Elsek & Elsek Group

EXPANDED POLYSTYRENE STYROFOAM (EPS)

Expanded polystyrene Styrofoam is made from expandable polystyrene, which is a rigid cellular plastic, containing an expansion agent. EPS is obtained from oil as can be seen from the diagram.

The impact on the environment of everyday materials is increasingly important if we are to reduce our carbon footprint and protect our natural heritage for future generations. Our aim, therefore, in this extract is to provide you with factual, well-documented information about the environmental credentials of EPS. EPS (Expanded Polystyrene Styrofoam) is an excellent material for packaging and for construction as it is light yet rigid foam with good thermal insulation and high impact resistance. This explanation aims to provide balanced information based on the manufacture, use and recovery from waste of EPS in the packaging and construction sectors. We also aim to demonstrate to customers, government organizations, consumer associations and the public that, by choosing or using EPS, you can be confident it is safe, complies with all relevant technical and environmental standards and can easily be recycled at the end of its primary use.

elsek_eps

Manufacturing Process

We can see from the diagram that EPS is brought to us from the oil well through a chemical process. Now we will look at what happens in the transformation that leads us to Expanded Polystyrene (EPS). The conversion of expandable polystyrene to expanded polystyrene is carried out in three stages.

elsek_ups_process

1st stage – Pre-expansion:

The raw material is heated in special machines called pre-expanders with steam at temperatures of between 80-100°C. The density of the material falls from some 630kg/m3 to values of between 10 and 35kg/m3 . During this process of pre-expansion the raw material’s compact beads turn into cellular plastic beads with small closed cells that hold air in their interior.

2nd stage – Intermediate Maturing and Stabilization:

On cooling, the recently expanded particles from a vacuum in their interior and this must be compensated for by air diffusion. This process is carried out during the material’s intermediate maturing in aerated silos. The beads are dried at the same time. This is how the beads achieve greater mechanical elasticity and improve expansion capacity — very important in the following transformation stage.

3rd stage – Expansion and Final Moulding:

During this stage, the stabilized pre-expanded beads are transported to moulds where they are again subjected to steam so that the beads bind together. In this way moulded shapes or large blocks are obtained (that are later sectioned to the required shape like boards, panels, cylinders etc.).

Applications as a Construction Material:

EPS is used in many aspects of building work including large structures such as roads, bridges, railway lines, public buildings or even small family residences. The characteristics of EPS make it ideal for use as lightweight filler, insulation, as an element for decorating or imaginative touches, as a lightweight filling material in roads, to facilitate land drainage and so on. We could visit any construction or building site and find products made from EPS carrying out diverse and important functions.

The following properties are important for these applications:
elsek_eps-02Low thermal conductivity due to its closed air-filled cell structure that inhibits the passage of heat or cold, a high capacity for thermal insulation is achieved.
Low weight Densities of between 10 and 35kg/m2 allow light and safe construction works Mechanical resistance EPS has excellent mechanical properties making it good choice for load-bearing roof insulation, sub-pavement flooring, road-building, as loadbearing insulation, and so on.
Low water absorption: EPS does not absorb moisture and its thermal and mechanical properties are unaffected by damp, humidity or moisture. Ease of handling and installation the material can be handled in the usual way. You are guaranteed a perfect finish.
The low weight of EPS makes it easy to handle and to transport to site.
Chemical resistance of EPS is completely compatible with other materials used in construction including cements, plasters, salt, fresh water and so on.
The Versatility of EPS enables it to be cut into the shape or size required by the construction project.

All of the properties listed above are retained over the whole of the material’s life and will last as long as the building itself. EPS is not altered by external agents such as fungi or parasites as they find no nutritional value in the material.

Life Cycle Analysis:

Life cycle analysis is a technique intended to quantify the total impact of a product during its production, distribution, use, recycling, treatment and disposal. As individuals, and as organizations, all our daily actions have an impact on the environment. We use energy and resources, generate emissions into the atmosphere, pollute water and produce waste. One of the tasks of a responsible business is to calculate its impact on the environment and to find ways to mitigate it. However, some businesses use the concern about the environment as a marketing tool and make claims that their products or materials are ‘environmentally-friendly’ or have a low carbon footprint. Responsible organizations and companies like ours will either conduct a thorough life-cycle analysis of a product, or calculate its carbon footprint using Carbon Trust methodology, (making their research public) before making statements of this kind Reliable life cycle analyses will measure:
– Energy consumption
– Air pollution
– Water pollution
– Global warming potential
– Volume of solid waste

Conclusion
  1. – EPS is a good example of the efficient use of natural resources – it is 98% air.
  2. – The manufacture and use of EPS does not generate any risk to health or to the environment.
  3. – EPS does not damage the ozone layer since it does not use CFCs or HCFCs in the manufacturing process.
  4. – The transformation process consumes little energy and does not generate waste.
  5. – The use of EPS for thermal insulation in the construction industry contributes significant savings on heating and cooling buildings and a drastic reduction in the emission of polluting gases CO² and SO² ).
  6. – EPS packaging protects products, helping to reduce wastage and its lightweight nature helps to reduce fuel consumption.
  7. – EPS packaging can come directly into contact with foodstuffs as it meets all the prevailing international health regulations.
  8. – Fungi and bacteria cannot easily grow on EPS.
  9. – EPS makes up only a tiny part of Muncipal Solid Waste (0.1%).
  10. – EPS holds a high calorific value. 1kg of EPS is equivalent to 1.3 liters of liquid fuel, making it an ideal material for energy recovery.
  11. – As it does not biodegrade EPS does not contaminate the air or water with gases or hydro soluble substances.
  12. – EPS is 100% recyclable Final Conclusion Life cycle analyses have shown that EPS has far less impact on the environment than other competitive materials for the same use.