Filaments for additive manufacturing reinforced with carbon fibers from waste stream
Topic(s) : Life cycle performance
Co-authors :
Bhuvesh KAUSHIK , Karina KROOS (GERMANY), Sabrina DINIZ (GERMANY), Jens BACHMANN (GERMANY), Souvik CHAKRABORTY (GERMANY), Jan-Uwe Reinhard SCHMIDT (GERMANY), Steffen OPITZAbstract :
Thermoplastics can be used efficiently in products as customized material systems. Their use as a bespoke/customizable material system means that a particular matrix system can be functionalized to tailor certain properties – strength, stiffness, etc. This is often achieved by the introduction of the reinforcements such as continuous fiber tows. Such semi-finished products are often used in advanced manufacturing processes with high performance requirements (aviation, automotive, etc) and market potential. The market volume for continuous fibre-reinforced materials for additive manufacturing was estimated at USD 127 million in 2019 and is expected to grow at a CAGR of 21.5% to USD 733 million by 2028. However, to the best of our knowledge, when it comes to carbon fiber based reinforcement, most of it is made up of virgin material. With the push towards a more sustainable composite industry and the eventual enforcement of EU’s ecodesign requirements, it may soon be stipulated to have a minimum rate of recycled materials in such products. This will undoubtedly increase the demand for recycled materials based semi-finished products in the near future.
With the continued commitment towards excellence and innovation in the composite field, DLR has embarked on the path towards developing filaments via extrusion for additive manufacturing using carbon fibers from waste stream (production and/or recycled) as reinforcements. To help adapt existing infrastructure, demonstrate its processing and to give a new service life, this current work demonstrates filaments reinforced with carbon fibers tows from production rejects. The filaments are processed using DLR’s state-of-art compounder line with high performance thermoplastic matrix (Polyphenylene sulfide PPS or similar). Herein, the process parameters’ influence on the structural properties (tensile, pull strength, etc) is presented, which will be complemented by microstructural characterization of the filament cross-section to investigate the fiber-matrix adhesion and voids. Additionally, CT/X-Ray analysis is carried out to demonstrate the volumetric distribution of voids or defects (if any). In DLR’s continued effort towards sustainability, a preliminary cradle-to-gate Life Cycle Assessment (LCA) of the production process has been discussed to establish the potential environmental impacts of the filament processing. The LCA is based on measurements of relevant Life Cycle Inventory (LCI) data including the main process steps, for instance materials flows and the electricity consumption of heating elements, extruder and Sonotrode. Considering data gaps and necessary steps for a potential industrialization of the whole process.
With the continued commitment towards excellence and innovation in the composite field, DLR has embarked on the path towards developing filaments via extrusion for additive manufacturing using carbon fibers from waste stream (production and/or recycled) as reinforcements. To help adapt existing infrastructure, demonstrate its processing and to give a new service life, this current work demonstrates filaments reinforced with carbon fibers tows from production rejects. The filaments are processed using DLR’s state-of-art compounder line with high performance thermoplastic matrix (Polyphenylene sulfide PPS or similar). Herein, the process parameters’ influence on the structural properties (tensile, pull strength, etc) is presented, which will be complemented by microstructural characterization of the filament cross-section to investigate the fiber-matrix adhesion and voids. Additionally, CT/X-Ray analysis is carried out to demonstrate the volumetric distribution of voids or defects (if any). In DLR’s continued effort towards sustainability, a preliminary cradle-to-gate Life Cycle Assessment (LCA) of the production process has been discussed to establish the potential environmental impacts of the filament processing. The LCA is based on measurements of relevant Life Cycle Inventory (LCI) data including the main process steps, for instance materials flows and the electricity consumption of heating elements, extruder and Sonotrode. Considering data gaps and necessary steps for a potential industrialization of the whole process.