The first step is to separate the waste EPS material into either ‘contaminated’ or clean categories: ‘Contaminated’ EPS could have paper labels, staples, sticky tape or colour dye on it, or been used to carry fish, plants, fruit or vegetables. Clean EPS has no extra labelling or marks and will have been used to package electrical goods or car parts or similar items.
Both clean and contaminated EPS packaging can be recycled but the process is different so it is vital that the two are separated.
Recycling companies will collect EPS packaging for recycling once a sufficient quantity has been stored up. Some will take the packaging exactly as it is, other will want the packaging compacted.
Compaction EPS can be compacted to one-fortieth of its original size for easy, cost-effective transportation. Companies such as Sony or Hitachi have a compacting machine installed on their sites to compact EPS packaging before it is collected by the recycler.
The Recycling Process
The recycler feeds the compacted blocks of EPS into a granulator which chops the material into smaller pieces. The material is passed into a blender for thorough mixing with similar granules. This material is fed into the extruder, where it is melted. Colour is added and the extruded material is then moulded into its new shape, such as strips of wood replacement to build garden benches. Colour is added and the material is then extruded into XPS insulation panels for the construction industry.
EPS is an ideal material for landfill because it remains inert, is non-toxic, odour-free and non-biodegradable. Landfill sites are not intended to be compost heaps but to be reclaimed when full. EPS provides stability within landfill sites and helps to make the site suitable for re-use.
Energy recovery is the reclamation of energy, usually in the form of heat from the incineration of waste. When the incinerator conforms to EC regulations for safety and pollution abatement, incinerating expanded polystyrene (EPS) is a safe disposal method.
- Energy recovery is one way of generating real value from used packaging materials
- In a modern incinerator, EPS releases most of its energy as heat, aiding in the burning of other garbage and emitting only carbon dioxide, water vapour and a trace of non-toxic ash
- Plastics, such as EPS, in effect ‘borrow’ the energy available from petroleum that is used to produce them and then ‘return’ it when it is used as a fuel in the waste-to-energy conversion
- EPS has a higher calorific value for heat recovery than coal and could potentially provide a valuable source of energy if incinerated