Recycling of bottles made of polyethylene terephthalate
Clockwise from top left: - Sorting at a material recovery facility
- Bales of colour-sorted PET bottles
- A reprocessing facility where used bottles are converted into clean flakes or pellets suitable for remoulding into new items
- Recycled PET flakes
- A water bottle made from recycled PET (bottle-to-bottle recycling)
- A polyester bag made from recycled PET
- A food tray made from recycled PET bearing the rPET symbol
Although PET is used in several applications (principally textile fibres for apparel and upholstery, bottles and other rigid packaging, flexible packaging and electrical and electronic goods), as of 2022 only bottles are collected at a substantial scale. The main motivations have been either cost reduction (when oil prices spike) or recycle content of retail goods (driven by regulations or public opinion). An increasing amount is recycled back into bottles, the rest goes into fibres, film, thermoformed packaging and strapping.[1]
After sorting, cleaning and grinding, 'bottle flake' is obtained, which is then processed by either:
- 'basic' or 'physical' recycling. Bottle flake is melted into its new shape directly with basic changes in its physical properties.[2]
- 'chemical' or 'advanced' recycle. Bottle flake (or possibly a less pure feedstock) is partially or totally depolymerized then enabling purification. The resulting oligomers or monomers are repolymerized to PET polymer, which is then processed in the same way as virgin polymer.
In either case, the resulting feedstock is known as "r-PET" or "RPET".[2]