Near-Infrared (NIR) sensor technology coupled with highly sensitive algorithms are likely the most efficient and consistent plastic sorting technologies due to their high sorting accuracy in separating desired plastics from mixed waste, as well as sorting plastics by color and resin types. Identification algorithms then rapidly categorize the different “signatures” of polymers from their infrared spectra.

While other sensor based sorting technologies, such as x-ray, laser, and light emitting device (LED), are capable of distinguishing between colors and densities, NIR with identification algorithms is likely to be the most consistent, accurate, and time-efficient of the various sensor based sorting options in terms of sorting plastics. Lasers and LED have the ability to detect color differences but cannot determine the different resin types of plastics. X-ray technology can decipher plastics from non-plastics but it cannot distinguish different colors and resin types, therefore lessening its overall efficiency in effective plastic sorting. NIR sensors used with identification algorithms are able to consistently complete all necessary tasks in the sorting of plastics.