Expanded Polystyrene Rigid Foam (EPS – Expanded Polystyren Foam) is a typically white thermoplastic material with closed pores in foam form obtained from petroleum by polymerization of styrene monomer. There are also products in gray / black tones in which the particles are processed to reflect long wave radiation in special production.

In EPS products obtained by inflating and fusing polystyrene particles, the blowing gas used to inflate the particles and obtain foam is ‘Pentane’. Pentane, an organic component, is replaced by air in a very short time during and after production, after allowing the formation of many small pores in the particles. The pentane gas released turns into CO2 and water vapor-H2O, which are already in the atmosphere. With the release of pentane, still air is trapped in the large number of small closed porous cells in the material (3-6 billion in 1 m3 EPS depending on density). 98% of the material is inert air,

After the material is supplied as raw material in small granules, it goes through pre-puffing process. Meanwhile, the pentane gas in the particles and the air are exchanged and the desired density of the material is largely achieved at this stage. Later, the expanded particles rested in a special silo are fused with each other with the help of water vapor in the mold and the material gains its properties. As a result of the fusion of the grains with each other, a continuous mass formed by polygons fused with each other without any gaps in the honeycomb appearance occurs. Subsequent production steps vary according to the usage area of the material (for thermal insulation purposes or as packaging material).

As it is known, stagnant air is the most economical, environmentally friendly and excellent thermal insulation material. The superior thermal insulation properties of EPS are due to the stagnant air contained in a large number of particles. EPS, one of the few materials that provide the best thermal insulation available in the world, is the only material that provides the same performance more economically than other thermal insulation materials used in our country.

The thermal conductivity of EPS varies between 0.033 W / Mk and 0.040 W / Mk, depending on the density in the white product. As the density increases, the thermal conductivity decreases. The thermal conductivity of graphite or carbon EPS used in jacketing is between 0.031-0.032 W / Mk for 16 kg / m3 density.

EPS used in buildings must be non-flammable, class E in European standards and B-1 in German DIN norm.

EPS is produced in desired densities according to the area of use. Since its properties can be changed in the desired direction, it does not cause material waste and unnecessary cost increases. EPS boards, which are generally used at densities of 15-30kg / m3 for thermal insulation, are very light. EPS products are used extensively in the thermal insulation of buildings and in the packaging industry by giving sheets, pipes and shapes.

Technical Specifications of EPS

TS EN 13163 Conformity Table   Unit Class Relevant Standard
Thermal Conductivity Group 040     TS EN 12667
Density* 10 kg/m3   TS EN 1602
Thermal Conductivity Coefficient (A) 0.039 W/mK   TS EN 12667
Water Vapor Permeability (p) 20-40 Kg/m3   TS EN 12086
Vertical Tensile Strength to Surfaces ≥ 100 kPa TR100 TS EN 1607
Tensile Strength Perpendicular to Surfaces at 10% Deformation

Compressive Strength

 ≥ 70 kPa CS(10) 120 TS EN 826
Length Tolerance ± 2 mm L2 TS EN822
Width  Tolerance ± 2 mm W2 TS EN 822
Thickness  Tolerance ± 1 mm T2 TS  EN 823
Miter  Tolerance ± 2 mm/m S2 TS EN 824
Flatness Tolerance ± 5 mm P4 TS EN 825
Dimensional Stability ± %0.2   DS(N)3 TS EN 1603—1604
Water Absorption in Long Term Partial Immersion ≤ 0.5 Kg/m2 Limits TS EN 12087
Usage Temperature -50 /+75 °C    
Fire Resistance Hardly flammable   E EN 13501-1
Dimensions 60×125 cm    
Thicknesses 1-2-3-4-5 cm    

TS 7316 ve EN 13163’e göre EPS Levhaların sınıflandırılması ile ilgili örnek


* Styrofoam can be produced in different densities upon request.

EPS TYPE Compressive Stress at 10% Deformation, kPa Flexural Strength kPa Water vapor diffusion resistance factor µ Approximate Densitykg/m3 Thermal Conductivity

W / mK
EPS 50 50 75 20-40 16 0,039
EPS 60 60 100 20-40 17 0,038
EPS 70 70 115 20-40 18 0,038
EPS 80 80 125 20-40 19 0,037
EPS 90 90 135 30-70 20 0,037
EPS 100 100 150 30-70 21 0,037
EPS 120 120 170 30-70 23 0,036
EPS 150 150 200 40-100 26 0,035
EPS 200 200 250 40-100 31 0,034
EPS 250 250 350 40-100 36 0,034
EPS 300 300 450 40-100 41 0,033
EPS 350 350 525 40-100 46 0,033
EPS 400 400 600 40-100 51 0,033
EPS 500 500 750 40-100 61 0,033