Processing parameter optimisation for automated fibre placement (AFP) manufactured thermoplastic composites

Abstract

Automated fibre placement (AFP) technique has been progressively being adapted for high-quality fibre reinforced composite manufacturing for narrow tow placement, near-net shape output (low wastage) and reduced cycle times. Laser or hot-gas torch (HGT) is commonly used as the heating source in this process which has a significant influence on the quality of manufactured laminates. The capability of HGT-based AFP for manufacturing high-quality thermoplastic composite laminates and its parametric optimisation is investigated in this study. A series of AFP made coupon samples are manufactured using various processing parameters such as the deposition rate (60 mm/s-90 mm/s), consolidation force (180 N–450 N) and HGT/melting temperature (650–950 °C) to investigate on the processing parameters for optimisation. The interlaminar shear strength (ILSS) is evaluated for the samples using the short beam strength experiments on the manufactured samples using different parametric conditions. The influence of manufacturing processing parameters on the mechanical strength are discussed. Also, it is shown how the processing parameters will affect the overall quality of the laminate. The structural analysis confirmed a sandwich type layered structure in all laminates. However, the processing parameters influence on the resin-rich area within the laminates. Further, a sever fibre damage phenomenon observed in the sample manufactured at 450 N and 950 °C. Therefore, the mechanical strength and the specimen quality of laminates are critically dependent on the choice of processing parameters and appropriate selection of them would provide optimal mechanical properties.