Bio-based materials have been in increasing demand for years. Especially the aerospace industry needs to improve its ecological footprint to keep flying available as an attractive means of transport. Bio-based materials can reduce the weight and thus lower CO2 emissions and therefore improve the ecological footprint. This paper aims to investigate the thermoforming behaviour of natural fibre reinforced sheet material. The organosheets consist of maleic acid anhydride grafted polypropylene and a flax fibre fabric.  Experiments were conducted to find the optimal heating temperature for the organosheets. The temperature measurement was conducted with pyrometers integrated in an IR-heating field. For the thermoforming process a hydraulic press was used. The press was equipped with different spherical shaped punches.
The experiments showed that the optimal temperature for thermoforming of the organosheets is 195°C (Tm, PP = 165°C). A good forming behaviour could be observed with the punches with a larger radius (r = 30 mm). The smaller radii resulted in delamination. To solve this problem, the tool was heated up resulting in punch temperatures of 90°C for the smallest punch radius (r = 5mm) and 95°C for the punch with 15 mm radius. With this temperature setting smaller radii (r = 5 mm and 15 mm) could also sufficiently be formed.
Additionally to the experiments, a FE code was developed to simulate the draping behaviour during the forming process. Due to the lack of material data, the relevant values for the materials were gained from the literature. The simulation showed a similar draping behaviour like the experiments.