The German Institutes of Textile and Fiber Research Denkendorf (DITF) is one of 13 project partners from seven countries committed to REWIND, an EU-funded project exploring ways to reuse composite waste derived from the wind energy industry. The organization highlights the part it is taking in developing basic technologies and processes for the dismantling, recycling and reuse of these materials.
The consortium has already validated a model that can predict the mechanical behavior of recovered materials with an accuracy of more than 90%. This makes them suitable for demanding applications, such as in electric vehicles or as an insulation material.
At the DITF, yarns and fabrics are developed from both glass and carbon fibers recycled by the project partners for use in new components or repair kits for wind turbines. In an initial step, the recycled fibers (rCF, rGF) were examined, primarily to determine which processing methods they are suitable for.
The research team is currently pursuing two different approaches. In the first process route, rGF are processed into high-value textile reinforcements. To do this, the fibers are pre-opened, carded, spun into yarns and then processed into fabrics that are reinforced in one or two directions. The DITF highlights an initial milestone: the development of rGF-reinforced PA6 yarn with a fiber volume content of around 40%, which is suitable for thermoplastic composite (TPC) applications, such as structural components in automotive engineering.
Furthermore, researchers have succeeded in producing a yarn consisting of as much as 98% rGF. The yarn was then used to manufacture a woven fabric with parallel fiber orientation (unidirectional/UD). This demonstrated, for the first time the DITF contends, that specifically oriented textile reinforcement structures made from rGF can be produced that are optimally adapted to mechanical loads.
The second process route investigates the processing of long fiber delamination (LFD) tapes — planed directly from wind turbine blades — into UD fabrics. These LFD tapes represent a novel class of semi-finished textile products manufactured from fully cured rGF-reinforced polymer composites. Currently, research is being conducted to determine the extent to which these intermediate products are suitable as high-performance reinforcement structures for fiber-reinforced composites.
Yarns manufactured from recycled glass fibers. Source | DITF
