Polystyrene has many uses as a packaging material but disposing of or recycling this material can be problematic and expensive. Purex International think their new Styromelt™ thermal densifier can save money and help the environment.
Uses of EPS
Expanded polystyrene (or EPS) is used everyday by just about everyone in some shape or form. It is used mainly as a packaging material because of its impact resistance, ability to be shaped and its thermal insulating properties which make it ideal to protect thousands of different products including:
- Fish and meat
- Electronic goods such as TVs, computers and monitors
- Fridges, freezers and cookers
- Small products (Loose fill EPS chips)
- Flat pack furniture
- Machines and parts
- and electronic components.
EPS is produced in thousands of different forms for specific packaging requirements and is also used to make products such as disposable cups, trays, cutlery, cartons, CD cases and containers.
It is conservatively estimated that well over 300,000 tons of waste EPS are produced on an annual basis in the UK. In the USA according to the EPA over 377,579 tons of Polystyrene are produced in California alone.
The question is, what happens to all this packaging once the goods it protects have been delivered? Although some companies have a recycling policy for this material if they use large amounts, unfortunately, most EPS will find its way into landfill sites around the world.
Because EPS is so light, the volume of landfill space it takes up compared to its weight is considerable. To put this in perspective 300,000 tons equates to approximately 37.5 million cubic metres or enough to fill 15,000 Olympic sized swimming pools each year!
Most household EPS is simply put in the bin and dumped into landfill which is a real environmental problem as the cost of landfill is growing while the availability is fast diminishing. Anyone who has unpacked a cooker or Plasma TV will know how large the protective packaging can be and therefore how much volume of landfill space it would take.
In industry, many companies simply place their waste EPS in hire skips which are collected by waste disposal companies. This has several drawbacks.
Manufactures, retailers, supermarkets, fish merchants, education establishments, sports stadiums, cruise/ferry ships and hospitals (amongst others) may find that a significant volume of their waste skip by volume is filled with EPS. Depending on the size of the skip they use and the frequency of collection, the cost of hire can be hundreds or thousands of pounds per week. As EPS is over 90% air it means that the company which hires the skip is paying to dispose of mainly fresh air!
Once waste EPS is put into a mixed skip it may be contaminated by other materials which makes recycling difficult or impossible. In the case of fish merchants and supermarkets the EPS boxes they use will be contaminated with organic waste such as water and blood which may make it even more difficult to dispose of.
After collection the waste EPS usually ends up in landfill sites where it occupies a significant volume of space and because of its lack of weight it can be blown around and cause a nuisance in the surrounding area.
Landfill is fast becoming more and more expensive and scarce plus, government plans to fine local authorities for not hitting recycling and landfill diversion targets make sending EPS to landfill potentially even more expensive.
This material is not generally a high profile target in recycling terms unlike glass, paper, aluminium cans, batteries, tyres and the like. Many companies and local authorities may not have considered the implications of just how much EPS they are dumping. So what is the solution? The answer is separation, compaction and recycling.
One of the first things a company or local authority recycling centre can do is to take note of just how much waste EPS they produce. Running a trial of separating EPS before it goes into a skip may show just how much could be potentially recycled.
EPS is compacted to reduce the amount of space needed for storage and also to reduce transport costs. The historical method of EPS compaction is by mechanical means. The EPS is pushed through a compactor to reduce its volume by around half, it is then formed into blocks and stored.
The main drawbacks of this method are that it only compacts EPS by around 50%, it can also create lots of noise and dust, a full time operator is usually required to feed the compactor and foreign objects introduced in error (or deliberately) can damage the machine itself leading to expensive repair costs and downtime. Contaminated EPS such as fish boxes cannot be compacted in this way due to health and safety reasons as blood and other organic matter will be present. Storage of boxes contaminated in this way can also be a problem as they take up significant space, can create an odour problem and attract vermin.
The new alternative to mechanical compaction is the Styromelt ‘Thermal Compaction and Densification System’ from Purex International (purexltd.co.uk).
Using these systems is simplicity itself. The machine has a loading area of two cubic metres which is filled with EPS, the door is then closed and locked and the machine switched on. Two temperature controlled thermal plates then heat the EPS to melting point where it releases all the air and other gases it contains forming a dense resin which is collected in a tray where it cools. Once cool, the resin block is removed from the tray and stored for recycling.
The most astonishing thing about this process is that the EPS is reduced by up to 95% of its original volume and the resin block is completely sterilised so it can be stored indefinitely, easily handled or transported without a problem.
Fumes from the process are passed through a filter system and the machine is IP56 rated and manufactured from stainless steel so it can be situated outdoors.
Reducing the amount of landfill space EPS takes by up to 95% would be reason enough to thermally compact and densify this material.
But EPS holds a few recycling secrets.
This material can be recycled into a myriad of new products. The thermally condensed blocks can be turned into coat hangers, picture frames, replacement hardwood, disposable cameras and CD cases to name but a few. There is also an emerging market for EPS blocks for the production of fuels such as green diesel and LPG.
The thermally compacted blocks can also be sold to a variety of outlets for incineration (or energy recovery). The reason for this demand is that incineration of polystyrene generates large quantities of usable energy - approximately 16,000 BTUs/pound, which is twice that of coal!
Alternatively organisations who produce thermally compacted blocks can also take advantage of a service to collect the material in the UK free of charge subject to volume agreements.
It is a fact that as a society we produce too much waste. Landfill sites are becoming increasingly full and cannot last forever. Therefore any method of taking a product from cradle to grave and recycling it has to be more than welcome.
According to Purex, the beauty of the Styromelt™ Thermal Compactor (styromelt.com) is that, not only does it remove significant amounts waste EPS from the transport and waste management system altogether thereby reducing landfill and environmental impact, it can also help turn this material into new products and materials or generate new fuels and energy.