High speed processing of low-melt Polyarylether-ketone Prepreg using in-situ consolidation Automated Fiber Placement

Kurzfassung

Thermoplastic Automated Fiber Placement (AFP) has great potential to reduce the manufacturing time and cost of large-scale primary structures by means of in-situ consolidation. Layup speed and thus productivity has long been limited by high melt-viscosities of high-performance polymers such as PEEK or PPS. With the recent development of a novel polyaryletherketone resin system, Low-melt PAEK (LM-PAEK), higher layup rates without compromising mechanical performance are a viable possibility. This study addresses the processability and resulting laminate quality of CF/LM-PAEK materials at elevated layup speeds (125 mm/s and 250 mm/s) using in-situ consolidation. Two different unidirectional prepreg tapes with fiber-volume-fractions of 55 % and 60 % were processed using an AFPT tape placement facility and a 6-kW diode laser. Quasiisotropic laminates of 16 plies were manufactured and investigated using microsectioning and differential scanning calorimetry. Tensile and compressive tests were used to determine the mechanical performance of the laminates. Interlaminar properties were determined by means of five-point bending tests. The 55 % fiber-volume-fraction material achieved higher baseline strength values than the 60 % fiber-volume-fraction material. For the increased layup speed of 250 mm/s tensile and compressive strength decreased by 16 % and 13 %, respectively for the 55 % material whereas it remained on the same lower level for the 60 % material. The results for the 60 % material indicate almost identical mechanical properties for a two-fold increase in production rate.