After glass is removed in the previous stage of the recycling process, only plastic containers remain from the original mixed recyclables.
The plastic bottles go through a machine, where infrared light shines onto the conveyor. A sensor detects the wavelengths in the reflected light, identifying the type of plastic.
The plastic sorting machine
The sensor triggers a jet of air to hit the plastic bottle and remove it from the conveyor. It separates out two different type of plastic:
- High Density Polyethylene (HDPE) – for example milk bottles, washing up bottles.
- Polyethylene Terephthalate (PET) – for example fizzy drinks bottles.
Previous stage: sorting paper
Next stage: baling