Since October 2020, the Central Innovation Program for SMEs (ZIM) has been funding a joint project between the HAWK in Göttingen, RWTH Aachen University and the companies Tigres GmbH and Ecocoat GmbH with 750,000 euros. In the "Plasmahybrid" project of the Plasma Technology working group led by Prof. Dr. Wolfgang Viöl, a meltable and formable carbon fiber material is being produced using cold plasma spraying.
In this process, a thermoplastic polymer (a meltable plastic that holds the fibers together in the composite) is applied directly to the fibers using a plasma nozzle. "We see applications for this technology, for example in the field of e-mobility and in sports equipment made of carbon," says Viöl, project manager and Vice President for Research and Transfer at HAWK.
Classic carbon fiber materials in combination with epoxy resins are already established in lightweight construction and are particularly well known from sports equipment such as racing bikes. However, carbon parts are still very expensive due to their complicated manufacturing process and are often a luxury product. Thermoplastic-coated carbon fibers are intended to simplify production. "The aim is to deliver a flexible mat that can be draped as desired. To harden the component, it only needs to be heated to 180 °C," says Ann-Kathrin Kirschner, a member of the project team. "This can make carbon bicycles cheaper and electric cars lighter."
Cold plasma spraying is a method that can also be used to coat sensitive materials that are difficult to wet, such as PTFE. The coating is applied via a plasma nozzle, which chemically activates both the particles and the surface to be coated so that the two materials bond firmly together. The temperature in the plasma nozzle can be adjusted so that coatings with polymers as well as metals or ceramics are possible.
