Expanded Polystyrene (EPS) beads are expanded and moulded by the end product manufacturers using a blowing agent. EPS beads typically use pentane as blowing agent in their manufacture. However, stricter ecological norms and environmental concerns have provided scientists with an incentive to develop a novel process that is not based on Pentane. Currently, pentane is used, but it is an inflammable as well as volatile organic compound (VOC), and almost half remains in the EPS after processing and is slowly released into the atmosphere during storage and use.

EUREKA project E! 2683 VOC FREE EPS met the ecological concerns by producing a VOC free alternative in the world’s first water-blown expandable polystyrene bead. The new-patented process creates a molecular bond encapsulating starch in a shell of polystyrene. The chemically bonded starch absorbs micro-drops of water, which becomes a safer, more environmental friendly blowing agent inside the beads. To take advantage of stricter legislative controls on VOC release, the partners may take the unusual step of commercially launching the product in USA first.

The project achieved a considerable reduction in VOC emissions resulting from polystyrene foam, an improvement in productivity for foam moulders and improved safety during production of the foam. Increasing VOC emission reduction targets will necessitate the installation of pentane ‘capture and destroy’ systems. These will require significant investment and will reduce the problem but will never solve it completely.
While Nova Chemicals developed the new expansion process for VOC free EPS, the German partner Teubert GmbH designed and built the new EPS expansion machine.