Polystyrene (abbreviated PS), a synthetic aromatic hydrocarbon polymer, is one of the most widely used plastics, the scale of its production being several million tonnes per year. PS can be naturally transparent, but can be coloured with colourants. PS is available either as expanded polystyrene (EPS) or extruded polystyrene (XPS), which is valued for its insulating and cushioning characteristics.
Main applications include home appliances, automotive, electronics, insulation, packaging (such as CD and DVD cases), medical and food services (such as disposable cutlery).
Expanded polystyrene (EPS) is a rigid and tough, closed-cell foam, usually white and made of pre-expanded polystyrene beads. EPS is used for food containers, moulded sheets for building insulation, and packing material either as solid blocks formed to accommodate the item being protected or as loose-fill "peanuts" cushioning fragile items inside boxes.
Extruded polystyrene (XPS) consists of closed cells. It offers improved surface roughness, higher stiffness and reduced thermal conductivity. XPS is a rigid insulation that has also formed with polystyrene polymer, but manufactured using an extrusion process. This type of insulation can significantly reduce a building’s energy consumption and therefore, is used in many commercial and residential construction applications.