For decades the particle foam EPS (expanded polystyrene) contributes to many scopes of application, e.g. packing for fragile goods and groceries, wall or perimeter thermal and acoustic insulation etc. However, the steam-based production processes along the EPS processing chain has been no subject of major changes in the last decades. Blowing agent loaded polystyrene microgranules are still exposed to steam for a default pressure and time. This results in an expansion of the microgranules and leads to foamed EPS beads [1, 2]. In this work, a novel radiation-based pre-foaming process is presented. Compared to the conventional process described above this technology reveals several advantages. Steam-based pre-foaming, according to the state of the art, requires an extensive peripheral equipment, which is cost-intensive in its purchase and operation because consisting of the supply of natural gas, steam generation, steam storage and supply lines. However the novel radiation-based process only requires a usage of dedicated power supply. The interaction of the radiation with the blowing agent loaded polystyrene microgranules is investigated and conclusions on the resulting effects of the beads regarding density and morphology are drawn. In detail it can be presented that during the novel process a smaller cell structure inside the beads can be achieved compared to state of the art beads exhibiting the same density (30 g/l). Furthermore, investigations on the energy consumptions indicate that the energy saving potential is up to 30 % compared to the state of the art steam based process. The weldability of the radiation based EPS has been verified, too. Thus mechanical and thermal trials have been conducted to compare both processes. First results revealed that due to the smaller cell morphology the compressive strength could be increased by approx. 22 % and also the thermal conductivity was reduced by approx. 5 %. Reference: [1] Cube, H.Pohl, K. Die Technologie des schäumbaren Polystyrols. Madison : Hüthig, 1965. [2] Schips, C. Verfahren zur Herstellung von expandierbaren thermoplastischen Partikeln durch Nachimprägnierung. 2011