Foamex STYROBOARD EPS expanded polystyrene is a rigid cellular plastic foam material derived from petroleum and natural gas by-products.
Styrene is produced from benzene and ethylene, and is polymerised in the presence of catalysts, usually organic peroxides. To create the expanded polystyrene blocks and sheets that you are familiar with, steam is applied to tiny grains or beads of styrene that contain a minute amount of pentane. This steam process causes the thermoplastic polystyrene to soften and expand up to 40 times its original volume. Again using steam in the process, the expanded beads are then moulded into a shape or large blocks which are then sliced into boards. The EPS product is then dried and finished by a number of processes, such as hot wire cutting or lamination.
Unlike the manufacturing process for many other synthetic materials, the EPS manufacturing process also does not involved the use of ozone-layer-depleting CFCs and HCFCs, nor are there harmful materials present in the finished product. The small amount of pentane gas used in the process has no known effect on the upper ozone layer.
The manufacturing process for EPS is an excellent example of an efficient use of a natural resource as the transformation process uses relatively little energy during manufacture.