A Novel Way to Optimize Zero-Waste Prepreg Production Through the Integration of AFP and Online-PrePreg Technologies
Topic(s) : Manufacturing
Co-authors :
Gaurab Sundar DUTTA (GERMANY), Johannes BAUER (GERMANY), Grigori OEHL , Stefan CAROSELLA , Peter MIDDENDORF , Gerhard ZIEGMANNAbstract :
Automation in the composite sector underwent drastic advancements in recent years, allowing production of precise, cost- and material-efficient lay-ups, leading to novel application possibilities for the once extremely expensive high-performance materials. Automated fiber placement (AFP) is one such technology where, instead of just mimicking hand lay-up process, customized fiber and roving orientations, in this case in the form of dry spread tapes, allow load optimized patterns and stacking sequences to achieve outstanding mechanical performance as well as a substantial reduction of waste. On the other hand, resin infusion and injection technologies often reach their limits with these preforms like these, leading to the need for alternatives. The novel online-prepreg (OPP) technology is a material efficiency driven process development which allows fully automated preparation of semi-finished prepreg products, starting from dry fiber textiles, thus paving a way to reduce resin contaminated waste and increase recyclability. This work proposes an innovative way to realize close to zero waste pre-impregnated preforms at both the dry fiber placement as well as resin distribution level by combining both of these technologies.
Thus, dry preform lay-ups were prepared with three types of binder content levels and different fiber orientation sequences using AFP technology and transferred to the OPP set-up. Resin application optimization for uniform distribution at desired fiber-volume contents were realized by taking resin flow and robot speed as well as impregnation path into account. The resulting prepregs were later cured as panes to allow optimal sample preparation for further analysis.
Investigations of interlaminar shear strength (ILSS) was performed by extracting samples for mechanical testing. Furthermore, representative areas of the laminate were examined with CT-scanning to observe trapped air bubbles and data compared to manual optical microscopy. Obtained information were fed back to resin distribution process to further optimize the process.
Thus, dry preform lay-ups were prepared with three types of binder content levels and different fiber orientation sequences using AFP technology and transferred to the OPP set-up. Resin application optimization for uniform distribution at desired fiber-volume contents were realized by taking resin flow and robot speed as well as impregnation path into account. The resulting prepregs were later cured as panes to allow optimal sample preparation for further analysis.
Investigations of interlaminar shear strength (ILSS) was performed by extracting samples for mechanical testing. Furthermore, representative areas of the laminate were examined with CT-scanning to observe trapped air bubbles and data compared to manual optical microscopy. Obtained information were fed back to resin distribution process to further optimize the process.