Recycling Plastics Bottles
Plastic is one of the most popular and useful materials of modern times. However, its popularity is part of the problem: we now use about 20 times more plastic than we did 50 years ago.
To combat the ever increasing amount of waste sent to landfill, nearly all of UK local authorities now offer collection facilities for plastic bottles, either by kerbside collection or at recycling centres. Because the decomposition process of plastic in landfill doesn’t begin for around 700 years, it is important environmentally to recycle this material so it can be reused.
Mechanical recycling is the process of recycling plastics by sorting, shredding, washing, melting, and finally extruding it into pellets. It is a two-stage process:
- Sorting is mainly done automatically with a manual polish;
- Plastic is either melted down directly using band heaters/strip heaters and thermocouples and moulded into a new shape, or shredded into flakes then melted down before being processed into granulates.
Plastic bottles are usually made from two easily recyclable plastics – PET (Polyethylene terephthalate) and HDPE (High-density polyethylene). PET is used to make fizzy drink bottles and oven-ready meal trays whilst HDPE is used to make milk cartons and bottles for washing up liquids. When these plastics are recycled they can be reprocessed into a number of different products, using specialist heaters, including:
- polyethylene bin liners and carrier bags
- new plastic bottles
- flooring (including carpet) and window frames
- building insulation board
- video and compact disc cassette cases
- fencing and garden furniture
- water butts, garden sheds and composters
- seed trays
- fibre filling for sleeping bags and duvets, and
- a variety of office accessories
During its lifetime a piece of plastic could, at some stage, become any one of the above items, but this is only possible if consumers habitually recycle their plastics, to ensure the process can begin again.