Polystyrene is extracted from oil. Thousands of small units of styrene, called monomers, link together to form large molecules of polystyrene by a process called polymerization.
The Expandable Polystyrene (EPS) production process uses a pure hydrocarbon, which does not contain any halogens and does not damage the earth's protective ozone layer, as the expansion agent.

How is EXPANDABLE POLYSTYRENE (EPS) processed?
The process involved in making EXPANDABLE POLYSTYRENE (EPS) is quite easy to explain. Expanded polystyrene starts as small spherical beads with a typical diameter of 0.5-1.5mm. They contain an expanding agent. When the beads are heated with steam, the agent starts to boil, the polymer softens and the beads expand to about forty times their initial size. After a maturing period to equilibrate temperature and pressure, the pre-foamed beads, which now have a closed cellular foam structure, are packed in a mold and again reheated with steam. The mold is made in the same shape as the finished article. The pre-foamed beads expand further, completely fill the mold cavity and fuse together. When molded, nearly all the volume of the EXPANDABLE POLYSTYRENE (EPS) foam (in fact 98%) is air. This is what makes EXPANDABLE POLYSTYRENE (EPS) so lightweight and buoyant.

What can EXPANDABLE POLYSTYRENE (EPS) be used for?
A major use of EXPANDABLE POLYSTYRENE (EPS) is as a packaging material it can be used in rigid shapes designed to fit closely around an item such as a television set or as small pieces as a cushioning material to fill the space around products in a box.
EXPANDABLE POLYSTYRENE (EPS) is used within the car, electrical goods, construction and leisure industries as well as many others.
EXPANDABLE POLYSTYRENE (EPS) is widely used in the construction industry like cold storage house to keep buildings warm (or cold!) and to reduce impact noise levels. It is produced in large, rigid, lightweight sheets that can be easily fixed to walls, ceilings and floors. Being so light in weight means that it is easy to fix and carry around the building site. It is also easy to cut with a fine tooth saw, knife or hot wire.
EXPANDABLE POLYSTYRENE (EPS) panels that are packed in the cavity of a house wall will reduce heat loss up to five times that of a wall with no insulation.
EXPANDABLE POLYSTYRENE (EPS) can also be used to improve impact sound insulation in office blocks with solid concrete floors by damping impact vibrations. Large slabs can be laid quickly with no special equipment. Because it is so buoyant.