Sorting of the Polymer Fraction

TUDelft - Recycling of Electornics - Ruud Balkenende
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Durable goods are often sorted with density.
FMCG uses NIR technology.

Main Takeaways

  • Sink float density separation is a commonly used sorting method. Polymer fragments are fed into a flotation bath in which they either float or sink, depending on their densities.
  • Triboelectric separation is based on the differences in electrostatic properties between polymers.
  • Near infrared spectroscopy is an optical sorting method that is based on how different polymers reflect light of different wavelengths.
  • Avoid creating permanent connections between different polymers. If fragments remain connected after shredding, they are unlikely to be sorted and will end up as waste.
  • Whenever possible also try to avoid additives, coatings, paints and polymer blends. These can contaminate the recycled stream or even alter the density of the polymer, causing it to be misidentified.

Further Reading (optional)

Below we have listed a few useful resources about plastics recycling. They are not required to complete the course.
 
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You can download a larger infographic of the visual in the following link: Understanding recycling | ecosystem