Property Information
Recycle Fraction
Overview
- The fraction recycled is a measure of the proportion of a material in use in products which can economically be recycled.
- Materials which can be remelted (like metals or thermoplastics) or shredded (like paper and wood) are most easily recycled. Some materials are difficult or impossible to recycle because they cannot be returned to their previous condition (like ceramics, thermosets and fibre composites).
- Many other factors influence whether a material is recycled. It must be possible to collect and separate the materials from products at the end of their lifetime. Recycling has costs associated with transport, separating and remelting or shredding, and these must be lower than the cost of using new raw material.
- Recycling is closely related to energy content, as energy is a significant factor in both the cost of recycling and the cost of new raw material. The highest fractions recycled tend to be for high energy content materials (e.g. gold) and for materials which use much less energy to recycle than to produce (e.g. aluminium).
Design issues
- Materials can only be recycled if the different materials in a product can be easily separated and identified. For example, steel can be pulled out of mixed scrap using magnets, and products are increasingly labelled with the material used (e.g. polythene or PET on bottles).
- Designers of complex systems such as cars, which contain many different materials, increasingly consider how a car could be made easier to dismantle at the end of its life to recover separate materials. Speed is critical is disassembly is to be economic.
- In general, the more different materials used in a product, the harder it will be to recycle them.
- Bottles, cans and newspaper can be cheaply recycled if individuals and organisations return them to central collection banks.
Measurement
The fraction recycled is measured by governments, environmental agencies and material suppliers. Estimates for whether a material is likely to have a high or low fraction recycled can be made by considering the costs of recycling compared to the costs of using new raw material.
Units & Values
Fraction recycled is simply a number between 0 and 1 (or a percentage) and has no units.
Precise numerical ranges are not given here for material classes as they are not useful - see material selection charts for individual materials.