Experimental investigation on fabrication of thermoset prepreg composites using automated fibre placement process and 3D printed substrate

Abstract

Robot-based Automated fibre placement (AFP) techniques are continuously progressing towards maturity. However, as AFP becomes mainstream, the manufacturing of tooling used in AFP requires additional attention for large and complex-geometry composite structures. Based on this requirement, fused deposition modeling (FDM) has been identified as the most suitable technology of choice for rapid production of high-temperature, low volume, composite lay-up and repair tools, also for moderate temperature production tooling. In this current research, 3D printing and AFP technology are combined to manufacture the composite parts with high complexity. Also, the curing process of prepreg material, which is most important for manufacturing process, has been monitored. The cure behavior was first characterized using differential scanning calorimetry (DSC) using isothermal condition. Then, the 3D printed substrates were fabricated and AFP prepreg lay-up experiments were conducted. Prepreg lay-up can undergo deformation and slip between each layer over a 3D printed substrate. As a result, the final product quality gets affected, with defects such as delamination, overlaps and gaps. Therefore, experimental investigations were done with an in-house robot-based AFP system by varying process parameters like bed temperature, compaction force and lay-up speed. In addition, the fibre placement was done over different 3D printed polymer material substrates and tested for oven curing capabilities. The fabricated samples were tested to determine their mechanical properties.