How are Plastics Recycled?
THERE ARE A LOT OF DIFFERENT POLYMER TYPES AND FORMS OF PLASTIC IN THE WASTE STREAM
There are a lot of different polymer types and forms of plastic in the waste stream. This makes it more difficult to sort and reprocess than other materials. Due to the light nature of most plastic packaging it means that a lot needs to be collected to make it economic to do so. Therefore, most collections have focused on key packaging types where there is an end market in place i.e. plastic bottles, which are heavier than most other plastics and therefore relatively easy to handle and sort.
While it is technically possible to recycle most plastic polymers, the complexity and cost of doing so has prevented this happening in the past. There are some reprocessors that will take mixed polymers; however, the materials produced tend to be of low grade and value.
Another issue that plastics reprocessors face is that sometimes food waste is left on packaging. Often packaging can consist of more than one polymer type, which makes it more difficult to recycle.
Reprocessing technology is constantly improving and more uses are being found for waste plastics…
Plastic bottles are the most commonly collected plastic packaging type. This is because they are easy to sort and there are well developed markets for the recyclate. The bulk of bottles are made from PET or HDPE, which account for about 90%.
Note: The UK has a much higher use of HDPE bottles than most countries due to its use for containing milk.
Plastic bottles are normally made from one of only four polymer types and are very easily identified, both by members of the public and those sorting the collected bottles. The four polymer types used are:
- PET (e.g. fizzy drink bottles and squash bottles)
- HDPE (e.g. milk bottles and detergent bottles)
- PP (e.g. ketchup bottles)
- PVC (e.g. large squash bottles). Although the use of PVC in such applications is in decline
Plastic lids / caps
Due to the fact that plastic lids can be of a different polymer/colour to the bottle itself they can contaminate the bottle stream; therefore, require extra processing to separate them.
Until recently, consumers were advised to remove lids from their plastic bottles. However, most reprocessors will now take the bottles and will separate the lids. Please remember, if possible, to wash and squash your bottles to maximise recycling capacity.
You may well have noticed that the caps on HDPE clear milk bottles are much lighter colours now, which has been done on purpose to help minimise colour contamination.
Pots, tubs and trays
We frequently get asked if flowerpots can be recycled. The majority of flowerpots are made from polypropylene (PP), although some are made from polystyrene. As in the case of rigid food containers and some yogurt pots, there are few outlets for collected material and a higher level of contamination mainly due to soil.
That said, some garden centres do accept them for recycling. In addition, some retailers are now selling plants that can be planted directly into the ground while still inside their container, as the packaging is bio-degradable.