application of long fibers.

In the research project “CarboSteer”, IVW and the special machinery manufacturer Automation Steeg und Hoffmeyer GmbH jointly develop a process for the effective recycling of carbon fibers. The aim is to avoid downcycling by type-appropriate processing and targeted application of long fibers. The starting material is a staple fiber sliver that consists of carbon fibers and polymer fibers in certain proportions. In a first step, this sliver is processed into tapes by applying heat in the fully automated calendaring process at IVW. The process also specifically straightens the individual fibers in the resulting semi-finished product. The further processing of these tapes into tape-preforms takes place in the tape-laying process. Due to the load path mapping with the straightened staple fibers, the mechanical properties of the component parts increase drastically compared to quasi-isotropic fiber orientation - which ultimately saves material. The material use follows the credo “as little as possible, as much as necessary”. In contrast to continuous fibers, staple fibers allow quasi-plastic deformation behavior, which allows the neutral fiber to shift its position. Residual stresses in the tapepreform can thus be reduced in complex laying paths. The last process step is the thermoforming of the tapepreforms into the final geometry. The rapid cooling cycle times of only a few minutes makes this process route suitable not only for small series.

The aim of the research project is the effective recycling of carbon fibers in the tape-laying/thermoforming process. Therefore, an end effector is being developed for the automated depositing of staple fiber tapes.

• Automation Steeg und Hoffmeyer GmbH