Thursday 4 January 2007

Focus On Plastic



With all plastic bottles, (beverages, water etc),
we should rinse and then crush them to maximise space in collection systems. It is best to replace the cap as this helps keep bottles crushed and prevents air entry and bottle reshaping.
Generally plastic is marked with a triangle and a number 1 - 7 to help identify the different types. Most Commonly accepted are numbers 1 and 2 which are PET and HDPE.
However, in Ireland, many plastic collection systems do collect plastic wrap from breads, toilet rolls etc and some trays. If in doubt about your collection leave it out. Ideally confirm with your collector what they accept as different Local Authorities and recovery operators collect different things.

A recycling plant uses seven steps to turn plastic trash into recycled plastic:

1. Inspection
Workers inspect the plastic trash for contaminants like rock and glass, and for plastics that the plant cannot recycle.

2. Chopping and Washing
The plastic is washed and chopped into flakes.

3. Flotation Tank
If mixed plastics are being recycled, they are sorted in a flotation tank, where some types of plastic sink and others float.

4. Drying
The plastic flakes are dried in a tumble dryer.

5. Melting
The dried flakes are fed into an extruder, where heat and pressure melt the plastic. Different types of plastics melt at different temperatures.

6. Filtering
The molten plastic is forced through a fine screen to remove any contaminants that slipped through the washing process. The molten plastic is then formed into strands.

7. Pelletizing
The strands are cooled in water, then chopped into uniform pellets. Manufacturing companies buy the plastic pellets from recyclers to make new products. Recycled plastics also can be made into flowerpots, lumber, and carpeting. Source: www.eia.doe.gov

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