Materials
Available today in many shapes and forms, plastics have become part our everyday life. However, their popularity and almost endless applications present a series of challenges for the recycling industry.
We now use about 20 times more plastic than we did 50 years ago and certain post-consumer products contain as many as 20 different types of plastic materials. This widespread use of all kinds of plastic makes it difficult to collect large enough quantities of certain types to make recycling viable. At the same time, each variety has a particular molecular composition and as a result, a different recycling process must be employed. Identification and separation technologies are crucial for efficient and effective plastic recycling.
Recycling helps to reduce energy consumption, air and water pollution, but also the amount of plastic that ends up in landfills. Plastics are polymers composed primarily of petroleum, thus the recycling industry plays an important role in preserving this vital natural resource.
Recycling Processes
Recycling plastics requires a series chemical and mechanical procedures:
Granulation of plastic for recycling
Baled PET bottles for recycling
Car bumpers made from recycled plastic
- Sorting: This critical part of the process can be performed both manually and mechanically.
- Shredding and compacting: When necessary, sorted plastics are shredded into smaller pieces and bailed to facilitate handling and transportation.
- Washing: Scrap plastic goes through various mechanical processes to remove filth and dirt. It is then washed and ground into smaller flakes. Flotation tanks are also used to separate plastics from contaminants.
- Melting: Plastic is either melted down or shaped into granulates or pellets.
- Reforming: The granulates are shipped to manufacturing plants where they are made into new products.
The Sorting Challenge
The biggest problem with plastic recycling is that it is labour intensive and this is because it is difficult to automate the sorting process. Numeric codes are used to indicate different types of plastic. New mechanical sorting processes using spectrometry are being developed and implemented to increase plastic recycling capacities and efficiency.
Containers are usually made from a single type of plastic, making them relatively easy to sort. However, mobile phones for example, usually have various components made from different types of plastic. New research and development programmes are being set up to improve dissassembling technologies and to increase the recovery and recycling rates of plastic products.
Applications
Unlike metals, recycling usually affects the physical properties of plastics to some extent. This makes it difficult to recover large amounts of certain types of plastics for use in the same applications that they were originally produced for. Thanks to intensive research and technological developments made by recycling companies, recycled plastic can be used in almost as many applications and products as those using virgin materials.
These are just a few products that can be made from recycled plastic:
- Polyethylene bin liners and carrier bags
- Plastic bottles
- Flooring and window frames
- Building insulation board
- DVD and CD cases
- Garden furniture and fencing
- Garden sheds and composters
- Seed trays
- Fleeces
- Fibre filling for sleeping bags and duvets
- Office accessories
Recycling Facts
- One tonne of recycled plastic saves 5,774 kWh of energy, 16.3 barrels (2,604 litres) of oil, 98 million Btu's of energy, and 22 cubic metres of landfill .
- There is an 80 to 90% reduction in energy consumption by producing recycled plastic compared to producing plastic from virgin materials (oil and gas).
- Recycling a single plastic bottle can conserve enough energy to light a 60-watt bulb for up to six hours.
- Recycling 5 PET plastic bottles produces enough fibre for one t-shirt.
- Recycling 100 million cell phones saves enough energy to power more than 194,000 US households for one year.
- Worldwide trade of recyclable plastics represents is valued at $5 billion per year and is estimated to represent a total of 12 million tonnes.
- EUROPE recycled 21.3% of plastic waste during 2008 representing about 5.3 million tonnes.
- A recent study shows that if all landfilled plastics waste are recycled or recovered into energy, then 7% of EU quota of CARBON GAS REDUCTION will be fulfilled
Our Experts
For more information on technical issues, contact our experts working on the Plastics Commodity Committee: