What is EPS?

Expanded Polystyrene, or EPS for short, is an economical, versatile, lightweight, rigid, plastic foam insulation material produced from solid beads of polystyrene. The end product is made up of fine spherical cells that comprise 98% air.

EPS has a very high strength-to-weight ratio that, depending on the density, offers exceptional compressive and flexural strength and dimensional stability characteristics. It can be moulded or shaped to meet almost any design requirement.

Who needs EPS?

Architects, civil engineers, marine engineers, builders, concreters, packaging companies, creative designers, et al; Insulation, building applications (including cladding and concreting), road and bridge works, flotation, protective packaging, theming (creative works in theme parks and on buildings). Your imagination is the limit.

Expanded Polystyrene and the environment

EPS offers substantial environmental advantages:

• EPS is safe, non-toxic and inert. At no time in its life cycle does it contain any Chlorofluorocarbons (CFCs) or Hydrochlorofluorocarbons (HCFCs). It is also absent of any nutritional value, so no fungi or micro-organisms, such as mould, can grow with EPS.
• EPS is recyclable: EPS can be recycled in many ways once it comes to the end of its life. These include recycling directly into new building products and incineration to recover its inherent energy content (waste to energy). The choice of a recycling method is based on technical, environmental and economic considerations.
• EPS presents no dangers to health in installation, during use and in the waste stage.
• EPS insulation saves money by reducing energy bills;
• EPS, as an effective insulation material prevents energy loss and therefore helps to conserve fossil fuels, and prevents carbon dioxide emissions which cause the greenhouse effect and global warming.

Recent years have shown growing concern for the environment and in particular an increased demand for sustainable building and development. For the construction industry, this means a need for accurate information about the environmental impact of the building materials and products that they use. Expanded polystyrene stacks up. The most reliable way to present this information has proven to be the Life Cycle Assessment (LCA) approach. This approach investigates the processes involved in the manufacture, use and disposal of a product or a system – from cradle to grave.

Expanded polystyrene insulation has a long lifetime in buildings so there is only limited current need to recycle this material. However, since EPS does not degrade or deteriorate, it can be recycled in several ways at the end of its useful lifetime:

• Regranulated EPS can be reused in measured quantities in the production of selected products such as waffle pods and some block applications. The quantities used are dependent on the required technical performance.
• There are a number of non-foam applications. Recycled EPS can be moulded into new applications such as coat hangers, flower pots, park benches or fence posts.

EPS waste can also be reground and mixed with concrete to produce building products such as prefabricated lightweight concrete blocks. Adding EPS regrind also increases the thermal performance of these products.

Unlike the main competitive insulation materials, polystyrene is easily recycled. Not only does the EPS Industry recycle factory waste but also post-consumer packaging waste is collected and processed by arrangement.

Recycling saves money, energy and reduces the impact on the environment. EPS is not seen as waste in most European countries but as a valuable resource. EPS is the most easily recycled of all the insulating materials and therefore easy to align with the “cradle to cradle (C2C)” principle.

The EPS National Industry Group (EPSA) has established collection centres in each capital city of Australia.
EPS organisations from more than 25 countries around the world have signed the International Agreement on Re-cycling.

A process not yet commonly used in Australia, is “waste to energy”. Energy recovery is usually in the form of heat from the incineration of waste. The process gives materials, which cannot be recycled economically, a genuine post-consumer use. Energy recovery is a safe and environmentally sound means of generating real environmental and economic value from EPS used for fish boxes, horticultural trays or other contaminated EPS waste.

In a modern incinerator, EPS releases most of its energy as heat, aiding the burning of municipal solid waste and emitting only carbon dioxide, water vapour and trace non-toxic ash. Pollution control equipment such as scrubbers and filters reduce pollutants released during the incineration process. EPS is safely burned at high temperatures in this process without giving off toxic or environmentally damaging fumes.

Manufacturing process

NPS manufacturing plants are operated in conformance with the stringent health and safety legislation and in consultation with employees and safety professionals.

There are 5 manufacturing stages:

1) Pre-expansion:

Polystyrene granules are expanded by free exposure to steam to form larger beads, each consisting of a series of non-interconnecting cells.

2) Conditioning (Curing):

After expansion, the beads still contain small quantities of both condensed steam and pentane gas. As they cool, the air gradually diffuses into the pores, replacing, in part, the other components.

3) Moulding:

The expanded polystyrene beads are moulded to form blocks or customised products. The mould serves to shape and form the pre-foam, and steam is again used to promote expansion. During moulding, the steam causes the fusion of each bead with its neighbours, thus forming a homogeneous product.

4) Cutting and Shaping of Expanded Polystyrene Blocks:

Following a short cooling period, the moulded block is removed from the machine and after further conditioning, may be cut or shaped as required using hot wire elements or other appropriate techniques.

5) Post-production processing:

The finished product can be laminated with steel, foils, plastics, fibreboard or other facings to form many and varied building products.